[PATCH v3 00/11] mempolicy2, mbind2, and weighted interleave

[PATCH v3 00/11] mempolicy2, mbind2, and weighted interleave

[Gregory Price]

=====================================================================
v3:
  Biggest takeaway - LTP backward compatibility tests, new LTP tests,
  and MLC benchmark showed 40% performance bump over DRAM and nearly
  200% performance over default interleave.

  changes / adds:
- get2(): actually fetch the il_weights (doh!)
- get2(): retrieve home_node
- get2(): addr as arg instead of struct member, drop MPOL_F_NODE flag
          get_mempolicy() can be used for this, don't duplicate warts
	  Suggested-by: Ying Huang <ying.huang@intel.com>
- get2(): only copy weights if mode is weighted interleave
- mbind2(): addr/len instead of iovec
            user can use a for loop...
- sysfs: remove possible_nodes
	 Suggested-by: Ying Huang <ying.huang@intel.com>
- sysfs: simplify to weighted_interleave/nodeN
         Suggested-by: Ying Huang <ying.huang@intel.com>
- sysfs: add default weight mechanism (echo > nodeN)
	 Suggested-by: Ying Huang <ying.huang@intel.com>

  fixes:
- build: syscalls.h mpol_args definition missing
- build: missing `__user` from weights_ptr definition
- bug:   uninitialized weight_total in bulk allocator
- bug:   bad pointer to copy_struct_from_user in mbind2
- bug:   get_mempolicy2 uninitialized data copied to user
- bug:   get_vma_mempolicy policy reference counting
- bug:   MPOL_F_GWEIGHTS not set correctly in set_mempolicy2
- bug:   MPOL_F_GWEIGHTS not set correctly in mbind2
- bug:   get_mempolicy2 error not checked on nodemask userland copy
- bug:   mbind2 did not parse nodemask correctly

  tests:
- ltp branch: https://github.com/gmprice/ltp/tree/mempolicy2
- new set_mempolicy2() tests
     1) set_mempolicy() tests w/ new syscall
     2) weighted interleave validation
- new get_mempolicy2() tests
     1) get_mempolicy() tests w/ new syscall
     2) weighted interleave validation
- new mbind2() tests
     1) mbind() tests w/ new syscall
- new performance tests (MLC) from Ravi @ Micron
     Example:
        Workload:                               W5
        Data Signature:                         1:1 read:write
        DRAM only bandwidth (GBps):             273.2
        DRAM + CXL (default interleave) (GBps): 117.23
        DRAM + CXL (weighted interleave)(GBps): 382.7
        Gain over DRAM only:                    1.4x

=====================================================================
v2:
  changes / adds:
- flatted weight matrix to an array at requested of Ying Huang
- Updated ABI docs per Davidlohr Bueso request
- change uapi structure to use aligned/fixed-length members
- Implemented weight fetch logic in get_mempolicy2
- mbind2 was changed to take (iovec,len) as function arguments
  rather than add them to the uapi structure, since they describe
  where to apply the mempolicy - as opposed to being part of it.

  fixes:
- fixed bug reported by Seungjun Ha <seungjun.ha@samsung.com>
  Link: https://lore.kernel.org/linux-cxl/20231206080944epcms2p76ebb230b9f4595f5cfcd2531d67ab3ce@epcms2p7/
- fixed bug in mbind2 where MPOL_F_GWEIGHTS was not set when il_weights
  was omitted after local weights were added as an option
- fixed bug in interleave logic where an OOB access was made if
  next_node_in returned MAX_NUMNODES
- fixed bug in bulk weighted interleave allocator where over-allocation
  could occur.

  tests:
- LTP: validated existing get_mempolicy, set_mempolicy, and mbind tests
- LTP: validated existing get_mempolicy, set_mempolicy, and mbind with
       MPOL_WEIGHTED_INTERLEAVE added.
- basic set_mempolicy2 tests and numactl -w --interleave tests

  numactl:
- Sample numactl extension for set_mempolicy available here:
  Link: https://github.com/gmprice/numactl/tree/weighted_interleave_master

(added summary of test reports to end of cover letter)

=====================================================================

This patch set extends the mempolicy interface to enable new
mempolicies which may require extended data to operate. One
such policy is included with this set as an example.

There are 3 major "phases" in the patch set:
1) Implement a "global weight" mechanism via sysfs, which allows
   set_mempolicy to implement MPOL_WEIGHTED_INTERLEAVE utilizing
   weights set by the administrator (or system daemon).

2) A refactor of the mempolicy creation mechanism to accept an
   extensible argument structure `struct mempolicy_args` to promote
   code re-use between the original mempolicy/mbind interfaces and
   the new extended mempolicy/mbind interfaces.

3) Implementation of set_mempolicy2, get_mempolicy2, and mbind2,
   along with the addition of task-local weights so that per-task
   weights can be registered for MPOL_WEIGHTED_INTERLEAVE.

=====================================================================
(Patch 1) : sysfs addition - /sys/kernel/mm/mempolicy/

This feature  provides a way to set interleave weight information under
sysfs at /sys/kernel/mm/mempolicy/weighted_interleave/

    The sysfs structure is designed as follows.

      $ tree /sys/kernel/mm/mempolicy/
      /sys/kernel/mm/mempolicy/
      └── weighted_interleave
          ├── nodeN
          └── nodeN+X

'mempolicy' is added to '/sys/kernel/mm/' as a control group for
the mempolicy subsystem.

Internally, weights are represented as an array of unsigned char

static unsigned char iw_table[MAX_NUMNODES];

char was chosen as most reasonable distributions can be represented
as factors <100, and to minimize memory usage (1KB)

We present possible nodes, instead of online nodes, to simplify the
management interface, considering that a) the table is of size
MAX_NUMNODES anyway to simplify fetching of weights (no need to track
sizes, and MAX_NUMNODES is typically at most 1kb), and b) it simplifies
management of hotplug events, allowing for weights to be set prior to
a node coming online, which may be beneficial for immediate use.

the 'weight' of a node (an unsigned char of value 1-255) is the number
of pages that are allocated during a "weighted interleave" round.
(See 'weighted interleave' for more details').

=====================================================================
(Patch 2) set_mempolicy: MPOL_WEIGHTED_INTERLEAVE

Weighted interleave is a new memory policy that interleaves memory
across numa nodes in the provided nodemask based on the weights
described in patch 1 (sysfs global weights).

When a system has multiple NUMA nodes and it becomes bandwidth hungry,
the current MPOL_INTERLEAVE could be an wise option.

However, if those NUMA nodes consist of different types of memory such
as having local DRAM and CXL memory together, the current round-robin
based interleaving policy doesn't maximize the overall bandwidth
because of their different bandwidth characteristics.

Instead, the interleaving can be more efficient when the allocation
policy follows each NUMA nodes' bandwidth weight rather than having 1:1
round-robin allocation.

This patch introduces a new memory policy, MPOL_WEIGHTED_INTERLEAVE,
which enables weighted interleaving between NUMA nodes.  Weighted
interleave allows for a proportional distribution of memory across
multiple numa nodes, preferablly apportioned to match the bandwidth
capacity of each node from the perspective of the accessing node.

For example, if a system has 1 CPU node (0), and 2 memory nodes (0,1),
with a relative bandwidth of (100GB/s, 50GB/s) respectively, the
appropriate weight distribution is (2:1).

Weights will be acquired from the global weight array exposed by the
sysfs extension: /sys/kernel/mm/mempolicy/weighted_interleave/

The policy will then allocate the number of pages according to the
set weights.  For example, if the weights are (2,1), then 2 pages
will be allocated on node0 for every 1 page allocated on node1.

The new flag MPOL_WEIGHTED_INTERLEAVE can be used in set_mempolicy(2)
and mbind(2).

=====================================================================
(Patches 3-6) Refactoring mempolicy for code-reuse

To avoid multiple paths of mempolicy creation, we should refactor the
existing code to enable the designed extensibility, and refactor
existing users to utilize the new interface (while retaining the
existing userland interface).

This set of patches introduces a new mempolicy_args structure, which
is used to more fully describe a requested mempolicy - to include
existing and future extensions.

/*
 * Describes settings of a mempolicy during set/get syscalls and
 * kernel internal calls to do_set_mempolicy()
 */
struct mempolicy_args {
    unsigned short mode;            /* policy mode */
    unsigned short mode_flags;      /* policy mode flags */
    int home_node;                  /* mbind: use MPOL_MF_HOME_NODE */
    nodemask_t *policy_nodes;       /* get/set/mbind */
    unsigned char *il_weights;      /* for mode MPOL_WEIGHTED_INTERLEAVE */
    int policy_node;                /* get: policy node information */
};

This arg structure will eventually be utilized by the following
interfaces:
    mpol_new() - new mempolicy creation
    do_get_mempolicy() - acquiring information about mempolicy
    do_set_mempolicy() - setting the task mempolicy
    do_mbind()         - setting a vma mempolicy

do_get_mempolicy() is completely refactored to break it out into
separate functionality based on the flags provided by get_mempolicy(2)
    MPOL_F_MEMS_ALLOWED: acquires task->mems_allowed
    MPOL_F_ADDR: acquires information on vma policies
    MPOL_F_NODE: changes the output for the policy arg to node info

We refactor the get_mempolicy syscall flatten the logic based on these
flags, and aloow for set_mempolicy2() to re-use the underlying logic.

The result of this refactor, and the new mempolicy_args structure, is
that extensions like 'sys_set_mempolicy_home_node' can now be directly
integrated into the initial call to 'set_mempolicy2', and that more
complete information about a mempolicy can be returned with a single
call to 'get_mempolicy2', rather than multiple calls to 'get_mempolicy'


=====================================================================
(Patches 7-10) set_mempolicy2, get_mempolicy2, mbind2

These interfaces are the 'extended' counterpart to their relatives.
They use the userland 'struct mpol_args' structure to communicate a
complete mempolicy configuration to the kernel.  This structure
looks very much like the kernel-internal 'struct mempolicy_args':

struct mpol_args {
        /* Basic mempolicy settings */
        __u16 mode;
        __u16 mode_flags;
        __s32 home_node;
        __aligned_u64 pol_nodes;
        __aligned_u64 *il_weights;      /* of size pol_maxnodes */
        __u64 pol_maxnodes;
        __s32 policy_node;
};

The basic mempolicy settings which are shared across all interfaces
are captured at the top of the structure, while extensions such as
'policy_node' and 'addr' are collected beneath.

The syscalls are uniform and defined as follows:

long sys_mbind2(unsigned long addr, unsigned long len,
                struct mpol_args *args, size_t usize,
                unsigned long flags);

long sys_get_mempolicy2(struct mpol_args *args, size_t size,
                        unsigned long addr, unsigned long flags);

long sys_set_mempolicy2(struct mpol_args *args, size_t size,
                        unsigned long flags);

The 'flags' argument for mbind2 is the same as 'mbind', except with
the addition of MPOL_MF_HOME_NODE to denote whether the 'home_node'
field should be utilized.

The 'flags' argument for get_mempolicy2 allows for MPOL_F_ADDR to
allow operating on VMA policies, but MPOL_F_NODE and MPOL_F_MEMS_ALLOWED
behavior has been omitted, since get_mempolicy() provides this already.

The 'flags' argument is not used by 'set_mempolicy' at this time, but
may end up allowing the use of MPOL_MF_HOME_NODE if such functionality
is desired.

The extensions can be summed up as follows:

get_mempolicy2 extensions:
    'mode' and 'policy_node' can now be fetched with a single call
    rather than multiple with a combination of flags.
    - 'mode' will always return the policy mode
    - 'policy_node' will replace the functionality of MPOL_F_NODE
    - MPOL_F_MEMS_ALLOWED and MPOL_F_NODE are otherwise not supported

set_mempolicy2:
    - task-local interleave weights can be set via 'il_weights'
      (see next patch)

mbind2:
    - 'home_node' field sets policy home node w/ MPOL_MF_HOME_NODE
    - task-local interleave weights can be set via 'il_weights'
      (see next patch)

=====================================================================
(Patch 11) set_mempolicy2/mbind2: MPOL_WEIGHTED_INTERLEAVE

This patch shows the explicit extension pattern when adding new
policies to mempolicy2/mbind2.  This adds the 'il_weights' field
to mpol_args and adds the logic to fill in task-local weights.

There are now two ways to weight a mempolicy: global and local.
To denote which mode the task is in, we add the internal flag:
MPOL_F_GWEIGHT /* Utilize global weights */

When MPOL_F_GWEIGHT is set, the global weights are used, and
when it is not set, task-local weights are used.

Example logic:
if (pol->flags & MPOL_F_GWEIGHT)
       pol_weights = iw_table;
else
       pol_weights = pol->wil.weights;

set_mempolicy is changed to always set MPOL_F_GWEIGHT, since this
syscall is incapable of passing weights via its interfaces, while
set_mempolicy2 sets MPOL_F_GWEIGHT if MPOL_F_WEIGHTED_INTERLEAVE
is required but (*il_weights) in mpol_args is null.

The operation of task-local weighted is otherwise exactly the
same - except for what occurs on task migration.

On task migration, the system presently has no way of determining
what the new weights "should be", or what the user "intended".

For this reason, we default all weights to '1' and do not allow
weights to be '0'.  This means, should a migration occur where
one or more nodes appear into the nodemask - the effective weight
for that node will be '1'.  This avoids a potential allocation
failure condition if a migration occurs and introduces a node
which otherwise did not have a weight.

For this reason, users should use task-local weighting when
migrations are not expected, and global weighting when migrations
are expected or possible.

=====================================================================
Existing LTP Tests: https://github.com/gmprice/ltp/tree/mempolicy2

LTP set_mempolicy, get_mempolicy, mbind regression tests:

MPOL_WEIGHTED_INTERLEAVE added manually to test basic functionality
but did not adjust tests for weighting.  Basically the weights were
set to 1, which is the default, and it should behavior like standard
MPOL_INTERLEAVE if logic is correct.

== set_mempolicy01
passed   18
failed   0

== set_mempolicy02
passed   10
failed   0

== set_mempolicy03
passed   64
failed   0

== set_mempolicy04
passed   32
failed   0

== set_mempolicy05 - n/a on non-x86

== set_mempolicy06 - set_mempolicy02 + MPOL_WEIGHTED_INTERLEAVE
passed   10
failed   0

== set_mempolicy07 - set_mempolicy04 + MPOL_WEIGHTED_INTERLEAVE
passed   32
failed   0

== get_mempolicy01 - added MPOL_WEIGHTED_INTERLEAVE
passed   12
failed   0

== get_mempolicy02
passed   2
failed   0

== mbind01 - added WEIGHTED_INTERLEAVE
passed   15
failed   0

== mbind02 - added WEIGHTED_INTERLEAVE
passed   4
failed   0

== mbind03 - added WEIGHTED_INTERLEAVE
passed   16
failed   0

== mbind04 - added WEIGHTED_INTERLEAVE
passed   48
failed   0

=====================================================================
New LTP Tests: https://github.com/gmprice/ltp/tree/mempolicy2

set_mempolicy2, get_mempolicy2, mbind2

Took the original set_mempolicy and get_mempolicy tests, and updated
them to utilize the new mempolicy2 interfaces.  Added additional tests
for setting task-local weights to validate behavior.

== set_mempolicy201 - set_mempolicy01 equiv
passed   18
failed   0

== set_mempolicy202 - set_mempolicy02 equiv
passed   10
failed   0

== set_mempolicy203 - set_mempolicy03 equiv
passed   64
failed   0

== set_mempolicy204 - set_mempolicy04 equiv
passed   32
failed   0

== set_mempolicy205 - set_mempolicy06 equiv
passed   10
failed   0

== set_mempolicy206 - set_mempolicy07 equiv
passed   32
failed   0

== set_mempolicy207 - MPOL_WEIGHTED_INTERLEAVE with task-local weights
passed   6
failed   0

== get_mempolicy201 - get_mempolicy01 equiv
passed   12
failed   0

== get_mempolicy202 - get_mempolicy02 equiv
passed   2
failed   0

== get_mempolicy203 - NEW - fetch global and local weights
passed   6
failed   0

== mbind201 - mbind01 equiv
passed   15
failed   0

== mbind202 - mbind02 equiv
passed   4
failed   0

== mbind203 - mbind03 equiv
passed   16
failed   0

== mbind204 - mbind04 equiv
passed   48
failed   0

=====================================================================
Basic set_mempolicy2 test

set_mempolicy2 w/ weighted interleave, task-local weights and uses
pthread_create to demonstrate the mempolicy is overwritten by child.

Manually validating the distribution via numa_maps

007c0000 weighted interleave:0-1 heap anon=65794 dirty=65794 active=0 N0=54829 N1=10965 kernelpagesize_kB=4
7f3f2c000000 weighted interleave:0-1 anon=32768 dirty=32768 active=0 N0=5461 N1=27307 kernelpagesize_kB=4
7f3f34000000 weighted interleave:0-1 anon=16384 dirty=16384 active=0 N0=2731 N1=13653 kernelpagesize_kB=4
7f3f3bffe000 weighted interleave:0-1 anon=65538 dirty=65538 active=0 N0=10924 N1=54614 kernelpagesize_kB=4
7f3f5c000000 weighted interleave:0-1 anon=16384 dirty=16384 active=0 N0=2731 N1=13653 kernelpagesize_kB=4
7f3f60dfe000 weighted interleave:0-1 anon=65537 dirty=65537 active=0 N0=54615 N1=10922 kernelpagesize_kB=4

Expected distribution is 5:1 or 1:5 (less node should be ~16.666%)
1) 10965/65794 : 16.6656...
2) 5461/32768  : 16.6656...
3) 2731/16384  : 16.6687...
4) 10924/65538 : 16.6682...
5) 2731/16384  : 16.6687...
6) 10922/65537 : 16.6653...


#define _GNU_SOURCE
#include <stdio.h>
#include <stdlib.h>
#include <numa.h>
#include <errno.h>
#include <numaif.h>
#include <unistd.h>
#include <pthread.h>
#include <sys/uio.h>
#include <sys/types.h>
#include <stdint.h>

#define MPOL_WEIGHTED_INTERLEAVE 6
#define SET_MEMPOLICY2(a, b) syscall(457, a, b, 0)

#define M256 (1024*1024*256)
#define PAGE_SIZE (4096)

struct mpol_args {
        /* Basic mempolicy settings */
        uint16_t mode;
        uint16_t mode_flags;
        int32_t home_node;
        uint64_t pol_nodes;
        uint64_t il_weights;
        uint64_t pol_maxnodes;
        int32_t policy_node;
};

struct mpol_args wil_args;
struct bitmask *wil_nodes;
unsigned char *weights;
int total_nodes = -1;
pthread_t tid;

void set_mempolicy_call(int which)
{
        weights = (unsigned char *)calloc(total_nodes, sizeof(unsigned char));
        wil_nodes = numa_allocate_nodemask();

        numa_bitmask_setbit(wil_nodes, 0); weights[0] = which ? 1 : 5;
        numa_bitmask_setbit(wil_nodes, 1); weights[1] = which ? 5 : 1;

        memset(&wil_args, 0, sizeof(wil_args));
        wil_args.mode = MPOL_WEIGHTED_INTERLEAVE;
        wil_args.mode_flags = 0;
        wil_args.pol_nodes = wil_nodes->maskp;
        wil_args.pol_maxnodes = total_nodes;
        wil_args.il_weights = weights;

        int ret = SET_MEMPOLICY2(&wil_args, sizeof(wil_args));
        fprintf(stderr, "set_mempolicy2 result: %d(%s)\n", ret, strerror(errno));
}

void *func(void *arg)
{
        char *mainmem = malloc(M256);
        int i;

        set_mempolicy_call(1); /* weight 1 heavier */

        mainmem = malloc(M256);
        memset(mainmem, 1, M256);
        for (i = 0; i < (M256/PAGE_SIZE); i++) {
                mainmem = malloc(PAGE_SIZE);
                mainmem[0] = 1;
        }
        printf("thread done %d\n", getpid());
        getchar();
        return arg;
}

int main()
{
        char * mainmem;
        int i;

        total_nodes = numa_max_node() + 1;

        set_mempolicy_call(0); /* weight 0 heavier */
        pthread_create(&tid, NULL, func, NULL);

        mainmem = malloc(M256);
        memset(mainmem, 1, M256);
        for (i = 0; i < (M256/PAGE_SIZE); i++) {
                mainmem = malloc(PAGE_SIZE);
                mainmem[0] = 1;
        }
        printf("main done %d\n", getpid());
        getchar();

        return 0;
}

=====================================================================
numactl (set_mempolicy) w/ global weighting test
numactl fork: https://github.com/gmprice/numactl/tree/weighted_interleave_master

command: numactl -w --interleave=0,1 ./eatmem

result (weights 1:1):
0176a000 weighted interleave:0-1 heap anon=65793 dirty=65793 active=0 N0=32897 N1=32896 kernelpagesize_kB=4
7fceeb9ff000 weighted interleave:0-1 anon=65537 dirty=65537 active=0 N0=32768 N1=32769 kernelpagesize_kB=4
50% distribution is correct

result (weights 5:1):
01b14000 weighted interleave:0-1 heap anon=65793 dirty=65793 active=0 N0=54828 N1=10965 kernelpagesize_kB=4
7f47a1dff000 weighted interleave:0-1 anon=65537 dirty=65537 active=0 N0=54614 N1=10923 kernelpagesize_kB=4
16.666% distribution is correct

result (weights 1:5):
01f07000 weighted interleave:0-1 heap anon=65793 dirty=65793 active=0 N0=10966 N1=54827 kernelpagesize_kB=4
7f17b1dff000 weighted interleave:0-1 anon=65537 dirty=65537 active=0 N0=10923 N1=54614 kernelpagesize_kB=4
16.666% distribution is correct

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
int main (void)
{
        char* mem = malloc(1024*1024*256);
        memset(mem, 1, 1024*1024*256);
        for (int i = 0; i  < ((1024*1024*256)/4096); i++)
        {
                mem = malloc(4096);
                mem[0] = 1;
        }
        printf("done\n");
        getchar();
        return 0;
}

=====================================================================
Performance tests - MLC
From Ravi Jonnalagadda <ravis.opensrc@micron.com>

Workload:                               W2
Data Signature:                         2:1 read:write
DRAM only bandwidth (GBps):             298.8
DRAM + CXL (default interleave) (GBps): 113.04
DRAM + CXL (weighted interleave)(GBps): 412.5
Gain over DRAM only:                    1.38x

Workload:                               W5
Data Signature:                         1:1 read:write
DRAM only bandwidth (GBps):             273.2
DRAM + CXL (default interleave) (GBps): 117.23
DRAM + CXL (weighted interleave)(GBps): 382.7
Gain over DRAM only:                    1.4x

=====================================================================

Suggested-by: Gregory Price <gregory.price@memverge.com>
Suggested-by: Johannes Weiner <hannes@cmpxchg.org>
Suggested-by: Hasan Al Maruf <hasanalmaruf@fb.com>
Suggested-by: Hao Wang <haowang3@fb.com>
Suggested-by: Ying Huang <ying.huang@intel.com>
Suggested-by: Dan Williams <dan.j.williams@intel.com>
Suggested-by: Michal Hocko <mhocko@suse.com>
Suggested-by: tj <tj@kernel.org>
Suggested-by: Zhongkun He <hezhongkun.hzk@bytedance.com>
Suggested-by: Frank van der Linden <fvdl@google.com>
Suggested-by: John Groves <john@jagalactic.com>
Suggested-by: Vinicius Tavares Petrucci <vtavarespetr@micron.com>
Suggested-by: Srinivasulu Thanneeru <sthanneeru@micron.com>
Suggested-by: Ravi Jonnalagadda <ravis.opensrc@micron.com>
Suggested-by: Jonathan Cameron <Jonathan.Cameron@Huawei.com>
Signed-off-by: Gregory Price <gregory.price@memverge.com>

Gregory Price (10):
  mm/mempolicy: introduce MPOL_WEIGHTED_INTERLEAVE for weighted
    interleaving
  mm/mempolicy: refactor sanitize_mpol_flags for reuse
  mm/mempolicy: create struct mempolicy_args for creating new
    mempolicies
  mm/mempolicy: refactor kernel_get_mempolicy for code re-use
  mm/mempolicy: allow home_node to be set by mpol_new
  mm/mempolicy: add userland mempolicy arg structure
  mm/mempolicy: add set_mempolicy2 syscall
  mm/mempolicy: add get_mempolicy2 syscall
  mm/mempolicy: add the mbind2 syscall
  mm/mempolicy: extend set_mempolicy2 and mbind2 to support weighted
    interleave

Rakie Kim (1):
  mm/mempolicy: implement the sysfs-based weighted_interleave interface

 .../ABI/testing/sysfs-kernel-mm-mempolicy     |   4 +
 ...fs-kernel-mm-mempolicy-weighted-interleave |  22 +
 .../admin-guide/mm/numa_memory_policy.rst     |  67 ++
 arch/alpha/kernel/syscalls/syscall.tbl        |   3 +
 arch/arm/tools/syscall.tbl                    |   3 +
 arch/m68k/kernel/syscalls/syscall.tbl         |   3 +
 arch/microblaze/kernel/syscalls/syscall.tbl   |   3 +
 arch/mips/kernel/syscalls/syscall_n32.tbl     |   3 +
 arch/mips/kernel/syscalls/syscall_o32.tbl     |   3 +
 arch/parisc/kernel/syscalls/syscall.tbl       |   3 +
 arch/powerpc/kernel/syscalls/syscall.tbl      |   3 +
 arch/s390/kernel/syscalls/syscall.tbl         |   3 +
 arch/sh/kernel/syscalls/syscall.tbl           |   3 +
 arch/sparc/kernel/syscalls/syscall.tbl        |   3 +
 arch/x86/entry/syscalls/syscall_32.tbl        |   3 +
 arch/x86/entry/syscalls/syscall_64.tbl        |   3 +
 arch/xtensa/kernel/syscalls/syscall.tbl       |   3 +
 include/linux/mempolicy.h                     |  19 +
 include/linux/syscalls.h                      |   8 +
 include/uapi/asm-generic/unistd.h             |   8 +-
 include/uapi/linux/mempolicy.h                |  18 +-
 mm/mempolicy.c                                | 921 +++++++++++++++---
 22 files changed, 994 insertions(+), 115 deletions(-)
 create mode 100644 Documentation/ABI/testing/sysfs-kernel-mm-mempolicy
 create mode 100644 Documentation/ABI/testing/sysfs-kernel-mm-mempolicy-weighted-interleave

-- 
2.39.1

[PATCH v3 01/11] mm/mempolicy: implement the sysfs-based weighted_interleave interface

[Gregory Price]

From: Rakie Kim <rakie.kim@sk.com>

This patch provides a way to set interleave weight information under
sysfs at /sys/kernel/mm/mempolicy/weighted_interleave/nodeN

The sysfs structure is designed as follows.

  $ tree /sys/kernel/mm/mempolicy/
  /sys/kernel/mm/mempolicy/ [1]
  └── weighted_interleave [2]
      ├── node0 [3]
      └── node1

Each file above can be explained as follows.

[1] mm/mempolicy: configuration interface for mempolicy subsystem

[2] weighted_interleave/: config interface for weighted interleave policy

[3] weighted_interleave/nodeN: weight for nodeN

Signed-off-by: Rakie Kim <rakie.kim@sk.com>
Signed-off-by: Honggyu Kim <honggyu.kim@sk.com>
Co-developed-by: Gregory Price <gregory.price@memverge.com>
Signed-off-by: Gregory Price <gregory.price@memverge.com>
Co-developed-by: Hyeongtak Ji <hyeongtak.ji@sk.com>
Signed-off-by: Hyeongtak Ji <hyeongtak.ji@sk.com>
---
 .../ABI/testing/sysfs-kernel-mm-mempolicy     |   4 +
 ...fs-kernel-mm-mempolicy-weighted-interleave |  22 +++
 mm/mempolicy.c                                | 143 ++++++++++++++++++
 3 files changed, 169 insertions(+)
 create mode 100644 Documentation/ABI/testing/sysfs-kernel-mm-mempolicy
 create mode 100644 Documentation/ABI/testing/sysfs-kernel-mm-mempolicy-weighted-interleave

diff --git a/Documentation/ABI/testing/sysfs-kernel-mm-mempolicy b/Documentation/ABI/testing/sysfs-kernel-mm-mempolicy
new file mode 100644
index 000000000000..2dcf24f4384a
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-kernel-mm-mempolicy
@@ -0,0 +1,4 @@
+What:		/sys/kernel/mm/mempolicy/
+Date:		December 2023
+Contact:	Linux memory management mailing list <linux-mm@kvack.org>
+Description:	Interface for Mempolicy
diff --git a/Documentation/ABI/testing/sysfs-kernel-mm-mempolicy-weighted-interleave b/Documentation/ABI/testing/sysfs-kernel-mm-mempolicy-weighted-interleave
new file mode 100644
index 000000000000..aa27fdf08c19
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-kernel-mm-mempolicy-weighted-interleave
@@ -0,0 +1,22 @@
+What:		/sys/kernel/mm/mempolicy/weighted_interleave/
+Date:		December 2023
+Contact:	Linux memory management mailing list <linux-mm@kvack.org>
+Description:	Configuration Interface for the Weighted Interleave policy
+
+What:		/sys/kernel/mm/mempolicy/weighted_interleave/nodeN
+Date:		December 2023
+Contact:	Linux memory management mailing list <linux-mm@kvack.org>
+Description:	Weight configuration interface for nodeN
+
+		The interleave weight for a memory node (N). These weights are
+		utilized by processes which have set their mempolicy to
+		MPOL_WEIGHTED_INTERLEAVE and have opted into global weights by
+		omitting a task-local weight array.
+
+		These weights only affect new allocations, and changes at runtime
+		will not cause migrations on already allocated pages.
+
+		Writing an empty string resets the weight value to 1.
+
+		Minimum weight: 1
+		Maximum weight: 255
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 10a590ee1c89..5310021181ab 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -131,6 +131,8 @@ static struct mempolicy default_policy = {
 
 static struct mempolicy preferred_node_policy[MAX_NUMNODES];
 
+static char iw_table[MAX_NUMNODES];
+
 /**
  * numa_nearest_node - Find nearest node by state
  * @node: Node id to start the search
@@ -3067,3 +3069,144 @@ void mpol_to_str(char *buffer, int maxlen, struct mempolicy *pol)
 		p += scnprintf(p, buffer + maxlen - p, ":%*pbl",
 			       nodemask_pr_args(&nodes));
 }
+
+struct iw_node_attr {
+	struct kobj_attribute kobj_attr;
+	int nid;
+};
+
+static ssize_t node_show(struct kobject *kobj, struct kobj_attribute *attr,
+			 char *buf)
+{
+	struct iw_node_attr *node_attr;
+
+	node_attr = container_of(attr, struct iw_node_attr, kobj_attr);
+	return sysfs_emit(buf, "%d\n", iw_table[node_attr->nid]);
+}
+
+static ssize_t node_store(struct kobject *kobj, struct kobj_attribute *attr,
+			  const char *buf, size_t count)
+{
+	struct iw_node_attr *node_attr;
+	unsigned char weight = 0;
+
+	node_attr = container_of(attr, struct iw_node_attr, kobj_attr);
+	/* If no input, set default weight to 1 */
+	if (count == 0 || sysfs_streq(buf, ""))
+		weight = 1;
+	else if (kstrtou8(buf, 0, &weight) || !weight)
+		return -EINVAL;
+
+	iw_table[node_attr->nid] = weight;
+	return count;
+}
+
+static struct iw_node_attr *node_attrs[MAX_NUMNODES];
+
+static void sysfs_wi_node_release(struct iw_node_attr *node_attr,
+				  struct kobject *parent)
+{
+	if (!node_attr)
+		return;
+	sysfs_remove_file(parent, &node_attr->kobj_attr.attr);
+	kfree(node_attr->kobj_attr.attr.name);
+	kfree(node_attr);
+}
+
+static void sysfs_mempolicy_release(struct kobject *mempolicy_kobj)
+{
+	int i;
+
+	for (i = 0; i < MAX_NUMNODES; i++)
+		sysfs_wi_node_release(node_attrs[i], mempolicy_kobj);
+	kobject_put(mempolicy_kobj);
+}
+
+static const struct kobj_type mempolicy_ktype = {
+	.sysfs_ops = &kobj_sysfs_ops,
+	.release = sysfs_mempolicy_release,
+};
+
+static int add_weight_node(int nid, struct kobject *wi_kobj)
+{
+	struct iw_node_attr *node_attr;
+	char *name;
+
+	node_attr = kzalloc(sizeof(*node_attr), GFP_KERNEL);
+	if (!node_attr)
+		return -ENOMEM;
+
+	name = kasprintf(GFP_KERNEL, "node%d", nid);
+	if (!name) {
+		kfree(node_attr);
+		return -ENOMEM;
+	}
+
+	sysfs_attr_init(&node_attr->attr);
+	node_attr->kobj_attr.attr.name = name;
+	node_attr->kobj_attr.attr.mode = 0644;
+	node_attr->kobj_attr.show = node_show;
+	node_attr->kobj_attr.store = node_store;
+	node_attr->nid = nid;
+
+	if (sysfs_create_file(wi_kobj, &node_attr->kobj_attr.attr)) {
+		kfree(node_attr->kobj_attr.attr.name);
+		kfree(node_attr);
+		pr_err("failed to add attribute to weighted_interleave\n");
+		return -ENOMEM;
+	}
+
+	node_attrs[nid] = node_attr;
+	return 0;
+}
+
+static int add_weighted_interleave_group(struct kobject *root_kobj)
+{
+	struct kobject *wi_kobj;
+	int nid, err;
+
+	wi_kobj = kzalloc(sizeof(struct kobject), GFP_KERNEL);
+	if (!wi_kobj)
+		return -ENOMEM;
+
+	err = kobject_init_and_add(wi_kobj, &mempolicy_ktype, root_kobj,
+				   "weighted_interleave");
+	if (err) {
+		kfree(wi_kobj);
+		return err;
+	}
+
+	memset(node_attrs, 0, sizeof(node_attrs));
+	for_each_node_state(nid, N_POSSIBLE) {
+		err = add_weight_node(nid, wi_kobj);
+		if (err) {
+			pr_err("failed to add sysfs [node%d]\n", nid);
+			break;
+		}
+	}
+	if (err)
+		kobject_put(wi_kobj);
+	return 0;
+}
+
+static int __init mempolicy_sysfs_init(void)
+{
+	int err;
+	struct kobject *root_kobj;
+
+	memset(&iw_table, 1, sizeof(iw_table));
+
+	root_kobj = kobject_create_and_add("mempolicy", mm_kobj);
+	if (!root_kobj) {
+		pr_err("failed to add mempolicy kobject to the system\n");
+		return -ENOMEM;
+	}
+
+	err = add_weighted_interleave_group(root_kobj);
+
+	if (err)
+		kobject_put(root_kobj);
+	return err;
+
+}
+late_initcall(mempolicy_sysfs_init);
-- 
2.39.1

[PATCH v3 02/11] mm/mempolicy: introduce MPOL_WEIGHTED_INTERLEAVE for weighted interleaving

[Gregory Price]

When a system has multiple NUMA nodes and it becomes bandwidth hungry,
the current MPOL_INTERLEAVE could be an wise option.

However, if those NUMA nodes consist of different types of memory such
as having local DRAM and CXL memory together, the current round-robin
based interleaving policy doesn't maximize the overall bandwidth because
of their different bandwidth characteristics.

Instead, the interleaving can be more efficient when the allocation
policy follows each NUMA nodes' bandwidth weight rather than having 1:1
round-robin allocation.

This patch introduces a new memory policy, MPOL_WEIGHTED_INTERLEAVE, which
enables weighted interleaving between NUMA nodes.  Weighted interleave
allows for a proportional distribution of memory across multiple numa
nodes, preferablly apportioned to match the bandwidth capacity of each
node from the perspective of the accessing node.

For example, if a system has 1 CPU node (0), and 2 memory nodes (0,1),
with a relative bandwidth of (100GB/s, 50GB/s) respectively, the
appropriate weight distribution is (2:1).

Weights will be acquired from the global weight matrix exposed by the
sysfs extension: /sys/kernel/mm/mempolicy/weighted_interleave/

The policy will then allocate the number of pages according to the
set weights.  For example, if the weights are (2,1), then 2 pages
will be allocated on node0 for every 1 page allocated on node1.

The new flag MPOL_WEIGHTED_INTERLEAVE can be used in set_mempolicy(2)
and mbind(2).

There are 3 integration points:

weighted_interleave_nodes:
    Counts the number of allocations as they occur, and applies the
    weight for the current node.  When the weight reaches 0, switch
    to the next node. Applied by `mempolicy_slab_node()` and
    `policy_nodemask()`

weighted_interleave_nid:
    Gets the total weight of the nodemask as well as each individual
    node weight, then calculates the node based on the given index.
    Applied by `policy_nodemask()` and `mpol_misplaced()`

bulk_array_weighted_interleave:
    Gets the total weight of the nodemask as well as each individual
    node weight, then calculates the number of "interleave rounds" as
    well as any delta ("partial round").  Calculates the number of
    pages for each node and allocates them.

    If a node was scheduled for interleave via interleave_nodes, the
    current weight (pol->cur_weight) will be allocated first, before
    the remaining bulk calculation is done. This simplifies the
    calculation at the cost of an additional allocation call.

One piece of complexity is the interaction between a recent refactor
which split the logic to acquire the "ilx" (interleave index) of an
allocation and the actually application of the interleave.  The
calculation of the `interleave index` is done by `get_vma_policy()`,
while the actual selection of the node will be later appliex by the
relevant weighted_interleave function.

Suggested-by: Hasan Al Maruf <Hasan.Maruf@amd.com>
Signed-off-by: Gregory Price <gregory.price@memverge.com>
Co-developed-by: Rakie Kim <rakie.kim@sk.com>
Signed-off-by: Rakie Kim <rakie.kim@sk.com>
Co-developed-by: Honggyu Kim <honggyu.kim@sk.com>
Signed-off-by: Honggyu Kim <honggyu.kim@sk.com>
Co-developed-by: Hyeongtak Ji <hyeongtak.ji@sk.com>
Signed-off-by: Hyeongtak Ji <hyeongtak.ji@sk.com>
Co-developed-by: Srinivasulu Thanneeru <sthanneeru.opensrc@micron.com>
Signed-off-by: Srinivasulu Thanneeru <sthanneeru.opensrc@micron.com>
Co-developed-by: Ravi Jonnalagadda <ravis.opensrc@micron.com>
Signed-off-by: Ravi Jonnalagadda <ravis.opensrc@micron.com>
---
 .../admin-guide/mm/numa_memory_policy.rst     |  11 +
 include/linux/mempolicy.h                     |   5 +
 include/uapi/linux/mempolicy.h                |   1 +
 mm/mempolicy.c                                | 197 +++++++++++++++++-
 4 files changed, 211 insertions(+), 3 deletions(-)

diff --git a/Documentation/admin-guide/mm/numa_memory_policy.rst b/Documentation/admin-guide/mm/numa_memory_policy.rst
index eca38fa81e0f..d2c8e712785b 100644
--- a/Documentation/admin-guide/mm/numa_memory_policy.rst
+++ b/Documentation/admin-guide/mm/numa_memory_policy.rst
@@ -250,6 +250,17 @@ MPOL_PREFERRED_MANY
 	can fall back to all existing numa nodes. This is effectively
 	MPOL_PREFERRED allowed for a mask rather than a single node.
 
+MPOL_WEIGHTED_INTERLEAVE
+	This mode operates the same as MPOL_INTERLEAVE, except that
+	interleaving behavior is executed based on weights set in
+	/sys/kernel/mm/mempolicy/weighted_interleave/
+
+	Weighted interleave allocations pages on nodes according to
+	their weight.  For example if nodes [0,1] are weighted [5,2]
+	respectively, 5 pages will be allocated on node0 for every
+	2 pages allocated on node1.  This can better distribute data
+	according to bandwidth on heterogeneous memory systems.
+
 NUMA memory policy supports the following optional mode flags:
 
 MPOL_F_STATIC_NODES
diff --git a/include/linux/mempolicy.h b/include/linux/mempolicy.h
index 931b118336f4..ba09167e80f7 100644
--- a/include/linux/mempolicy.h
+++ b/include/linux/mempolicy.h
@@ -54,6 +54,11 @@ struct mempolicy {
 		nodemask_t cpuset_mems_allowed;	/* relative to these nodes */
 		nodemask_t user_nodemask;	/* nodemask passed by user */
 	} w;
+
+	/* Weighted interleave settings */
+	struct {
+		unsigned char cur_weight;
+	} wil;
 };
 
 /*
diff --git a/include/uapi/linux/mempolicy.h b/include/uapi/linux/mempolicy.h
index a8963f7ef4c2..1f9bb10d1a47 100644
--- a/include/uapi/linux/mempolicy.h
+++ b/include/uapi/linux/mempolicy.h
@@ -23,6 +23,7 @@ enum {
 	MPOL_INTERLEAVE,
 	MPOL_LOCAL,
 	MPOL_PREFERRED_MANY,
+	MPOL_WEIGHTED_INTERLEAVE,
 	MPOL_MAX,	/* always last member of enum */
 };
 
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 5310021181ab..bd233aed103c 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -305,6 +305,7 @@ static struct mempolicy *mpol_new(unsigned short mode, unsigned short flags,
 	policy->mode = mode;
 	policy->flags = flags;
 	policy->home_node = NUMA_NO_NODE;
+	policy->wil.cur_weight = 0;
 
 	return policy;
 }
@@ -417,6 +418,10 @@ static const struct mempolicy_operations mpol_ops[MPOL_MAX] = {
 		.create = mpol_new_nodemask,
 		.rebind = mpol_rebind_preferred,
 	},
+	[MPOL_WEIGHTED_INTERLEAVE] = {
+		.create = mpol_new_nodemask,
+		.rebind = mpol_rebind_nodemask,
+	},
 };
 
 static bool migrate_folio_add(struct folio *folio, struct list_head *foliolist,
@@ -838,7 +843,8 @@ static long do_set_mempolicy(unsigned short mode, unsigned short flags,
 
 	old = current->mempolicy;
 	current->mempolicy = new;
-	if (new && new->mode == MPOL_INTERLEAVE)
+	if (new && (new->mode == MPOL_INTERLEAVE ||
+		    new->mode == MPOL_WEIGHTED_INTERLEAVE))
 		current->il_prev = MAX_NUMNODES-1;
 	task_unlock(current);
 	mpol_put(old);
@@ -864,6 +870,7 @@ static void get_policy_nodemask(struct mempolicy *pol, nodemask_t *nodes)
 	case MPOL_INTERLEAVE:
 	case MPOL_PREFERRED:
 	case MPOL_PREFERRED_MANY:
+	case MPOL_WEIGHTED_INTERLEAVE:
 		*nodes = pol->nodes;
 		break;
 	case MPOL_LOCAL:
@@ -948,6 +955,13 @@ static long do_get_mempolicy(int *policy, nodemask_t *nmask,
 		} else if (pol == current->mempolicy &&
 				pol->mode == MPOL_INTERLEAVE) {
 			*policy = next_node_in(current->il_prev, pol->nodes);
+		} else if (pol == current->mempolicy &&
+				(pol->mode == MPOL_WEIGHTED_INTERLEAVE)) {
+			if (pol->wil.cur_weight)
+				*policy = current->il_prev;
+			else
+				*policy = next_node_in(current->il_prev,
+						       pol->nodes);
 		} else {
 			err = -EINVAL;
 			goto out;
@@ -1777,7 +1791,8 @@ struct mempolicy *get_vma_policy(struct vm_area_struct *vma,
 	pol = __get_vma_policy(vma, addr, ilx);
 	if (!pol)
 		pol = get_task_policy(current);
-	if (pol->mode == MPOL_INTERLEAVE) {
+	if (pol->mode == MPOL_INTERLEAVE ||
+	    pol->mode == MPOL_WEIGHTED_INTERLEAVE) {
 		*ilx += vma->vm_pgoff >> order;
 		*ilx += (addr - vma->vm_start) >> (PAGE_SHIFT + order);
 	}
@@ -1827,6 +1842,24 @@ bool apply_policy_zone(struct mempolicy *policy, enum zone_type zone)
 	return zone >= dynamic_policy_zone;
 }
 
+static unsigned int weighted_interleave_nodes(struct mempolicy *policy)
+{
+	unsigned int next;
+	struct task_struct *me = current;
+
+	next = next_node_in(me->il_prev, policy->nodes);
+	if (next == MAX_NUMNODES)
+		return next;
+
+	if (!policy->wil.cur_weight)
+		policy->wil.cur_weight = iw_table[next];
+
+	policy->wil.cur_weight--;
+	if (!policy->wil.cur_weight)
+		me->il_prev = next;
+	return next;
+}
+
 /* Do dynamic interleaving for a process */
 static unsigned int interleave_nodes(struct mempolicy *policy)
 {
@@ -1861,6 +1894,9 @@ unsigned int mempolicy_slab_node(void)
 	case MPOL_INTERLEAVE:
 		return interleave_nodes(policy);
 
+	case MPOL_WEIGHTED_INTERLEAVE:
+		return weighted_interleave_nodes(policy);
+
 	case MPOL_BIND:
 	case MPOL_PREFERRED_MANY:
 	{
@@ -1885,6 +1921,41 @@ unsigned int mempolicy_slab_node(void)
 	}
 }
 
+static unsigned int weighted_interleave_nid(struct mempolicy *pol, pgoff_t ilx)
+{
+	nodemask_t nodemask = pol->nodes;
+	unsigned int target, weight_total = 0;
+	int nid;
+	unsigned char weights[MAX_NUMNODES];
+	unsigned char weight;
+
+	barrier();
+
+	/* first ensure we have a valid nodemask */
+	nid = first_node(nodemask);
+	if (nid == MAX_NUMNODES)
+		return nid;
+
+	/* Then collect weights on stack and calculate totals */
+	for_each_node_mask(nid, nodemask) {
+		weight = iw_table[nid];
+		weight_total += weight;
+		weights[nid] = weight;
+	}
+
+	/* Finally, calculate the node offset based on totals */
+	target = (unsigned int)ilx % weight_total;
+	nid = first_node(nodemask);
+	while (target) {
+		weight = weights[nid];
+		if (target < weight)
+			break;
+		target -= weight;
+		nid = next_node_in(nid, nodemask);
+	}
+	return nid;
+}
+
 /*
  * Do static interleaving for interleave index @ilx.  Returns the ilx'th
  * node in pol->nodes (starting from ilx=0), wrapping around if ilx
@@ -1953,6 +2024,11 @@ static nodemask_t *policy_nodemask(gfp_t gfp, struct mempolicy *pol,
 		*nid = (ilx == NO_INTERLEAVE_INDEX) ?
 			interleave_nodes(pol) : interleave_nid(pol, ilx);
 		break;
+	case MPOL_WEIGHTED_INTERLEAVE:
+		*nid = (ilx == NO_INTERLEAVE_INDEX) ?
+			weighted_interleave_nodes(pol) :
+			weighted_interleave_nid(pol, ilx);
+		break;
 	}
 
 	return nodemask;
@@ -2014,6 +2090,7 @@ bool init_nodemask_of_mempolicy(nodemask_t *mask)
 	case MPOL_PREFERRED_MANY:
 	case MPOL_BIND:
 	case MPOL_INTERLEAVE:
+	case MPOL_WEIGHTED_INTERLEAVE:
 		*mask = mempolicy->nodes;
 		break;
 
@@ -2113,7 +2190,8 @@ struct page *alloc_pages_mpol(gfp_t gfp, unsigned int order,
 		 * If the policy is interleave or does not allow the current
 		 * node in its nodemask, we allocate the standard way.
 		 */
-		if (pol->mode != MPOL_INTERLEAVE &&
+		if ((pol->mode != MPOL_INTERLEAVE &&
+		    pol->mode != MPOL_WEIGHTED_INTERLEAVE) &&
 		    (!nodemask || node_isset(nid, *nodemask))) {
 			/*
 			 * First, try to allocate THP only on local node, but
@@ -2249,6 +2327,106 @@ static unsigned long alloc_pages_bulk_array_interleave(gfp_t gfp,
 	return total_allocated;
 }
 
+static unsigned long alloc_pages_bulk_array_weighted_interleave(gfp_t gfp,
+		struct mempolicy *pol, unsigned long nr_pages,
+		struct page **page_array)
+{
+	struct task_struct *me = current;
+	unsigned long total_allocated = 0;
+	unsigned long nr_allocated;
+	unsigned long rounds;
+	unsigned long node_pages, delta;
+	unsigned char weight;
+	unsigned char weights[MAX_NUMNODES];
+	unsigned int weight_total = 0;
+	unsigned long rem_pages = nr_pages;
+	nodemask_t nodes = pol->nodes;
+	int nnodes, node, prev_node;
+	int i;
+
+	/* Stabilize the nodemask on the stack */
+	barrier();
+
+	nnodes = nodes_weight(nodes);
+
+	/* Collect weights and save them on stack so they don't change */
+	for_each_node_mask(node, nodes) {
+		weight = iw_table[node];
+		weight_total += weight;
+		weights[node] = weight;
+	}
+
+	/* Continue allocating from most recent node and adjust the nr_pages */
+	if (pol->wil.cur_weight) {
+		node = next_node_in(me->il_prev, nodes);
+		node_pages = pol->wil.cur_weight;
+		if (node_pages > rem_pages)
+			node_pages = rem_pages;
+		nr_allocated = __alloc_pages_bulk(gfp, node, NULL, node_pages,
+						  NULL, page_array);
+		page_array += nr_allocated;
+		total_allocated += nr_allocated;
+		/* if that's all the pages, no need to interleave */
+		if (rem_pages <= pol->wil.cur_weight) {
+			pol->wil.cur_weight -= rem_pages;
+			return total_allocated;
+		}
+		/* Otherwise we adjust nr_pages down, and continue from there */
+		rem_pages -= pol->wil.cur_weight;
+		pol->wil.cur_weight = 0;
+		prev_node = node;
+	}
+
+	/* Now we can continue allocating as if from 0 instead of an offset */
+	rounds = rem_pages / weight_total;
+	delta = rem_pages % weight_total;
+	for (i = 0; i < nnodes; i++) {
+		node = next_node_in(prev_node, nodes);
+		weight = weights[node];
+		node_pages = weight * rounds;
+		if (delta) {
+			if (delta > weight) {
+				node_pages += weight;
+				delta -= weight;
+			} else {
+				node_pages += delta;
+				delta = 0;
+			}
+		}
+		/* We may not make it all the way around */
+		if (!node_pages)
+			break;
+		/* If an over-allocation would occur, floor it */
+		if (node_pages + total_allocated > nr_pages) {
+			node_pages = nr_pages - total_allocated;
+			delta = 0;
+		}
+		nr_allocated = __alloc_pages_bulk(gfp, node, NULL, node_pages,
+						  NULL, page_array);
+		page_array += nr_allocated;
+		total_allocated += nr_allocated;
+		prev_node = node;
+	}
+
+	/*
+	 * Finally, we need to update me->il_prev and pol->wil.cur_weight
+	 * if there were overflow pages, but not equivalent to the node
+	 * weight, set the cur_weight to node_weight - delta and the
+	 * me->il_prev to the previous node. Otherwise if it was perfect
+	 * we can simply set il_prev to node and cur_weight to 0
+	 */
+	if (node_pages) {
+		me->il_prev = prev_node;
+		node_pages %= weight;
+		pol->wil.cur_weight = weight - node_pages;
+	} else {
+		me->il_prev = node;
+		pol->wil.cur_weight = 0;
+	}
+
+	return total_allocated;
+}
+
 static unsigned long alloc_pages_bulk_array_preferred_many(gfp_t gfp, int nid,
 		struct mempolicy *pol, unsigned long nr_pages,
 		struct page **page_array)
@@ -2289,6 +2467,11 @@ unsigned long alloc_pages_bulk_array_mempolicy(gfp_t gfp,
 		return alloc_pages_bulk_array_interleave(gfp, pol,
 							 nr_pages, page_array);
 
+	if (pol->mode == MPOL_WEIGHTED_INTERLEAVE)
+		return alloc_pages_bulk_array_weighted_interleave(gfp, pol,
+								  nr_pages,
+								  page_array);
+
 	if (pol->mode == MPOL_PREFERRED_MANY)
 		return alloc_pages_bulk_array_preferred_many(gfp,
 				numa_node_id(), pol, nr_pages, page_array);
@@ -2364,6 +2547,7 @@ bool __mpol_equal(struct mempolicy *a, struct mempolicy *b)
 	case MPOL_INTERLEAVE:
 	case MPOL_PREFERRED:
 	case MPOL_PREFERRED_MANY:
+	case MPOL_WEIGHTED_INTERLEAVE:
 		return !!nodes_equal(a->nodes, b->nodes);
 	case MPOL_LOCAL:
 		return true;
@@ -2500,6 +2684,10 @@ int mpol_misplaced(struct folio *folio, struct vm_area_struct *vma,
 		polnid = interleave_nid(pol, ilx);
 		break;
 
+	case MPOL_WEIGHTED_INTERLEAVE:
+		polnid = weighted_interleave_nid(pol, ilx);
+		break;
+
 	case MPOL_PREFERRED:
 		if (node_isset(curnid, pol->nodes))
 			goto out;
@@ -2874,6 +3062,7 @@ static const char * const policy_modes[] =
 	[MPOL_PREFERRED]  = "prefer",
 	[MPOL_BIND]       = "bind",
 	[MPOL_INTERLEAVE] = "interleave",
+	[MPOL_WEIGHTED_INTERLEAVE] = "weighted interleave",
 	[MPOL_LOCAL]      = "local",
 	[MPOL_PREFERRED_MANY]  = "prefer (many)",
 };
@@ -2933,6 +3122,7 @@ int mpol_parse_str(char *str, struct mempolicy **mpol)
 		}
 		break;
 	case MPOL_INTERLEAVE:
+	case MPOL_WEIGHTED_INTERLEAVE:
 		/*
 		 * Default to online nodes with memory if no nodelist
 		 */
@@ -3043,6 +3233,7 @@ void mpol_to_str(char *buffer, int maxlen, struct mempolicy *pol)
 	case MPOL_PREFERRED_MANY:
 	case MPOL_BIND:
 	case MPOL_INTERLEAVE:
+	case MPOL_WEIGHTED_INTERLEAVE:
 		nodes = pol->nodes;
 		break;
 	default:
-- 
2.39.1

[PATCH v3 03/11] mm/mempolicy: refactor sanitize_mpol_flags for reuse

[Gregory Price]

split sanitize_mpol_flags into sanitize and validate.

Sanitize is used by set_mempolicy to split (int mode) into mode
and mode_flags, and then validates them.

Validate validates already split flags.

Validate will be reused for new syscalls that accept already
split mode and mode_flags.

Signed-off-by: Gregory Price <gregory.price@memverge.com>
---
 mm/mempolicy.c | 29 ++++++++++++++++++++++-------
 1 file changed, 22 insertions(+), 7 deletions(-)

diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index bd233aed103c..e55a8fa13e45 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -1463,24 +1463,39 @@ static int copy_nodes_to_user(unsigned long __user *mask, unsigned long maxnode,
 	return copy_to_user(mask, nodes_addr(*nodes), copy) ? -EFAULT : 0;
 }
 
-/* Basic parameter sanity check used by both mbind() and set_mempolicy() */
-static inline int sanitize_mpol_flags(int *mode, unsigned short *flags)
+/*
+ * Basic parameter sanity check used by mbind/set_mempolicy
+ * May modify flags to include internal flags (e.g. MPOL_F_MOF/F_MORON)
+ */
+static inline int validate_mpol_flags(unsigned short mode, unsigned short *flags)
 {
-	*flags = *mode & MPOL_MODE_FLAGS;
-	*mode &= ~MPOL_MODE_FLAGS;
-
-	if ((unsigned int)(*mode) >=  MPOL_MAX)
+	if ((unsigned int)(mode) >= MPOL_MAX)
 		return -EINVAL;
 	if ((*flags & MPOL_F_STATIC_NODES) && (*flags & MPOL_F_RELATIVE_NODES))
 		return -EINVAL;
 	if (*flags & MPOL_F_NUMA_BALANCING) {
-		if (*mode != MPOL_BIND)
+		if (mode != MPOL_BIND)
 			return -EINVAL;
 		*flags |= (MPOL_F_MOF | MPOL_F_MORON);
 	}
 	return 0;
 }
 
+/*
+ * Used by mbind/set_memplicy to split and validate mode/flags
+ * set_mempolicy combines (mode | flags), split them out into separate
+ * fields and return just the mode in mode_arg and flags in flags.
+ */
+static inline int sanitize_mpol_flags(int *mode_arg, unsigned short *flags)
+{
+	unsigned short mode = (*mode_arg & ~MPOL_MODE_FLAGS);
+
+	*flags = *mode_arg & MPOL_MODE_FLAGS;
+	*mode_arg = mode;
+
+	return validate_mpol_flags(mode, flags);
+}
+
 static long kernel_mbind(unsigned long start, unsigned long len,
 			 unsigned long mode, const unsigned long __user *nmask,
 			 unsigned long maxnode, unsigned int flags)
-- 
2.39.1

[PATCH v3 04/11] mm/mempolicy: create struct mempolicy_args for creating new mempolicies

[Gregory Price]

This patch adds a new kernel structure `struct mempolicy_args`,
intended to be used for an extensible get/set_mempolicy interface.

This implements the fields required to support the existing syscall
interfaces interfaces, but does not expose any user-facing arg
structure.

mpol_new is refactored to take the argument structure so that future
mempolicy extensions can all be managed in the mempolicy constructor.

The get_mempolicy and mbind syscalls are refactored to utilize the
new argument structure, as are all the callers of mpol_new() and
do_set_mempolicy.

Signed-off-by: Gregory Price <gregory.price@memverge.com>
---
 include/linux/mempolicy.h | 12 +++++++
 mm/mempolicy.c            | 69 +++++++++++++++++++++++++++++----------
 2 files changed, 63 insertions(+), 18 deletions(-)

diff --git a/include/linux/mempolicy.h b/include/linux/mempolicy.h
index ba09167e80f7..aeac19dfc2b6 100644
--- a/include/linux/mempolicy.h
+++ b/include/linux/mempolicy.h
@@ -61,6 +61,18 @@ struct mempolicy {
 	} wil;
 };
 
+/*
+ * Describes settings of a mempolicy during set/get syscalls and
+ * kernel internal calls to do_set_mempolicy()
+ */
+struct mempolicy_args {
+	unsigned short mode;		/* policy mode */
+	unsigned short mode_flags;	/* policy mode flags */
+	int home_node;			/* mbind: use MPOL_MF_HOME_NODE */
+	nodemask_t *policy_nodes;	/* get/set/mbind */
+	int policy_node;		/* get: policy node information */
+};
+
 /*
  * Support for managing mempolicy data objects (clone, copy, destroy)
  * The default fast path of a NULL MPOL_DEFAULT policy is always inlined.
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index e55a8fa13e45..a2353b208af7 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -265,10 +265,12 @@ static int mpol_set_nodemask(struct mempolicy *pol,
  * This function just creates a new policy, does some check and simple
  * initialization. You must invoke mpol_set_nodemask() to set nodes.
  */
-static struct mempolicy *mpol_new(unsigned short mode, unsigned short flags,
-				  nodemask_t *nodes)
+static struct mempolicy *mpol_new(struct mempolicy_args *args)
 {
 	struct mempolicy *policy;
+	unsigned short mode = args->mode;
+	unsigned short flags = args->mode_flags;
+	nodemask_t *nodes = args->policy_nodes;
 
 	if (mode == MPOL_DEFAULT) {
 		if (nodes && !nodes_empty(*nodes))
@@ -817,8 +819,7 @@ static int mbind_range(struct vma_iterator *vmi, struct vm_area_struct *vma,
 }
 
 /* Set the process memory policy */
-static long do_set_mempolicy(unsigned short mode, unsigned short flags,
-			     nodemask_t *nodes)
+static long do_set_mempolicy(struct mempolicy_args *args)
 {
 	struct mempolicy *new, *old;
 	NODEMASK_SCRATCH(scratch);
@@ -827,14 +828,14 @@ static long do_set_mempolicy(unsigned short mode, unsigned short flags,
 	if (!scratch)
 		return -ENOMEM;
 
-	new = mpol_new(mode, flags, nodes);
+	new = mpol_new(args);
 	if (IS_ERR(new)) {
 		ret = PTR_ERR(new);
 		goto out;
 	}
 
 	task_lock(current);
-	ret = mpol_set_nodemask(new, nodes, scratch);
+	ret = mpol_set_nodemask(new, args->policy_nodes, scratch);
 	if (ret) {
 		task_unlock(current);
 		mpol_put(new);
@@ -1232,8 +1233,7 @@ static struct folio *alloc_migration_target_by_mpol(struct folio *src,
 #endif
 
 static long do_mbind(unsigned long start, unsigned long len,
-		     unsigned short mode, unsigned short mode_flags,
-		     nodemask_t *nmask, unsigned long flags)
+		     struct mempolicy_args *margs, unsigned long flags)
 {
 	struct mm_struct *mm = current->mm;
 	struct vm_area_struct *vma, *prev;
@@ -1253,7 +1253,7 @@ static long do_mbind(unsigned long start, unsigned long len,
 	if (start & ~PAGE_MASK)
 		return -EINVAL;
 
-	if (mode == MPOL_DEFAULT)
+	if (margs->mode == MPOL_DEFAULT)
 		flags &= ~MPOL_MF_STRICT;
 
 	len = PAGE_ALIGN(len);
@@ -1264,7 +1264,7 @@ static long do_mbind(unsigned long start, unsigned long len,
 	if (end == start)
 		return 0;
 
-	new = mpol_new(mode, mode_flags, nmask);
+	new = mpol_new(margs);
 	if (IS_ERR(new))
 		return PTR_ERR(new);
 
@@ -1281,7 +1281,8 @@ static long do_mbind(unsigned long start, unsigned long len,
 		NODEMASK_SCRATCH(scratch);
 		if (scratch) {
 			mmap_write_lock(mm);
-			err = mpol_set_nodemask(new, nmask, scratch);
+			err = mpol_set_nodemask(new, margs->policy_nodes,
+						scratch);
 			if (err)
 				mmap_write_unlock(mm);
 		} else
@@ -1295,7 +1296,7 @@ static long do_mbind(unsigned long start, unsigned long len,
 	 * Lock the VMAs before scanning for pages to migrate,
 	 * to ensure we don't miss a concurrently inserted page.
 	 */
-	nr_failed = queue_pages_range(mm, start, end, nmask,
+	nr_failed = queue_pages_range(mm, start, end, margs->policy_nodes,
 			flags | MPOL_MF_INVERT | MPOL_MF_WRLOCK, &pagelist);
 
 	if (nr_failed < 0) {
@@ -1500,6 +1501,7 @@ static long kernel_mbind(unsigned long start, unsigned long len,
 			 unsigned long mode, const unsigned long __user *nmask,
 			 unsigned long maxnode, unsigned int flags)
 {
+	struct mempolicy_args margs;
 	unsigned short mode_flags;
 	nodemask_t nodes;
 	int lmode = mode;
@@ -1514,7 +1516,12 @@ static long kernel_mbind(unsigned long start, unsigned long len,
 	if (err)
 		return err;
 
-	return do_mbind(start, len, lmode, mode_flags, &nodes, flags);
+	memset(&margs, 0, sizeof(margs));
+	margs.mode = lmode;
+	margs.mode_flags = mode_flags;
+	margs.policy_nodes = &nodes;
+
+	return do_mbind(start, len, &margs, flags);
 }
 
 SYSCALL_DEFINE4(set_mempolicy_home_node, unsigned long, start, unsigned long, len,
@@ -1595,6 +1602,7 @@ SYSCALL_DEFINE6(mbind, unsigned long, start, unsigned long, len,
 static long kernel_set_mempolicy(int mode, const unsigned long __user *nmask,
 				 unsigned long maxnode)
 {
+	struct mempolicy_args args;
 	unsigned short mode_flags;
 	nodemask_t nodes;
 	int lmode = mode;
@@ -1608,7 +1616,12 @@ static long kernel_set_mempolicy(int mode, const unsigned long __user *nmask,
 	if (err)
 		return err;
 
-	return do_set_mempolicy(lmode, mode_flags, &nodes);
+	memset(&args, 0, sizeof(args));
+	args.mode = lmode;
+	args.mode_flags = mode_flags;
+	args.policy_nodes = &nodes;
+
+	return do_set_mempolicy(&args);
 }
 
 SYSCALL_DEFINE3(set_mempolicy, int, mode, const unsigned long __user *, nmask,
@@ -2890,6 +2903,7 @@ static int shared_policy_replace(struct shared_policy *sp, pgoff_t start,
 void mpol_shared_policy_init(struct shared_policy *sp, struct mempolicy *mpol)
 {
 	int ret;
+	struct mempolicy_args margs;
 
 	sp->root = RB_ROOT;		/* empty tree == default mempolicy */
 	rwlock_init(&sp->lock);
@@ -2902,8 +2916,12 @@ void mpol_shared_policy_init(struct shared_policy *sp, struct mempolicy *mpol)
 		if (!scratch)
 			goto put_mpol;
 
+		memset(&margs, 0, sizeof(margs));
+		margs.mode = mpol->mode;
+		margs.mode_flags = mpol->flags;
+		margs.policy_nodes = &mpol->w.user_nodemask;
 		/* contextualize the tmpfs mount point mempolicy to this file */
-		npol = mpol_new(mpol->mode, mpol->flags, &mpol->w.user_nodemask);
+		npol = mpol_new(&margs);
 		if (IS_ERR(npol))
 			goto free_scratch; /* no valid nodemask intersection */
 
@@ -3011,6 +3029,7 @@ static inline void __init check_numabalancing_enable(void)
 
 void __init numa_policy_init(void)
 {
+	struct mempolicy_args args;
 	nodemask_t interleave_nodes;
 	unsigned long largest = 0;
 	int nid, prefer = 0;
@@ -3056,7 +3075,11 @@ void __init numa_policy_init(void)
 	if (unlikely(nodes_empty(interleave_nodes)))
 		node_set(prefer, interleave_nodes);
 
-	if (do_set_mempolicy(MPOL_INTERLEAVE, 0, &interleave_nodes))
+	memset(&args, 0, sizeof(args));
+	args.mode = MPOL_INTERLEAVE;
+	args.policy_nodes = &interleave_nodes;
+
+	if (do_set_mempolicy(&args))
 		pr_err("%s: interleaving failed\n", __func__);
 
 	check_numabalancing_enable();
@@ -3065,7 +3088,12 @@ void __init numa_policy_init(void)
 /* Reset policy of current process to default */
 void numa_default_policy(void)
 {
-	do_set_mempolicy(MPOL_DEFAULT, 0, NULL);
+	struct mempolicy_args args;
+
+	memset(&args, 0, sizeof(args));
+	args.mode = MPOL_DEFAULT;
+
+	do_set_mempolicy(&args);
 }
 
 /*
@@ -3095,6 +3123,7 @@ static const char * const policy_modes[] =
  */
 int mpol_parse_str(char *str, struct mempolicy **mpol)
 {
+	struct mempolicy_args margs;
 	struct mempolicy *new = NULL;
 	unsigned short mode_flags;
 	nodemask_t nodes;
@@ -3181,7 +3210,11 @@ int mpol_parse_str(char *str, struct mempolicy **mpol)
 			goto out;
 	}
 
-	new = mpol_new(mode, mode_flags, &nodes);
+	memset(&margs, 0, sizeof(margs));
+	margs.mode = mode;
+	margs.mode_flags = mode_flags;
+	margs.policy_nodes = &nodes;
+	new = mpol_new(&margs);
 	if (IS_ERR(new))
 		goto out;
 
-- 
2.39.1

[PATCH v3 05/11] mm/mempolicy: refactor kernel_get_mempolicy for code re-use

[Gregory Price]

Pull operation flag checking from inside do_get_mempolicy out
to kernel_get_mempolicy.  This allows us to flatten the
internal code, and break it into separate functions for future
syscalls (get_mempolicy2, process_get_mempolicy) to re-use the
code, even after additional extensions are made.

The primary change is that the flag is treated as the multiplexer
that it actually is.  For get_mempolicy, the flags represents 3
different primary operations:

if (flags & MPOL_F_MEMS_ALLOWED)
	return task->mems_allowed
else if (flags & MPOL_F_ADDR)
	return vma mempolicy information
else
	return task mempolicy information

Plus the behavior modifying flag:

if (flags & MPOL_F_NODE)
	change the return value of (int __user *policy)
	based on whether MPOL_F_ADDR was set.

The original behavior of get_mempolicy is retained, but we utilize
the new mempolicy_args structure to pass the operations down the
stack.  This will allow us to extend the internal functions without
affecting the legacy behavior of get_mempolicy.

Signed-off-by: Gregory Price <gregory.price@memverge.com>
---
 mm/mempolicy.c | 245 +++++++++++++++++++++++++++++++------------------
 1 file changed, 155 insertions(+), 90 deletions(-)

diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index a2353b208af7..7956edcc57fd 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -895,106 +895,111 @@ static int lookup_node(struct mm_struct *mm, unsigned long addr)
 	return ret;
 }
 
-/* Retrieve NUMA policy */
-static long do_get_mempolicy(int *policy, nodemask_t *nmask,
-			     unsigned long addr, unsigned long flags)
+/* Retrieve the mems_allowed for current task */
+static inline long do_get_mems_allowed(nodemask_t *nmask)
 {
-	int err;
-	struct mm_struct *mm = current->mm;
-	struct vm_area_struct *vma = NULL;
-	struct mempolicy *pol = current->mempolicy, *pol_refcount = NULL;
+	task_lock(current);
+	*nmask  = cpuset_current_mems_allowed;
+	task_unlock(current);
+	return 0;
+}
 
-	if (flags &
-		~(unsigned long)(MPOL_F_NODE|MPOL_F_ADDR|MPOL_F_MEMS_ALLOWED))
-		return -EINVAL;
+/* If the policy has additional node information to retrieve, return it */
+static long do_get_policy_node(struct mempolicy *pol)
+{
+	/*
+	 * For MPOL_INTERLEAVE, the extended node information is the next
+	 * node that will be selected for interleave. For weighted interleave
+	 * we return the next node based on the current weight.
+	 */
+	if (pol == current->mempolicy && pol->mode == MPOL_INTERLEAVE)
+		return next_node_in(current->il_prev, pol->nodes);
 
-	if (flags & MPOL_F_MEMS_ALLOWED) {
-		if (flags & (MPOL_F_NODE|MPOL_F_ADDR))
-			return -EINVAL;
-		*policy = 0;	/* just so it's initialized */
+	if (pol == current->mempolicy &&
+	    pol->mode == MPOL_WEIGHTED_INTERLEAVE) {
+		if (pol->wil.cur_weight)
+			return current->il_prev;
+		else
+			return next_node_in(current->il_prev, pol->nodes);
+	}
+	return -EINVAL;
+}
+
+/* Handle user_nodemask condition when fetching nodemask for userspace */
+static void do_get_mempolicy_nodemask(struct mempolicy *pol, nodemask_t *nmask)
+{
+	if (mpol_store_user_nodemask(pol)) {
+		*nmask = pol->w.user_nodemask;
+	} else {
 		task_lock(current);
-		*nmask  = cpuset_current_mems_allowed;
+		get_policy_nodemask(pol, nmask);
 		task_unlock(current);
-		return 0;
 	}
+}
 
-	if (flags & MPOL_F_ADDR) {
-		pgoff_t ilx;		/* ignored here */
-		/*
-		 * Do NOT fall back to task policy if the
-		 * vma/shared policy at addr is NULL.  We
-		 * want to return MPOL_DEFAULT in this case.
-		 */
-		mmap_read_lock(mm);
-		vma = vma_lookup(mm, addr);
-		if (!vma) {
-			mmap_read_unlock(mm);
-			return -EFAULT;
-		}
-		pol = __get_vma_policy(vma, addr, &ilx);
-	} else if (addr)
-		return -EINVAL;
+/* Retrieve NUMA policy for a VMA assocated with a given address  */
+static long do_get_vma_mempolicy(unsigned long addr, int *addr_node,
+				 struct mempolicy_args *args)
+{
+	pgoff_t ilx;
+	struct mm_struct *mm = current->mm;
+	struct vm_area_struct *vma = NULL;
+	struct mempolicy *pol = NULL;
 
+	mmap_read_lock(mm);
+	vma = vma_lookup(mm, addr);
+	if (!vma) {
+		mmap_read_unlock(mm);
+		return -EFAULT;
+	}
+	pol = __get_vma_policy(vma, addr, &ilx);
 	if (!pol)
-		pol = &default_policy;	/* indicates default behavior */
+		pol = &default_policy;
+	else
+		mpol_get(pol);
+	mmap_read_unlock(mm);
 
-	if (flags & MPOL_F_NODE) {
-		if (flags & MPOL_F_ADDR) {
-			/*
-			 * Take a refcount on the mpol, because we are about to
-			 * drop the mmap_lock, after which only "pol" remains
-			 * valid, "vma" is stale.
-			 */
-			pol_refcount = pol;
-			vma = NULL;
-			mpol_get(pol);
-			mmap_read_unlock(mm);
-			err = lookup_node(mm, addr);
-			if (err < 0)
-				goto out;
-			*policy = err;
-		} else if (pol == current->mempolicy &&
-				pol->mode == MPOL_INTERLEAVE) {
-			*policy = next_node_in(current->il_prev, pol->nodes);
-		} else if (pol == current->mempolicy &&
-				(pol->mode == MPOL_WEIGHTED_INTERLEAVE)) {
-			if (pol->wil.cur_weight)
-				*policy = current->il_prev;
-			else
-				*policy = next_node_in(current->il_prev,
-						       pol->nodes);
-		} else {
-			err = -EINVAL;
-			goto out;
-		}
-	} else {
-		*policy = pol == &default_policy ? MPOL_DEFAULT :
-						pol->mode;
-		/*
-		 * Internal mempolicy flags must be masked off before exposing
-		 * the policy to userspace.
-		 */
-		*policy |= (pol->flags & MPOL_MODE_FLAGS);
-	}
+	/* Fetch the node for the given address */
+	if (addr_node)
+		*addr_node = lookup_node(mm, addr);
 
-	err = 0;
-	if (nmask) {
-		if (mpol_store_user_nodemask(pol)) {
-			*nmask = pol->w.user_nodemask;
-		} else {
-			task_lock(current);
-			get_policy_nodemask(pol, nmask);
-			task_unlock(current);
-		}
+	args->mode = pol == &default_policy ? MPOL_DEFAULT : pol->mode;
+	args->mode_flags = (pol->flags & MPOL_MODE_FLAGS);
+	args->home_node = pol->home_node;
+
+	/* If this policy has extra node info, fetch that */
+	args->policy_node = do_get_policy_node(pol);
+
+	if (args->policy_nodes)
+		do_get_mempolicy_nodemask(pol, args->policy_nodes);
+
+	if (pol != &default_policy) {
+		mpol_put(pol);
+		mpol_cond_put(pol);
 	}
 
- out:
-	mpol_cond_put(pol);
-	if (vma)
-		mmap_read_unlock(mm);
-	if (pol_refcount)
-		mpol_put(pol_refcount);
-	return err;
+	return 0;
+}
+
+/* Retrieve NUMA policy for the current task */
+static long do_get_task_mempolicy(struct mempolicy_args *args)
+{
+	struct mempolicy *pol = current->mempolicy;
+
+	if (!pol)
+		pol = &default_policy;	/* indicates default behavior */
+
+	args->mode = pol == &default_policy ? MPOL_DEFAULT : pol->mode;
+	/* Internal flags must be masked off before exposing to userspace */
+	args->mode_flags = (pol->flags & MPOL_MODE_FLAGS);
+	args->home_node = NUMA_NO_NODE;
+
+	args->policy_node = do_get_policy_node(pol);
+
+	if (args->policy_nodes)
+		do_get_mempolicy_nodemask(pol, args->policy_nodes);
+
+	return 0;
 }
 
 #ifdef CONFIG_MIGRATION
@@ -1731,16 +1736,76 @@ static int kernel_get_mempolicy(int __user *policy,
 				unsigned long addr,
 				unsigned long flags)
 {
+	struct mempolicy_args args;
 	int err;
-	int pval;
+	int address_node = NUMA_NO_NODE;
+	int pval = 0;
 	nodemask_t nodes;
 
 	if (nmask != NULL && maxnode < nr_node_ids)
 		return -EINVAL;
 
-	addr = untagged_addr(addr);
+	if (flags &
+		~(unsigned long)(MPOL_F_NODE|MPOL_F_ADDR|MPOL_F_MEMS_ALLOWED))
+		return -EINVAL;
 
-	err = do_get_mempolicy(&pval, &nodes, addr, flags);
+	/* Ensure any data that may be copied to userland is initialized */
+	memset(&args, 0, sizeof(args));
+	args.policy_nodes = &nodes;
+
+	/*
+	 * set_mempolicy was originally multiplexed based on 3 flags:
+	 *   MPOL_F_MEMS_ALLOWED:  fetch task->mems_allowed
+	 *   MPOL_F_ADDR        :  operate on vma->mempolicy
+	 *   MPOL_F_NODE        :  change return value of *policy
+	 *
+	 * Split this behavior out here, rather than internal functions,
+	 * so that the internal functions can be re-used by future
+	 * get_mempolicy2 interfaces and the arg structure made extensible
+	 */
+	if (flags & MPOL_F_MEMS_ALLOWED) {
+		if (flags & (MPOL_F_NODE|MPOL_F_ADDR))
+			return -EINVAL;
+		pval = 0;	/* just so it's initialized */
+		err = do_get_mems_allowed(&nodes);
+	} else if (flags & MPOL_F_ADDR) {
+		/* If F_ADDR, we operation on a vma policy (or default) */
+		err = do_get_vma_mempolicy(untagged_addr(addr),
+					   &address_node, &args);
+		if (err)
+			return err;
+		 /* if (F_ADDR | F_NODE), *pval is the address' node */
+		if (flags & MPOL_F_NODE) {
+			/* if we failed to fetch, that's likely an EFAULT */
+			if (address_node < 0)
+				return address_node;
+			pval = address_node;
+		} else
+			pval = args.mode | args.mode_flags;
+	} else {
+		 /* if not F_ADDR and addr != null, EINVAL */
+		if (addr)
+			return -EINVAL;
+
+		err = do_get_task_mempolicy(&args);
+		if (err)
+			return err;
+		/*
+		 * if F_NODE was set and mode was MPOL_INTERLEAVE
+		 * *pval is equal to next interleave node.
+		 *
+		 * if args.policy_node < 0, this means the mode did
+		 * not have a policy.  This presently emulates the
+		 * original behavior of (F_NODE) & (!MPOL_INTERLEAVE)
+		 * producing -EINVAL
+		 */
+		if (flags & MPOL_F_NODE) {
+			if (args.policy_node < 0)
+				return args.policy_node;
+			pval = args.policy_node;
+		} else
+			pval = args.mode | args.mode_flags;
+	}
 
 	if (err)
 		return err;
-- 
2.39.1

[PATCH v3 06/11] mm/mempolicy: allow home_node to be set by mpol_new

[Gregory Price]

This patch adds the plumbing into mpol_new() to allow the argument
structure's home_node field to be set during mempolicy creation.

The syscall sys_set_mempolicy_home_node was added to allow a home
node to be registered for a vma.

For set_mempolicy2 and mbind2 syscalls, it would be useful to add
this as an extension to allow the user to submit a fully formed
mempolicy configuration in a single call, rather than require
multiple calls to configure a mempolicy.

This will become particularly useful if/when pidfd interfaces to
change process mempolicies from outside the task appear, as each
call to change the mempolicy does an atomic swap of that policy
in the task, rather than mutate the policy.

Signed-off-by: Gregory Price <gregory.price@memverge.com>
---
 mm/mempolicy.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 7956edcc57fd..705ddf1ccdd9 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -306,7 +306,7 @@ static struct mempolicy *mpol_new(struct mempolicy_args *args)
 	atomic_set(&policy->refcnt, 1);
 	policy->mode = mode;
 	policy->flags = flags;
-	policy->home_node = NUMA_NO_NODE;
+	policy->home_node = args->home_node;
 	policy->wil.cur_weight = 0;
 
 	return policy;
@@ -1625,6 +1625,7 @@ static long kernel_set_mempolicy(int mode, const unsigned long __user *nmask,
 	args.mode = lmode;
 	args.mode_flags = mode_flags;
 	args.policy_nodes = &nodes;
+	args.home_node = NUMA_NO_NODE;
 
 	return do_set_mempolicy(&args);
 }
@@ -2985,6 +2986,8 @@ void mpol_shared_policy_init(struct shared_policy *sp, struct mempolicy *mpol)
 		margs.mode = mpol->mode;
 		margs.mode_flags = mpol->flags;
 		margs.policy_nodes = &mpol->w.user_nodemask;
+		margs.home_node = NUMA_NO_NODE;
+
 		/* contextualize the tmpfs mount point mempolicy to this file */
 		npol = mpol_new(&margs);
 		if (IS_ERR(npol))
@@ -3143,6 +3146,7 @@ void __init numa_policy_init(void)
 	memset(&args, 0, sizeof(args));
 	args.mode = MPOL_INTERLEAVE;
 	args.policy_nodes = &interleave_nodes;
+	args.home_node = NUMA_NO_NODE;
 
 	if (do_set_mempolicy(&args))
 		pr_err("%s: interleaving failed\n", __func__);
@@ -3157,6 +3161,7 @@ void numa_default_policy(void)
 
 	memset(&args, 0, sizeof(args));
 	args.mode = MPOL_DEFAULT;
+	args.home_node = NUMA_NO_NODE;
 
 	do_set_mempolicy(&args);
 }
@@ -3279,6 +3284,8 @@ int mpol_parse_str(char *str, struct mempolicy **mpol)
 	margs.mode = mode;
 	margs.mode_flags = mode_flags;
 	margs.policy_nodes = &nodes;
+	margs.home_node = NUMA_NO_NODE;
+
 	new = mpol_new(&margs);
 	if (IS_ERR(new))
 		goto out;
-- 
2.39.1

[PATCH v3 07/11] mm/mempolicy: add userland mempolicy arg structure

[Gregory Price]

This patch adds the new user-api argument structure intended for
set_mempolicy2 and mbind2.

struct mpol_args {
  __u16 mode;
  __u16 mode_flags;
  __s32 home_node;          /* mbind2: policy home node */
  __aligned_u64 *pol_nodes;
  __u64 pol_maxnodes;
  __s32 policy_node;        /* get_mempolicy: policy node info */
};

This structure is intended to be extensible as new mempolicy extensions
are added.

For example, set_mempolicy_home_node was added to allow vma mempolicies
to have a preferred/home node assigned.  This structure allows the
addition of that setting at the time the mempolicy is set, rather
than requiring additional calls to modify the policy.

Full breakdown of arguments as of this patch:
    mode:         Mempolicy mode (MPOL_DEFAULT, MPOL_INTERLEAVE)

    mode_flags:   Flags previously or'd into mode in set_mempolicy
                  (e.g.: MPOL_F_STATIC_NODES, MPOL_F_RELATIVE_NODES)

    home_node:    for mbind2.  Allows the setting of a policy's home
                  with the use of MPOL_MF_HOME_NODE

    pol_nodes:    Policy nodemask

    pol_maxnodes: Max number of nodes in the policy nodemask

    policy_node:  for get_mempolicy2.  Returns extended information
                  about a policy that was previously reported by
                  passing MPOL_F_NODE to get_mempolicy.  Instead of
                  overriding the mode value, simply add a field.

Suggested-by: Frank van der Linden <fvdl@google.com>
Suggested-by: Vinicius Tavares Petrucci <vtavarespetr@micron.com>
Suggested-by: Hasan Al Maruf <Hasan.Maruf@amd.com>
Signed-off-by: Gregory Price <gregory.price@memverge.com>
Co-developed-by: Vinicius Tavares Petrucci <vtavarespetr@micron.com>
Signed-off-by: Vinicius Tavares Petrucci <vtavarespetr@micron.com>
---
 .../admin-guide/mm/numa_memory_policy.rst      | 18 ++++++++++++++++++
 include/linux/syscalls.h                       |  1 +
 include/uapi/linux/mempolicy.h                 | 10 ++++++++++
 3 files changed, 29 insertions(+)

diff --git a/Documentation/admin-guide/mm/numa_memory_policy.rst b/Documentation/admin-guide/mm/numa_memory_policy.rst
index d2c8e712785b..d5fcebdd7996 100644
--- a/Documentation/admin-guide/mm/numa_memory_policy.rst
+++ b/Documentation/admin-guide/mm/numa_memory_policy.rst
@@ -482,6 +482,24 @@ closest to which page allocation will come from. Specifying the home node overri
 the default allocation policy to allocate memory close to the local node for an
 executing CPU.
 
+Extended Mempolicy Arguments::
+
+	struct mpol_args {
+		__u16 mode;
+		__u16 mode_flags;
+		__s32 home_node; /* mbind2: policy home node */
+		__aligned_u64 pol_nodes; /* nodemask pointer */
+		__u64 pol_maxnodes;
+		__s32 policy_node; /* get_mempolicy2: policy node information */
+	};
+
+The extended mempolicy argument structure is defined to allow the mempolicy
+interfaces future extensibility without the need for additional system calls.
+
+The core arguments (mode, mode_flags, pol_nodes, and pol_maxnodes) apply to
+all interfaces relative to their non-extended counterparts. Each additional
+field may only apply to specific extended interfaces.  See the respective
+extended interface man page for more details.
 
 Memory Policy Command Line Interface
 ====================================
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index fd9d12de7e92..a52395ca3f00 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -74,6 +74,7 @@ struct landlock_ruleset_attr;
 enum landlock_rule_type;
 struct cachestat_range;
 struct cachestat;
+struct mpol_args;
 
 #include <linux/types.h>
 #include <linux/aio_abi.h>
diff --git a/include/uapi/linux/mempolicy.h b/include/uapi/linux/mempolicy.h
index 1f9bb10d1a47..c06f2afa7fe3 100644
--- a/include/uapi/linux/mempolicy.h
+++ b/include/uapi/linux/mempolicy.h
@@ -27,6 +27,16 @@ enum {
 	MPOL_MAX,	/* always last member of enum */
 };
 
+struct mpol_args {
+	/* Basic mempolicy settings */
+	__u16 mode;
+	__u16 mode_flags;
+	__s32 home_node;	/* mbind2: policy home node */
+	__aligned_u64 pol_nodes;
+	__u64 pol_maxnodes;
+	__s32 policy_node;	/* get_mempolicy: policy node info */
+};
+
 /* Flags for set_mempolicy */
 #define MPOL_F_STATIC_NODES	(1 << 15)
 #define MPOL_F_RELATIVE_NODES	(1 << 14)
-- 
2.39.1

[PATCH v3 08/11] mm/mempolicy: add set_mempolicy2 syscall

[Gregory Price]

set_mempolicy2 is an extensible set_mempolicy interface which allows
a user to set the per-task memory policy.

Defined as:

set_mempolicy2(struct mpol_args *args, size_t size, unsigned long flags);

relevant mpol_args fields include the following:

mode:         The MPOL_* policy (DEFAULT, INTERLEAVE, etc.)
mode_flags:   The MPOL_F_* flags that were previously passed in or'd
              into the mode.  This was split to hopefully allow future
              extensions additional mode/flag space.
pol_nodes:    the nodemask to apply for the memory policy
pol_maxnodes: The max number of nodes described by pol_nodes

The usize arg is intended for the user to pass in sizeof(mpol_args)
to allow forward/backward compatibility whenever possible.

The flags argument is intended to future proof the syscall against
future extensions which may require interpreting the arguments in
the structure differently.

Semantics of `set_mempolicy` are otherwise the same as `set_mempolicy`
as of this patch.

Suggested-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Gregory Price <gregory.price@memverge.com>
---
 .../admin-guide/mm/numa_memory_policy.rst     | 10 ++++++
 arch/alpha/kernel/syscalls/syscall.tbl        |  1 +
 arch/arm/tools/syscall.tbl                    |  1 +
 arch/m68k/kernel/syscalls/syscall.tbl         |  1 +
 arch/microblaze/kernel/syscalls/syscall.tbl   |  1 +
 arch/mips/kernel/syscalls/syscall_n32.tbl     |  1 +
 arch/mips/kernel/syscalls/syscall_o32.tbl     |  1 +
 arch/parisc/kernel/syscalls/syscall.tbl       |  1 +
 arch/powerpc/kernel/syscalls/syscall.tbl      |  1 +
 arch/s390/kernel/syscalls/syscall.tbl         |  1 +
 arch/sh/kernel/syscalls/syscall.tbl           |  1 +
 arch/sparc/kernel/syscalls/syscall.tbl        |  1 +
 arch/x86/entry/syscalls/syscall_32.tbl        |  1 +
 arch/x86/entry/syscalls/syscall_64.tbl        |  1 +
 arch/xtensa/kernel/syscalls/syscall.tbl       |  1 +
 include/linux/syscalls.h                      |  2 ++
 include/uapi/asm-generic/unistd.h             |  4 ++-
 mm/mempolicy.c                                | 36 +++++++++++++++++++
 18 files changed, 65 insertions(+), 1 deletion(-)

diff --git a/Documentation/admin-guide/mm/numa_memory_policy.rst b/Documentation/admin-guide/mm/numa_memory_policy.rst
index d5fcebdd7996..e57d400d0281 100644
--- a/Documentation/admin-guide/mm/numa_memory_policy.rst
+++ b/Documentation/admin-guide/mm/numa_memory_policy.rst
@@ -432,6 +432,8 @@ Set [Task] Memory Policy::
 
 	long set_mempolicy(int mode, const unsigned long *nmask,
 					unsigned long maxnode);
+	long set_mempolicy2(struct mpol_args args, size_t size,
+			    unsigned long flags);
 
 Set's the calling task's "task/process memory policy" to mode
 specified by the 'mode' argument and the set of nodes defined by
@@ -440,6 +442,12 @@ specified by the 'mode' argument and the set of nodes defined by
 'mode' argument with the flag (for example: MPOL_INTERLEAVE |
 MPOL_F_STATIC_NODES).
 
+set_mempolicy2() is an extended version of set_mempolicy() capable
+of setting a mempolicy which requires more information than can be
+passed via get_mempolicy().  For example, weighted interleave with
+task-local weights requires a weight array to be passed via the
+'mpol_args->il_weights' argument in the 'struct mpol_args' arg.
+
 See the set_mempolicy(2) man page for more details
 
 
@@ -496,6 +504,8 @@ Extended Mempolicy Arguments::
 The extended mempolicy argument structure is defined to allow the mempolicy
 interfaces future extensibility without the need for additional system calls.
 
+Extended interfaces (set_mempolicy2) use this argument structure.
+
 The core arguments (mode, mode_flags, pol_nodes, and pol_maxnodes) apply to
 all interfaces relative to their non-extended counterparts. Each additional
 field may only apply to specific extended interfaces.  See the respective
diff --git a/arch/alpha/kernel/syscalls/syscall.tbl b/arch/alpha/kernel/syscalls/syscall.tbl
index 18c842ca6c32..0dc288a1118a 100644
--- a/arch/alpha/kernel/syscalls/syscall.tbl
+++ b/arch/alpha/kernel/syscalls/syscall.tbl
@@ -496,3 +496,4 @@
 564	common	futex_wake			sys_futex_wake
 565	common	futex_wait			sys_futex_wait
 566	common	futex_requeue			sys_futex_requeue
+567	common	set_mempolicy2			sys_set_mempolicy2
diff --git a/arch/arm/tools/syscall.tbl b/arch/arm/tools/syscall.tbl
index 584f9528c996..50172ec0e1f5 100644
--- a/arch/arm/tools/syscall.tbl
+++ b/arch/arm/tools/syscall.tbl
@@ -470,3 +470,4 @@
 454	common	futex_wake			sys_futex_wake
 455	common	futex_wait			sys_futex_wait
 456	common	futex_requeue			sys_futex_requeue
+457	common	set_mempolicy2			sys_set_mempolicy2
diff --git a/arch/m68k/kernel/syscalls/syscall.tbl b/arch/m68k/kernel/syscalls/syscall.tbl
index 7a4b780e82cb..839d90c535f2 100644
--- a/arch/m68k/kernel/syscalls/syscall.tbl
+++ b/arch/m68k/kernel/syscalls/syscall.tbl
@@ -456,3 +456,4 @@
 454	common	futex_wake			sys_futex_wake
 455	common	futex_wait			sys_futex_wait
 456	common	futex_requeue			sys_futex_requeue
+457	common	set_mempolicy2			sys_set_mempolicy2
diff --git a/arch/microblaze/kernel/syscalls/syscall.tbl b/arch/microblaze/kernel/syscalls/syscall.tbl
index 5b6a0b02b7de..567c8b883735 100644
--- a/arch/microblaze/kernel/syscalls/syscall.tbl
+++ b/arch/microblaze/kernel/syscalls/syscall.tbl
@@ -462,3 +462,4 @@
 454	common	futex_wake			sys_futex_wake
 455	common	futex_wait			sys_futex_wait
 456	common	futex_requeue			sys_futex_requeue
+457	common	set_mempolicy2			sys_set_mempolicy2
diff --git a/arch/mips/kernel/syscalls/syscall_n32.tbl b/arch/mips/kernel/syscalls/syscall_n32.tbl
index a842b41c8e06..cc0640e16f2f 100644
--- a/arch/mips/kernel/syscalls/syscall_n32.tbl
+++ b/arch/mips/kernel/syscalls/syscall_n32.tbl
@@ -395,3 +395,4 @@
 454	n32	futex_wake			sys_futex_wake
 455	n32	futex_wait			sys_futex_wait
 456	n32	futex_requeue			sys_futex_requeue
+457	n32	set_mempolicy2			sys_set_mempolicy2
diff --git a/arch/mips/kernel/syscalls/syscall_o32.tbl b/arch/mips/kernel/syscalls/syscall_o32.tbl
index 525cc54bc63b..f7262fde98d9 100644
--- a/arch/mips/kernel/syscalls/syscall_o32.tbl
+++ b/arch/mips/kernel/syscalls/syscall_o32.tbl
@@ -444,3 +444,4 @@
 454	o32	futex_wake			sys_futex_wake
 455	o32	futex_wait			sys_futex_wait
 456	o32	futex_requeue			sys_futex_requeue
+457	o32	set_mempolicy2			sys_set_mempolicy2
diff --git a/arch/parisc/kernel/syscalls/syscall.tbl b/arch/parisc/kernel/syscalls/syscall.tbl
index a47798fed54e..e10f0e8bd064 100644
--- a/arch/parisc/kernel/syscalls/syscall.tbl
+++ b/arch/parisc/kernel/syscalls/syscall.tbl
@@ -455,3 +455,4 @@
 454	common	futex_wake			sys_futex_wake
 455	common	futex_wait			sys_futex_wait
 456	common	futex_requeue			sys_futex_requeue
+457	common	set_mempolicy2			sys_set_mempolicy2
diff --git a/arch/powerpc/kernel/syscalls/syscall.tbl b/arch/powerpc/kernel/syscalls/syscall.tbl
index 7fab411378f2..4f03f5f42b78 100644
--- a/arch/powerpc/kernel/syscalls/syscall.tbl
+++ b/arch/powerpc/kernel/syscalls/syscall.tbl
@@ -543,3 +543,4 @@
 454	common	futex_wake			sys_futex_wake
 455	common	futex_wait			sys_futex_wait
 456	common	futex_requeue			sys_futex_requeue
+457	common	set_mempolicy2			sys_set_mempolicy2
diff --git a/arch/s390/kernel/syscalls/syscall.tbl b/arch/s390/kernel/syscalls/syscall.tbl
index 86fec9b080f6..f98dadc2e9df 100644
--- a/arch/s390/kernel/syscalls/syscall.tbl
+++ b/arch/s390/kernel/syscalls/syscall.tbl
@@ -459,3 +459,4 @@
 454  common	futex_wake		sys_futex_wake			sys_futex_wake
 455  common	futex_wait		sys_futex_wait			sys_futex_wait
 456  common	futex_requeue		sys_futex_requeue		sys_futex_requeue
+457  common	set_mempolicy2		sys_set_mempolicy2		sys_set_mempolicy2
diff --git a/arch/sh/kernel/syscalls/syscall.tbl b/arch/sh/kernel/syscalls/syscall.tbl
index 363fae0fe9bf..f47ba9f2d05d 100644
--- a/arch/sh/kernel/syscalls/syscall.tbl
+++ b/arch/sh/kernel/syscalls/syscall.tbl
@@ -459,3 +459,4 @@
 454	common	futex_wake			sys_futex_wake
 455	common	futex_wait			sys_futex_wait
 456	common	futex_requeue			sys_futex_requeue
+457	common	set_mempolicy2			sys_set_mempolicy2
diff --git a/arch/sparc/kernel/syscalls/syscall.tbl b/arch/sparc/kernel/syscalls/syscall.tbl
index 7bcaa3d5ea44..53fb16616728 100644
--- a/arch/sparc/kernel/syscalls/syscall.tbl
+++ b/arch/sparc/kernel/syscalls/syscall.tbl
@@ -502,3 +502,4 @@
 454	common	futex_wake			sys_futex_wake
 455	common	futex_wait			sys_futex_wait
 456	common	futex_requeue			sys_futex_requeue
+457	common	set_mempolicy2			sys_set_mempolicy2
diff --git a/arch/x86/entry/syscalls/syscall_32.tbl b/arch/x86/entry/syscalls/syscall_32.tbl
index c8fac5205803..4b4dc41b24ee 100644
--- a/arch/x86/entry/syscalls/syscall_32.tbl
+++ b/arch/x86/entry/syscalls/syscall_32.tbl
@@ -461,3 +461,4 @@
 454	i386	futex_wake		sys_futex_wake
 455	i386	futex_wait		sys_futex_wait
 456	i386	futex_requeue		sys_futex_requeue
+457	i386	set_mempolicy2		sys_set_mempolicy2
diff --git a/arch/x86/entry/syscalls/syscall_64.tbl b/arch/x86/entry/syscalls/syscall_64.tbl
index 8cb8bf68721c..1bc2190bec27 100644
--- a/arch/x86/entry/syscalls/syscall_64.tbl
+++ b/arch/x86/entry/syscalls/syscall_64.tbl
@@ -378,6 +378,7 @@
 454	common	futex_wake		sys_futex_wake
 455	common	futex_wait		sys_futex_wait
 456	common	futex_requeue		sys_futex_requeue
+457	common	set_mempolicy2		sys_set_mempolicy2
 
 #
 # Due to a historical design error, certain syscalls are numbered differently
diff --git a/arch/xtensa/kernel/syscalls/syscall.tbl b/arch/xtensa/kernel/syscalls/syscall.tbl
index 06eefa9c1458..e26dc89399eb 100644
--- a/arch/xtensa/kernel/syscalls/syscall.tbl
+++ b/arch/xtensa/kernel/syscalls/syscall.tbl
@@ -427,3 +427,4 @@
 454	common	futex_wake			sys_futex_wake
 455	common	futex_wait			sys_futex_wait
 456	common	futex_requeue			sys_futex_requeue
+457	common	set_mempolicy2			sys_set_mempolicy2
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index a52395ca3f00..451f0089601f 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -823,6 +823,8 @@ asmlinkage long sys_get_mempolicy(int __user *policy,
 				unsigned long addr, unsigned long flags);
 asmlinkage long sys_set_mempolicy(int mode, const unsigned long __user *nmask,
 				unsigned long maxnode);
+asmlinkage long sys_set_mempolicy2(struct mpol_args __user *args, size_t size,
+				   unsigned long flags);
 asmlinkage long sys_migrate_pages(pid_t pid, unsigned long maxnode,
 				const unsigned long __user *from,
 				const unsigned long __user *to);
diff --git a/include/uapi/asm-generic/unistd.h b/include/uapi/asm-generic/unistd.h
index 756b013fb832..55486aba099f 100644
--- a/include/uapi/asm-generic/unistd.h
+++ b/include/uapi/asm-generic/unistd.h
@@ -828,9 +828,11 @@ __SYSCALL(__NR_futex_wake, sys_futex_wake)
 __SYSCALL(__NR_futex_wait, sys_futex_wait)
 #define __NR_futex_requeue 456
 __SYSCALL(__NR_futex_requeue, sys_futex_requeue)
+#define __NR_set_mempolicy2 457
+__SYSCALL(__NR_set_mempolicy2, sys_set_mempolicy2)
 
 #undef __NR_syscalls
-#define __NR_syscalls 457
+#define __NR_syscalls 458
 
 /*
  * 32 bit systems traditionally used different
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 705ddf1ccdd9..4bf563f3732b 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -1636,6 +1636,42 @@ SYSCALL_DEFINE3(set_mempolicy, int, mode, const unsigned long __user *, nmask,
 	return kernel_set_mempolicy(mode, nmask, maxnode);
 }
 
+SYSCALL_DEFINE3(set_mempolicy2, struct mpol_args __user *, uargs, size_t, usize,
+		unsigned long, flags)
+{
+	struct mpol_args kargs;
+	struct mempolicy_args margs;
+	int err;
+	nodemask_t policy_nodemask;
+	unsigned long __user *nodes_ptr;
+
+	if (flags)
+		return -EINVAL;
+
+	err = copy_struct_from_user(&kargs, sizeof(kargs), uargs, usize);
+	if (err)
+		return err;
+
+	err = validate_mpol_flags(kargs.mode, &kargs.mode_flags);
+	if (err)
+		return err;
+
+	memset(&margs, 0, sizeof(margs));
+	margs.mode = kargs.mode;
+	margs.mode_flags = kargs.mode_flags;
+	if (kargs.pol_nodes) {
+		nodes_ptr = u64_to_user_ptr(kargs.pol_nodes);
+		err = get_nodes(&policy_nodemask, nodes_ptr,
+				kargs.pol_maxnodes);
+		if (err)
+			return err;
+		margs.policy_nodes = &policy_nodemask;
+	} else
+		margs.policy_nodes = NULL;
+
+	return do_set_mempolicy(&margs);
+}
+
 static int kernel_migrate_pages(pid_t pid, unsigned long maxnode,
 				const unsigned long __user *old_nodes,
 				const unsigned long __user *new_nodes)
-- 
2.39.1

[PATCH v3 09/11] mm/mempolicy: add get_mempolicy2 syscall

[Gregory Price]

get_mempolicy2 is an extensible get_mempolicy interface which allows
a user to retrieve the memory policy for a task or address.

Defined as:

get_mempolicy2(struct mpol_args *args, size_t size,
               unsigned long addr, unsigned long flags)

Top level input values:

mpol_args:    The field which collects information about the mempolicy
              returned to userspace.
addr:         if MPOL_F_ADDR is passed in `flags`, this address will be
              used to return the mempolicy details of the vma the
              address belongs to
flags:        if MPOL_F_ADDR, return mempolicy info vma containing addr
              else, returns task mempolicy information

Input values include the following fields of mpol_args:

pol_nodes:    if set, the nodemask of the policy returned here
pol_maxnodes: if pol_nodes is set, must describe max number of nodes
              to be copied to pol_nodes

Output values include the following fields of mpol_args:

mode:         mempolicy mode
mode_flags:   mempolicy mode flags
home_node:    policy home node will be returned here, or -1 if not.
pol_nodes:    if set, the nodemask for the mempolicy
policy_node:  if the policy has extended node information, it will
              be placed here.  For example MPOL_INTERLEAVE will
              return the next node which will be used for allocation

MPOL_F_NODE has been dropped from get_mempolicy2 (EINVAL).

Suggested-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Gregory Price <gregory.price@memverge.com>
---
 .../admin-guide/mm/numa_memory_policy.rst     | 10 ++++-
 arch/alpha/kernel/syscalls/syscall.tbl        |  1 +
 arch/arm/tools/syscall.tbl                    |  1 +
 arch/m68k/kernel/syscalls/syscall.tbl         |  1 +
 arch/microblaze/kernel/syscalls/syscall.tbl   |  1 +
 arch/mips/kernel/syscalls/syscall_n32.tbl     |  1 +
 arch/mips/kernel/syscalls/syscall_o32.tbl     |  1 +
 arch/parisc/kernel/syscalls/syscall.tbl       |  1 +
 arch/powerpc/kernel/syscalls/syscall.tbl      |  1 +
 arch/s390/kernel/syscalls/syscall.tbl         |  1 +
 arch/sh/kernel/syscalls/syscall.tbl           |  1 +
 arch/sparc/kernel/syscalls/syscall.tbl        |  1 +
 arch/x86/entry/syscalls/syscall_32.tbl        |  1 +
 arch/x86/entry/syscalls/syscall_64.tbl        |  1 +
 arch/xtensa/kernel/syscalls/syscall.tbl       |  1 +
 include/linux/syscalls.h                      |  2 +
 include/uapi/asm-generic/unistd.h             |  4 +-
 mm/mempolicy.c                                | 43 +++++++++++++++++++
 18 files changed, 71 insertions(+), 2 deletions(-)

diff --git a/Documentation/admin-guide/mm/numa_memory_policy.rst b/Documentation/admin-guide/mm/numa_memory_policy.rst
index e57d400d0281..8c1fcdb30602 100644
--- a/Documentation/admin-guide/mm/numa_memory_policy.rst
+++ b/Documentation/admin-guide/mm/numa_memory_policy.rst
@@ -456,11 +456,19 @@ Get [Task] Memory Policy or Related Information::
 	long get_mempolicy(int *mode,
 			   const unsigned long *nmask, unsigned long maxnode,
 			   void *addr, int flags);
+	long get_mempolicy2(struct mpol_args args, size_t size,
+			    unsigned long addr, unsigned long flags);
 
 Queries the "task/process memory policy" of the calling task, or the
 policy or location of a specified virtual address, depending on the
 'flags' argument.
 
+get_mempolicy2() is an extended version of get_mempolicy() capable of
+acquiring extended information about a mempolicy, including those
+that can only be set via set_mempolicy2() or mbind2().
+
+MPOL_F_NODE functionality has been removed from get_mempolicy2().
+
 See the get_mempolicy(2) man page for more details
 
 
@@ -504,7 +512,7 @@ Extended Mempolicy Arguments::
 The extended mempolicy argument structure is defined to allow the mempolicy
 interfaces future extensibility without the need for additional system calls.
 
-Extended interfaces (set_mempolicy2) use this argument structure.
+Extended interfaces (set_mempolicy2 and get_mempolicy2) use this structure.
 
 The core arguments (mode, mode_flags, pol_nodes, and pol_maxnodes) apply to
 all interfaces relative to their non-extended counterparts. Each additional
diff --git a/arch/alpha/kernel/syscalls/syscall.tbl b/arch/alpha/kernel/syscalls/syscall.tbl
index 0dc288a1118a..0301a8b0a262 100644
--- a/arch/alpha/kernel/syscalls/syscall.tbl
+++ b/arch/alpha/kernel/syscalls/syscall.tbl
@@ -497,3 +497,4 @@
 565	common	futex_wait			sys_futex_wait
 566	common	futex_requeue			sys_futex_requeue
 567	common	set_mempolicy2			sys_set_mempolicy2
+568	common	get_mempolicy2			sys_get_mempolicy2
diff --git a/arch/arm/tools/syscall.tbl b/arch/arm/tools/syscall.tbl
index 50172ec0e1f5..771a33446e8e 100644
--- a/arch/arm/tools/syscall.tbl
+++ b/arch/arm/tools/syscall.tbl
@@ -471,3 +471,4 @@
 455	common	futex_wait			sys_futex_wait
 456	common	futex_requeue			sys_futex_requeue
 457	common	set_mempolicy2			sys_set_mempolicy2
+458	common	get_mempolicy2			sys_get_mempolicy2
diff --git a/arch/m68k/kernel/syscalls/syscall.tbl b/arch/m68k/kernel/syscalls/syscall.tbl
index 839d90c535f2..048a409e684c 100644
--- a/arch/m68k/kernel/syscalls/syscall.tbl
+++ b/arch/m68k/kernel/syscalls/syscall.tbl
@@ -457,3 +457,4 @@
 455	common	futex_wait			sys_futex_wait
 456	common	futex_requeue			sys_futex_requeue
 457	common	set_mempolicy2			sys_set_mempolicy2
+458	common	get_mempolicy2			sys_get_mempolicy2
diff --git a/arch/microblaze/kernel/syscalls/syscall.tbl b/arch/microblaze/kernel/syscalls/syscall.tbl
index 567c8b883735..327b01bd6793 100644
--- a/arch/microblaze/kernel/syscalls/syscall.tbl
+++ b/arch/microblaze/kernel/syscalls/syscall.tbl
@@ -463,3 +463,4 @@
 455	common	futex_wait			sys_futex_wait
 456	common	futex_requeue			sys_futex_requeue
 457	common	set_mempolicy2			sys_set_mempolicy2
+458	common	get_mempolicy2			sys_get_mempolicy2
diff --git a/arch/mips/kernel/syscalls/syscall_n32.tbl b/arch/mips/kernel/syscalls/syscall_n32.tbl
index cc0640e16f2f..921d58e1da23 100644
--- a/arch/mips/kernel/syscalls/syscall_n32.tbl
+++ b/arch/mips/kernel/syscalls/syscall_n32.tbl
@@ -396,3 +396,4 @@
 455	n32	futex_wait			sys_futex_wait
 456	n32	futex_requeue			sys_futex_requeue
 457	n32	set_mempolicy2			sys_set_mempolicy2
+458	n32	get_mempolicy2			sys_get_mempolicy2
diff --git a/arch/mips/kernel/syscalls/syscall_o32.tbl b/arch/mips/kernel/syscalls/syscall_o32.tbl
index f7262fde98d9..9271c83c9993 100644
--- a/arch/mips/kernel/syscalls/syscall_o32.tbl
+++ b/arch/mips/kernel/syscalls/syscall_o32.tbl
@@ -445,3 +445,4 @@
 455	o32	futex_wait			sys_futex_wait
 456	o32	futex_requeue			sys_futex_requeue
 457	o32	set_mempolicy2			sys_set_mempolicy2
+458	o32	get_mempolicy2			sys_get_mempolicy2
diff --git a/arch/parisc/kernel/syscalls/syscall.tbl b/arch/parisc/kernel/syscalls/syscall.tbl
index e10f0e8bd064..0654f3f89fc7 100644
--- a/arch/parisc/kernel/syscalls/syscall.tbl
+++ b/arch/parisc/kernel/syscalls/syscall.tbl
@@ -456,3 +456,4 @@
 455	common	futex_wait			sys_futex_wait
 456	common	futex_requeue			sys_futex_requeue
 457	common	set_mempolicy2			sys_set_mempolicy2
+458	common	get_mempolicy2			sys_get_mempolicy2
diff --git a/arch/powerpc/kernel/syscalls/syscall.tbl b/arch/powerpc/kernel/syscalls/syscall.tbl
index 4f03f5f42b78..ac11d2064e7a 100644
--- a/arch/powerpc/kernel/syscalls/syscall.tbl
+++ b/arch/powerpc/kernel/syscalls/syscall.tbl
@@ -544,3 +544,4 @@
 455	common	futex_wait			sys_futex_wait
 456	common	futex_requeue			sys_futex_requeue
 457	common	set_mempolicy2			sys_set_mempolicy2
+458	common	get_mempolicy2			sys_get_mempolicy2
diff --git a/arch/s390/kernel/syscalls/syscall.tbl b/arch/s390/kernel/syscalls/syscall.tbl
index f98dadc2e9df..1cdcafe1ccca 100644
--- a/arch/s390/kernel/syscalls/syscall.tbl
+++ b/arch/s390/kernel/syscalls/syscall.tbl
@@ -460,3 +460,4 @@
 455  common	futex_wait		sys_futex_wait			sys_futex_wait
 456  common	futex_requeue		sys_futex_requeue		sys_futex_requeue
 457  common	set_mempolicy2		sys_set_mempolicy2		sys_set_mempolicy2
+458  common	get_mempolicy2		sys_get_mempolicy2		sys_get_mempolicy2
diff --git a/arch/sh/kernel/syscalls/syscall.tbl b/arch/sh/kernel/syscalls/syscall.tbl
index f47ba9f2d05d..f71742024c29 100644
--- a/arch/sh/kernel/syscalls/syscall.tbl
+++ b/arch/sh/kernel/syscalls/syscall.tbl
@@ -460,3 +460,4 @@
 455	common	futex_wait			sys_futex_wait
 456	common	futex_requeue			sys_futex_requeue
 457	common	set_mempolicy2			sys_set_mempolicy2
+458	common	get_mempolicy2			sys_get_mempolicy2
diff --git a/arch/sparc/kernel/syscalls/syscall.tbl b/arch/sparc/kernel/syscalls/syscall.tbl
index 53fb16616728..2fbf5dbe0620 100644
--- a/arch/sparc/kernel/syscalls/syscall.tbl
+++ b/arch/sparc/kernel/syscalls/syscall.tbl
@@ -503,3 +503,4 @@
 455	common	futex_wait			sys_futex_wait
 456	common	futex_requeue			sys_futex_requeue
 457	common	set_mempolicy2			sys_set_mempolicy2
+458	common	get_mempolicy2			sys_get_mempolicy2
diff --git a/arch/x86/entry/syscalls/syscall_32.tbl b/arch/x86/entry/syscalls/syscall_32.tbl
index 4b4dc41b24ee..0af813b9a118 100644
--- a/arch/x86/entry/syscalls/syscall_32.tbl
+++ b/arch/x86/entry/syscalls/syscall_32.tbl
@@ -462,3 +462,4 @@
 455	i386	futex_wait		sys_futex_wait
 456	i386	futex_requeue		sys_futex_requeue
 457	i386	set_mempolicy2		sys_set_mempolicy2
+458	i386	get_mempolicy2		sys_get_mempolicy2
diff --git a/arch/x86/entry/syscalls/syscall_64.tbl b/arch/x86/entry/syscalls/syscall_64.tbl
index 1bc2190bec27..0b777876fc15 100644
--- a/arch/x86/entry/syscalls/syscall_64.tbl
+++ b/arch/x86/entry/syscalls/syscall_64.tbl
@@ -379,6 +379,7 @@
 455	common	futex_wait		sys_futex_wait
 456	common	futex_requeue		sys_futex_requeue
 457	common	set_mempolicy2		sys_set_mempolicy2
+458	common	get_mempolicy2		sys_get_mempolicy2
 
 #
 # Due to a historical design error, certain syscalls are numbered differently
diff --git a/arch/xtensa/kernel/syscalls/syscall.tbl b/arch/xtensa/kernel/syscalls/syscall.tbl
index e26dc89399eb..4536c9a4227d 100644
--- a/arch/xtensa/kernel/syscalls/syscall.tbl
+++ b/arch/xtensa/kernel/syscalls/syscall.tbl
@@ -428,3 +428,4 @@
 455	common	futex_wait			sys_futex_wait
 456	common	futex_requeue			sys_futex_requeue
 457	common	set_mempolicy2			sys_set_mempolicy2
+458	common	get_mempolicy2			sys_get_mempolicy2
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index 451f0089601f..f696855cbe8c 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -821,6 +821,8 @@ asmlinkage long sys_get_mempolicy(int __user *policy,
 				unsigned long __user *nmask,
 				unsigned long maxnode,
 				unsigned long addr, unsigned long flags);
+asmlinkage long sys_get_mempolicy2(struct mpol_args __user *args, size_t size,
+				   unsigned long addr, unsigned long flags);
 asmlinkage long sys_set_mempolicy(int mode, const unsigned long __user *nmask,
 				unsigned long maxnode);
 asmlinkage long sys_set_mempolicy2(struct mpol_args __user *args, size_t size,
diff --git a/include/uapi/asm-generic/unistd.h b/include/uapi/asm-generic/unistd.h
index 55486aba099f..719accc731db 100644
--- a/include/uapi/asm-generic/unistd.h
+++ b/include/uapi/asm-generic/unistd.h
@@ -830,9 +830,11 @@ __SYSCALL(__NR_futex_wait, sys_futex_wait)
 __SYSCALL(__NR_futex_requeue, sys_futex_requeue)
 #define __NR_set_mempolicy2 457
 __SYSCALL(__NR_set_mempolicy2, sys_set_mempolicy2)
+#define __NR_get_mempolicy2 458
+__SYSCALL(__NR_get_mempolicy2, sys_get_mempolicy2)
 
 #undef __NR_syscalls
-#define __NR_syscalls 458
+#define __NR_syscalls 459
 
 /*
  * 32 bit systems traditionally used different
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 4bf563f3732b..09c613113c7c 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -1863,6 +1863,49 @@ SYSCALL_DEFINE5(get_mempolicy, int __user *, policy,
 	return kernel_get_mempolicy(policy, nmask, maxnode, addr, flags);
 }
 
+SYSCALL_DEFINE4(get_mempolicy2, struct mpol_args __user *, uargs, size_t, usize,
+		unsigned long, addr, unsigned long, flags)
+{
+	struct mpol_args kargs;
+	struct mempolicy_args margs;
+	int err;
+	nodemask_t policy_nodemask;
+	unsigned long __user *nodes_ptr;
+
+	if (flags & ~(MPOL_F_ADDR))
+		return -EINVAL;
+
+	/* initialize any memory liable to be copied to userland */
+	memset(&margs, 0, sizeof(margs));
+
+	err = copy_struct_from_user(&kargs, sizeof(kargs), uargs, usize);
+	if (err)
+		return -EINVAL;
+
+	margs.policy_nodes = kargs.pol_nodes ? &policy_nodemask : NULL;
+	if (flags & MPOL_F_ADDR)
+		err = do_get_vma_mempolicy(untagged_addr(addr), NULL, &margs);
+	else
+		err = do_get_task_mempolicy(&margs);
+
+	if (err)
+		return err;
+
+	kargs.mode = margs.mode;
+	kargs.mode_flags = margs.mode_flags;
+	kargs.policy_node = margs.policy_node;
+	kargs.home_node = margs.home_node;
+	if (kargs.pol_nodes) {
+		nodes_ptr = u64_to_user_ptr(kargs.pol_nodes);
+		err = copy_nodes_to_user(nodes_ptr, kargs.pol_maxnodes,
+					 margs.policy_nodes);
+		if (err)
+			return err;
+	}
+
+	return copy_to_user(uargs, &kargs, usize) ? -EFAULT : 0;
+}
+
 bool vma_migratable(struct vm_area_struct *vma)
 {
 	if (vma->vm_flags & (VM_IO | VM_PFNMAP))
-- 
2.39.1

[PATCH v3 10/11] mm/mempolicy: add the mbind2 syscall

[Gregory Price]

mbind2 is an extensible mbind interface which allows a user to
set the mempolicy for one or more address ranges.

Defined as:

mbind2(unsigned long addr, unsigned long len, struct mpol_args *args,
       size_t size, unsigned long flags)

addr:         address of the memory range to operate on
len:          length of the memory range
flags:        MPOL_MF_HOME_NODE + original mbind() flags

Input values include the following fields of mpol_args:

mode:         The MPOL_* policy (DEFAULT, INTERLEAVE, etc.)
mode_flags:   The MPOL_F_* flags that were previously passed in or'd
	      into the mode.  This was split to hopefully allow future
	      extensions additional mode/flag space.
pol_nodes:    the nodemask to apply for the memory policy
pol_maxnodes: The max number of nodes described by pol_nodes
home_node:    if MPOL_MF_HOME_NODE, set home node of policy to this
              otherwise it is ignored.

The semantics are otherwise the same as mbind(), except that
the home_node can be set.

Suggested-by: Michal Hocko <mhocko@suse.com>
Suggested-by: Frank van der Linden <fvdl@google.com>
Suggested-by: Vinicius Tavares Petrucci <vtavarespetr@micron.com>
Suggested-by: Rakie Kim <rakie.kim@sk.com>
Suggested-by: Hyeongtak Ji <hyeongtak.ji@sk.com>
Suggested-by: Honggyu Kim <honggyu.kim@sk.com>
Signed-off-by: Gregory Price <gregory.price@memverge.com>
Co-developed-by: Vinicius Tavares Petrucci <vtavarespetr@micron.com>
---
 .../admin-guide/mm/numa_memory_policy.rst     | 12 +++++-
 arch/alpha/kernel/syscalls/syscall.tbl        |  1 +
 arch/arm/tools/syscall.tbl                    |  1 +
 arch/m68k/kernel/syscalls/syscall.tbl         |  1 +
 arch/microblaze/kernel/syscalls/syscall.tbl   |  1 +
 arch/mips/kernel/syscalls/syscall_n32.tbl     |  1 +
 arch/mips/kernel/syscalls/syscall_o32.tbl     |  1 +
 arch/parisc/kernel/syscalls/syscall.tbl       |  1 +
 arch/powerpc/kernel/syscalls/syscall.tbl      |  1 +
 arch/s390/kernel/syscalls/syscall.tbl         |  1 +
 arch/sh/kernel/syscalls/syscall.tbl           |  1 +
 arch/sparc/kernel/syscalls/syscall.tbl        |  1 +
 arch/x86/entry/syscalls/syscall_32.tbl        |  1 +
 arch/x86/entry/syscalls/syscall_64.tbl        |  1 +
 arch/xtensa/kernel/syscalls/syscall.tbl       |  1 +
 include/linux/syscalls.h                      |  3 ++
 include/uapi/asm-generic/unistd.h             |  4 +-
 include/uapi/linux/mempolicy.h                |  5 ++-
 mm/mempolicy.c                                | 43 +++++++++++++++++++
 19 files changed, 77 insertions(+), 4 deletions(-)

diff --git a/Documentation/admin-guide/mm/numa_memory_policy.rst b/Documentation/admin-guide/mm/numa_memory_policy.rst
index 8c1fcdb30602..99e1f732cade 100644
--- a/Documentation/admin-guide/mm/numa_memory_policy.rst
+++ b/Documentation/admin-guide/mm/numa_memory_policy.rst
@@ -477,12 +477,18 @@ Install VMA/Shared Policy for a Range of Task's Address Space::
 	long mbind(void *start, unsigned long len, int mode,
 		   const unsigned long *nmask, unsigned long maxnode,
 		   unsigned flags);
+	long mbind2(void* start, unsigned long len, struct mpol_args args,
+		    size_t size, unsigned long flags);
 
 mbind() installs the policy specified by (mode, nmask, maxnodes) as a
 VMA policy for the range of the calling task's address space specified
 by the 'start' and 'len' arguments.  Additional actions may be
 requested via the 'flags' argument.
 
+mbind2() is an extended version of mbind() capable of setting extended
+mempolicy features. For example, one can set the home node for the memory
+policy without an additional call to set_mempolicy_home_node().
+
 See the mbind(2) man page for more details.
 
 Set home node for a Range of Task's Address Spacec::
@@ -498,6 +504,9 @@ closest to which page allocation will come from. Specifying the home node overri
 the default allocation policy to allocate memory close to the local node for an
 executing CPU.
 
+mbind2() also provides a way for the home node to be set at the time the
+mempolicy is set. See the mbind(2) man page for more details.
+
 Extended Mempolicy Arguments::
 
 	struct mpol_args {
@@ -512,7 +521,8 @@ Extended Mempolicy Arguments::
 The extended mempolicy argument structure is defined to allow the mempolicy
 interfaces future extensibility without the need for additional system calls.
 
-Extended interfaces (set_mempolicy2 and get_mempolicy2) use this structure.
+Extended interfaces (set_mempolicy2, get_mempolicy2, and mbind2) use this
+this argument structure.
 
 The core arguments (mode, mode_flags, pol_nodes, and pol_maxnodes) apply to
 all interfaces relative to their non-extended counterparts. Each additional
diff --git a/arch/alpha/kernel/syscalls/syscall.tbl b/arch/alpha/kernel/syscalls/syscall.tbl
index 0301a8b0a262..e8239293c35a 100644
--- a/arch/alpha/kernel/syscalls/syscall.tbl
+++ b/arch/alpha/kernel/syscalls/syscall.tbl
@@ -498,3 +498,4 @@
 566	common	futex_requeue			sys_futex_requeue
 567	common	set_mempolicy2			sys_set_mempolicy2
 568	common	get_mempolicy2			sys_get_mempolicy2
+569	common	mbind2				sys_mbind2
diff --git a/arch/arm/tools/syscall.tbl b/arch/arm/tools/syscall.tbl
index 771a33446e8e..a3f39750257a 100644
--- a/arch/arm/tools/syscall.tbl
+++ b/arch/arm/tools/syscall.tbl
@@ -472,3 +472,4 @@
 456	common	futex_requeue			sys_futex_requeue
 457	common	set_mempolicy2			sys_set_mempolicy2
 458	common	get_mempolicy2			sys_get_mempolicy2
+459	common	mbind2				sys_mbind2
diff --git a/arch/m68k/kernel/syscalls/syscall.tbl b/arch/m68k/kernel/syscalls/syscall.tbl
index 048a409e684c..9a12dface18e 100644
--- a/arch/m68k/kernel/syscalls/syscall.tbl
+++ b/arch/m68k/kernel/syscalls/syscall.tbl
@@ -458,3 +458,4 @@
 456	common	futex_requeue			sys_futex_requeue
 457	common	set_mempolicy2			sys_set_mempolicy2
 458	common	get_mempolicy2			sys_get_mempolicy2
+459	common	mbind2				sys_mbind2
diff --git a/arch/microblaze/kernel/syscalls/syscall.tbl b/arch/microblaze/kernel/syscalls/syscall.tbl
index 327b01bd6793..6cb740123137 100644
--- a/arch/microblaze/kernel/syscalls/syscall.tbl
+++ b/arch/microblaze/kernel/syscalls/syscall.tbl
@@ -464,3 +464,4 @@
 456	common	futex_requeue			sys_futex_requeue
 457	common	set_mempolicy2			sys_set_mempolicy2
 458	common	get_mempolicy2			sys_get_mempolicy2
+459	common	mbind2				sys_mbind2
diff --git a/arch/mips/kernel/syscalls/syscall_n32.tbl b/arch/mips/kernel/syscalls/syscall_n32.tbl
index 921d58e1da23..52cf720f8ae2 100644
--- a/arch/mips/kernel/syscalls/syscall_n32.tbl
+++ b/arch/mips/kernel/syscalls/syscall_n32.tbl
@@ -397,3 +397,4 @@
 456	n32	futex_requeue			sys_futex_requeue
 457	n32	set_mempolicy2			sys_set_mempolicy2
 458	n32	get_mempolicy2			sys_get_mempolicy2
+459	n32	mbind2				sys_mbind2
diff --git a/arch/mips/kernel/syscalls/syscall_o32.tbl b/arch/mips/kernel/syscalls/syscall_o32.tbl
index 9271c83c9993..fd37c5301a48 100644
--- a/arch/mips/kernel/syscalls/syscall_o32.tbl
+++ b/arch/mips/kernel/syscalls/syscall_o32.tbl
@@ -446,3 +446,4 @@
 456	o32	futex_requeue			sys_futex_requeue
 457	o32	set_mempolicy2			sys_set_mempolicy2
 458	o32	get_mempolicy2			sys_get_mempolicy2
+459	o32	mbind2				sys_mbind2
diff --git a/arch/parisc/kernel/syscalls/syscall.tbl b/arch/parisc/kernel/syscalls/syscall.tbl
index 0654f3f89fc7..fcd67bc405b1 100644
--- a/arch/parisc/kernel/syscalls/syscall.tbl
+++ b/arch/parisc/kernel/syscalls/syscall.tbl
@@ -457,3 +457,4 @@
 456	common	futex_requeue			sys_futex_requeue
 457	common	set_mempolicy2			sys_set_mempolicy2
 458	common	get_mempolicy2			sys_get_mempolicy2
+459	common	mbind2				sys_mbind2
diff --git a/arch/powerpc/kernel/syscalls/syscall.tbl b/arch/powerpc/kernel/syscalls/syscall.tbl
index ac11d2064e7a..89715417014c 100644
--- a/arch/powerpc/kernel/syscalls/syscall.tbl
+++ b/arch/powerpc/kernel/syscalls/syscall.tbl
@@ -545,3 +545,4 @@
 456	common	futex_requeue			sys_futex_requeue
 457	common	set_mempolicy2			sys_set_mempolicy2
 458	common	get_mempolicy2			sys_get_mempolicy2
+459	common	mbind2				sys_mbind2
diff --git a/arch/s390/kernel/syscalls/syscall.tbl b/arch/s390/kernel/syscalls/syscall.tbl
index 1cdcafe1ccca..c8304e0d0aa7 100644
--- a/arch/s390/kernel/syscalls/syscall.tbl
+++ b/arch/s390/kernel/syscalls/syscall.tbl
@@ -461,3 +461,4 @@
 456  common	futex_requeue		sys_futex_requeue		sys_futex_requeue
 457  common	set_mempolicy2		sys_set_mempolicy2		sys_set_mempolicy2
 458  common	get_mempolicy2		sys_get_mempolicy2		sys_get_mempolicy2
+459  common	mbind2			sys_mbind2			sys_mbind2
diff --git a/arch/sh/kernel/syscalls/syscall.tbl b/arch/sh/kernel/syscalls/syscall.tbl
index f71742024c29..e5c51b6c367f 100644
--- a/arch/sh/kernel/syscalls/syscall.tbl
+++ b/arch/sh/kernel/syscalls/syscall.tbl
@@ -461,3 +461,4 @@
 456	common	futex_requeue			sys_futex_requeue
 457	common	set_mempolicy2			sys_set_mempolicy2
 458	common	get_mempolicy2			sys_get_mempolicy2
+459	common	mbind2				sys_mbind2
diff --git a/arch/sparc/kernel/syscalls/syscall.tbl b/arch/sparc/kernel/syscalls/syscall.tbl
index 2fbf5dbe0620..74527f585500 100644
--- a/arch/sparc/kernel/syscalls/syscall.tbl
+++ b/arch/sparc/kernel/syscalls/syscall.tbl
@@ -504,3 +504,4 @@
 456	common	futex_requeue			sys_futex_requeue
 457	common	set_mempolicy2			sys_set_mempolicy2
 458	common	get_mempolicy2			sys_get_mempolicy2
+459	common	mbind2				sys_mbind2
diff --git a/arch/x86/entry/syscalls/syscall_32.tbl b/arch/x86/entry/syscalls/syscall_32.tbl
index 0af813b9a118..be2e2aa17dd8 100644
--- a/arch/x86/entry/syscalls/syscall_32.tbl
+++ b/arch/x86/entry/syscalls/syscall_32.tbl
@@ -463,3 +463,4 @@
 456	i386	futex_requeue		sys_futex_requeue
 457	i386	set_mempolicy2		sys_set_mempolicy2
 458	i386	get_mempolicy2		sys_get_mempolicy2
+459	i386	mbind2			sys_mbind2
diff --git a/arch/x86/entry/syscalls/syscall_64.tbl b/arch/x86/entry/syscalls/syscall_64.tbl
index 0b777876fc15..6e2347eb8773 100644
--- a/arch/x86/entry/syscalls/syscall_64.tbl
+++ b/arch/x86/entry/syscalls/syscall_64.tbl
@@ -380,6 +380,7 @@
 456	common	futex_requeue		sys_futex_requeue
 457	common	set_mempolicy2		sys_set_mempolicy2
 458	common	get_mempolicy2		sys_get_mempolicy2
+459	common	mbind2			sys_mbind2
 
 #
 # Due to a historical design error, certain syscalls are numbered differently
diff --git a/arch/xtensa/kernel/syscalls/syscall.tbl b/arch/xtensa/kernel/syscalls/syscall.tbl
index 4536c9a4227d..f00a21317dc0 100644
--- a/arch/xtensa/kernel/syscalls/syscall.tbl
+++ b/arch/xtensa/kernel/syscalls/syscall.tbl
@@ -429,3 +429,4 @@
 456	common	futex_requeue			sys_futex_requeue
 457	common	set_mempolicy2			sys_set_mempolicy2
 458	common	get_mempolicy2			sys_get_mempolicy2
+459	common	mbind2				sys_mbind2
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index f696855cbe8c..b42622ea9ed9 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -817,6 +817,9 @@ asmlinkage long sys_mbind(unsigned long start, unsigned long len,
 				const unsigned long __user *nmask,
 				unsigned long maxnode,
 				unsigned flags);
+asmlinkage long sys_mbind2(unsigned long start, unsigned long len,
+			   const struct mpol_args __user *uargs, size_t usize,
+			   unsigned long flags);
 asmlinkage long sys_get_mempolicy(int __user *policy,
 				unsigned long __user *nmask,
 				unsigned long maxnode,
diff --git a/include/uapi/asm-generic/unistd.h b/include/uapi/asm-generic/unistd.h
index 719accc731db..cd31599bb9cc 100644
--- a/include/uapi/asm-generic/unistd.h
+++ b/include/uapi/asm-generic/unistd.h
@@ -832,9 +832,11 @@ __SYSCALL(__NR_futex_requeue, sys_futex_requeue)
 __SYSCALL(__NR_set_mempolicy2, sys_set_mempolicy2)
 #define __NR_get_mempolicy2 458
 __SYSCALL(__NR_get_mempolicy2, sys_get_mempolicy2)
+#define __NR_mbind2 459
+__SYSCALL(__NR_mbind2, sys_mbind2)
 
 #undef __NR_syscalls
-#define __NR_syscalls 459
+#define __NR_syscalls 460
 
 /*
  * 32 bit systems traditionally used different
diff --git a/include/uapi/linux/mempolicy.h b/include/uapi/linux/mempolicy.h
index c06f2afa7fe3..ec1402dae35b 100644
--- a/include/uapi/linux/mempolicy.h
+++ b/include/uapi/linux/mempolicy.h
@@ -54,13 +54,14 @@ struct mpol_args {
 #define MPOL_F_ADDR	(1<<1)	/* look up vma using address */
 #define MPOL_F_MEMS_ALLOWED (1<<2) /* return allowed memories */
 
-/* Flags for mbind */
+/* Flags for mbind/mbind2 */
 #define MPOL_MF_STRICT	(1<<0)	/* Verify existing pages in the mapping */
 #define MPOL_MF_MOVE	 (1<<1)	/* Move pages owned by this process to conform
 				   to policy */
 #define MPOL_MF_MOVE_ALL (1<<2)	/* Move every page to conform to policy */
 #define MPOL_MF_LAZY	 (1<<3)	/* UNSUPPORTED FLAG: Lazy migrate on fault */
-#define MPOL_MF_INTERNAL (1<<4)	/* Internal flags start here */
+#define MPOL_MF_HOME_NODE (1<<4)	/* mbind2: set home node */
+#define MPOL_MF_INTERNAL (1<<5)	/* Internal flags start here */
 
 #define MPOL_MF_VALID	(MPOL_MF_STRICT   | 	\
 			 MPOL_MF_MOVE     | 	\
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 09c613113c7c..68ea8e177217 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -1603,6 +1603,49 @@ SYSCALL_DEFINE6(mbind, unsigned long, start, unsigned long, len,
 	return kernel_mbind(start, len, mode, nmask, maxnode, flags);
 }
 
+SYSCALL_DEFINE5(mbind2, unsigned long, start, unsigned long, len,
+		const struct mpol_args __user *, uargs, size_t, usize,
+		unsigned long, flags)
+{
+	struct mpol_args kargs;
+	struct mempolicy_args margs;
+	nodemask_t policy_nodes;
+	unsigned long __user *nodes_ptr;
+	int err;
+
+	if (!start || !len)
+		return -EINVAL;
+
+	err = copy_struct_from_user(&kargs, sizeof(kargs), uargs, usize);
+	if (err)
+		return -EINVAL;
+
+	err = validate_mpol_flags(kargs.mode, &kargs.mode_flags);
+	if (err)
+		return err;
+
+	margs.mode = kargs.mode;
+	margs.mode_flags = kargs.mode_flags;
+
+	/* if home node given, validate it is online */
+	if (flags & MPOL_MF_HOME_NODE) {
+		if ((kargs.home_node >= MAX_NUMNODES) ||
+			!node_online(kargs.home_node))
+			return -EINVAL;
+		margs.home_node = kargs.home_node;
+	} else
+		margs.home_node = NUMA_NO_NODE;
+	flags &= ~MPOL_MF_HOME_NODE;
+
+	nodes_ptr = u64_to_user_ptr(kargs.pol_nodes);
+	err = get_nodes(&policy_nodes, nodes_ptr, kargs.pol_maxnodes);
+	if (err)
+		return err;
+	margs.policy_nodes = &policy_nodes;
+
+	return do_mbind(untagged_addr(start), len, &margs, flags);
+}
+
 /* Set the process memory policy */
 static long kernel_set_mempolicy(int mode, const unsigned long __user *nmask,
 				 unsigned long maxnode)
-- 
2.39.1

[PATCH v3 11/11] mm/mempolicy: extend set_mempolicy2 and mbind2 to support weighted interleave

[Gregory Price]

Extend set_mempolicy2 and mbind2 to support weighted interleave, and
demonstrate the extensibility of the mpol_args structure.

To support weighted interleave we add interleave weight fields to the
following structures:

Kernel Internal:  (include/linux/mempolicy.h)
struct mempolicy {
	/* task-local weights to apply to weighted interleave */
	unsigned char weights[MAX_NUMNODES];
}
struct mempolicy_args {
	/* Optional: interleave weights for MPOL_WEIGHTED_INTERLEAVE */
	unsigned char *il_weights;	/* of size MAX_NUMNODES */
}

UAPI: (/include/uapi/linux/mempolicy.h)
struct mpol_args {
	/* Optional: interleave weights for MPOL_WEIGHTED_INTERLEAVE */
	unsigned char *il_weights;	/* of size pol_max_nodes */
}

The task-local weights are a single, one-dimensional array of weights
that apply to all possible nodes on the system.  If a node is set in
the mempolicy nodemask, the weight in `il_weights` must be >= 1,
otherwise set_mempolicy2() will return -EINVAL.  If a node is not
set in pol_nodemask, the weight will default to `1` in the task policy.

The default value of `1` is required to handle the situation where a
task migrates to a set of nodes for which weights were not set (up to
and including the local numa node).  For example, a migrated task whose
nodemask changes entirely will have all its weights defaulted back
to `1`, or if the nodemask changes to include a mix of nodes that
were not previously accounted for - the weighted interleave may be
suboptimal.

If migrations are expected, a task should prefer not to use task-local
interleave weights, and instead utilize the global settings for natural
re-weighting on migration.

To support global vs local weighting,  we add the kernel-internal flag:
MPOL_F_GWEIGHT (1 << 5) /* Utilize global weights */

This flag is set when il_weights is omitted by set_mempolicy2(), or
when MPOL_WEIGHTED_INTERLEAVE is set by set_mempolicy(). This internal
mode_flag dictates whether global weights or task-local weights are
utilized by the the various weighted interleave functions:

* weighted_interleave_nodes
* weighted_interleave_nid
* alloc_pages_bulk_array_weighted_interleave

if (pol->flags & MPOL_F_GWEIGHT)
	pol_weights = iw_table;
else
	pol_weights = pol->wil.weights;

To simplify creations and duplication of mempolicies, the weights are
added as a structure directly within mempolicy. This allows the
existing logic in __mpol_dup to copy the weights without additional
allocations:

if (old == current->mempolicy) {
	task_lock(current);
	*new = *old;
	task_unlock(current);
} else
	*new = *old

Suggested-by: Rakie Kim <rakie.kim@sk.com>
Suggested-by: Hyeongtak Ji <hyeongtak.ji@sk.com>
Suggested-by: Honggyu Kim <honggyu.kim@sk.com>
Suggested-by: Vinicius Tavares Petrucci <vtavarespetr@micron.com>
Signed-off-by: Gregory Price <gregory.price@memverge.com>
Co-developed-by: Rakie Kim <rakie.kim@sk.com>
Signed-off-by: Rakie Kim <rakie.kim@sk.com>
Co-developed-by: Hyeongtak Ji <hyeongtak.ji@sk.com>
Signed-off-by: Hyeongtak Ji <hyeongtak.ji@sk.com>
Co-developed-by: Honggyu Kim <honggyu.kim@sk.com>
Signed-off-by: Honggyu Kim <honggyu.kim@sk.com>
Co-developed-by: Vinicius Tavares Petrucci <vtavarespetr@micron.com>
Signed-off-by: Vinicius Tavares Petrucci <vtavarespetr@micron.com>
---
 .../admin-guide/mm/numa_memory_policy.rst     |  10 ++
 include/linux/mempolicy.h                     |   2 +
 include/uapi/linux/mempolicy.h                |   2 +
 mm/mempolicy.c                                | 129 +++++++++++++++++-
 4 files changed, 139 insertions(+), 4 deletions(-)

diff --git a/Documentation/admin-guide/mm/numa_memory_policy.rst b/Documentation/admin-guide/mm/numa_memory_policy.rst
index 99e1f732cade..0e91efe9e769 100644
--- a/Documentation/admin-guide/mm/numa_memory_policy.rst
+++ b/Documentation/admin-guide/mm/numa_memory_policy.rst
@@ -254,6 +254,8 @@ MPOL_WEIGHTED_INTERLEAVE
 	This mode operates the same as MPOL_INTERLEAVE, except that
 	interleaving behavior is executed based on weights set in
 	/sys/kernel/mm/mempolicy/weighted_interleave/
+	when configured to utilize global weights, or based on task-local
+	weights configured with set_mempolicy2(2) or mbind2(2).
 
 	Weighted interleave allocations pages on nodes according to
 	their weight.  For example if nodes [0,1] are weighted [5,2]
@@ -261,6 +263,13 @@ MPOL_WEIGHTED_INTERLEAVE
 	2 pages allocated on node1.  This can better distribute data
 	according to bandwidth on heterogeneous memory systems.
 
+	When utilizing task-local weights, weights are not rebalanced
+	in the event of a task migration.  If a weight has not been
+	explicitly set for a node set in the new nodemask, the
+	value of that weight defaults to "1".  For this reason, if
+	migrations are expected or possible, users should consider
+	utilizing global interleave weights.
+
 NUMA memory policy supports the following optional mode flags:
 
 MPOL_F_STATIC_NODES
@@ -514,6 +523,7 @@ Extended Mempolicy Arguments::
 		__u16 mode_flags;
 		__s32 home_node; /* mbind2: policy home node */
 		__aligned_u64 pol_nodes; /* nodemask pointer */
+		__aligned_u64 il_weights;  /* u8 buf of size pol_maxnodes */
 		__u64 pol_maxnodes;
 		__s32 policy_node; /* get_mempolicy2: policy node information */
 	};
diff --git a/include/linux/mempolicy.h b/include/linux/mempolicy.h
index aeac19dfc2b6..387c5c418a66 100644
--- a/include/linux/mempolicy.h
+++ b/include/linux/mempolicy.h
@@ -58,6 +58,7 @@ struct mempolicy {
 	/* Weighted interleave settings */
 	struct {
 		unsigned char cur_weight;
+		unsigned char weights[MAX_NUMNODES];
 	} wil;
 };
 
@@ -70,6 +71,7 @@ struct mempolicy_args {
 	unsigned short mode_flags;	/* policy mode flags */
 	int home_node;			/* mbind: use MPOL_MF_HOME_NODE */
 	nodemask_t *policy_nodes;	/* get/set/mbind */
+	unsigned char *il_weights;	/* for mode MPOL_WEIGHTED_INTERLEAVE */
 	int policy_node;		/* get: policy node information */
 };
 
diff --git a/include/uapi/linux/mempolicy.h b/include/uapi/linux/mempolicy.h
index ec1402dae35b..16fedf966166 100644
--- a/include/uapi/linux/mempolicy.h
+++ b/include/uapi/linux/mempolicy.h
@@ -33,6 +33,7 @@ struct mpol_args {
 	__u16 mode_flags;
 	__s32 home_node;	/* mbind2: policy home node */
 	__aligned_u64 pol_nodes;
+	__aligned_u64 il_weights; /* size: pol_maxnodes * sizeof(char) */
 	__u64 pol_maxnodes;
 	__s32 policy_node;	/* get_mempolicy: policy node info */
 };
@@ -75,6 +76,7 @@ struct mpol_args {
 #define MPOL_F_SHARED  (1 << 0)	/* identify shared policies */
 #define MPOL_F_MOF	(1 << 3) /* this policy wants migrate on fault */
 #define MPOL_F_MORON	(1 << 4) /* Migrate On protnone Reference On Node */
+#define MPOL_F_GWEIGHT	(1 << 5) /* Utilize global weights */
 
 /*
  * These bit locations are exposed in the vm.zone_reclaim_mode sysctl
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 68ea8e177217..15d047098429 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -271,6 +271,7 @@ static struct mempolicy *mpol_new(struct mempolicy_args *args)
 	unsigned short mode = args->mode;
 	unsigned short flags = args->mode_flags;
 	nodemask_t *nodes = args->policy_nodes;
+	int node;
 
 	if (mode == MPOL_DEFAULT) {
 		if (nodes && !nodes_empty(*nodes))
@@ -297,6 +298,19 @@ static struct mempolicy *mpol_new(struct mempolicy_args *args)
 		    (flags & MPOL_F_STATIC_NODES) ||
 		    (flags & MPOL_F_RELATIVE_NODES))
 			return ERR_PTR(-EINVAL);
+	} else if (mode == MPOL_WEIGHTED_INTERLEAVE) {
+		/* weighted interleave requires a nodemask and weights > 0 */
+		if (nodes_empty(*nodes))
+			return ERR_PTR(-EINVAL);
+		if (args->il_weights) {
+			node = first_node(*nodes);
+			while (node != MAX_NUMNODES) {
+				if (!args->il_weights[node])
+					return ERR_PTR(-EINVAL);
+				node = next_node(node, *nodes);
+			}
+		} else if (!(args->mode_flags & MPOL_F_GWEIGHT))
+			return ERR_PTR(-EINVAL);
 	} else if (nodes_empty(*nodes))
 		return ERR_PTR(-EINVAL);
 
@@ -309,6 +323,17 @@ static struct mempolicy *mpol_new(struct mempolicy_args *args)
 	policy->home_node = args->home_node;
 	policy->wil.cur_weight = 0;
 
+	if (policy->mode == MPOL_WEIGHTED_INTERLEAVE && args->il_weights) {
+		policy->wil.cur_weight = 0;
+		/* Minimum weight value is always 1 */
+		memset(policy->wil.weights, 1, MAX_NUMNODES);
+		node = first_node(*nodes);
+		while (node != MAX_NUMNODES) {
+			policy->wil.weights[node] = args->il_weights[node];
+			node = next_node(node, *nodes);
+		}
+	}
+
 	return policy;
 }
 
@@ -937,6 +962,17 @@ static void do_get_mempolicy_nodemask(struct mempolicy *pol, nodemask_t *nmask)
 	}
 }
 
+static void do_get_mempolicy_il_weights(struct mempolicy *pol,
+					unsigned char weights[MAX_NUMNODES])
+{
+	if (pol->mode != MPOL_WEIGHTED_INTERLEAVE)
+		memset(weights, 0, MAX_NUMNODES);
+	else if (pol->flags & MPOL_F_GWEIGHT)
+		memcpy(weights, iw_table, MAX_NUMNODES);
+	else
+		memcpy(weights, pol->wil.weights, MAX_NUMNODES);
+}
+
 /* Retrieve NUMA policy for a VMA assocated with a given address  */
 static long do_get_vma_mempolicy(unsigned long addr, int *addr_node,
 				 struct mempolicy_args *args)
@@ -973,6 +1009,9 @@ static long do_get_vma_mempolicy(unsigned long addr, int *addr_node,
 	if (args->policy_nodes)
 		do_get_mempolicy_nodemask(pol, args->policy_nodes);
 
+	if (args->il_weights)
+		do_get_mempolicy_il_weights(pol, args->il_weights);
+
 	if (pol != &default_policy) {
 		mpol_put(pol);
 		mpol_cond_put(pol);
@@ -999,6 +1038,9 @@ static long do_get_task_mempolicy(struct mempolicy_args *args)
 	if (args->policy_nodes)
 		do_get_mempolicy_nodemask(pol, args->policy_nodes);
 
+	if (args->il_weights)
+		do_get_mempolicy_il_weights(pol, args->il_weights);
+
 	return 0;
 }
 
@@ -1521,6 +1563,9 @@ static long kernel_mbind(unsigned long start, unsigned long len,
 	if (err)
 		return err;
 
+	if (mode & MPOL_WEIGHTED_INTERLEAVE)
+		mode_flags |= MPOL_F_GWEIGHT;
+
 	memset(&margs, 0, sizeof(margs));
 	margs.mode = lmode;
 	margs.mode_flags = mode_flags;
@@ -1611,6 +1656,8 @@ SYSCALL_DEFINE5(mbind2, unsigned long, start, unsigned long, len,
 	struct mempolicy_args margs;
 	nodemask_t policy_nodes;
 	unsigned long __user *nodes_ptr;
+	unsigned char weights[MAX_NUMNODES];
+	unsigned char __user *weights_ptr;
 	int err;
 
 	if (!start || !len)
@@ -1643,6 +1690,23 @@ SYSCALL_DEFINE5(mbind2, unsigned long, start, unsigned long, len,
 		return err;
 	margs.policy_nodes = &policy_nodes;
 
+	if (kargs.mode == MPOL_WEIGHTED_INTERLEAVE) {
+		weights_ptr = u64_to_user_ptr(kargs.il_weights);
+		if (weights_ptr) {
+			err = copy_struct_from_user(weights,
+						    sizeof(weights),
+						    weights_ptr,
+						    kargs.pol_maxnodes);
+			if (err)
+				return err;
+			margs.il_weights = weights;
+		} else {
+			margs.il_weights = NULL;
+			margs.mode_flags |= MPOL_F_GWEIGHT;
+		}
+	} else
+		margs.il_weights = NULL;
+
 	return do_mbind(untagged_addr(start), len, &margs, flags);
 }
 
@@ -1664,6 +1728,9 @@ static long kernel_set_mempolicy(int mode, const unsigned long __user *nmask,
 	if (err)
 		return err;
 
+	if (mode & MPOL_WEIGHTED_INTERLEAVE)
+		mode_flags |= MPOL_F_GWEIGHT;
+
 	memset(&args, 0, sizeof(args));
 	args.mode = lmode;
 	args.mode_flags = mode_flags;
@@ -1687,6 +1754,8 @@ SYSCALL_DEFINE3(set_mempolicy2, struct mpol_args __user *, uargs, size_t, usize,
 	int err;
 	nodemask_t policy_nodemask;
 	unsigned long __user *nodes_ptr;
+	unsigned char weights[MAX_NUMNODES];
+	unsigned char __user *weights_ptr;
 
 	if (flags)
 		return -EINVAL;
@@ -1712,6 +1781,20 @@ SYSCALL_DEFINE3(set_mempolicy2, struct mpol_args __user *, uargs, size_t, usize,
 	} else
 		margs.policy_nodes = NULL;
 
+	if (kargs.mode == MPOL_WEIGHTED_INTERLEAVE && kargs.il_weights) {
+		weights_ptr = u64_to_user_ptr(kargs.il_weights);
+		err = copy_struct_from_user(weights,
+					    sizeof(weights),
+					    weights_ptr,
+					    kargs.pol_maxnodes);
+		if (err)
+			return err;
+		margs.il_weights = weights;
+	} else {
+		margs.il_weights = NULL;
+		margs.mode_flags |= MPOL_F_GWEIGHT;
+	}
+
 	return do_set_mempolicy(&margs);
 }
 
@@ -1914,17 +1997,25 @@ SYSCALL_DEFINE4(get_mempolicy2, struct mpol_args __user *, uargs, size_t, usize,
 	int err;
 	nodemask_t policy_nodemask;
 	unsigned long __user *nodes_ptr;
+	unsigned char __user *weights_ptr;
+	unsigned char weights[MAX_NUMNODES];
 
 	if (flags & ~(MPOL_F_ADDR))
 		return -EINVAL;
 
 	/* initialize any memory liable to be copied to userland */
 	memset(&margs, 0, sizeof(margs));
+	memset(weights, 0, sizeof(weights));
 
 	err = copy_struct_from_user(&kargs, sizeof(kargs), uargs, usize);
 	if (err)
 		return -EINVAL;
 
+	if (kargs.il_weights)
+		margs.il_weights = weights;
+	else
+		margs.il_weights = NULL;
+
 	margs.policy_nodes = kargs.pol_nodes ? &policy_nodemask : NULL;
 	if (flags & MPOL_F_ADDR)
 		err = do_get_vma_mempolicy(untagged_addr(addr), NULL, &margs);
@@ -1946,6 +2037,13 @@ SYSCALL_DEFINE4(get_mempolicy2, struct mpol_args __user *, uargs, size_t, usize,
 			return err;
 	}
 
+	if (kargs.mode == MPOL_WEIGHTED_INTERLEAVE && kargs.il_weights) {
+		weights_ptr = u64_to_user_ptr(kargs.il_weights);
+		err = copy_to_user(weights_ptr, weights, kargs.pol_maxnodes);
+		if (err)
+			return err;
+	}
+
 	return copy_to_user(uargs, &kargs, usize) ? -EFAULT : 0;
 }
 
@@ -2062,13 +2160,18 @@ static unsigned int weighted_interleave_nodes(struct mempolicy *policy)
 {
 	unsigned int next;
 	struct task_struct *me = current;
+	unsigned char next_weight;
 
 	next = next_node_in(me->il_prev, policy->nodes);
 	if (next == MAX_NUMNODES)
 		return next;
 
-	if (!policy->wil.cur_weight)
-		policy->wil.cur_weight = iw_table[next];
+	if (!policy->wil.cur_weight) {
+		next_weight = (policy->flags & MPOL_F_GWEIGHT) ?
+				iw_table[next] :
+				policy->wil.weights[next];
+		policy->wil.cur_weight = next_weight ? next_weight : 1;
+	}
 
 	policy->wil.cur_weight--;
 	if (!policy->wil.cur_weight)
@@ -2142,6 +2245,7 @@ static unsigned int weighted_interleave_nid(struct mempolicy *pol, pgoff_t ilx)
 	nodemask_t nodemask = pol->nodes;
 	unsigned int target, weight_total = 0;
 	int nid;
+	unsigned char *pol_weights;
 	unsigned char weights[MAX_NUMNODES];
 	unsigned char weight;
 
@@ -2153,8 +2257,13 @@ static unsigned int weighted_interleave_nid(struct mempolicy *pol, pgoff_t ilx)
 		return nid;
 
 	/* Then collect weights on stack and calculate totals */
+	if (pol->flags & MPOL_F_GWEIGHT)
+		pol_weights = iw_table;
+	else
+		pol_weights = pol->wil.weights;
+
 	for_each_node_mask(nid, nodemask) {
-		weight = iw_table[nid];
+		weight = pol_weights[nid];
 		weight_total += weight;
 		weights[nid] = weight;
 	}
@@ -2552,6 +2661,7 @@ static unsigned long alloc_pages_bulk_array_weighted_interleave(gfp_t gfp,
 	unsigned long nr_allocated;
 	unsigned long rounds;
 	unsigned long node_pages, delta;
+	unsigned char *pol_weights;
 	unsigned char weight;
 	unsigned char weights[MAX_NUMNODES];
 	unsigned int weight_total = 0;
@@ -2565,9 +2675,14 @@ static unsigned long alloc_pages_bulk_array_weighted_interleave(gfp_t gfp,
 
 	nnodes = nodes_weight(nodes);
 
+	if (pol->flags & MPOL_F_GWEIGHT)
+		pol_weights = iw_table;
+	else
+		pol_weights = pol->wil.weights;
+
 	/* Collect weights and save them on stack so they don't change */
 	for_each_node_mask(node, nodes) {
-		weight = iw_table[node];
+		weight = pol_weights[node];
 		weight_total += weight;
 		weights[node] = weight;
 	}
@@ -3092,6 +3207,7 @@ void mpol_shared_policy_init(struct shared_policy *sp, struct mempolicy *mpol)
 {
 	int ret;
 	struct mempolicy_args margs;
+	unsigned char weights[MAX_NUMNODES];
 
 	sp->root = RB_ROOT;		/* empty tree == default mempolicy */
 	rwlock_init(&sp->lock);
@@ -3109,6 +3225,11 @@ void mpol_shared_policy_init(struct shared_policy *sp, struct mempolicy *mpol)
 		margs.mode_flags = mpol->flags;
 		margs.policy_nodes = &mpol->w.user_nodemask;
 		margs.home_node = NUMA_NO_NODE;
+		if (margs.mode == MPOL_WEIGHTED_INTERLEAVE &&
+		    !(margs.mode_flags & MPOL_F_GWEIGHT)) {
+			memcpy(weights, mpol->wil.weights, sizeof(weights));
+			margs.il_weights = weights;
+		}
 
 		/* contextualize the tmpfs mount point mempolicy to this file */
 		npol = mpol_new(&margs);
-- 
2.39.1

Re: [PATCH v3 01/11] mm/mempolicy: implement the sysfs-based weighted_interleave interface

[kernel test robot]

Hi Gregory,

kernel test robot noticed the following build errors:

[auto build test ERROR on akpm-mm/mm-everything]
[also build test ERROR on geert-m68k/for-next geert-m68k/for-linus deller-parisc/for-next powerpc/next powerpc/fixes s390/features jcmvbkbc-xtensa/xtensa-for-next arnd-asm-generic/master linus/master tip/x86/asm v6.7-rc5 next-20231214]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Gregory-Price/mm-mempolicy-implement-the-sysfs-based-weighted_interleave-interface/20231214-064236
base:   https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything
patch link:    https://lore.kernel.org/r/20231213224118.1949-2-gregory.price%40memverge.com
patch subject: [PATCH v3 01/11] mm/mempolicy: implement the sysfs-based weighted_interleave interface
config: x86_64-randconfig-161-20231214 (https://download.01.org/0day-ci/archive/20231214/202312141733.PALHOosm-lkp@intel.com/config)
compiler: gcc-9 (Debian 9.3.0-22) 9.3.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231214/202312141733.PALHOosm-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202312141733.PALHOosm-lkp@intel.com/

All errors (new ones prefixed by >>):

   In file included from include/linux/kobject.h:20,
                    from include/linux/energy_model.h:7,
                    from include/linux/device.h:16,
                    from include/linux/node.h:18,
                    from include/linux/cpu.h:17,
                    from include/linux/static_call.h:135,
                    from include/linux/tracepoint.h:22,
                    from include/trace/events/tlb.h:9,
                    from arch/x86/include/asm/mmu_context.h:10,
                    from include/linux/mmu_context.h:5,
                    from include/linux/cpuset.h:18,
                    from mm/mempolicy.c:83:
   mm/mempolicy.c: In function 'add_weight_node':
>> mm/mempolicy.c:3145:28: error: 'struct iw_node_attr' has no member named 'attr'
    3145 |  sysfs_attr_init(&node_attr->attr);
         |                            ^~
   include/linux/sysfs.h:55:3: note: in definition of macro 'sysfs_attr_init'
      55 |  (attr)->key = &__key;    \
         |   ^~~~

Kconfig warnings: (for reference only)
   WARNING: unmet direct dependencies detected for DRM_I915_DEBUG_GEM
   Depends on [n]: HAS_IOMEM [=y] && DRM_I915 [=m] && EXPERT [=y] && DRM_I915_WERROR [=n]
   Selected by [m]:
   - DRM_I915_DEBUG [=y] && HAS_IOMEM [=y] && DRM_I915 [=m] && EXPERT [=y] && !COMPILE_TEST [=n]


vim +3145 mm/mempolicy.c

  3129	
  3130	static int add_weight_node(int nid, struct kobject *wi_kobj)
  3131	{
  3132		struct iw_node_attr *node_attr;
  3133		char *name;
  3134	
  3135		node_attr = kzalloc(sizeof(*node_attr), GFP_KERNEL);
  3136		if (!node_attr)
  3137			return -ENOMEM;
  3138	
  3139		name = kasprintf(GFP_KERNEL, "node%d", nid);
  3140		if (!name) {
  3141			kfree(node_attr);
  3142			return -ENOMEM;
  3143		}
  3144	
> 3145		sysfs_attr_init(&node_attr->attr);
  3146		node_attr->kobj_attr.attr.name = name;
  3147		node_attr->kobj_attr.attr.mode = 0644;
  3148		node_attr->kobj_attr.show = node_show;
  3149		node_attr->kobj_attr.store = node_store;
  3150		node_attr->nid = nid;
  3151	
  3152		if (sysfs_create_file(wi_kobj, &node_attr->kobj_attr.attr)) {
  3153			kfree(node_attr->kobj_attr.attr.name);
  3154			kfree(node_attr);
  3155			pr_err("failed to add attribute to weighted_interleave\n");
  3156			return -ENOMEM;
  3157		}
  3158	
  3159		node_attrs[nid] = node_attr;
  3160		return 0;
  3161	}
  3162	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

Re: [PATCH v3 08/11] mm/mempolicy: add set_mempolicy2 syscall

[kernel test robot]

Hi Gregory,

kernel test robot noticed the following build errors:

[auto build test ERROR on akpm-mm/mm-everything]
[also build test ERROR on deller-parisc/for-next powerpc/next powerpc/fixes s390/features jcmvbkbc-xtensa/xtensa-for-next arnd-asm-generic/master linus/master v6.7-rc5]
[cannot apply to geert-m68k/for-next geert-m68k/for-linus tip/x86/asm next-20231214]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Gregory-Price/mm-mempolicy-implement-the-sysfs-based-weighted_interleave-interface/20231214-064236
base:   https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything
patch link:    https://lore.kernel.org/r/20231213224118.1949-9-gregory.price%40memverge.com
patch subject: [PATCH v3 08/11] mm/mempolicy: add set_mempolicy2 syscall
config: x86_64-randconfig-002-20231214 (https://download.01.org/0day-ci/archive/20231215/202312150125.MYsauj7B-lkp@intel.com/config)
compiler: clang version 16.0.4 (https://github.com/llvm/llvm-project.git ae42196bc493ffe877a7e3dff8be32035dea4d07)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231215/202312150125.MYsauj7B-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202312150125.MYsauj7B-lkp@intel.com/

All errors (new ones prefixed by >>):

>> ld.lld: error: undefined symbol: __x64_sys_set_mempolicy2
   >>> referenced by syscall_64.c
   >>>               arch/x86/entry/syscall_64.o:(sys_call_table) in archive vmlinux.a
   >>> did you mean: __x64_sys_set_mempolicy
   >>> defined in: vmlinux.a(kernel/sys_ni.o)

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

Re: [PATCH v3 08/11] mm/mempolicy: add set_mempolicy2 syscall

[kernel test robot]

Hi Gregory,

kernel test robot noticed the following build errors:

[auto build test ERROR on akpm-mm/mm-everything]
[also build test ERROR on deller-parisc/for-next powerpc/next powerpc/fixes s390/features jcmvbkbc-xtensa/xtensa-for-next arnd-asm-generic/master linus/master v6.7-rc5]
[cannot apply to geert-m68k/for-next geert-m68k/for-linus tip/x86/asm next-20231214]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Gregory-Price/mm-mempolicy-implement-the-sysfs-based-weighted_interleave-interface/20231214-064236
base:   https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything
patch link:    https://lore.kernel.org/r/20231213224118.1949-9-gregory.price%40memverge.com
patch subject: [PATCH v3 08/11] mm/mempolicy: add set_mempolicy2 syscall
config: um-randconfig-002-20231214 (https://download.01.org/0day-ci/archive/20231215/202312150311.RPwbE1sK-lkp@intel.com/config)
compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231215/202312150311.RPwbE1sK-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202312150311.RPwbE1sK-lkp@intel.com/

All errors (new ones prefixed by >>):

   /usr/bin/ld: arch/um/drivers/pcap.o: in function `dbus_write':
   pcap-dbus.o:(.text+0x2432f): undefined reference to `dbus_message_demarshal'
   /usr/bin/ld: pcap-dbus.o:(.text+0x24345): undefined reference to `dbus_connection_send'
   /usr/bin/ld: pcap-dbus.o:(.text+0x2434e): undefined reference to `dbus_connection_flush'
   /usr/bin/ld: pcap-dbus.o:(.text+0x24356): undefined reference to `dbus_message_unref'
   /usr/bin/ld: pcap-dbus.o:(.text+0x243a4): undefined reference to `dbus_error_free'
   /usr/bin/ld: arch/um/drivers/pcap.o: in function `dbus_read':
   pcap-dbus.o:(.text+0x243f0): undefined reference to `dbus_connection_pop_message'
   /usr/bin/ld: pcap-dbus.o:(.text+0x24412): undefined reference to `dbus_connection_pop_message'
   /usr/bin/ld: pcap-dbus.o:(.text+0x24428): undefined reference to `dbus_connection_read_write'
   /usr/bin/ld: pcap-dbus.o:(.text+0x24492): undefined reference to `dbus_message_is_signal'
   /usr/bin/ld: pcap-dbus.o:(.text+0x244ae): undefined reference to `dbus_message_marshal'
   /usr/bin/ld: pcap-dbus.o:(.text+0x24516): undefined reference to `dbus_free'
   /usr/bin/ld: arch/um/drivers/pcap.o: in function `dbus_cleanup':
   pcap-dbus.o:(.text+0x2457c): undefined reference to `dbus_connection_unref'
   /usr/bin/ld: arch/um/drivers/pcap.o: in function `dbus_activate':
   pcap-dbus.o:(.text+0x24626): undefined reference to `dbus_connection_open'
   /usr/bin/ld: pcap-dbus.o:(.text+0x2463e): undefined reference to `dbus_bus_register'
   /usr/bin/ld: pcap-dbus.o:(.text+0x2472c): undefined reference to `dbus_bus_add_match'
   /usr/bin/ld: pcap-dbus.o:(.text+0x24734): undefined reference to `dbus_error_is_set'
   /usr/bin/ld: pcap-dbus.o:(.text+0x2477b): undefined reference to `dbus_bus_get'
   /usr/bin/ld: pcap-dbus.o:(.text+0x247ac): undefined reference to `dbus_error_free'
   /usr/bin/ld: pcap-dbus.o:(.text+0x247bd): undefined reference to `dbus_bus_add_match'
   /usr/bin/ld: pcap-dbus.o:(.text+0x247c5): undefined reference to `dbus_error_is_set'
   /usr/bin/ld: pcap-dbus.o:(.text+0x247fe): undefined reference to `dbus_error_free'
   /usr/bin/ld: pcap-dbus.o:(.text+0x2480a): undefined reference to `dbus_connection_unref'
   /usr/bin/ld: pcap-dbus.o:(.text+0x24836): undefined reference to `dbus_bus_get'
   /usr/bin/ld: pcap-dbus.o:(.text+0x24872): undefined reference to `dbus_error_free'
   /usr/bin/ld: pcap-dbus.o:(.text+0x24885): undefined reference to `dbus_connection_set_max_received_size'
   /usr/bin/ld: pcap-dbus.o:(.text+0x24896): undefined reference to `dbus_connection_unref'
   /usr/bin/ld: pcap-dbus.o:(.text+0x2490c): undefined reference to `dbus_error_free'
   /usr/bin/ld: pcap-dbus.o:(.text+0x2494a): undefined reference to `dbus_error_free'
>> /usr/bin/ld: arch/x86/um/sys_call_table_64.o:(.rodata+0xe48): undefined reference to `sys_set_mempolicy2'
   collect2: error: ld returned 1 exit status

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

Re: [PATCH v3 09/11] mm/mempolicy: add get_mempolicy2 syscall

[kernel test robot]

Hi Gregory,

kernel test robot noticed the following build errors:

[auto build test ERROR on akpm-mm/mm-everything]
[also build test ERROR on deller-parisc/for-next powerpc/next powerpc/fixes s390/features jcmvbkbc-xtensa/xtensa-for-next arnd-asm-generic/master linus/master v6.7-rc5]
[cannot apply to geert-m68k/for-next geert-m68k/for-linus tip/x86/asm next-20231214]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Gregory-Price/mm-mempolicy-implement-the-sysfs-based-weighted_interleave-interface/20231214-064236
base:   https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything
patch link:    https://lore.kernel.org/r/20231213224118.1949-10-gregory.price%40memverge.com
patch subject: [PATCH v3 09/11] mm/mempolicy: add get_mempolicy2 syscall
config: x86_64-randconfig-002-20231214 (https://download.01.org/0day-ci/archive/20231215/202312150958.WYyFWIdr-lkp@intel.com/config)
compiler: clang version 16.0.4 (https://github.com/llvm/llvm-project.git ae42196bc493ffe877a7e3dff8be32035dea4d07)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231215/202312150958.WYyFWIdr-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202312150958.WYyFWIdr-lkp@intel.com/

All errors (new ones prefixed by >>):

>> ld.lld: error: undefined symbol: __x64_sys_get_mempolicy2
   >>> referenced by syscall_64.c
   >>>               arch/x86/entry/syscall_64.o:(sys_call_table) in archive vmlinux.a
   >>> did you mean: __x64_sys_get_mempolicy
   >>> defined in: vmlinux.a(kernel/sys_ni.o)

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

RE: [PATCH v3 00/11] mempolicy2, mbind2, and weighted interleave

[Hyeongtak Ji]

Hi Gregory,

Thank you for the v3 patch.

Gregory Price <gourry.memverge@gmail.com> write:

[snip]

> =====================================================================
> Performance tests - MLC
> From Ravi Jonnalagadda <ravis.opensrc@micron.com>
> 
> Workload:                               W2
> Data Signature:                         2:1 read:write
> DRAM only bandwidth (GBps):             298.8
> DRAM + CXL (default interleave) (GBps): 113.04
> DRAM + CXL (weighted interleave)(GBps): 412.5
> Gain over DRAM only:                    1.38x
> 
> Workload:                               W5
> Data Signature:                         1:1 read:write
> DRAM only bandwidth (GBps):             273.2
> DRAM + CXL (default interleave) (GBps): 117.23
> DRAM + CXL (weighted interleave)(GBps): 382.7
> Gain over DRAM only:                    1.4x

I've run XSBench based on the v3 patch and got numbers below. I used
your sample numactl extension from here:
Link: https://github.com/gmprice/numactl/tree/weighted_interleave_master

Performance tests – XSBench
NUMA node 0: 56 logical cores, 128 GB memory
NUMA node 2: 96 GB CXL memory

  1. dram only
  $ numactl -membind 0 ./XSBench -s XL –p 5000000
  Threads:     56
  Runtime:     36.235 seconds
  Lookups:     170,000,000
  Lookups/s:   4,691,618
 
  2. default interleave
  $ numactl –-interleave 0,2 ./XSBench –s XL –p 5000000
  Threads:     56
  Runtime:     55.243 seconds
  Lookups:     170,000,000
  Lookups/s:   3,077,293

  3. weighted interleave
  $ numactl --weighted --interleave 0,2 ./XSBench –s XL –p 5000000
  Threads:     56
  Runtime:     29.262 seconds
  Lookups:     170,000,000
  Lookups/s:   5,809,513

In terms of runtime, weighted-interleaving shows 1.19x improvement
compared to dram only, and 1.47x compared to default interleave.  I’ve
repeatedly run XSBench and have not observed any significant variations
across the runs.

Kind regards,
Hyeongtak

Re: [PATCH v3 00/11] mempolicy2, mbind2, and weighted interleave

[Arnd Bergmann]

On Wed, Dec 13, 2023, at 22:41, Gregory Price wrote:
>  .../ABI/testing/sysfs-kernel-mm-mempolicy     |   4 +
>  ...fs-kernel-mm-mempolicy-weighted-interleave |  22 +
>  .../admin-guide/mm/numa_memory_policy.rst     |  67 ++
>  arch/alpha/kernel/syscalls/syscall.tbl        |   3 +
>  arch/arm/tools/syscall.tbl                    |   3 +
>  arch/m68k/kernel/syscalls/syscall.tbl         |   3 +
>  arch/microblaze/kernel/syscalls/syscall.tbl   |   3 +

In the patches that add the system call numbers, you still need to
modify __NR_compat_syscalls in arch/arm64/include/asm/unistd.h,
and add the compat syscall in arch/arm64/include/asm/unistd32.h.

One day I'll get around to fixing this so it's no longer
necessary.

      Arnd

Re: [PATCH v3 00/11] mempolicy2, mbind2, and weighted interleave

[Gregory Price]

On Mon, Dec 18, 2023 at 04:07:48PM +0900, Hyeongtak Ji wrote:
> Hi Gregory,
> 
> Thank you for the v3 patch.
> 
> Gregory Price <gourry.memverge@gmail.com> write:
> 
> [snip]
> 

Hi Hyeongtak!

Thanks for the tests! Added test notes to the v4 cover.

> Performance tests – XSBench
> NUMA node 0: 56 logical cores, 128 GB memory
> NUMA node 2: 96 GB CXL memory
> 
>   1. dram only
>   $ numactl -membind 0 ./XSBench -s XL –p 5000000
>   Threads:     56
>   Runtime:     36.235 seconds
>   Lookups:     170,000,000
>   Lookups/s:   4,691,618
>  
>   2. default interleave
>   $ numactl –-interleave 0,2 ./XSBench –s XL –p 5000000
>   Threads:     56
>   Runtime:     55.243 seconds
>   Lookups:     170,000,000
>   Lookups/s:   3,077,293
> 
>   3. weighted interleave
>   $ numactl --weighted --interleave 0,2 ./XSBench –s XL –p 5000000
>   Threads:     56
>   Runtime:     29.262 seconds
>   Lookups:     170,000,000
>   Lookups/s:   5,809,513
>