* Re: [PATCH 5/7] genirq/affinity: move group_cpus_evenly() into lib/
@ 2021-08-15 1:49 kernel test robot
2021-08-16 10:08 ` kernel test robot
0 siblings, 1 reply; 12+ messages in thread
From: kernel test robot @ 2021-08-15 1:49 UTC (permalink / raw)
To: kbuild
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CC: clang-built-linux(a)googlegroups.com
CC: kbuild-all(a)lists.01.org
In-Reply-To: <20210814123532.229494-6-ming.lei@redhat.com>
References: <20210814123532.229494-6-ming.lei@redhat.com>
TO: Ming Lei <ming.lei@redhat.com>
TO: Thomas Gleixner <tglx@linutronix.de>
TO: Jens Axboe <axboe@kernel.dk>
CC: linux-kernel(a)vger.kernel.org
CC: linux-block(a)vger.kernel.org
CC: Christoph Hellwig <hch@lst.de>
CC: Ming Lei <ming.lei@redhat.com>
Hi Ming,
Thank you for the patch! Perhaps something to improve:
[auto build test WARNING on tip/irq/core]
[also build test WARNING on next-20210813]
[cannot apply to block/for-next linux/master linus/master v5.14-rc5]
[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]
url: https://github.com/0day-ci/linux/commits/Ming-Lei/genirq-affinity-abstract-new-API-from-managed-irq-affinity-spread/20210814-203741
base: https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git 04c2721d3530f0723b4c922a8fa9f26b202a20de
:::::: branch date: 13 hours ago
:::::: commit date: 13 hours ago
config: x86_64-randconfig-c001-20210814 (attached as .config)
compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project 1f7b25ea76a925aca690da28de9d78db7ca99d0c)
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# install x86_64 cross compiling tool for clang build
# apt-get install binutils-x86-64-linux-gnu
# https://github.com/0day-ci/linux/commit/759f72186bfdd5c3ba8b53ac0749cf7ba930012c
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review Ming-Lei/genirq-affinity-abstract-new-API-from-managed-irq-affinity-spread/20210814-203741
git checkout 759f72186bfdd5c3ba8b53ac0749cf7ba930012c
# save the attached .config to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64 clang-analyzer
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>
clang-analyzer warnings: (new ones prefixed by >>)
6 warnings generated.
Suppressed 6 warnings (6 in non-user code).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
6 warnings generated.
Suppressed 6 warnings (6 in non-user code).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
6 warnings generated.
Suppressed 6 warnings (6 in non-user code).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
6 warnings generated.
Suppressed 6 warnings (6 in non-user code).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
6 warnings generated.
Suppressed 6 warnings (6 in non-user code).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
6 warnings generated.
Suppressed 6 warnings (6 in non-user code).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
6 warnings generated.
Suppressed 6 warnings (6 in non-user code).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
6 warnings generated.
Suppressed 6 warnings (6 in non-user code).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
6 warnings generated.
Suppressed 6 warnings (6 in non-user code).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
6 warnings generated.
Suppressed 6 warnings (6 in non-user code).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
6 warnings generated.
Suppressed 6 warnings (6 in non-user code).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
7 warnings generated.
Suppressed 7 warnings (6 in non-user code, 1 with check filters).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
5 warnings generated.
Suppressed 5 warnings (5 in non-user code).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
5 warnings generated.
Suppressed 5 warnings (5 in non-user code).
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5 warnings generated.
Suppressed 5 warnings (5 in non-user code).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
5 warnings generated.
Suppressed 5 warnings (5 in non-user code).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
3 warnings generated.
Suppressed 3 warnings (3 in non-user code).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
7 warnings generated.
lib/glob.c:48:32: warning: Assigned value is garbage or undefined [clang-analyzer-core.uninitialized.Assign]
char const *back_pat = NULL, *back_str = back_str;
^ ~~~~~~~~
lib/glob.c:48:32: note: Assigned value is garbage or undefined
char const *back_pat = NULL, *back_str = back_str;
^ ~~~~~~~~
Suppressed 6 warnings (6 in non-user code).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
6 warnings generated.
Suppressed 6 warnings (6 in non-user code).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
6 warnings generated.
Suppressed 6 warnings (6 in non-user code).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
7 warnings generated.
lib/strnlen_user.c:34:2: warning: Value stored to 'src' is never read [clang-analyzer-deadcode.DeadStores]
src -= align;
^ ~~~~~
lib/strnlen_user.c:34:2: note: Value stored to 'src' is never read
src -= align;
^ ~~~~~
Suppressed 6 warnings (6 in non-user code).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
7 warnings generated.
Suppressed 7 warnings (7 in non-user code).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
7 warnings generated.
Suppressed 7 warnings (7 in non-user code).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
6 warnings generated.
Suppressed 6 warnings (6 in non-user code).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
6 warnings generated.
Suppressed 6 warnings (6 in non-user code).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
7 warnings generated.
lib/oid_registry.c:149:3: warning: Value stored to 'num' is never read [clang-analyzer-deadcode.DeadStores]
num = 0;
^ ~
lib/oid_registry.c:149:3: note: Value stored to 'num' is never read
num = 0;
^ ~
Suppressed 6 warnings (6 in non-user code).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
9 warnings generated.
Suppressed 9 warnings (2 in non-user code, 7 with check filters).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
7 warnings generated.
>> lib/group_cpus.c:236:22: warning: Division by zero [clang-analyzer-core.DivideZero]
numgrps * ncpus / remaining_ncpus);
^
lib/group_cpus.c:352:2: note: Taking false branch
if (!zalloc_cpumask_var(&nmsk, GFP_KERNEL))
^
lib/group_cpus.c:355:2: note: Taking false branch
if (!zalloc_cpumask_var(&npresmsk, GFP_KERNEL))
^
lib/group_cpus.c:359:7: note: 'node_to_cpumask' is non-null
if (!node_to_cpumask)
^~~~~~~~~~~~~~~
lib/group_cpus.c:359:2: note: Taking false branch
if (!node_to_cpumask)
^
lib/group_cpus.c:363:6: note: Assuming 'masks' is non-null
if (!masks)
^~~~~~
lib/group_cpus.c:363:2: note: Taking false branch
if (!masks)
^
lib/group_cpus.c:371:8: note: Calling '__group_cpus_evenly'
ret = __group_cpus_evenly(curgrp, numgrps, node_to_cpumask,
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
lib/group_cpus.c:257:6: note: Assuming the condition is false
if (!cpumask_weight(cpu_mask))
^~~~~~~~~~~~~~~~~~~~~~~~~
lib/group_cpus.c:257:2: note: Taking false branch
if (!cpumask_weight(cpu_mask))
^
lib/group_cpus.c:266:6: note: Assuming 'numgrps' is > 'nodes'
if (numgrps <= nodes) {
^~~~~~~~~~~~~~~~
lib/group_cpus.c:266:2: note: Taking false branch
if (numgrps <= nodes) {
^
lib/group_cpus.c:279:6: note: Assuming 'node_groups' is non-null
if (!node_groups)
^~~~~~~~~~~~
lib/group_cpus.c:279:2: note: Taking false branch
if (!node_groups)
^
lib/group_cpus.c:283:2: note: Calling 'alloc_nodes_groups'
alloc_nodes_groups(numgrps, node_to_cpumask, cpu_mask,
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
lib/group_cpus.c:134:14: note: 'remaining_ncpus' initialized to 0
unsigned n, remaining_ncpus = 0;
^~~~~~~~~~~~~~~
lib/group_cpus.c:136:2: note: Loop condition is true. Entering loop body
for (n = 0; n < nr_node_ids; n++) {
^
lib/group_cpus.c:136:2: note: Loop condition is false. Execution continues on line 141
lib/group_cpus.c:141:2: note: Taking false branch
for_each_node_mask(n, nodemsk) {
^
include/linux/nodemask.h:384:2: note: expanded from macro 'for_each_node_mask'
if (!nodes_empty(mask)) \
^
lib/group_cpus.c:153:12: note: '__UNIQUE_ID___x401' is < '__UNIQUE_ID___y402'
numgrps = min_t(unsigned, remaining_ncpus, numgrps);
^
include/linux/minmax.h:104:27: note: expanded from macro 'min_t'
#define min_t(type, x, y) __careful_cmp((type)(x), (type)(y), <)
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
include/linux/minmax.h:38:3: note: expanded from macro '__careful_cmp'
__cmp_once(x, y, __UNIQUE_ID(__x), __UNIQUE_ID(__y), op))
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
include/linux/minmax.h:33:3: note: expanded from macro '__cmp_once'
__cmp(unique_x, unique_y, op); })
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
include/linux/minmax.h:28:26: note: expanded from macro '__cmp'
#define __cmp(x, y, op) ((x) op (y) ? (x) : (y))
^~~
lib/group_cpus.c:153:12: note: '?' condition is true
numgrps = min_t(unsigned, remaining_ncpus, numgrps);
^
include/linux/minmax.h:104:27: note: expanded from macro 'min_t'
#define min_t(type, x, y) __careful_cmp((type)(x), (type)(y), <)
^
include/linux/minmax.h:38:3: note: expanded from macro '__careful_cmp'
__cmp_once(x, y, __UNIQUE_ID(__x), __UNIQUE_ID(__y), op))
^
include/linux/minmax.h:33:3: note: expanded from macro '__cmp_once'
__cmp(unique_x, unique_y, op); })
^
include/linux/minmax.h:28:26: note: expanded from macro '__cmp'
#define __cmp(x, y, op) ((x) op (y) ? (x) : (y))
^
lib/group_cpus.c:226:2: note: Loop condition is true. Entering loop body
for (n = 0; n < nr_node_ids; n++) {
^
lib/group_cpus.c:229:7: note: Assuming the condition is false
if (node_groups[n].ncpus == UINT_MAX)
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
lib/group_cpus.c:229:3: note: Taking false branch
if (node_groups[n].ncpus == UINT_MAX)
^
lib/group_cpus.c:232:3: note: Taking true branch
WARN_ON_ONCE(numgrps == 0);
^
include/asm-generic/bug.h:105:2: note: expanded from macro 'WARN_ON_ONCE'
vim +236 lib/group_cpus.c
759f72186bfdd5 Ming Lei 2021-08-14 113
759f72186bfdd5 Ming Lei 2021-08-14 114 /*
759f72186bfdd5 Ming Lei 2021-08-14 115 * Allocate group number for each node, so that for each node:
759f72186bfdd5 Ming Lei 2021-08-14 116 *
759f72186bfdd5 Ming Lei 2021-08-14 117 * 1) the allocated number is >= 1
759f72186bfdd5 Ming Lei 2021-08-14 118 *
759f72186bfdd5 Ming Lei 2021-08-14 119 * 2) the allocated number is <= active CPU number of this node
759f72186bfdd5 Ming Lei 2021-08-14 120 *
759f72186bfdd5 Ming Lei 2021-08-14 121 * The actual allocated total groups may be less than @numgrps when
759f72186bfdd5 Ming Lei 2021-08-14 122 * active total CPU number is less than @numgrps.
759f72186bfdd5 Ming Lei 2021-08-14 123 *
759f72186bfdd5 Ming Lei 2021-08-14 124 * Active CPUs means the CPUs in '@cpu_mask AND @node_to_cpumask[]'
759f72186bfdd5 Ming Lei 2021-08-14 125 * for each node.
759f72186bfdd5 Ming Lei 2021-08-14 126 */
759f72186bfdd5 Ming Lei 2021-08-14 127 static void alloc_nodes_groups(unsigned int numgrps,
759f72186bfdd5 Ming Lei 2021-08-14 128 cpumask_var_t *node_to_cpumask,
759f72186bfdd5 Ming Lei 2021-08-14 129 const struct cpumask *cpu_mask,
759f72186bfdd5 Ming Lei 2021-08-14 130 const nodemask_t nodemsk,
759f72186bfdd5 Ming Lei 2021-08-14 131 struct cpumask *nmsk,
759f72186bfdd5 Ming Lei 2021-08-14 132 struct node_groups *node_groups)
759f72186bfdd5 Ming Lei 2021-08-14 133 {
759f72186bfdd5 Ming Lei 2021-08-14 134 unsigned n, remaining_ncpus = 0;
759f72186bfdd5 Ming Lei 2021-08-14 135
759f72186bfdd5 Ming Lei 2021-08-14 136 for (n = 0; n < nr_node_ids; n++) {
759f72186bfdd5 Ming Lei 2021-08-14 137 node_groups[n].id = n;
759f72186bfdd5 Ming Lei 2021-08-14 138 node_groups[n].ncpus = UINT_MAX;
759f72186bfdd5 Ming Lei 2021-08-14 139 }
759f72186bfdd5 Ming Lei 2021-08-14 140
759f72186bfdd5 Ming Lei 2021-08-14 141 for_each_node_mask(n, nodemsk) {
759f72186bfdd5 Ming Lei 2021-08-14 142 unsigned ncpus;
759f72186bfdd5 Ming Lei 2021-08-14 143
759f72186bfdd5 Ming Lei 2021-08-14 144 cpumask_and(nmsk, cpu_mask, node_to_cpumask[n]);
759f72186bfdd5 Ming Lei 2021-08-14 145 ncpus = cpumask_weight(nmsk);
759f72186bfdd5 Ming Lei 2021-08-14 146
759f72186bfdd5 Ming Lei 2021-08-14 147 if (!ncpus)
759f72186bfdd5 Ming Lei 2021-08-14 148 continue;
759f72186bfdd5 Ming Lei 2021-08-14 149 remaining_ncpus += ncpus;
759f72186bfdd5 Ming Lei 2021-08-14 150 node_groups[n].ncpus = ncpus;
759f72186bfdd5 Ming Lei 2021-08-14 151 }
759f72186bfdd5 Ming Lei 2021-08-14 152
759f72186bfdd5 Ming Lei 2021-08-14 153 numgrps = min_t(unsigned, remaining_ncpus, numgrps);
759f72186bfdd5 Ming Lei 2021-08-14 154
759f72186bfdd5 Ming Lei 2021-08-14 155 sort(node_groups, nr_node_ids, sizeof(node_groups[0]),
759f72186bfdd5 Ming Lei 2021-08-14 156 ncpus_cmp_func, NULL);
759f72186bfdd5 Ming Lei 2021-08-14 157
759f72186bfdd5 Ming Lei 2021-08-14 158 /*
759f72186bfdd5 Ming Lei 2021-08-14 159 * Allocate groups for each node according to the ratio of this
759f72186bfdd5 Ming Lei 2021-08-14 160 * node's nr_cpus to remaining un-assigned ncpus. 'numgrps' is
759f72186bfdd5 Ming Lei 2021-08-14 161 * bigger than number of active numa nodes. Always start the
759f72186bfdd5 Ming Lei 2021-08-14 162 * allocation from the node with minimized nr_cpus.
759f72186bfdd5 Ming Lei 2021-08-14 163 *
759f72186bfdd5 Ming Lei 2021-08-14 164 * This way guarantees that each active node gets allocated at
759f72186bfdd5 Ming Lei 2021-08-14 165 * least one group, and the theory is simple: over-allocation
759f72186bfdd5 Ming Lei 2021-08-14 166 * is only done when this node is assigned by one group, so
759f72186bfdd5 Ming Lei 2021-08-14 167 * other nodes will be allocated >= 1 groups, since 'numgrps' is
759f72186bfdd5 Ming Lei 2021-08-14 168 * bigger than number of numa nodes.
759f72186bfdd5 Ming Lei 2021-08-14 169 *
759f72186bfdd5 Ming Lei 2021-08-14 170 * One perfect invariant is that number of allocated groups for
759f72186bfdd5 Ming Lei 2021-08-14 171 * each node is <= CPU count of this node:
759f72186bfdd5 Ming Lei 2021-08-14 172 *
759f72186bfdd5 Ming Lei 2021-08-14 173 * 1) suppose there are two nodes: A and B
759f72186bfdd5 Ming Lei 2021-08-14 174 * ncpu(X) is CPU count of node X
759f72186bfdd5 Ming Lei 2021-08-14 175 * grps(X) is the group count allocated to node X via this
759f72186bfdd5 Ming Lei 2021-08-14 176 * algorithm
759f72186bfdd5 Ming Lei 2021-08-14 177 *
759f72186bfdd5 Ming Lei 2021-08-14 178 * ncpu(A) <= ncpu(B)
759f72186bfdd5 Ming Lei 2021-08-14 179 * ncpu(A) + ncpu(B) = N
759f72186bfdd5 Ming Lei 2021-08-14 180 * grps(A) + grps(B) = G
759f72186bfdd5 Ming Lei 2021-08-14 181 *
759f72186bfdd5 Ming Lei 2021-08-14 182 * grps(A) = max(1, round_down(G * ncpu(A) / N))
759f72186bfdd5 Ming Lei 2021-08-14 183 * grps(B) = G - grps(A)
759f72186bfdd5 Ming Lei 2021-08-14 184 *
759f72186bfdd5 Ming Lei 2021-08-14 185 * both N and G are integer, and 2 <= G <= N, suppose
759f72186bfdd5 Ming Lei 2021-08-14 186 * G = N - delta, and 0 <= delta <= N - 2
759f72186bfdd5 Ming Lei 2021-08-14 187 *
759f72186bfdd5 Ming Lei 2021-08-14 188 * 2) obviously grps(A) <= ncpu(A) because:
759f72186bfdd5 Ming Lei 2021-08-14 189 *
759f72186bfdd5 Ming Lei 2021-08-14 190 * if grps(A) is 1, then grps(A) <= ncpu(A) given
759f72186bfdd5 Ming Lei 2021-08-14 191 * ncpu(A) >= 1
759f72186bfdd5 Ming Lei 2021-08-14 192 *
759f72186bfdd5 Ming Lei 2021-08-14 193 * otherwise,
759f72186bfdd5 Ming Lei 2021-08-14 194 * grps(A) <= G * ncpu(A) / N <= ncpu(A), given G <= N
759f72186bfdd5 Ming Lei 2021-08-14 195 *
759f72186bfdd5 Ming Lei 2021-08-14 196 * 3) prove how grps(B) <= ncpu(B):
759f72186bfdd5 Ming Lei 2021-08-14 197 *
759f72186bfdd5 Ming Lei 2021-08-14 198 * if round_down(G * ncpu(A) / N) == 0, vecs(B) won't be
759f72186bfdd5 Ming Lei 2021-08-14 199 * over-allocated, so grps(B) <= ncpu(B),
759f72186bfdd5 Ming Lei 2021-08-14 200 *
759f72186bfdd5 Ming Lei 2021-08-14 201 * otherwise:
759f72186bfdd5 Ming Lei 2021-08-14 202 *
759f72186bfdd5 Ming Lei 2021-08-14 203 * grps(A) =
759f72186bfdd5 Ming Lei 2021-08-14 204 * round_down(G * ncpu(A) / N) =
759f72186bfdd5 Ming Lei 2021-08-14 205 * round_down((N - delta) * ncpu(A) / N) =
759f72186bfdd5 Ming Lei 2021-08-14 206 * round_down((N * ncpu(A) - delta * ncpu(A)) / N) >=
759f72186bfdd5 Ming Lei 2021-08-14 207 * round_down((N * ncpu(A) - delta * N) / N) =
759f72186bfdd5 Ming Lei 2021-08-14 208 * cpu(A) - delta
759f72186bfdd5 Ming Lei 2021-08-14 209 *
759f72186bfdd5 Ming Lei 2021-08-14 210 * then:
759f72186bfdd5 Ming Lei 2021-08-14 211 *
759f72186bfdd5 Ming Lei 2021-08-14 212 * grps(A) - G >= ncpu(A) - delta - G
759f72186bfdd5 Ming Lei 2021-08-14 213 * =>
759f72186bfdd5 Ming Lei 2021-08-14 214 * G - grps(A) <= G + delta - ncpu(A)
759f72186bfdd5 Ming Lei 2021-08-14 215 * =>
759f72186bfdd5 Ming Lei 2021-08-14 216 * grps(B) <= N - ncpu(A)
759f72186bfdd5 Ming Lei 2021-08-14 217 * =>
759f72186bfdd5 Ming Lei 2021-08-14 218 * grps(B) <= cpu(B)
759f72186bfdd5 Ming Lei 2021-08-14 219 *
759f72186bfdd5 Ming Lei 2021-08-14 220 * For nodes >= 3, it can be thought as one node and another big
759f72186bfdd5 Ming Lei 2021-08-14 221 * node given that is exactly what this algorithm is implemented,
759f72186bfdd5 Ming Lei 2021-08-14 222 * and we always re-calculate 'remaining_ncpus' & 'numgrps', and
759f72186bfdd5 Ming Lei 2021-08-14 223 * finally for each node X: grps(X) <= ncpu(X).
759f72186bfdd5 Ming Lei 2021-08-14 224 *
759f72186bfdd5 Ming Lei 2021-08-14 225 */
759f72186bfdd5 Ming Lei 2021-08-14 226 for (n = 0; n < nr_node_ids; n++) {
759f72186bfdd5 Ming Lei 2021-08-14 227 unsigned ngroups, ncpus;
759f72186bfdd5 Ming Lei 2021-08-14 228
759f72186bfdd5 Ming Lei 2021-08-14 229 if (node_groups[n].ncpus == UINT_MAX)
759f72186bfdd5 Ming Lei 2021-08-14 230 continue;
759f72186bfdd5 Ming Lei 2021-08-14 231
759f72186bfdd5 Ming Lei 2021-08-14 232 WARN_ON_ONCE(numgrps == 0);
759f72186bfdd5 Ming Lei 2021-08-14 233
759f72186bfdd5 Ming Lei 2021-08-14 234 ncpus = node_groups[n].ncpus;
759f72186bfdd5 Ming Lei 2021-08-14 235 ngroups = max_t(unsigned, 1,
759f72186bfdd5 Ming Lei 2021-08-14 @236 numgrps * ncpus / remaining_ncpus);
759f72186bfdd5 Ming Lei 2021-08-14 237 WARN_ON_ONCE(ngroups > ncpus);
759f72186bfdd5 Ming Lei 2021-08-14 238
759f72186bfdd5 Ming Lei 2021-08-14 239 node_groups[n].ngroups = ngroups;
759f72186bfdd5 Ming Lei 2021-08-14 240
759f72186bfdd5 Ming Lei 2021-08-14 241 remaining_ncpus -= ncpus;
759f72186bfdd5 Ming Lei 2021-08-14 242 numgrps -= ngroups;
759f72186bfdd5 Ming Lei 2021-08-14 243 }
759f72186bfdd5 Ming Lei 2021-08-14 244 }
759f72186bfdd5 Ming Lei 2021-08-14 245
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all(a)lists.01.org
[-- Attachment #2: config.gz --]
[-- Type: application/gzip, Size: 31626 bytes --]
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH 5/7] genirq/affinity: move group_cpus_evenly() into lib/
2021-08-15 1:49 [PATCH 5/7] genirq/affinity: move group_cpus_evenly() into lib/ kernel test robot
@ 2021-08-16 10:08 ` kernel test robot
0 siblings, 0 replies; 12+ messages in thread
From: kernel test robot @ 2021-08-16 10:08 UTC (permalink / raw)
To: Ming Lei, Thomas Gleixner, Jens Axboe
Cc: clang-built-linux, kbuild-all, linux-kernel, linux-block,
Christoph Hellwig, Ming Lei
[-- Attachment #1: Type: text/plain, Size: 23074 bytes --]
Hi Ming,
Thank you for the patch! Perhaps something to improve:
[auto build test WARNING on tip/irq/core]
[also build test WARNING on next-20210813]
[cannot apply to block/for-next linux/master linus/master v5.14-rc5]
[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]
url:
https://github.com/0day-ci/linux/commits/Ming-Lei/genirq-affinity-abstract-new-API-from-managed-irq-affinity-spread/20210814-203741
base: https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git
04c2721d3530f0723b4c922a8fa9f26b202a20de
config: x86_64-randconfig-c001-20210814 (attached as .config)
compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project
1f7b25ea76a925aca690da28de9d78db7ca99d0c)
reproduce (this is a W=1 build):
wget
https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross
-O ~/bin/make.cross
chmod +x ~/bin/make.cross
# install x86_64 cross compiling tool for clang build
# apt-get install binutils-x86-64-linux-gnu
#
https://github.com/0day-ci/linux/commit/759f72186bfdd5c3ba8b53ac0749cf7ba930012c
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review
Ming-Lei/genirq-affinity-abstract-new-API-from-managed-irq-affinity-spread/20210814-203741
git checkout 759f72186bfdd5c3ba8b53ac0749cf7ba930012c
# save the attached .config to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross
ARCH=x86_64 clang-analyzer
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>
clang-analyzer warnings: (new ones prefixed by >>)
6 warnings generated.
Suppressed 6 warnings (6 in non-user code).
Use -header-filter=.* to display errors from all non-system headers.
Use -system-headers to display errors from system headers as well.
6 warnings generated.
Suppressed 6 warnings (6 in non-user code).
Use -header-filter=.* to display errors from all non-system headers.
Use -system-headers to display errors from system headers as well.
6 warnings generated.
Suppressed 6 warnings (6 in non-user code).
Use -header-filter=.* to display errors from all non-system headers.
Use -system-headers to display errors from system headers as well.
6 warnings generated.
Suppressed 6 warnings (6 in non-user code).
Use -header-filter=.* to display errors from all non-system headers.
Use -system-headers to display errors from system headers as well.
6 warnings generated.
Suppressed 6 warnings (6 in non-user code).
Use -header-filter=.* to display errors from all non-system headers.
Use -system-headers to display errors from system headers as well.
6 warnings generated.
Suppressed 6 warnings (6 in non-user code).
Use -header-filter=.* to display errors from all non-system headers.
Use -system-headers to display errors from system headers as well.
6 warnings generated.
Suppressed 6 warnings (6 in non-user code).
Use -header-filter=.* to display errors from all non-system headers.
Use -system-headers to display errors from system headers as well.
6 warnings generated.
Suppressed 6 warnings (6 in non-user code).
Use -header-filter=.* to display errors from all non-system headers.
Use -system-headers to display errors from system headers as well.
6 warnings generated.
Suppressed 6 warnings (6 in non-user code).
Use -header-filter=.* to display errors from all non-system headers.
Use -system-headers to display errors from system headers as well.
6 warnings generated.
Suppressed 6 warnings (6 in non-user code).
Use -header-filter=.* to display errors from all non-system headers.
Use -system-headers to display errors from system headers as well.
6 warnings generated.
Suppressed 6 warnings (6 in non-user code).
Use -header-filter=.* to display errors from all non-system headers.
Use -system-headers to display errors from system headers as well.
7 warnings generated.
Suppressed 7 warnings (6 in non-user code, 1 with check filters).
Use -header-filter=.* to display errors from all non-system headers.
Use -system-headers to display errors from system headers as well.
5 warnings generated.
Suppressed 5 warnings (5 in non-user code).
Use -header-filter=.* to display errors from all non-system headers.
Use -system-headers to display errors from system headers as well.
5 warnings generated.
Suppressed 5 warnings (5 in non-user code).
Use -header-filter=.* to display errors from all non-system headers.
Use -system-headers to display errors from system headers as well.
5 warnings generated.
Suppressed 5 warnings (5 in non-user code).
Use -header-filter=.* to display errors from all non-system headers.
Use -system-headers to display errors from system headers as well.
5 warnings generated.
Suppressed 5 warnings (5 in non-user code).
Use -header-filter=.* to display errors from all non-system headers.
Use -system-headers to display errors from system headers as well.
3 warnings generated.
Suppressed 3 warnings (3 in non-user code).
Use -header-filter=.* to display errors from all non-system headers.
Use -system-headers to display errors from system headers as well.
7 warnings generated.
lib/glob.c:48:32: warning: Assigned value is garbage or undefined
[clang-analyzer-core.uninitialized.Assign]
char const *back_pat = NULL, *back_str = back_str;
^ ~~~~~~~~
lib/glob.c:48:32: note: Assigned value is garbage or undefined
char const *back_pat = NULL, *back_str = back_str;
^ ~~~~~~~~
Suppressed 6 warnings (6 in non-user code).
Use -header-filter=.* to display errors from all non-system headers.
Use -system-headers to display errors from system headers as well.
6 warnings generated.
Suppressed 6 warnings (6 in non-user code).
Use -header-filter=.* to display errors from all non-system headers.
Use -system-headers to display errors from system headers as well.
6 warnings generated.
Suppressed 6 warnings (6 in non-user code).
Use -header-filter=.* to display errors from all non-system headers.
Use -system-headers to display errors from system headers as well.
7 warnings generated.
lib/strnlen_user.c:34:2: warning: Value stored to 'src' is never
read [clang-analyzer-deadcode.DeadStores]
src -= align;
^ ~~~~~
lib/strnlen_user.c:34:2: note: Value stored to 'src' is never read
src -= align;
^ ~~~~~
Suppressed 6 warnings (6 in non-user code).
Use -header-filter=.* to display errors from all non-system headers.
Use -system-headers to display errors from system headers as well.
7 warnings generated.
Suppressed 7 warnings (7 in non-user code).
Use -header-filter=.* to display errors from all non-system headers.
Use -system-headers to display errors from system headers as well.
7 warnings generated.
Suppressed 7 warnings (7 in non-user code).
Use -header-filter=.* to display errors from all non-system headers.
Use -system-headers to display errors from system headers as well.
6 warnings generated.
Suppressed 6 warnings (6 in non-user code).
Use -header-filter=.* to display errors from all non-system headers.
Use -system-headers to display errors from system headers as well.
6 warnings generated.
Suppressed 6 warnings (6 in non-user code).
Use -header-filter=.* to display errors from all non-system headers.
Use -system-headers to display errors from system headers as well.
7 warnings generated.
lib/oid_registry.c:149:3: warning: Value stored to 'num' is never
read [clang-analyzer-deadcode.DeadStores]
num = 0;
^ ~
lib/oid_registry.c:149:3: note: Value stored to 'num' is never read
num = 0;
^ ~
Suppressed 6 warnings (6 in non-user code).
Use -header-filter=.* to display errors from all non-system headers.
Use -system-headers to display errors from system headers as well.
9 warnings generated.
Suppressed 9 warnings (2 in non-user code, 7 with check filters).
Use -header-filter=.* to display errors from all non-system headers.
Use -system-headers to display errors from system headers as well.
7 warnings generated.
>> lib/group_cpus.c:236:22: warning: Division by zero [clang-analyzer-core.DivideZero]
numgrps * ncpus / remaining_ncpus);
^
lib/group_cpus.c:352:2: note: Taking false branch
if (!zalloc_cpumask_var(&nmsk, GFP_KERNEL))
^
lib/group_cpus.c:355:2: note: Taking false branch
if (!zalloc_cpumask_var(&npresmsk, GFP_KERNEL))
^
lib/group_cpus.c:359:7: note: 'node_to_cpumask' is non-null
if (!node_to_cpumask)
^~~~~~~~~~~~~~~
lib/group_cpus.c:359:2: note: Taking false branch
if (!node_to_cpumask)
^
lib/group_cpus.c:363:6: note: Assuming 'masks' is non-null
if (!masks)
^~~~~~
lib/group_cpus.c:363:2: note: Taking false branch
if (!masks)
^
lib/group_cpus.c:371:8: note: Calling '__group_cpus_evenly'
ret = __group_cpus_evenly(curgrp, numgrps, node_to_cpumask,
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
lib/group_cpus.c:257:6: note: Assuming the condition is false
if (!cpumask_weight(cpu_mask))
^~~~~~~~~~~~~~~~~~~~~~~~~
lib/group_cpus.c:257:2: note: Taking false branch
if (!cpumask_weight(cpu_mask))
^
lib/group_cpus.c:266:6: note: Assuming 'numgrps' is > 'nodes'
if (numgrps <= nodes) {
^~~~~~~~~~~~~~~~
lib/group_cpus.c:266:2: note: Taking false branch
if (numgrps <= nodes) {
^
lib/group_cpus.c:279:6: note: Assuming 'node_groups' is non-null
if (!node_groups)
^~~~~~~~~~~~
lib/group_cpus.c:279:2: note: Taking false branch
if (!node_groups)
^
lib/group_cpus.c:283:2: note: Calling 'alloc_nodes_groups'
alloc_nodes_groups(numgrps, node_to_cpumask, cpu_mask,
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
lib/group_cpus.c:134:14: note: 'remaining_ncpus' initialized to 0
unsigned n, remaining_ncpus = 0;
^~~~~~~~~~~~~~~
lib/group_cpus.c:136:2: note: Loop condition is true. Entering loop
body
for (n = 0; n < nr_node_ids; n++) {
^
lib/group_cpus.c:136:2: note: Loop condition is false. Execution
continues on line 141
lib/group_cpus.c:141:2: note: Taking false branch
for_each_node_mask(n, nodemsk) {
^
include/linux/nodemask.h:384:2: note: expanded from macro
'for_each_node_mask'
if (!nodes_empty(mask)) \
^
lib/group_cpus.c:153:12: note: '__UNIQUE_ID___x401' is <
'__UNIQUE_ID___y402'
numgrps = min_t(unsigned, remaining_ncpus, numgrps);
^
include/linux/minmax.h:104:27: note: expanded from macro 'min_t'
#define min_t(type, x, y) __careful_cmp((type)(x), (type)(y), <)
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
include/linux/minmax.h:38:3: note: expanded from macro '__careful_cmp'
__cmp_once(x, y, __UNIQUE_ID(__x), __UNIQUE_ID(__y),
op))
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
include/linux/minmax.h:33:3: note: expanded from macro '__cmp_once'
__cmp(unique_x, unique_y, op); })
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
include/linux/minmax.h:28:26: note: expanded from macro '__cmp'
#define __cmp(x, y, op) ((x) op (y) ? (x) : (y))
^~~
lib/group_cpus.c:153:12: note: '?' condition is true
numgrps = min_t(unsigned, remaining_ncpus, numgrps);
^
include/linux/minmax.h:104:27: note: expanded from macro 'min_t'
#define min_t(type, x, y) __careful_cmp((type)(x), (type)(y), <)
^
include/linux/minmax.h:38:3: note: expanded from macro '__careful_cmp'
__cmp_once(x, y, __UNIQUE_ID(__x), __UNIQUE_ID(__y),
op))
^
include/linux/minmax.h:33:3: note: expanded from macro '__cmp_once'
__cmp(unique_x, unique_y, op); })
^
include/linux/minmax.h:28:26: note: expanded from macro '__cmp'
#define __cmp(x, y, op) ((x) op (y) ? (x) : (y))
^
lib/group_cpus.c:226:2: note: Loop condition is true. Entering loop
body
for (n = 0; n < nr_node_ids; n++) {
^
lib/group_cpus.c:229:7: note: Assuming the condition is false
if (node_groups[n].ncpus == UINT_MAX)
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
lib/group_cpus.c:229:3: note: Taking false branch
if (node_groups[n].ncpus == UINT_MAX)
^
lib/group_cpus.c:232:3: note: Taking true branch
WARN_ON_ONCE(numgrps == 0);
^
include/asm-generic/bug.h:105:2: note: expanded from macro
'WARN_ON_ONCE'
vim +236 lib/group_cpus.c
759f72186bfdd5 Ming Lei 2021-08-14 113 759f72186bfdd5 Ming Lei
2021-08-14 114 /*
759f72186bfdd5 Ming Lei 2021-08-14 115 * Allocate group number for
each node, so that for each node:
759f72186bfdd5 Ming Lei 2021-08-14 116 *
759f72186bfdd5 Ming Lei 2021-08-14 117 * 1) the allocated number is >= 1
759f72186bfdd5 Ming Lei 2021-08-14 118 *
759f72186bfdd5 Ming Lei 2021-08-14 119 * 2) the allocated number is
<= active CPU number of this node
759f72186bfdd5 Ming Lei 2021-08-14 120 *
759f72186bfdd5 Ming Lei 2021-08-14 121 * The actual allocated total
groups may be less than @numgrps when
759f72186bfdd5 Ming Lei 2021-08-14 122 * active total CPU number is
less than @numgrps.
759f72186bfdd5 Ming Lei 2021-08-14 123 *
759f72186bfdd5 Ming Lei 2021-08-14 124 * Active CPUs means the CPUs
in '@cpu_mask AND @node_to_cpumask[]'
759f72186bfdd5 Ming Lei 2021-08-14 125 * for each node.
759f72186bfdd5 Ming Lei 2021-08-14 126 */
759f72186bfdd5 Ming Lei 2021-08-14 127 static void
alloc_nodes_groups(unsigned int numgrps,
759f72186bfdd5 Ming Lei 2021-08-14 128 cpumask_var_t
*node_to_cpumask,
759f72186bfdd5 Ming Lei 2021-08-14 129 const struct cpumask
*cpu_mask,
759f72186bfdd5 Ming Lei 2021-08-14 130 const nodemask_t nodemsk,
759f72186bfdd5 Ming Lei 2021-08-14 131 struct cpumask *nmsk,
759f72186bfdd5 Ming Lei 2021-08-14 132 struct node_groups
*node_groups)
759f72186bfdd5 Ming Lei 2021-08-14 133 {
759f72186bfdd5 Ming Lei 2021-08-14 134 unsigned n, remaining_ncpus = 0;
759f72186bfdd5 Ming Lei 2021-08-14 135 759f72186bfdd5 Ming Lei
2021-08-14 136 for (n = 0; n < nr_node_ids; n++) {
759f72186bfdd5 Ming Lei 2021-08-14 137 node_groups[n].id = n;
759f72186bfdd5 Ming Lei 2021-08-14 138 node_groups[n].ncpus = UINT_MAX;
759f72186bfdd5 Ming Lei 2021-08-14 139 }
759f72186bfdd5 Ming Lei 2021-08-14 140 759f72186bfdd5 Ming Lei
2021-08-14 141 for_each_node_mask(n, nodemsk) {
759f72186bfdd5 Ming Lei 2021-08-14 142 unsigned ncpus;
759f72186bfdd5 Ming Lei 2021-08-14 143 759f72186bfdd5 Ming Lei
2021-08-14 144 cpumask_and(nmsk, cpu_mask, node_to_cpumask[n]);
759f72186bfdd5 Ming Lei 2021-08-14 145 ncpus = cpumask_weight(nmsk);
759f72186bfdd5 Ming Lei 2021-08-14 146 759f72186bfdd5 Ming Lei
2021-08-14 147 if (!ncpus)
759f72186bfdd5 Ming Lei 2021-08-14 148 continue;
759f72186bfdd5 Ming Lei 2021-08-14 149 remaining_ncpus += ncpus;
759f72186bfdd5 Ming Lei 2021-08-14 150 node_groups[n].ncpus = ncpus;
759f72186bfdd5 Ming Lei 2021-08-14 151 }
759f72186bfdd5 Ming Lei 2021-08-14 152 759f72186bfdd5 Ming Lei
2021-08-14 153 numgrps = min_t(unsigned, remaining_ncpus, numgrps);
759f72186bfdd5 Ming Lei 2021-08-14 154 759f72186bfdd5 Ming Lei
2021-08-14 155 sort(node_groups, nr_node_ids, sizeof(node_groups[0]),
759f72186bfdd5 Ming Lei 2021-08-14 156 ncpus_cmp_func, NULL);
759f72186bfdd5 Ming Lei 2021-08-14 157 759f72186bfdd5 Ming Lei
2021-08-14 158 /*
759f72186bfdd5 Ming Lei 2021-08-14 159 * Allocate groups for each
node according to the ratio of this
759f72186bfdd5 Ming Lei 2021-08-14 160 * node's nr_cpus to remaining
un-assigned ncpus. 'numgrps' is
759f72186bfdd5 Ming Lei 2021-08-14 161 * bigger than number of
active numa nodes. Always start the
759f72186bfdd5 Ming Lei 2021-08-14 162 * allocation from the node
with minimized nr_cpus.
759f72186bfdd5 Ming Lei 2021-08-14 163 *
759f72186bfdd5 Ming Lei 2021-08-14 164 * This way guarantees that
each active node gets allocated at
759f72186bfdd5 Ming Lei 2021-08-14 165 * least one group, and the
theory is simple: over-allocation
759f72186bfdd5 Ming Lei 2021-08-14 166 * is only done when this node
is assigned by one group, so
759f72186bfdd5 Ming Lei 2021-08-14 167 * other nodes will be
allocated >= 1 groups, since 'numgrps' is
759f72186bfdd5 Ming Lei 2021-08-14 168 * bigger than number of numa
nodes.
759f72186bfdd5 Ming Lei 2021-08-14 169 *
759f72186bfdd5 Ming Lei 2021-08-14 170 * One perfect invariant is
that number of allocated groups for
759f72186bfdd5 Ming Lei 2021-08-14 171 * each node is <= CPU count
of this node:
759f72186bfdd5 Ming Lei 2021-08-14 172 *
759f72186bfdd5 Ming Lei 2021-08-14 173 * 1) suppose there are two
nodes: A and B
759f72186bfdd5 Ming Lei 2021-08-14 174 * ncpu(X) is CPU count of node X
759f72186bfdd5 Ming Lei 2021-08-14 175 * grps(X) is the group count
allocated to node X via this
759f72186bfdd5 Ming Lei 2021-08-14 176 * algorithm
759f72186bfdd5 Ming Lei 2021-08-14 177 *
759f72186bfdd5 Ming Lei 2021-08-14 178 * ncpu(A) <= ncpu(B)
759f72186bfdd5 Ming Lei 2021-08-14 179 * ncpu(A) + ncpu(B) = N
759f72186bfdd5 Ming Lei 2021-08-14 180 * grps(A) + grps(B) = G
759f72186bfdd5 Ming Lei 2021-08-14 181 *
759f72186bfdd5 Ming Lei 2021-08-14 182 * grps(A) = max(1,
round_down(G * ncpu(A) / N))
759f72186bfdd5 Ming Lei 2021-08-14 183 * grps(B) = G - grps(A)
759f72186bfdd5 Ming Lei 2021-08-14 184 *
759f72186bfdd5 Ming Lei 2021-08-14 185 * both N and G are integer,
and 2 <= G <= N, suppose
759f72186bfdd5 Ming Lei 2021-08-14 186 * G = N - delta, and 0 <=
delta <= N - 2
759f72186bfdd5 Ming Lei 2021-08-14 187 *
759f72186bfdd5 Ming Lei 2021-08-14 188 * 2) obviously grps(A) <=
ncpu(A) because:
759f72186bfdd5 Ming Lei 2021-08-14 189 *
759f72186bfdd5 Ming Lei 2021-08-14 190 * if grps(A) is 1, then
grps(A) <= ncpu(A) given
759f72186bfdd5 Ming Lei 2021-08-14 191 * ncpu(A) >= 1
759f72186bfdd5 Ming Lei 2021-08-14 192 *
759f72186bfdd5 Ming Lei 2021-08-14 193 * otherwise,
759f72186bfdd5 Ming Lei 2021-08-14 194 * grps(A) <= G * ncpu(A) /
N <= ncpu(A), given G <= N
759f72186bfdd5 Ming Lei 2021-08-14 195 *
759f72186bfdd5 Ming Lei 2021-08-14 196 * 3) prove how grps(B) <=
ncpu(B):
759f72186bfdd5 Ming Lei 2021-08-14 197 *
759f72186bfdd5 Ming Lei 2021-08-14 198 * if round_down(G * ncpu(A)
/ N) == 0, vecs(B) won't be
759f72186bfdd5 Ming Lei 2021-08-14 199 * over-allocated, so grps(B)
<= ncpu(B),
759f72186bfdd5 Ming Lei 2021-08-14 200 *
759f72186bfdd5 Ming Lei 2021-08-14 201 * otherwise:
759f72186bfdd5 Ming Lei 2021-08-14 202 *
759f72186bfdd5 Ming Lei 2021-08-14 203 * grps(A) =
759f72186bfdd5 Ming Lei 2021-08-14 204 * round_down(G * ncpu(A) / N) =
759f72186bfdd5 Ming Lei 2021-08-14 205 * round_down((N - delta) *
ncpu(A) / N) =
759f72186bfdd5 Ming Lei 2021-08-14 206 * round_down((N * ncpu(A) -
delta * ncpu(A)) / N) >=
759f72186bfdd5 Ming Lei 2021-08-14 207 * round_down((N * ncpu(A) -
delta * N) / N) =
759f72186bfdd5 Ming Lei 2021-08-14 208 * cpu(A) - delta
759f72186bfdd5 Ming Lei 2021-08-14 209 *
759f72186bfdd5 Ming Lei 2021-08-14 210 * then:
759f72186bfdd5 Ming Lei 2021-08-14 211 *
759f72186bfdd5 Ming Lei 2021-08-14 212 * grps(A) - G >= ncpu(A) -
delta - G
759f72186bfdd5 Ming Lei 2021-08-14 213 * =>
759f72186bfdd5 Ming Lei 2021-08-14 214 * G - grps(A) <= G + delta -
ncpu(A)
759f72186bfdd5 Ming Lei 2021-08-14 215 * =>
759f72186bfdd5 Ming Lei 2021-08-14 216 * grps(B) <= N - ncpu(A)
759f72186bfdd5 Ming Lei 2021-08-14 217 * =>
759f72186bfdd5 Ming Lei 2021-08-14 218 * grps(B) <= cpu(B)
759f72186bfdd5 Ming Lei 2021-08-14 219 *
759f72186bfdd5 Ming Lei 2021-08-14 220 * For nodes >= 3, it can be
thought as one node and another big
759f72186bfdd5 Ming Lei 2021-08-14 221 * node given that is exactly
what this algorithm is implemented,
759f72186bfdd5 Ming Lei 2021-08-14 222 * and we always re-calculate
'remaining_ncpus' & 'numgrps', and
759f72186bfdd5 Ming Lei 2021-08-14 223 * finally for each node X:
grps(X) <= ncpu(X).
759f72186bfdd5 Ming Lei 2021-08-14 224 *
759f72186bfdd5 Ming Lei 2021-08-14 225 */
759f72186bfdd5 Ming Lei 2021-08-14 226 for (n = 0; n < nr_node_ids;
n++) {
759f72186bfdd5 Ming Lei 2021-08-14 227 unsigned ngroups, ncpus;
759f72186bfdd5 Ming Lei 2021-08-14 228 759f72186bfdd5 Ming Lei
2021-08-14 229 if (node_groups[n].ncpus == UINT_MAX)
759f72186bfdd5 Ming Lei 2021-08-14 230 continue;
759f72186bfdd5 Ming Lei 2021-08-14 231 759f72186bfdd5 Ming Lei
2021-08-14 232 WARN_ON_ONCE(numgrps == 0);
759f72186bfdd5 Ming Lei 2021-08-14 233 759f72186bfdd5 Ming Lei
2021-08-14 234 ncpus = node_groups[n].ncpus;
759f72186bfdd5 Ming Lei 2021-08-14 235 ngroups = max_t(unsigned, 1,
759f72186bfdd5 Ming Lei 2021-08-14 @236 numgrps * ncpus /
remaining_ncpus);
759f72186bfdd5 Ming Lei 2021-08-14 237 WARN_ON_ONCE(ngroups > ncpus);
759f72186bfdd5 Ming Lei 2021-08-14 238 759f72186bfdd5 Ming Lei
2021-08-14 239 node_groups[n].ngroups = ngroups;
759f72186bfdd5 Ming Lei 2021-08-14 240 759f72186bfdd5 Ming Lei
2021-08-14 241 remaining_ncpus -= ncpus;
759f72186bfdd5 Ming Lei 2021-08-14 242 numgrps -= ngroups;
759f72186bfdd5 Ming Lei 2021-08-14 243 }
759f72186bfdd5 Ming Lei 2021-08-14 244 }
759f72186bfdd5 Ming Lei 2021-08-14 245
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
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^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH 5/7] genirq/affinity: move group_cpus_evenly() into lib/
@ 2021-08-16 10:08 ` kernel test robot
0 siblings, 0 replies; 12+ messages in thread
From: kernel test robot @ 2021-08-16 10:08 UTC (permalink / raw)
To: kbuild-all
[-- Attachment #1: Type: text/plain, Size: 23537 bytes --]
Hi Ming,
Thank you for the patch! Perhaps something to improve:
[auto build test WARNING on tip/irq/core]
[also build test WARNING on next-20210813]
[cannot apply to block/for-next linux/master linus/master v5.14-rc5]
[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]
url:
https://github.com/0day-ci/linux/commits/Ming-Lei/genirq-affinity-abstract-new-API-from-managed-irq-affinity-spread/20210814-203741
base: https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git
04c2721d3530f0723b4c922a8fa9f26b202a20de
config: x86_64-randconfig-c001-20210814 (attached as .config)
compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project
1f7b25ea76a925aca690da28de9d78db7ca99d0c)
reproduce (this is a W=1 build):
wget
https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross
-O ~/bin/make.cross
chmod +x ~/bin/make.cross
# install x86_64 cross compiling tool for clang build
# apt-get install binutils-x86-64-linux-gnu
#
https://github.com/0day-ci/linux/commit/759f72186bfdd5c3ba8b53ac0749cf7ba930012c
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review
Ming-Lei/genirq-affinity-abstract-new-API-from-managed-irq-affinity-spread/20210814-203741
git checkout 759f72186bfdd5c3ba8b53ac0749cf7ba930012c
# save the attached .config to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross
ARCH=x86_64 clang-analyzer
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>
clang-analyzer warnings: (new ones prefixed by >>)
6 warnings generated.
Suppressed 6 warnings (6 in non-user code).
Use -header-filter=.* to display errors from all non-system headers.
Use -system-headers to display errors from system headers as well.
6 warnings generated.
Suppressed 6 warnings (6 in non-user code).
Use -header-filter=.* to display errors from all non-system headers.
Use -system-headers to display errors from system headers as well.
6 warnings generated.
Suppressed 6 warnings (6 in non-user code).
Use -header-filter=.* to display errors from all non-system headers.
Use -system-headers to display errors from system headers as well.
6 warnings generated.
Suppressed 6 warnings (6 in non-user code).
Use -header-filter=.* to display errors from all non-system headers.
Use -system-headers to display errors from system headers as well.
6 warnings generated.
Suppressed 6 warnings (6 in non-user code).
Use -header-filter=.* to display errors from all non-system headers.
Use -system-headers to display errors from system headers as well.
6 warnings generated.
Suppressed 6 warnings (6 in non-user code).
Use -header-filter=.* to display errors from all non-system headers.
Use -system-headers to display errors from system headers as well.
6 warnings generated.
Suppressed 6 warnings (6 in non-user code).
Use -header-filter=.* to display errors from all non-system headers.
Use -system-headers to display errors from system headers as well.
6 warnings generated.
Suppressed 6 warnings (6 in non-user code).
Use -header-filter=.* to display errors from all non-system headers.
Use -system-headers to display errors from system headers as well.
6 warnings generated.
Suppressed 6 warnings (6 in non-user code).
Use -header-filter=.* to display errors from all non-system headers.
Use -system-headers to display errors from system headers as well.
6 warnings generated.
Suppressed 6 warnings (6 in non-user code).
Use -header-filter=.* to display errors from all non-system headers.
Use -system-headers to display errors from system headers as well.
6 warnings generated.
Suppressed 6 warnings (6 in non-user code).
Use -header-filter=.* to display errors from all non-system headers.
Use -system-headers to display errors from system headers as well.
7 warnings generated.
Suppressed 7 warnings (6 in non-user code, 1 with check filters).
Use -header-filter=.* to display errors from all non-system headers.
Use -system-headers to display errors from system headers as well.
5 warnings generated.
Suppressed 5 warnings (5 in non-user code).
Use -header-filter=.* to display errors from all non-system headers.
Use -system-headers to display errors from system headers as well.
5 warnings generated.
Suppressed 5 warnings (5 in non-user code).
Use -header-filter=.* to display errors from all non-system headers.
Use -system-headers to display errors from system headers as well.
5 warnings generated.
Suppressed 5 warnings (5 in non-user code).
Use -header-filter=.* to display errors from all non-system headers.
Use -system-headers to display errors from system headers as well.
5 warnings generated.
Suppressed 5 warnings (5 in non-user code).
Use -header-filter=.* to display errors from all non-system headers.
Use -system-headers to display errors from system headers as well.
3 warnings generated.
Suppressed 3 warnings (3 in non-user code).
Use -header-filter=.* to display errors from all non-system headers.
Use -system-headers to display errors from system headers as well.
7 warnings generated.
lib/glob.c:48:32: warning: Assigned value is garbage or undefined
[clang-analyzer-core.uninitialized.Assign]
char const *back_pat = NULL, *back_str = back_str;
^ ~~~~~~~~
lib/glob.c:48:32: note: Assigned value is garbage or undefined
char const *back_pat = NULL, *back_str = back_str;
^ ~~~~~~~~
Suppressed 6 warnings (6 in non-user code).
Use -header-filter=.* to display errors from all non-system headers.
Use -system-headers to display errors from system headers as well.
6 warnings generated.
Suppressed 6 warnings (6 in non-user code).
Use -header-filter=.* to display errors from all non-system headers.
Use -system-headers to display errors from system headers as well.
6 warnings generated.
Suppressed 6 warnings (6 in non-user code).
Use -header-filter=.* to display errors from all non-system headers.
Use -system-headers to display errors from system headers as well.
7 warnings generated.
lib/strnlen_user.c:34:2: warning: Value stored to 'src' is never
read [clang-analyzer-deadcode.DeadStores]
src -= align;
^ ~~~~~
lib/strnlen_user.c:34:2: note: Value stored to 'src' is never read
src -= align;
^ ~~~~~
Suppressed 6 warnings (6 in non-user code).
Use -header-filter=.* to display errors from all non-system headers.
Use -system-headers to display errors from system headers as well.
7 warnings generated.
Suppressed 7 warnings (7 in non-user code).
Use -header-filter=.* to display errors from all non-system headers.
Use -system-headers to display errors from system headers as well.
7 warnings generated.
Suppressed 7 warnings (7 in non-user code).
Use -header-filter=.* to display errors from all non-system headers.
Use -system-headers to display errors from system headers as well.
6 warnings generated.
Suppressed 6 warnings (6 in non-user code).
Use -header-filter=.* to display errors from all non-system headers.
Use -system-headers to display errors from system headers as well.
6 warnings generated.
Suppressed 6 warnings (6 in non-user code).
Use -header-filter=.* to display errors from all non-system headers.
Use -system-headers to display errors from system headers as well.
7 warnings generated.
lib/oid_registry.c:149:3: warning: Value stored to 'num' is never
read [clang-analyzer-deadcode.DeadStores]
num = 0;
^ ~
lib/oid_registry.c:149:3: note: Value stored to 'num' is never read
num = 0;
^ ~
Suppressed 6 warnings (6 in non-user code).
Use -header-filter=.* to display errors from all non-system headers.
Use -system-headers to display errors from system headers as well.
9 warnings generated.
Suppressed 9 warnings (2 in non-user code, 7 with check filters).
Use -header-filter=.* to display errors from all non-system headers.
Use -system-headers to display errors from system headers as well.
7 warnings generated.
>> lib/group_cpus.c:236:22: warning: Division by zero [clang-analyzer-core.DivideZero]
numgrps * ncpus / remaining_ncpus);
^
lib/group_cpus.c:352:2: note: Taking false branch
if (!zalloc_cpumask_var(&nmsk, GFP_KERNEL))
^
lib/group_cpus.c:355:2: note: Taking false branch
if (!zalloc_cpumask_var(&npresmsk, GFP_KERNEL))
^
lib/group_cpus.c:359:7: note: 'node_to_cpumask' is non-null
if (!node_to_cpumask)
^~~~~~~~~~~~~~~
lib/group_cpus.c:359:2: note: Taking false branch
if (!node_to_cpumask)
^
lib/group_cpus.c:363:6: note: Assuming 'masks' is non-null
if (!masks)
^~~~~~
lib/group_cpus.c:363:2: note: Taking false branch
if (!masks)
^
lib/group_cpus.c:371:8: note: Calling '__group_cpus_evenly'
ret = __group_cpus_evenly(curgrp, numgrps, node_to_cpumask,
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
lib/group_cpus.c:257:6: note: Assuming the condition is false
if (!cpumask_weight(cpu_mask))
^~~~~~~~~~~~~~~~~~~~~~~~~
lib/group_cpus.c:257:2: note: Taking false branch
if (!cpumask_weight(cpu_mask))
^
lib/group_cpus.c:266:6: note: Assuming 'numgrps' is > 'nodes'
if (numgrps <= nodes) {
^~~~~~~~~~~~~~~~
lib/group_cpus.c:266:2: note: Taking false branch
if (numgrps <= nodes) {
^
lib/group_cpus.c:279:6: note: Assuming 'node_groups' is non-null
if (!node_groups)
^~~~~~~~~~~~
lib/group_cpus.c:279:2: note: Taking false branch
if (!node_groups)
^
lib/group_cpus.c:283:2: note: Calling 'alloc_nodes_groups'
alloc_nodes_groups(numgrps, node_to_cpumask, cpu_mask,
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
lib/group_cpus.c:134:14: note: 'remaining_ncpus' initialized to 0
unsigned n, remaining_ncpus = 0;
^~~~~~~~~~~~~~~
lib/group_cpus.c:136:2: note: Loop condition is true. Entering loop
body
for (n = 0; n < nr_node_ids; n++) {
^
lib/group_cpus.c:136:2: note: Loop condition is false. Execution
continues on line 141
lib/group_cpus.c:141:2: note: Taking false branch
for_each_node_mask(n, nodemsk) {
^
include/linux/nodemask.h:384:2: note: expanded from macro
'for_each_node_mask'
if (!nodes_empty(mask)) \
^
lib/group_cpus.c:153:12: note: '__UNIQUE_ID___x401' is <
'__UNIQUE_ID___y402'
numgrps = min_t(unsigned, remaining_ncpus, numgrps);
^
include/linux/minmax.h:104:27: note: expanded from macro 'min_t'
#define min_t(type, x, y) __careful_cmp((type)(x), (type)(y), <)
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
include/linux/minmax.h:38:3: note: expanded from macro '__careful_cmp'
__cmp_once(x, y, __UNIQUE_ID(__x), __UNIQUE_ID(__y),
op))
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
include/linux/minmax.h:33:3: note: expanded from macro '__cmp_once'
__cmp(unique_x, unique_y, op); })
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
include/linux/minmax.h:28:26: note: expanded from macro '__cmp'
#define __cmp(x, y, op) ((x) op (y) ? (x) : (y))
^~~
lib/group_cpus.c:153:12: note: '?' condition is true
numgrps = min_t(unsigned, remaining_ncpus, numgrps);
^
include/linux/minmax.h:104:27: note: expanded from macro 'min_t'
#define min_t(type, x, y) __careful_cmp((type)(x), (type)(y), <)
^
include/linux/minmax.h:38:3: note: expanded from macro '__careful_cmp'
__cmp_once(x, y, __UNIQUE_ID(__x), __UNIQUE_ID(__y),
op))
^
include/linux/minmax.h:33:3: note: expanded from macro '__cmp_once'
__cmp(unique_x, unique_y, op); })
^
include/linux/minmax.h:28:26: note: expanded from macro '__cmp'
#define __cmp(x, y, op) ((x) op (y) ? (x) : (y))
^
lib/group_cpus.c:226:2: note: Loop condition is true. Entering loop
body
for (n = 0; n < nr_node_ids; n++) {
^
lib/group_cpus.c:229:7: note: Assuming the condition is false
if (node_groups[n].ncpus == UINT_MAX)
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
lib/group_cpus.c:229:3: note: Taking false branch
if (node_groups[n].ncpus == UINT_MAX)
^
lib/group_cpus.c:232:3: note: Taking true branch
WARN_ON_ONCE(numgrps == 0);
^
include/asm-generic/bug.h:105:2: note: expanded from macro
'WARN_ON_ONCE'
vim +236 lib/group_cpus.c
759f72186bfdd5 Ming Lei 2021-08-14 113 759f72186bfdd5 Ming Lei
2021-08-14 114 /*
759f72186bfdd5 Ming Lei 2021-08-14 115 * Allocate group number for
each node, so that for each node:
759f72186bfdd5 Ming Lei 2021-08-14 116 *
759f72186bfdd5 Ming Lei 2021-08-14 117 * 1) the allocated number is >= 1
759f72186bfdd5 Ming Lei 2021-08-14 118 *
759f72186bfdd5 Ming Lei 2021-08-14 119 * 2) the allocated number is
<= active CPU number of this node
759f72186bfdd5 Ming Lei 2021-08-14 120 *
759f72186bfdd5 Ming Lei 2021-08-14 121 * The actual allocated total
groups may be less than @numgrps when
759f72186bfdd5 Ming Lei 2021-08-14 122 * active total CPU number is
less than @numgrps.
759f72186bfdd5 Ming Lei 2021-08-14 123 *
759f72186bfdd5 Ming Lei 2021-08-14 124 * Active CPUs means the CPUs
in '@cpu_mask AND @node_to_cpumask[]'
759f72186bfdd5 Ming Lei 2021-08-14 125 * for each node.
759f72186bfdd5 Ming Lei 2021-08-14 126 */
759f72186bfdd5 Ming Lei 2021-08-14 127 static void
alloc_nodes_groups(unsigned int numgrps,
759f72186bfdd5 Ming Lei 2021-08-14 128 cpumask_var_t
*node_to_cpumask,
759f72186bfdd5 Ming Lei 2021-08-14 129 const struct cpumask
*cpu_mask,
759f72186bfdd5 Ming Lei 2021-08-14 130 const nodemask_t nodemsk,
759f72186bfdd5 Ming Lei 2021-08-14 131 struct cpumask *nmsk,
759f72186bfdd5 Ming Lei 2021-08-14 132 struct node_groups
*node_groups)
759f72186bfdd5 Ming Lei 2021-08-14 133 {
759f72186bfdd5 Ming Lei 2021-08-14 134 unsigned n, remaining_ncpus = 0;
759f72186bfdd5 Ming Lei 2021-08-14 135 759f72186bfdd5 Ming Lei
2021-08-14 136 for (n = 0; n < nr_node_ids; n++) {
759f72186bfdd5 Ming Lei 2021-08-14 137 node_groups[n].id = n;
759f72186bfdd5 Ming Lei 2021-08-14 138 node_groups[n].ncpus = UINT_MAX;
759f72186bfdd5 Ming Lei 2021-08-14 139 }
759f72186bfdd5 Ming Lei 2021-08-14 140 759f72186bfdd5 Ming Lei
2021-08-14 141 for_each_node_mask(n, nodemsk) {
759f72186bfdd5 Ming Lei 2021-08-14 142 unsigned ncpus;
759f72186bfdd5 Ming Lei 2021-08-14 143 759f72186bfdd5 Ming Lei
2021-08-14 144 cpumask_and(nmsk, cpu_mask, node_to_cpumask[n]);
759f72186bfdd5 Ming Lei 2021-08-14 145 ncpus = cpumask_weight(nmsk);
759f72186bfdd5 Ming Lei 2021-08-14 146 759f72186bfdd5 Ming Lei
2021-08-14 147 if (!ncpus)
759f72186bfdd5 Ming Lei 2021-08-14 148 continue;
759f72186bfdd5 Ming Lei 2021-08-14 149 remaining_ncpus += ncpus;
759f72186bfdd5 Ming Lei 2021-08-14 150 node_groups[n].ncpus = ncpus;
759f72186bfdd5 Ming Lei 2021-08-14 151 }
759f72186bfdd5 Ming Lei 2021-08-14 152 759f72186bfdd5 Ming Lei
2021-08-14 153 numgrps = min_t(unsigned, remaining_ncpus, numgrps);
759f72186bfdd5 Ming Lei 2021-08-14 154 759f72186bfdd5 Ming Lei
2021-08-14 155 sort(node_groups, nr_node_ids, sizeof(node_groups[0]),
759f72186bfdd5 Ming Lei 2021-08-14 156 ncpus_cmp_func, NULL);
759f72186bfdd5 Ming Lei 2021-08-14 157 759f72186bfdd5 Ming Lei
2021-08-14 158 /*
759f72186bfdd5 Ming Lei 2021-08-14 159 * Allocate groups for each
node according to the ratio of this
759f72186bfdd5 Ming Lei 2021-08-14 160 * node's nr_cpus to remaining
un-assigned ncpus. 'numgrps' is
759f72186bfdd5 Ming Lei 2021-08-14 161 * bigger than number of
active numa nodes. Always start the
759f72186bfdd5 Ming Lei 2021-08-14 162 * allocation from the node
with minimized nr_cpus.
759f72186bfdd5 Ming Lei 2021-08-14 163 *
759f72186bfdd5 Ming Lei 2021-08-14 164 * This way guarantees that
each active node gets allocated at
759f72186bfdd5 Ming Lei 2021-08-14 165 * least one group, and the
theory is simple: over-allocation
759f72186bfdd5 Ming Lei 2021-08-14 166 * is only done when this node
is assigned by one group, so
759f72186bfdd5 Ming Lei 2021-08-14 167 * other nodes will be
allocated >= 1 groups, since 'numgrps' is
759f72186bfdd5 Ming Lei 2021-08-14 168 * bigger than number of numa
nodes.
759f72186bfdd5 Ming Lei 2021-08-14 169 *
759f72186bfdd5 Ming Lei 2021-08-14 170 * One perfect invariant is
that number of allocated groups for
759f72186bfdd5 Ming Lei 2021-08-14 171 * each node is <= CPU count
of this node:
759f72186bfdd5 Ming Lei 2021-08-14 172 *
759f72186bfdd5 Ming Lei 2021-08-14 173 * 1) suppose there are two
nodes: A and B
759f72186bfdd5 Ming Lei 2021-08-14 174 * ncpu(X) is CPU count of node X
759f72186bfdd5 Ming Lei 2021-08-14 175 * grps(X) is the group count
allocated to node X via this
759f72186bfdd5 Ming Lei 2021-08-14 176 * algorithm
759f72186bfdd5 Ming Lei 2021-08-14 177 *
759f72186bfdd5 Ming Lei 2021-08-14 178 * ncpu(A) <= ncpu(B)
759f72186bfdd5 Ming Lei 2021-08-14 179 * ncpu(A) + ncpu(B) = N
759f72186bfdd5 Ming Lei 2021-08-14 180 * grps(A) + grps(B) = G
759f72186bfdd5 Ming Lei 2021-08-14 181 *
759f72186bfdd5 Ming Lei 2021-08-14 182 * grps(A) = max(1,
round_down(G * ncpu(A) / N))
759f72186bfdd5 Ming Lei 2021-08-14 183 * grps(B) = G - grps(A)
759f72186bfdd5 Ming Lei 2021-08-14 184 *
759f72186bfdd5 Ming Lei 2021-08-14 185 * both N and G are integer,
and 2 <= G <= N, suppose
759f72186bfdd5 Ming Lei 2021-08-14 186 * G = N - delta, and 0 <=
delta <= N - 2
759f72186bfdd5 Ming Lei 2021-08-14 187 *
759f72186bfdd5 Ming Lei 2021-08-14 188 * 2) obviously grps(A) <=
ncpu(A) because:
759f72186bfdd5 Ming Lei 2021-08-14 189 *
759f72186bfdd5 Ming Lei 2021-08-14 190 * if grps(A) is 1, then
grps(A) <= ncpu(A) given
759f72186bfdd5 Ming Lei 2021-08-14 191 * ncpu(A) >= 1
759f72186bfdd5 Ming Lei 2021-08-14 192 *
759f72186bfdd5 Ming Lei 2021-08-14 193 * otherwise,
759f72186bfdd5 Ming Lei 2021-08-14 194 * grps(A) <= G * ncpu(A) /
N <= ncpu(A), given G <= N
759f72186bfdd5 Ming Lei 2021-08-14 195 *
759f72186bfdd5 Ming Lei 2021-08-14 196 * 3) prove how grps(B) <=
ncpu(B):
759f72186bfdd5 Ming Lei 2021-08-14 197 *
759f72186bfdd5 Ming Lei 2021-08-14 198 * if round_down(G * ncpu(A)
/ N) == 0, vecs(B) won't be
759f72186bfdd5 Ming Lei 2021-08-14 199 * over-allocated, so grps(B)
<= ncpu(B),
759f72186bfdd5 Ming Lei 2021-08-14 200 *
759f72186bfdd5 Ming Lei 2021-08-14 201 * otherwise:
759f72186bfdd5 Ming Lei 2021-08-14 202 *
759f72186bfdd5 Ming Lei 2021-08-14 203 * grps(A) =
759f72186bfdd5 Ming Lei 2021-08-14 204 * round_down(G * ncpu(A) / N) =
759f72186bfdd5 Ming Lei 2021-08-14 205 * round_down((N - delta) *
ncpu(A) / N) =
759f72186bfdd5 Ming Lei 2021-08-14 206 * round_down((N * ncpu(A) -
delta * ncpu(A)) / N) >=
759f72186bfdd5 Ming Lei 2021-08-14 207 * round_down((N * ncpu(A) -
delta * N) / N) =
759f72186bfdd5 Ming Lei 2021-08-14 208 * cpu(A) - delta
759f72186bfdd5 Ming Lei 2021-08-14 209 *
759f72186bfdd5 Ming Lei 2021-08-14 210 * then:
759f72186bfdd5 Ming Lei 2021-08-14 211 *
759f72186bfdd5 Ming Lei 2021-08-14 212 * grps(A) - G >= ncpu(A) -
delta - G
759f72186bfdd5 Ming Lei 2021-08-14 213 * =>
759f72186bfdd5 Ming Lei 2021-08-14 214 * G - grps(A) <= G + delta -
ncpu(A)
759f72186bfdd5 Ming Lei 2021-08-14 215 * =>
759f72186bfdd5 Ming Lei 2021-08-14 216 * grps(B) <= N - ncpu(A)
759f72186bfdd5 Ming Lei 2021-08-14 217 * =>
759f72186bfdd5 Ming Lei 2021-08-14 218 * grps(B) <= cpu(B)
759f72186bfdd5 Ming Lei 2021-08-14 219 *
759f72186bfdd5 Ming Lei 2021-08-14 220 * For nodes >= 3, it can be
thought as one node and another big
759f72186bfdd5 Ming Lei 2021-08-14 221 * node given that is exactly
what this algorithm is implemented,
759f72186bfdd5 Ming Lei 2021-08-14 222 * and we always re-calculate
'remaining_ncpus' & 'numgrps', and
759f72186bfdd5 Ming Lei 2021-08-14 223 * finally for each node X:
grps(X) <= ncpu(X).
759f72186bfdd5 Ming Lei 2021-08-14 224 *
759f72186bfdd5 Ming Lei 2021-08-14 225 */
759f72186bfdd5 Ming Lei 2021-08-14 226 for (n = 0; n < nr_node_ids;
n++) {
759f72186bfdd5 Ming Lei 2021-08-14 227 unsigned ngroups, ncpus;
759f72186bfdd5 Ming Lei 2021-08-14 228 759f72186bfdd5 Ming Lei
2021-08-14 229 if (node_groups[n].ncpus == UINT_MAX)
759f72186bfdd5 Ming Lei 2021-08-14 230 continue;
759f72186bfdd5 Ming Lei 2021-08-14 231 759f72186bfdd5 Ming Lei
2021-08-14 232 WARN_ON_ONCE(numgrps == 0);
759f72186bfdd5 Ming Lei 2021-08-14 233 759f72186bfdd5 Ming Lei
2021-08-14 234 ncpus = node_groups[n].ncpus;
759f72186bfdd5 Ming Lei 2021-08-14 235 ngroups = max_t(unsigned, 1,
759f72186bfdd5 Ming Lei 2021-08-14 @236 numgrps * ncpus /
remaining_ncpus);
759f72186bfdd5 Ming Lei 2021-08-14 237 WARN_ON_ONCE(ngroups > ncpus);
759f72186bfdd5 Ming Lei 2021-08-14 238 759f72186bfdd5 Ming Lei
2021-08-14 239 node_groups[n].ngroups = ngroups;
759f72186bfdd5 Ming Lei 2021-08-14 240 759f72186bfdd5 Ming Lei
2021-08-14 241 remaining_ncpus -= ncpus;
759f72186bfdd5 Ming Lei 2021-08-14 242 numgrps -= ngroups;
759f72186bfdd5 Ming Lei 2021-08-14 243 }
759f72186bfdd5 Ming Lei 2021-08-14 244 }
759f72186bfdd5 Ming Lei 2021-08-14 245
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all(a)lists.01.org
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^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH 5/7] genirq/affinity: move group_cpus_evenly() into lib/
2021-08-16 1:04 ` Ming Lei
@ 2021-08-17 4:52 ` Christoph Hellwig
-1 siblings, 0 replies; 12+ messages in thread
From: Christoph Hellwig @ 2021-08-17 4:52 UTC (permalink / raw)
To: Ming Lei
Cc: kernel test robot, Thomas Gleixner, Jens Axboe,
clang-built-linux, kbuild-all, linux-kernel, linux-block,
Christoph Hellwig
On Mon, Aug 16, 2021 at 09:04:21AM +0800, Ming Lei wrote:
> But the above symbol is exported via EXPORT_SYMBOL_GPL(), in current
> kernel tree, we usually keep such exported symbol as global, or is there
> some change in kernel coding style recently?
This is about prototypes. You need to include group_cpus.h in
group_cpus.c so that the prototype is visible at the implementation site.
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH 5/7] genirq/affinity: move group_cpus_evenly() into lib/
@ 2021-08-17 4:52 ` Christoph Hellwig
0 siblings, 0 replies; 12+ messages in thread
From: Christoph Hellwig @ 2021-08-17 4:52 UTC (permalink / raw)
To: kbuild-all
[-- Attachment #1: Type: text/plain, Size: 394 bytes --]
On Mon, Aug 16, 2021 at 09:04:21AM +0800, Ming Lei wrote:
> But the above symbol is exported via EXPORT_SYMBOL_GPL(), in current
> kernel tree, we usually keep such exported symbol as global, or is there
> some change in kernel coding style recently?
This is about prototypes. You need to include group_cpus.h in
group_cpus.c so that the prototype is visible at the implementation site.
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH 5/7] genirq/affinity: move group_cpus_evenly() into lib/
2021-08-14 17:01 ` kernel test robot
@ 2021-08-16 1:04 ` Ming Lei
-1 siblings, 0 replies; 12+ messages in thread
From: Ming Lei @ 2021-08-16 1:04 UTC (permalink / raw)
To: kernel test robot
Cc: Thomas Gleixner, Jens Axboe, clang-built-linux, kbuild-all,
linux-kernel, linux-block, Christoph Hellwig
Hello,
On Sun, Aug 15, 2021 at 01:01:07AM +0800, kernel test robot wrote:
> Hi Ming,
>
> Thank you for the patch! Perhaps something to improve:
>
> [auto build test WARNING on tip/irq/core]
> [also build test WARNING on next-20210813]
> [cannot apply to block/for-next linux/master linus/master v5.14-rc5]
> [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]
>
> url: https://github.com/0day-ci/linux/commits/Ming-Lei/genirq-affinity-abstract-new-API-from-managed-irq-affinity-spread/20210814-203741
> base: https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git 04c2721d3530f0723b4c922a8fa9f26b202a20de
> config: hexagon-randconfig-r041-20210814 (attached as .config)
> compiler: clang version 12.0.0
> reproduce (this is a W=1 build):
> wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
> chmod +x ~/bin/make.cross
> # https://github.com/0day-ci/linux/commit/759f72186bfdd5c3ba8b53ac0749cf7ba930012c
> git remote add linux-review https://github.com/0day-ci/linux
> git fetch --no-tags linux-review Ming-Lei/genirq-affinity-abstract-new-API-from-managed-irq-affinity-spread/20210814-203741
> git checkout 759f72186bfdd5c3ba8b53ac0749cf7ba930012c
> # save the attached .config to linux build tree
> COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=hexagon
>
> If you fix the issue, kindly add following tag as appropriate
> Reported-by: kernel test robot <lkp@intel.com>
>
> All warnings (new ones prefixed by >>):
>
> >> lib/group_cpus.c:344:17: warning: no previous prototype for function 'group_cpus_evenly' [-Wmissing-prototypes]
> struct cpumask *group_cpus_evenly(unsigned int numgrps)
> ^
> lib/group_cpus.c:344:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
> struct cpumask *group_cpus_evenly(unsigned int numgrps)
> ^
> static
> 1 warning generated.
>
>
> vim +/group_cpus_evenly +344 lib/group_cpus.c
>
> 328
> 329 /**
> 330 * group_cpus_evenly - Group all CPUs evenly per NUMA/CPU locality
> 331 * @numgrps: number of groups
> 332 *
> 333 * Return: cpumask array if successful, NULL otherwise. And each element
> 334 * includes CPUs assigned to this group
> 335 *
> 336 * Try to put close CPUs from viewpoint of CPU and NUMA locality into
> 337 * same group, and run two-stage grouping:
> 338 * 1) allocate present CPUs on these groups evenly first
> 339 * 2) allocate other possible CPUs on these groups evenly
> 340 *
> 341 * We guarantee in the resulted grouping that all CPUs are covered, and
> 342 * no same CPU is assigned to different groups
> 343 */
> > 344 struct cpumask *group_cpus_evenly(unsigned int numgrps)
But the above symbol is exported via EXPORT_SYMBOL_GPL(), in current
kernel tree, we usually keep such exported symbol as global, or is there
some change in kernel coding style recently?
Thanks,
Ming
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH 5/7] genirq/affinity: move group_cpus_evenly() into lib/
@ 2021-08-16 1:04 ` Ming Lei
0 siblings, 0 replies; 12+ messages in thread
From: Ming Lei @ 2021-08-16 1:04 UTC (permalink / raw)
To: kbuild-all
[-- Attachment #1: Type: text/plain, Size: 3253 bytes --]
Hello,
On Sun, Aug 15, 2021 at 01:01:07AM +0800, kernel test robot wrote:
> Hi Ming,
>
> Thank you for the patch! Perhaps something to improve:
>
> [auto build test WARNING on tip/irq/core]
> [also build test WARNING on next-20210813]
> [cannot apply to block/for-next linux/master linus/master v5.14-rc5]
> [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]
>
> url: https://github.com/0day-ci/linux/commits/Ming-Lei/genirq-affinity-abstract-new-API-from-managed-irq-affinity-spread/20210814-203741
> base: https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git 04c2721d3530f0723b4c922a8fa9f26b202a20de
> config: hexagon-randconfig-r041-20210814 (attached as .config)
> compiler: clang version 12.0.0
> reproduce (this is a W=1 build):
> wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
> chmod +x ~/bin/make.cross
> # https://github.com/0day-ci/linux/commit/759f72186bfdd5c3ba8b53ac0749cf7ba930012c
> git remote add linux-review https://github.com/0day-ci/linux
> git fetch --no-tags linux-review Ming-Lei/genirq-affinity-abstract-new-API-from-managed-irq-affinity-spread/20210814-203741
> git checkout 759f72186bfdd5c3ba8b53ac0749cf7ba930012c
> # save the attached .config to linux build tree
> COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=hexagon
>
> If you fix the issue, kindly add following tag as appropriate
> Reported-by: kernel test robot <lkp@intel.com>
>
> All warnings (new ones prefixed by >>):
>
> >> lib/group_cpus.c:344:17: warning: no previous prototype for function 'group_cpus_evenly' [-Wmissing-prototypes]
> struct cpumask *group_cpus_evenly(unsigned int numgrps)
> ^
> lib/group_cpus.c:344:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
> struct cpumask *group_cpus_evenly(unsigned int numgrps)
> ^
> static
> 1 warning generated.
>
>
> vim +/group_cpus_evenly +344 lib/group_cpus.c
>
> 328
> 329 /**
> 330 * group_cpus_evenly - Group all CPUs evenly per NUMA/CPU locality
> 331 * @numgrps: number of groups
> 332 *
> 333 * Return: cpumask array if successful, NULL otherwise. And each element
> 334 * includes CPUs assigned to this group
> 335 *
> 336 * Try to put close CPUs from viewpoint of CPU and NUMA locality into
> 337 * same group, and run two-stage grouping:
> 338 * 1) allocate present CPUs on these groups evenly first
> 339 * 2) allocate other possible CPUs on these groups evenly
> 340 *
> 341 * We guarantee in the resulted grouping that all CPUs are covered, and
> 342 * no same CPU is assigned to different groups
> 343 */
> > 344 struct cpumask *group_cpus_evenly(unsigned int numgrps)
But the above symbol is exported via EXPORT_SYMBOL_GPL(), in current
kernel tree, we usually keep such exported symbol as global, or is there
some change in kernel coding style recently?
Thanks,
Ming
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH 5/7] genirq/affinity: move group_cpus_evenly() into lib/
2021-08-14 12:35 ` [PATCH 5/7] genirq/affinity: move group_cpus_evenly() into lib/ Ming Lei
@ 2021-08-14 17:15 ` kernel test robot
2021-08-14 17:15 ` kernel test robot
1 sibling, 0 replies; 12+ messages in thread
From: kernel test robot @ 2021-08-14 17:15 UTC (permalink / raw)
To: Ming Lei, Thomas Gleixner, Jens Axboe
Cc: kbuild-all, linux-kernel, linux-block, Christoph Hellwig, Ming Lei
[-- Attachment #1: Type: text/plain, Size: 2698 bytes --]
Hi Ming,
Thank you for the patch! Perhaps something to improve:
[auto build test WARNING on tip/irq/core]
[also build test WARNING on next-20210813]
[cannot apply to block/for-next linux/master linus/master v5.14-rc5]
[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]
url: https://github.com/0day-ci/linux/commits/Ming-Lei/genirq-affinity-abstract-new-API-from-managed-irq-affinity-spread/20210814-203741
base: https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git 04c2721d3530f0723b4c922a8fa9f26b202a20de
config: arc-randconfig-r016-20210814 (attached as .config)
compiler: arc-elf-gcc (GCC) 11.2.0
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# https://github.com/0day-ci/linux/commit/759f72186bfdd5c3ba8b53ac0749cf7ba930012c
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review Ming-Lei/genirq-affinity-abstract-new-API-from-managed-irq-affinity-spread/20210814-203741
git checkout 759f72186bfdd5c3ba8b53ac0749cf7ba930012c
# save the attached .config to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross ARCH=arc
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>
All warnings (new ones prefixed by >>):
>> lib/group_cpus.c:344:17: warning: no previous prototype for 'group_cpus_evenly' [-Wmissing-prototypes]
344 | struct cpumask *group_cpus_evenly(unsigned int numgrps)
| ^~~~~~~~~~~~~~~~~
vim +/group_cpus_evenly +344 lib/group_cpus.c
328
329 /**
330 * group_cpus_evenly - Group all CPUs evenly per NUMA/CPU locality
331 * @numgrps: number of groups
332 *
333 * Return: cpumask array if successful, NULL otherwise. And each element
334 * includes CPUs assigned to this group
335 *
336 * Try to put close CPUs from viewpoint of CPU and NUMA locality into
337 * same group, and run two-stage grouping:
338 * 1) allocate present CPUs on these groups evenly first
339 * 2) allocate other possible CPUs on these groups evenly
340 *
341 * We guarantee in the resulted grouping that all CPUs are covered, and
342 * no same CPU is assigned to different groups
343 */
> 344 struct cpumask *group_cpus_evenly(unsigned int numgrps)
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 29044 bytes --]
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH 5/7] genirq/affinity: move group_cpus_evenly() into lib/
@ 2021-08-14 17:15 ` kernel test robot
0 siblings, 0 replies; 12+ messages in thread
From: kernel test robot @ 2021-08-14 17:15 UTC (permalink / raw)
To: kbuild-all
[-- Attachment #1: Type: text/plain, Size: 2758 bytes --]
Hi Ming,
Thank you for the patch! Perhaps something to improve:
[auto build test WARNING on tip/irq/core]
[also build test WARNING on next-20210813]
[cannot apply to block/for-next linux/master linus/master v5.14-rc5]
[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]
url: https://github.com/0day-ci/linux/commits/Ming-Lei/genirq-affinity-abstract-new-API-from-managed-irq-affinity-spread/20210814-203741
base: https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git 04c2721d3530f0723b4c922a8fa9f26b202a20de
config: arc-randconfig-r016-20210814 (attached as .config)
compiler: arc-elf-gcc (GCC) 11.2.0
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# https://github.com/0day-ci/linux/commit/759f72186bfdd5c3ba8b53ac0749cf7ba930012c
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review Ming-Lei/genirq-affinity-abstract-new-API-from-managed-irq-affinity-spread/20210814-203741
git checkout 759f72186bfdd5c3ba8b53ac0749cf7ba930012c
# save the attached .config to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross ARCH=arc
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>
All warnings (new ones prefixed by >>):
>> lib/group_cpus.c:344:17: warning: no previous prototype for 'group_cpus_evenly' [-Wmissing-prototypes]
344 | struct cpumask *group_cpus_evenly(unsigned int numgrps)
| ^~~~~~~~~~~~~~~~~
vim +/group_cpus_evenly +344 lib/group_cpus.c
328
329 /**
330 * group_cpus_evenly - Group all CPUs evenly per NUMA/CPU locality
331 * @numgrps: number of groups
332 *
333 * Return: cpumask array if successful, NULL otherwise. And each element
334 * includes CPUs assigned to this group
335 *
336 * Try to put close CPUs from viewpoint of CPU and NUMA locality into
337 * same group, and run two-stage grouping:
338 * 1) allocate present CPUs on these groups evenly first
339 * 2) allocate other possible CPUs on these groups evenly
340 *
341 * We guarantee in the resulted grouping that all CPUs are covered, and
342 * no same CPU is assigned to different groups
343 */
> 344 struct cpumask *group_cpus_evenly(unsigned int numgrps)
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all(a)lists.01.org
[-- Attachment #2: config.gz --]
[-- Type: application/gzip, Size: 29044 bytes --]
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH 5/7] genirq/affinity: move group_cpus_evenly() into lib/
2021-08-14 12:35 ` [PATCH 5/7] genirq/affinity: move group_cpus_evenly() into lib/ Ming Lei
@ 2021-08-14 17:01 ` kernel test robot
2021-08-14 17:15 ` kernel test robot
1 sibling, 0 replies; 12+ messages in thread
From: kernel test robot @ 2021-08-14 17:01 UTC (permalink / raw)
To: Ming Lei, Thomas Gleixner, Jens Axboe
Cc: clang-built-linux, kbuild-all, linux-kernel, linux-block,
Christoph Hellwig, Ming Lei
[-- Attachment #1: Type: text/plain, Size: 2899 bytes --]
Hi Ming,
Thank you for the patch! Perhaps something to improve:
[auto build test WARNING on tip/irq/core]
[also build test WARNING on next-20210813]
[cannot apply to block/for-next linux/master linus/master v5.14-rc5]
[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]
url: https://github.com/0day-ci/linux/commits/Ming-Lei/genirq-affinity-abstract-new-API-from-managed-irq-affinity-spread/20210814-203741
base: https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git 04c2721d3530f0723b4c922a8fa9f26b202a20de
config: hexagon-randconfig-r041-20210814 (attached as .config)
compiler: clang version 12.0.0
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# https://github.com/0day-ci/linux/commit/759f72186bfdd5c3ba8b53ac0749cf7ba930012c
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review Ming-Lei/genirq-affinity-abstract-new-API-from-managed-irq-affinity-spread/20210814-203741
git checkout 759f72186bfdd5c3ba8b53ac0749cf7ba930012c
# save the attached .config to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=hexagon
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>
All warnings (new ones prefixed by >>):
>> lib/group_cpus.c:344:17: warning: no previous prototype for function 'group_cpus_evenly' [-Wmissing-prototypes]
struct cpumask *group_cpus_evenly(unsigned int numgrps)
^
lib/group_cpus.c:344:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
struct cpumask *group_cpus_evenly(unsigned int numgrps)
^
static
1 warning generated.
vim +/group_cpus_evenly +344 lib/group_cpus.c
328
329 /**
330 * group_cpus_evenly - Group all CPUs evenly per NUMA/CPU locality
331 * @numgrps: number of groups
332 *
333 * Return: cpumask array if successful, NULL otherwise. And each element
334 * includes CPUs assigned to this group
335 *
336 * Try to put close CPUs from viewpoint of CPU and NUMA locality into
337 * same group, and run two-stage grouping:
338 * 1) allocate present CPUs on these groups evenly first
339 * 2) allocate other possible CPUs on these groups evenly
340 *
341 * We guarantee in the resulted grouping that all CPUs are covered, and
342 * no same CPU is assigned to different groups
343 */
> 344 struct cpumask *group_cpus_evenly(unsigned int numgrps)
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 25339 bytes --]
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH 5/7] genirq/affinity: move group_cpus_evenly() into lib/
@ 2021-08-14 17:01 ` kernel test robot
0 siblings, 0 replies; 12+ messages in thread
From: kernel test robot @ 2021-08-14 17:01 UTC (permalink / raw)
To: kbuild-all
[-- Attachment #1: Type: text/plain, Size: 2964 bytes --]
Hi Ming,
Thank you for the patch! Perhaps something to improve:
[auto build test WARNING on tip/irq/core]
[also build test WARNING on next-20210813]
[cannot apply to block/for-next linux/master linus/master v5.14-rc5]
[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]
url: https://github.com/0day-ci/linux/commits/Ming-Lei/genirq-affinity-abstract-new-API-from-managed-irq-affinity-spread/20210814-203741
base: https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git 04c2721d3530f0723b4c922a8fa9f26b202a20de
config: hexagon-randconfig-r041-20210814 (attached as .config)
compiler: clang version 12.0.0
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# https://github.com/0day-ci/linux/commit/759f72186bfdd5c3ba8b53ac0749cf7ba930012c
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review Ming-Lei/genirq-affinity-abstract-new-API-from-managed-irq-affinity-spread/20210814-203741
git checkout 759f72186bfdd5c3ba8b53ac0749cf7ba930012c
# save the attached .config to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=hexagon
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>
All warnings (new ones prefixed by >>):
>> lib/group_cpus.c:344:17: warning: no previous prototype for function 'group_cpus_evenly' [-Wmissing-prototypes]
struct cpumask *group_cpus_evenly(unsigned int numgrps)
^
lib/group_cpus.c:344:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
struct cpumask *group_cpus_evenly(unsigned int numgrps)
^
static
1 warning generated.
vim +/group_cpus_evenly +344 lib/group_cpus.c
328
329 /**
330 * group_cpus_evenly - Group all CPUs evenly per NUMA/CPU locality
331 * @numgrps: number of groups
332 *
333 * Return: cpumask array if successful, NULL otherwise. And each element
334 * includes CPUs assigned to this group
335 *
336 * Try to put close CPUs from viewpoint of CPU and NUMA locality into
337 * same group, and run two-stage grouping:
338 * 1) allocate present CPUs on these groups evenly first
339 * 2) allocate other possible CPUs on these groups evenly
340 *
341 * We guarantee in the resulted grouping that all CPUs are covered, and
342 * no same CPU is assigned to different groups
343 */
> 344 struct cpumask *group_cpus_evenly(unsigned int numgrps)
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all(a)lists.01.org
[-- Attachment #2: config.gz --]
[-- Type: application/gzip, Size: 25339 bytes --]
^ permalink raw reply [flat|nested] 12+ messages in thread
* [PATCH 5/7] genirq/affinity: move group_cpus_evenly() into lib/
2021-08-14 12:35 [PATCH 0/7] genirq/affinity: abstract new API from managed irq affinity spread Ming Lei
@ 2021-08-14 12:35 ` Ming Lei
2021-08-14 17:01 ` kernel test robot
2021-08-14 17:15 ` kernel test robot
0 siblings, 2 replies; 12+ messages in thread
From: Ming Lei @ 2021-08-14 12:35 UTC (permalink / raw)
To: Thomas Gleixner, Jens Axboe
Cc: linux-kernel, linux-block, Christoph Hellwig, Ming Lei
group_cpus_evenly() has become one generic helper which can be used for
other subsystems, so move it into lib/.
Signed-off-by: Ming Lei <ming.lei@redhat.com>
---
include/linux/group_cpus.h | 14 ++
kernel/irq/affinity.c | 398 +----------------------------------
lib/Makefile | 2 +
lib/group_cpus.c | 413 +++++++++++++++++++++++++++++++++++++
4 files changed, 430 insertions(+), 397 deletions(-)
create mode 100644 include/linux/group_cpus.h
create mode 100644 lib/group_cpus.c
diff --git a/include/linux/group_cpus.h b/include/linux/group_cpus.h
new file mode 100644
index 000000000000..e42807ec61f6
--- /dev/null
+++ b/include/linux/group_cpus.h
@@ -0,0 +1,14 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2016 Thomas Gleixner.
+ * Copyright (C) 2016-2017 Christoph Hellwig.
+ */
+
+#ifndef __LINUX_GROUP_CPUS_H
+#define __LINUX_GROUP_CPUS_H
+#include <linux/kernel.h>
+#include <linux/cpu.h>
+
+struct cpumask *group_cpus_evenly(unsigned int numgrps);
+
+#endif
diff --git a/kernel/irq/affinity.c b/kernel/irq/affinity.c
index ad0ce4b5a28e..44a4eba80315 100644
--- a/kernel/irq/affinity.c
+++ b/kernel/irq/affinity.c
@@ -7,403 +7,7 @@
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/cpu.h>
-#include <linux/sort.h>
-
-static void grp_spread_init_one(struct cpumask *irqmsk, struct cpumask *nmsk,
- unsigned int cpus_per_grp)
-{
- const struct cpumask *siblmsk;
- int cpu, sibl;
-
- for ( ; cpus_per_grp > 0; ) {
- cpu = cpumask_first(nmsk);
-
- /* Should not happen, but I'm too lazy to think about it */
- if (cpu >= nr_cpu_ids)
- return;
-
- cpumask_clear_cpu(cpu, nmsk);
- cpumask_set_cpu(cpu, irqmsk);
- cpus_per_grp--;
-
- /* If the cpu has siblings, use them first */
- siblmsk = topology_sibling_cpumask(cpu);
- for (sibl = -1; cpus_per_grp > 0; ) {
- sibl = cpumask_next(sibl, siblmsk);
- if (sibl >= nr_cpu_ids)
- break;
- if (!cpumask_test_and_clear_cpu(sibl, nmsk))
- continue;
- cpumask_set_cpu(sibl, irqmsk);
- cpus_per_grp--;
- }
- }
-}
-
-static cpumask_var_t *alloc_node_to_cpumask(void)
-{
- cpumask_var_t *masks;
- int node;
-
- masks = kcalloc(nr_node_ids, sizeof(cpumask_var_t), GFP_KERNEL);
- if (!masks)
- return NULL;
-
- for (node = 0; node < nr_node_ids; node++) {
- if (!zalloc_cpumask_var(&masks[node], GFP_KERNEL))
- goto out_unwind;
- }
-
- return masks;
-
-out_unwind:
- while (--node >= 0)
- free_cpumask_var(masks[node]);
- kfree(masks);
- return NULL;
-}
-
-static void free_node_to_cpumask(cpumask_var_t *masks)
-{
- int node;
-
- for (node = 0; node < nr_node_ids; node++)
- free_cpumask_var(masks[node]);
- kfree(masks);
-}
-
-static void build_node_to_cpumask(cpumask_var_t *masks)
-{
- int cpu;
-
- for_each_possible_cpu(cpu)
- cpumask_set_cpu(cpu, masks[cpu_to_node(cpu)]);
-}
-
-static int get_nodes_in_cpumask(cpumask_var_t *node_to_cpumask,
- const struct cpumask *mask, nodemask_t *nodemsk)
-{
- int n, nodes = 0;
-
- /* Calculate the number of nodes in the supplied affinity mask */
- for_each_node(n) {
- if (cpumask_intersects(mask, node_to_cpumask[n])) {
- node_set(n, *nodemsk);
- nodes++;
- }
- }
- return nodes;
-}
-
-struct node_groups {
- unsigned id;
-
- union {
- unsigned ngroups;
- unsigned ncpus;
- };
-};
-
-static int ncpus_cmp_func(const void *l, const void *r)
-{
- const struct node_groups *ln = l;
- const struct node_groups *rn = r;
-
- return ln->ncpus - rn->ncpus;
-}
-
-/*
- * Allocate group number for each node, so that for each node:
- *
- * 1) the allocated number is >= 1
- *
- * 2) the allocated number is <= active CPU number of this node
- *
- * The actual allocated total groups may be less than @numgrps when
- * active total CPU number is less than @numgrps.
- *
- * Active CPUs means the CPUs in '@cpu_mask AND @node_to_cpumask[]'
- * for each node.
- */
-static void alloc_nodes_groups(unsigned int numgrps,
- cpumask_var_t *node_to_cpumask,
- const struct cpumask *cpu_mask,
- const nodemask_t nodemsk,
- struct cpumask *nmsk,
- struct node_groups *node_groups)
-{
- unsigned n, remaining_ncpus = 0;
-
- for (n = 0; n < nr_node_ids; n++) {
- node_groups[n].id = n;
- node_groups[n].ncpus = UINT_MAX;
- }
-
- for_each_node_mask(n, nodemsk) {
- unsigned ncpus;
-
- cpumask_and(nmsk, cpu_mask, node_to_cpumask[n]);
- ncpus = cpumask_weight(nmsk);
-
- if (!ncpus)
- continue;
- remaining_ncpus += ncpus;
- node_groups[n].ncpus = ncpus;
- }
-
- numgrps = min_t(unsigned, remaining_ncpus, numgrps);
-
- sort(node_groups, nr_node_ids, sizeof(node_groups[0]),
- ncpus_cmp_func, NULL);
-
- /*
- * Allocate groups for each node according to the ratio of this
- * node's nr_cpus to remaining un-assigned ncpus. 'numgrps' is
- * bigger than number of active numa nodes. Always start the
- * allocation from the node with minimized nr_cpus.
- *
- * This way guarantees that each active node gets allocated at
- * least one group, and the theory is simple: over-allocation
- * is only done when this node is assigned by one group, so
- * other nodes will be allocated >= 1 groups, since 'numgrps' is
- * bigger than number of numa nodes.
- *
- * One perfect invariant is that number of allocated groups for
- * each node is <= CPU count of this node:
- *
- * 1) suppose there are two nodes: A and B
- * ncpu(X) is CPU count of node X
- * grps(X) is the group count allocated to node X via this
- * algorithm
- *
- * ncpu(A) <= ncpu(B)
- * ncpu(A) + ncpu(B) = N
- * grps(A) + grps(B) = G
- *
- * grps(A) = max(1, round_down(G * ncpu(A) / N))
- * grps(B) = G - grps(A)
- *
- * both N and G are integer, and 2 <= G <= N, suppose
- * G = N - delta, and 0 <= delta <= N - 2
- *
- * 2) obviously grps(A) <= ncpu(A) because:
- *
- * if grps(A) is 1, then grps(A) <= ncpu(A) given
- * ncpu(A) >= 1
- *
- * otherwise,
- * grps(A) <= G * ncpu(A) / N <= ncpu(A), given G <= N
- *
- * 3) prove how grps(B) <= ncpu(B):
- *
- * if round_down(G * ncpu(A) / N) == 0, vecs(B) won't be
- * over-allocated, so grps(B) <= ncpu(B),
- *
- * otherwise:
- *
- * grps(A) =
- * round_down(G * ncpu(A) / N) =
- * round_down((N - delta) * ncpu(A) / N) =
- * round_down((N * ncpu(A) - delta * ncpu(A)) / N) >=
- * round_down((N * ncpu(A) - delta * N) / N) =
- * cpu(A) - delta
- *
- * then:
- *
- * grps(A) - G >= ncpu(A) - delta - G
- * =>
- * G - grps(A) <= G + delta - ncpu(A)
- * =>
- * grps(B) <= N - ncpu(A)
- * =>
- * grps(B) <= cpu(B)
- *
- * For nodes >= 3, it can be thought as one node and another big
- * node given that is exactly what this algorithm is implemented,
- * and we always re-calculate 'remaining_ncpus' & 'numgrps', and
- * finally for each node X: grps(X) <= ncpu(X).
- *
- */
- for (n = 0; n < nr_node_ids; n++) {
- unsigned ngroups, ncpus;
-
- if (node_groups[n].ncpus == UINT_MAX)
- continue;
-
- WARN_ON_ONCE(numgrps == 0);
-
- ncpus = node_groups[n].ncpus;
- ngroups = max_t(unsigned, 1,
- numgrps * ncpus / remaining_ncpus);
- WARN_ON_ONCE(ngroups > ncpus);
-
- node_groups[n].ngroups = ngroups;
-
- remaining_ncpus -= ncpus;
- numgrps -= ngroups;
- }
-}
-
-static int __group_cpus_evenly(unsigned int startgrp, unsigned int numgrps,
- cpumask_var_t *node_to_cpumask,
- const struct cpumask *cpu_mask,
- struct cpumask *nmsk, struct cpumask *masks)
-{
- unsigned int i, n, nodes, cpus_per_grp, extra_grps, done = 0;
- unsigned int last_grp = numgrps;
- unsigned int curgrp = startgrp;
- nodemask_t nodemsk = NODE_MASK_NONE;
- struct node_groups *node_groups;
-
- if (!cpumask_weight(cpu_mask))
- return 0;
-
- nodes = get_nodes_in_cpumask(node_to_cpumask, cpu_mask, &nodemsk);
-
- /*
- * If the number of nodes in the mask is greater than or equal the
- * number of groups we just spread the groups across the nodes.
- */
- if (numgrps <= nodes) {
- for_each_node_mask(n, nodemsk) {
- cpumask_or(&masks[curgrp], &masks[curgrp],
- node_to_cpumask[n]);
- if (++curgrp == last_grp)
- curgrp = 0;
- }
- return numgrps;
- }
-
- node_groups = kcalloc(nr_node_ids,
- sizeof(struct node_groups),
- GFP_KERNEL);
- if (!node_groups)
- return -ENOMEM;
-
- /* allocate group number for each node */
- alloc_nodes_groups(numgrps, node_to_cpumask, cpu_mask,
- nodemsk, nmsk, node_groups);
-
- for (i = 0; i < nr_node_ids; i++) {
- unsigned int ncpus, v;
- struct node_groups *nv = &node_groups[i];
-
- if (nv->ngroups == UINT_MAX)
- continue;
-
- /* Get the cpus on this node which are in the mask */
- cpumask_and(nmsk, cpu_mask, node_to_cpumask[nv->id]);
- ncpus = cpumask_weight(nmsk);
- if (!ncpus)
- continue;
-
- WARN_ON_ONCE(nv->ngroups > ncpus);
-
- /* Account for rounding errors */
- extra_grps = ncpus - nv->ngroups * (ncpus / nv->ngroups);
-
- /* Spread allocated groups on CPUs of the current node */
- for (v = 0; v < nv->ngroups; v++, curgrp++) {
- cpus_per_grp = ncpus / nv->ngroups;
-
- /* Account for extra groups to compensate rounding errors */
- if (extra_grps) {
- cpus_per_grp++;
- --extra_grps;
- }
-
- /*
- * wrapping has to be considered given 'startgrp'
- * may start anywhere
- */
- if (curgrp >= last_grp)
- curgrp = 0;
- grp_spread_init_one(&masks[curgrp], nmsk,
- cpus_per_grp);
- }
- done += nv->ngroups;
- }
- kfree(node_groups);
- return done;
-}
-
-/*
- * build affinity in two stages for each group, and try to put close CPUs
- * in viewpoint of CPU and NUMA locality into same group, and we run
- * two-stage grouping:
- *
- * 1) allocate present CPUs on these groups evenly first
- * 2) allocate other possible CPUs on these groups evenly
- */
-static struct cpumask *group_cpus_evenly(unsigned int numgrps)
-{
- unsigned int curgrp = 0, nr_present = 0, nr_others = 0;
- cpumask_var_t *node_to_cpumask;
- cpumask_var_t nmsk, npresmsk;
- int ret = -ENOMEM;
- struct cpumask *masks = NULL;
-
- if (!zalloc_cpumask_var(&nmsk, GFP_KERNEL))
- return NULL;
-
- if (!zalloc_cpumask_var(&npresmsk, GFP_KERNEL))
- goto fail_nmsk;
-
- node_to_cpumask = alloc_node_to_cpumask();
- if (!node_to_cpumask)
- goto fail_npresmsk;
-
- masks = kcalloc(numgrps, sizeof(*masks), GFP_KERNEL);
- if (!masks)
- goto fail_node_to_cpumask;
-
- /* Stabilize the cpumasks */
- cpus_read_lock();
- build_node_to_cpumask(node_to_cpumask);
-
- /* grouping present CPUs first */
- ret = __group_cpus_evenly(curgrp, numgrps, node_to_cpumask,
- cpu_present_mask, nmsk, masks);
- if (ret < 0)
- goto fail_build_affinity;
- nr_present = ret;
-
- /*
- * Allocate non present CPUs starting from the next group to be
- * handled. If the grouping of present CPUs already exhausted the
- * group space, assign the non present CPUs to the already
- * allocated out groups.
- */
- if (nr_present >= numgrps)
- curgrp = 0;
- else
- curgrp = nr_present;
- cpumask_andnot(npresmsk, cpu_possible_mask, cpu_present_mask);
- ret = __group_cpus_evenly(curgrp, numgrps, node_to_cpumask,
- npresmsk, nmsk, masks);
- if (ret >= 0)
- nr_others = ret;
-
- fail_build_affinity:
- cpus_read_unlock();
-
- if (ret >= 0)
- WARN_ON(nr_present + nr_others < numgrps);
-
- fail_node_to_cpumask:
- free_node_to_cpumask(node_to_cpumask);
-
- fail_npresmsk:
- free_cpumask_var(npresmsk);
-
- fail_nmsk:
- free_cpumask_var(nmsk);
- if (ret < 0) {
- kfree(masks);
- return NULL;
- }
- return masks;
-}
+#include <linux/group_cpus.h>
static void default_calc_sets(struct irq_affinity *affd, unsigned int affvecs)
{
diff --git a/lib/Makefile b/lib/Makefile
index 5efd1b435a37..ff1cbe4958a1 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -338,6 +338,8 @@ obj-$(CONFIG_SBITMAP) += sbitmap.o
obj-$(CONFIG_PARMAN) += parman.o
+obj-$(CONFIG_SMP) += group_cpus.o
+
# GCC library routines
obj-$(CONFIG_GENERIC_LIB_ASHLDI3) += ashldi3.o
obj-$(CONFIG_GENERIC_LIB_ASHRDI3) += ashrdi3.o
diff --git a/lib/group_cpus.c b/lib/group_cpus.c
new file mode 100644
index 000000000000..c36fa67f8671
--- /dev/null
+++ b/lib/group_cpus.c
@@ -0,0 +1,413 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2016 Thomas Gleixner.
+ * Copyright (C) 2016-2017 Christoph Hellwig.
+ */
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/cpu.h>
+#include <linux/sort.h>
+
+static void grp_spread_init_one(struct cpumask *irqmsk, struct cpumask *nmsk,
+ unsigned int cpus_per_grp)
+{
+ const struct cpumask *siblmsk;
+ int cpu, sibl;
+
+ for ( ; cpus_per_grp > 0; ) {
+ cpu = cpumask_first(nmsk);
+
+ /* Should not happen, but I'm too lazy to think about it */
+ if (cpu >= nr_cpu_ids)
+ return;
+
+ cpumask_clear_cpu(cpu, nmsk);
+ cpumask_set_cpu(cpu, irqmsk);
+ cpus_per_grp--;
+
+ /* If the cpu has siblings, use them first */
+ siblmsk = topology_sibling_cpumask(cpu);
+ for (sibl = -1; cpus_per_grp > 0; ) {
+ sibl = cpumask_next(sibl, siblmsk);
+ if (sibl >= nr_cpu_ids)
+ break;
+ if (!cpumask_test_and_clear_cpu(sibl, nmsk))
+ continue;
+ cpumask_set_cpu(sibl, irqmsk);
+ cpus_per_grp--;
+ }
+ }
+}
+
+static cpumask_var_t *alloc_node_to_cpumask(void)
+{
+ cpumask_var_t *masks;
+ int node;
+
+ masks = kcalloc(nr_node_ids, sizeof(cpumask_var_t), GFP_KERNEL);
+ if (!masks)
+ return NULL;
+
+ for (node = 0; node < nr_node_ids; node++) {
+ if (!zalloc_cpumask_var(&masks[node], GFP_KERNEL))
+ goto out_unwind;
+ }
+
+ return masks;
+
+out_unwind:
+ while (--node >= 0)
+ free_cpumask_var(masks[node]);
+ kfree(masks);
+ return NULL;
+}
+
+static void free_node_to_cpumask(cpumask_var_t *masks)
+{
+ int node;
+
+ for (node = 0; node < nr_node_ids; node++)
+ free_cpumask_var(masks[node]);
+ kfree(masks);
+}
+
+static void build_node_to_cpumask(cpumask_var_t *masks)
+{
+ int cpu;
+
+ for_each_possible_cpu(cpu)
+ cpumask_set_cpu(cpu, masks[cpu_to_node(cpu)]);
+}
+
+static int get_nodes_in_cpumask(cpumask_var_t *node_to_cpumask,
+ const struct cpumask *mask, nodemask_t *nodemsk)
+{
+ int n, nodes = 0;
+
+ /* Calculate the number of nodes in the supplied affinity mask */
+ for_each_node(n) {
+ if (cpumask_intersects(mask, node_to_cpumask[n])) {
+ node_set(n, *nodemsk);
+ nodes++;
+ }
+ }
+ return nodes;
+}
+
+struct node_groups {
+ unsigned id;
+
+ union {
+ unsigned ngroups;
+ unsigned ncpus;
+ };
+};
+
+static int ncpus_cmp_func(const void *l, const void *r)
+{
+ const struct node_groups *ln = l;
+ const struct node_groups *rn = r;
+
+ return ln->ncpus - rn->ncpus;
+}
+
+/*
+ * Allocate group number for each node, so that for each node:
+ *
+ * 1) the allocated number is >= 1
+ *
+ * 2) the allocated number is <= active CPU number of this node
+ *
+ * The actual allocated total groups may be less than @numgrps when
+ * active total CPU number is less than @numgrps.
+ *
+ * Active CPUs means the CPUs in '@cpu_mask AND @node_to_cpumask[]'
+ * for each node.
+ */
+static void alloc_nodes_groups(unsigned int numgrps,
+ cpumask_var_t *node_to_cpumask,
+ const struct cpumask *cpu_mask,
+ const nodemask_t nodemsk,
+ struct cpumask *nmsk,
+ struct node_groups *node_groups)
+{
+ unsigned n, remaining_ncpus = 0;
+
+ for (n = 0; n < nr_node_ids; n++) {
+ node_groups[n].id = n;
+ node_groups[n].ncpus = UINT_MAX;
+ }
+
+ for_each_node_mask(n, nodemsk) {
+ unsigned ncpus;
+
+ cpumask_and(nmsk, cpu_mask, node_to_cpumask[n]);
+ ncpus = cpumask_weight(nmsk);
+
+ if (!ncpus)
+ continue;
+ remaining_ncpus += ncpus;
+ node_groups[n].ncpus = ncpus;
+ }
+
+ numgrps = min_t(unsigned, remaining_ncpus, numgrps);
+
+ sort(node_groups, nr_node_ids, sizeof(node_groups[0]),
+ ncpus_cmp_func, NULL);
+
+ /*
+ * Allocate groups for each node according to the ratio of this
+ * node's nr_cpus to remaining un-assigned ncpus. 'numgrps' is
+ * bigger than number of active numa nodes. Always start the
+ * allocation from the node with minimized nr_cpus.
+ *
+ * This way guarantees that each active node gets allocated at
+ * least one group, and the theory is simple: over-allocation
+ * is only done when this node is assigned by one group, so
+ * other nodes will be allocated >= 1 groups, since 'numgrps' is
+ * bigger than number of numa nodes.
+ *
+ * One perfect invariant is that number of allocated groups for
+ * each node is <= CPU count of this node:
+ *
+ * 1) suppose there are two nodes: A and B
+ * ncpu(X) is CPU count of node X
+ * grps(X) is the group count allocated to node X via this
+ * algorithm
+ *
+ * ncpu(A) <= ncpu(B)
+ * ncpu(A) + ncpu(B) = N
+ * grps(A) + grps(B) = G
+ *
+ * grps(A) = max(1, round_down(G * ncpu(A) / N))
+ * grps(B) = G - grps(A)
+ *
+ * both N and G are integer, and 2 <= G <= N, suppose
+ * G = N - delta, and 0 <= delta <= N - 2
+ *
+ * 2) obviously grps(A) <= ncpu(A) because:
+ *
+ * if grps(A) is 1, then grps(A) <= ncpu(A) given
+ * ncpu(A) >= 1
+ *
+ * otherwise,
+ * grps(A) <= G * ncpu(A) / N <= ncpu(A), given G <= N
+ *
+ * 3) prove how grps(B) <= ncpu(B):
+ *
+ * if round_down(G * ncpu(A) / N) == 0, vecs(B) won't be
+ * over-allocated, so grps(B) <= ncpu(B),
+ *
+ * otherwise:
+ *
+ * grps(A) =
+ * round_down(G * ncpu(A) / N) =
+ * round_down((N - delta) * ncpu(A) / N) =
+ * round_down((N * ncpu(A) - delta * ncpu(A)) / N) >=
+ * round_down((N * ncpu(A) - delta * N) / N) =
+ * cpu(A) - delta
+ *
+ * then:
+ *
+ * grps(A) - G >= ncpu(A) - delta - G
+ * =>
+ * G - grps(A) <= G + delta - ncpu(A)
+ * =>
+ * grps(B) <= N - ncpu(A)
+ * =>
+ * grps(B) <= cpu(B)
+ *
+ * For nodes >= 3, it can be thought as one node and another big
+ * node given that is exactly what this algorithm is implemented,
+ * and we always re-calculate 'remaining_ncpus' & 'numgrps', and
+ * finally for each node X: grps(X) <= ncpu(X).
+ *
+ */
+ for (n = 0; n < nr_node_ids; n++) {
+ unsigned ngroups, ncpus;
+
+ if (node_groups[n].ncpus == UINT_MAX)
+ continue;
+
+ WARN_ON_ONCE(numgrps == 0);
+
+ ncpus = node_groups[n].ncpus;
+ ngroups = max_t(unsigned, 1,
+ numgrps * ncpus / remaining_ncpus);
+ WARN_ON_ONCE(ngroups > ncpus);
+
+ node_groups[n].ngroups = ngroups;
+
+ remaining_ncpus -= ncpus;
+ numgrps -= ngroups;
+ }
+}
+
+static int __group_cpus_evenly(unsigned int startgrp, unsigned int numgrps,
+ cpumask_var_t *node_to_cpumask,
+ const struct cpumask *cpu_mask,
+ struct cpumask *nmsk, struct cpumask *masks)
+{
+ unsigned int i, n, nodes, cpus_per_grp, extra_grps, done = 0;
+ unsigned int last_grp = numgrps;
+ unsigned int curgrp = startgrp;
+ nodemask_t nodemsk = NODE_MASK_NONE;
+ struct node_groups *node_groups;
+
+ if (!cpumask_weight(cpu_mask))
+ return 0;
+
+ nodes = get_nodes_in_cpumask(node_to_cpumask, cpu_mask, &nodemsk);
+
+ /*
+ * If the number of nodes in the mask is greater than or equal the
+ * number of groups we just spread the groups across the nodes.
+ */
+ if (numgrps <= nodes) {
+ for_each_node_mask(n, nodemsk) {
+ cpumask_or(&masks[curgrp], &masks[curgrp],
+ node_to_cpumask[n]);
+ if (++curgrp == last_grp)
+ curgrp = 0;
+ }
+ return numgrps;
+ }
+
+ node_groups = kcalloc(nr_node_ids,
+ sizeof(struct node_groups),
+ GFP_KERNEL);
+ if (!node_groups)
+ return -ENOMEM;
+
+ /* allocate group number for each node */
+ alloc_nodes_groups(numgrps, node_to_cpumask, cpu_mask,
+ nodemsk, nmsk, node_groups);
+
+ for (i = 0; i < nr_node_ids; i++) {
+ unsigned int ncpus, v;
+ struct node_groups *nv = &node_groups[i];
+
+ if (nv->ngroups == UINT_MAX)
+ continue;
+
+ /* Get the cpus on this node which are in the mask */
+ cpumask_and(nmsk, cpu_mask, node_to_cpumask[nv->id]);
+ ncpus = cpumask_weight(nmsk);
+ if (!ncpus)
+ continue;
+
+ WARN_ON_ONCE(nv->ngroups > ncpus);
+
+ /* Account for rounding errors */
+ extra_grps = ncpus - nv->ngroups * (ncpus / nv->ngroups);
+
+ /* Spread allocated groups on CPUs of the current node */
+ for (v = 0; v < nv->ngroups; v++, curgrp++) {
+ cpus_per_grp = ncpus / nv->ngroups;
+
+ /* Account for extra groups to compensate rounding errors */
+ if (extra_grps) {
+ cpus_per_grp++;
+ --extra_grps;
+ }
+
+ /*
+ * wrapping has to be considered given 'startgrp'
+ * may start anywhere
+ */
+ if (curgrp >= last_grp)
+ curgrp = 0;
+ grp_spread_init_one(&masks[curgrp], nmsk,
+ cpus_per_grp);
+ }
+ done += nv->ngroups;
+ }
+ kfree(node_groups);
+ return done;
+}
+
+/**
+ * group_cpus_evenly - Group all CPUs evenly per NUMA/CPU locality
+ * @numgrps: number of groups
+ *
+ * Return: cpumask array if successful, NULL otherwise. And each element
+ * includes CPUs assigned to this group
+ *
+ * Try to put close CPUs from viewpoint of CPU and NUMA locality into
+ * same group, and run two-stage grouping:
+ * 1) allocate present CPUs on these groups evenly first
+ * 2) allocate other possible CPUs on these groups evenly
+ *
+ * We guarantee in the resulted grouping that all CPUs are covered, and
+ * no same CPU is assigned to different groups
+ */
+struct cpumask *group_cpus_evenly(unsigned int numgrps)
+{
+ unsigned int curgrp = 0, nr_present = 0, nr_others = 0;
+ cpumask_var_t *node_to_cpumask;
+ cpumask_var_t nmsk, npresmsk;
+ int ret = -ENOMEM;
+ struct cpumask *masks = NULL;
+
+ if (!zalloc_cpumask_var(&nmsk, GFP_KERNEL))
+ return NULL;
+
+ if (!zalloc_cpumask_var(&npresmsk, GFP_KERNEL))
+ goto fail_nmsk;
+
+ node_to_cpumask = alloc_node_to_cpumask();
+ if (!node_to_cpumask)
+ goto fail_npresmsk;
+
+ masks = kcalloc(numgrps, sizeof(*masks), GFP_KERNEL);
+ if (!masks)
+ goto fail_node_to_cpumask;
+
+ /* Stabilize the cpumasks */
+ cpus_read_lock();
+ build_node_to_cpumask(node_to_cpumask);
+
+ /* grouping present CPUs first */
+ ret = __group_cpus_evenly(curgrp, numgrps, node_to_cpumask,
+ cpu_present_mask, nmsk, masks);
+ if (ret < 0)
+ goto fail_build_affinity;
+ nr_present = ret;
+
+ /*
+ * Allocate non present CPUs starting from the next group to be
+ * handled. If the grouping of present CPUs already exhausted the
+ * group space, assign the non present CPUs to the already
+ * allocated out groups.
+ */
+ if (nr_present >= numgrps)
+ curgrp = 0;
+ else
+ curgrp = nr_present;
+ cpumask_andnot(npresmsk, cpu_possible_mask, cpu_present_mask);
+ ret = __group_cpus_evenly(curgrp, numgrps, node_to_cpumask,
+ npresmsk, nmsk, masks);
+ if (ret >= 0)
+ nr_others = ret;
+
+ fail_build_affinity:
+ cpus_read_unlock();
+
+ if (ret >= 0)
+ WARN_ON(nr_present + nr_others < numgrps);
+
+ fail_node_to_cpumask:
+ free_node_to_cpumask(node_to_cpumask);
+
+ fail_npresmsk:
+ free_cpumask_var(npresmsk);
+
+ fail_nmsk:
+ free_cpumask_var(nmsk);
+ if (ret < 0) {
+ kfree(masks);
+ return NULL;
+ }
+ return masks;
+}
+EXPORT_SYMBOL_GPL(group_cpus_evenly);
--
2.31.1
^ permalink raw reply related [flat|nested] 12+ messages in thread
end of thread, other threads:[~2021-08-17 4:52 UTC | newest]
Thread overview: 12+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-08-15 1:49 [PATCH 5/7] genirq/affinity: move group_cpus_evenly() into lib/ kernel test robot
2021-08-16 10:08 ` kernel test robot
2021-08-16 10:08 ` kernel test robot
-- strict thread matches above, loose matches on Subject: below --
2021-08-14 12:35 [PATCH 0/7] genirq/affinity: abstract new API from managed irq affinity spread Ming Lei
2021-08-14 12:35 ` [PATCH 5/7] genirq/affinity: move group_cpus_evenly() into lib/ Ming Lei
2021-08-14 17:01 ` kernel test robot
2021-08-14 17:01 ` kernel test robot
2021-08-16 1:04 ` Ming Lei
2021-08-16 1:04 ` Ming Lei
2021-08-17 4:52 ` Christoph Hellwig
2021-08-17 4:52 ` Christoph Hellwig
2021-08-14 17:15 ` kernel test robot
2021-08-14 17:15 ` kernel test robot
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