From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
stable@vger.kernel.org, Mathias Krause <minipli@googlemail.com>,
Herbert Xu <herbert@gondor.apana.org.au>,
Ben Hutchings <ben@decadent.org.uk>
Subject: [PATCH 4.4 05/65] padata: ensure padata_do_serial() runs on the correct CPU
Date: Tue, 26 May 2020 20:52:24 +0200 [thread overview]
Message-ID: <20200526183908.131959919@linuxfoundation.org> (raw)
In-Reply-To: <20200526183905.988782958@linuxfoundation.org>
From: Mathias Krause <minipli@googlemail.com>
commit 350ef88e7e922354f82a931897ad4a4ce6c686ff upstream.
If the algorithm we're parallelizing is asynchronous we might change
CPUs between padata_do_parallel() and padata_do_serial(). However, we
don't expect this to happen as we need to enqueue the padata object into
the per-cpu reorder queue we took it from, i.e. the same-cpu's parallel
queue.
Ensure we're not switching CPUs for a given padata object by tracking
the CPU within the padata object. If the serial callback gets called on
the wrong CPU, defer invoking padata_reorder() via a kernel worker on
the CPU we're expected to run on.
Signed-off-by: Mathias Krause <minipli@googlemail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
include/linux/padata.h | 2 ++
kernel/padata.c | 20 +++++++++++++++++++-
2 files changed, 21 insertions(+), 1 deletion(-)
--- a/include/linux/padata.h
+++ b/include/linux/padata.h
@@ -37,6 +37,7 @@
* @list: List entry, to attach to the padata lists.
* @pd: Pointer to the internal control structure.
* @cb_cpu: Callback cpu for serializatioon.
+ * @cpu: Cpu for parallelization.
* @seq_nr: Sequence number of the parallelized data object.
* @info: Used to pass information from the parallel to the serial function.
* @parallel: Parallel execution function.
@@ -46,6 +47,7 @@ struct padata_priv {
struct list_head list;
struct parallel_data *pd;
int cb_cpu;
+ int cpu;
int info;
void (*parallel)(struct padata_priv *padata);
void (*serial)(struct padata_priv *padata);
--- a/kernel/padata.c
+++ b/kernel/padata.c
@@ -132,6 +132,7 @@ int padata_do_parallel(struct padata_ins
padata->cb_cpu = cb_cpu;
target_cpu = padata_cpu_hash(pd);
+ padata->cpu = target_cpu;
queue = per_cpu_ptr(pd->pqueue, target_cpu);
spin_lock(&queue->parallel.lock);
@@ -375,10 +376,21 @@ void padata_do_serial(struct padata_priv
int cpu;
struct padata_parallel_queue *pqueue;
struct parallel_data *pd;
+ int reorder_via_wq = 0;
pd = padata->pd;
cpu = get_cpu();
+
+ /* We need to run on the same CPU padata_do_parallel(.., padata, ..)
+ * was called on -- or, at least, enqueue the padata object into the
+ * correct per-cpu queue.
+ */
+ if (cpu != padata->cpu) {
+ reorder_via_wq = 1;
+ cpu = padata->cpu;
+ }
+
pqueue = per_cpu_ptr(pd->pqueue, cpu);
spin_lock(&pqueue->reorder.lock);
@@ -395,7 +407,13 @@ void padata_do_serial(struct padata_priv
put_cpu();
- padata_reorder(pd);
+ /* If we're running on the wrong CPU, call padata_reorder() via a
+ * kernel worker.
+ */
+ if (reorder_via_wq)
+ queue_work_on(cpu, pd->pinst->wq, &pqueue->reorder_work);
+ else
+ padata_reorder(pd);
}
EXPORT_SYMBOL(padata_do_serial);
next prev parent reply other threads:[~2020-05-26 18:56 UTC|newest]
Thread overview: 74+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-26 18:52 [PATCH 4.4 00/65] 4.4.225-rc1 review Greg Kroah-Hartman
2020-05-26 18:52 ` [PATCH 4.4 01/65] igb: use igb_adapter->io_addr instead of e1000_hw->hw_addr Greg Kroah-Hartman
2020-05-26 18:52 ` [PATCH 4.4 02/65] padata: Remove unused but set variables Greg Kroah-Hartman
2020-05-26 18:52 ` [PATCH 4.4 03/65] padata: get_next is never NULL Greg Kroah-Hartman
2020-05-26 18:52 ` [PATCH 4.4 04/65] padata: ensure the reorder timer callback runs on the correct CPU Greg Kroah-Hartman
2020-05-26 18:52 ` Greg Kroah-Hartman [this message]
2020-05-26 18:52 ` [PATCH 4.4 06/65] evm: Check also if *tfm is an error pointer in init_desc() Greg Kroah-Hartman
2020-05-26 18:52 ` [PATCH 4.4 07/65] fix multiplication overflow in copy_fdtable() Greg Kroah-Hartman
2020-05-26 18:52 ` [PATCH 4.4 08/65] HID: multitouch: add eGalaxTouch P80H84 support Greg Kroah-Hartman
2020-05-26 18:52 ` [PATCH 4.4 09/65] ceph: fix double unlock in handle_cap_export() Greg Kroah-Hartman
2020-05-26 18:52 ` [PATCH 4.4 10/65] USB: core: Fix misleading driver bug report Greg Kroah-Hartman
2020-05-26 18:52 ` [PATCH 4.4 11/65] platform/x86: asus-nb-wmi: Do not load on Asus T100TA and T200TA Greg Kroah-Hartman
2020-05-26 18:52 ` [PATCH 4.4 12/65] ARM: futex: Address build warning Greg Kroah-Hartman
2020-05-26 18:52 ` [PATCH 4.4 13/65] media: Fix media_open() to clear filp->private_data in error leg Greg Kroah-Hartman
2020-05-26 18:52 ` [PATCH 4.4 14/65] drivers/media/media-devnode: clear private_data before put_device() Greg Kroah-Hartman
2020-05-26 18:52 ` [PATCH 4.4 15/65] media-devnode: add missing mutex lock in error handler Greg Kroah-Hartman
2020-05-26 18:52 ` [PATCH 4.4 16/65] media-devnode: fix namespace mess Greg Kroah-Hartman
2020-05-26 18:52 ` [PATCH 4.4 17/65] media-device: dynamically allocate struct media_devnode Greg Kroah-Hartman
2020-05-26 18:52 ` [PATCH 4.4 18/65] media: fix use-after-free in cdev_put() when app exits after driver unbind Greg Kroah-Hartman
2020-05-26 18:52 ` [PATCH 4.4 19/65] media: fix media devnode ioctl/syscall and unregister race Greg Kroah-Hartman
2020-05-26 18:52 ` [PATCH 4.4 20/65] i2c: dev: switch from register_chrdev to cdev API Greg Kroah-Hartman
2020-05-26 18:52 ` [PATCH 4.4 21/65] i2c: dev: dont start function name with return Greg Kroah-Hartman
2020-05-26 18:52 ` [PATCH 4.4 22/65] i2c: dev: use after free in detach Greg Kroah-Hartman
2020-05-26 18:52 ` [PATCH 4.4 23/65] i2c-dev: dont get i2c adapter via i2c_dev Greg Kroah-Hartman
2020-05-26 18:52 ` [PATCH 4.4 24/65] i2c: dev: Fix the race between the release of i2c_dev and cdev Greg Kroah-Hartman
2020-05-26 18:52 ` [PATCH 4.4 25/65] padata: set cpu_index of unused CPUs to -1 Greg Kroah-Hartman
2020-05-26 18:52 ` [PATCH 4.4 26/65] sched/fair, cpumask: Export for_each_cpu_wrap() Greg Kroah-Hartman
2020-05-27 7:50 ` nobuhiro1.iwamatsu
2020-05-27 8:09 ` Greg KH
2020-05-27 14:03 ` Daniel Jordan
2020-05-26 18:52 ` [PATCH 4.4 27/65] padata: Replace delayed timer with immediate workqueue in padata_reorder Greg Kroah-Hartman
2020-05-26 18:52 ` [PATCH 4.4 28/65] padata: initialize pd->cpu with effective cpumask Greg Kroah-Hartman
2020-05-26 18:52 ` [PATCH 4.4 29/65] padata: purge get_cpu and reorder_via_wq from padata_do_serial Greg Kroah-Hartman
2020-05-26 18:52 ` [PATCH 4.4 30/65] ALSA: pcm: fix incorrect hw_base increase Greg Kroah-Hartman
2020-05-26 18:52 ` [PATCH 4.4 31/65] ext4: lock the xattr block before checksuming it Greg Kroah-Hartman
2020-05-26 18:52 ` [PATCH 4.4 32/65] platform/x86: alienware-wmi: fix kfree on potentially uninitialized pointer Greg Kroah-Hartman
2020-05-26 18:52 ` [PATCH 4.4 33/65] libnvdimm/btt: Remove unnecessary code in btt_freelist_init Greg Kroah-Hartman
2020-05-26 18:52 ` [PATCH 4.4 34/65] l2tp: lock socket before checking flags in connect() Greg Kroah-Hartman
2020-05-26 18:52 ` [PATCH 4.4 35/65] l2tp: fix racy socket lookup in l2tp_ip and l2tp_ip6 bind() Greg Kroah-Hartman
2020-05-26 18:52 ` [PATCH 4.4 36/65] l2tp: hold session while sending creation notifications Greg Kroah-Hartman
2020-05-26 18:52 ` [PATCH 4.4 37/65] l2tp: take a reference on sessions used in genetlink handlers Greg Kroah-Hartman
2020-05-26 18:52 ` [PATCH 4.4 38/65] l2tp: dont use l2tp_tunnel_find() in l2tp_ip and l2tp_ip6 Greg Kroah-Hartman
2020-05-26 18:52 ` [PATCH 4.4 39/65] net: l2tp: export debug flags to UAPI Greg Kroah-Hartman
2020-05-26 18:52 ` [PATCH 4.4 40/65] net: l2tp: deprecate PPPOL2TP_MSG_* in favour of L2TP_MSG_* Greg Kroah-Hartman
2020-05-26 18:53 ` [PATCH 4.4 41/65] net: l2tp: ppp: change PPPOL2TP_MSG_* => L2TP_MSG_* Greg Kroah-Hartman
2020-05-26 18:53 ` [PATCH 4.4 42/65] New kernel function to get IP overhead on a socket Greg Kroah-Hartman
2020-05-26 18:53 ` [PATCH 4.4 43/65] L2TP:Adjust intf MTU, add underlay L3, L2 hdrs Greg Kroah-Hartman
2020-05-26 18:53 ` [PATCH 4.4 44/65] l2tp: remove useless duplicate session detection in l2tp_netlink Greg Kroah-Hartman
2020-05-26 18:53 ` [PATCH 4.4 45/65] l2tp: remove l2tp_session_find() Greg Kroah-Hartman
2020-05-26 18:53 ` [PATCH 4.4 46/65] l2tp: define parameters of l2tp_session_get*() as "const" Greg Kroah-Hartman
2020-05-26 18:53 ` [PATCH 4.4 47/65] l2tp: define parameters of l2tp_tunnel_find*() " Greg Kroah-Hartman
2020-05-26 18:53 ` [PATCH 4.4 48/65] l2tp: initialise sessions refcount before making it reachable Greg Kroah-Hartman
2020-05-26 18:53 ` [PATCH 4.4 49/65] l2tp: hold tunnel while looking up sessions in l2tp_netlink Greg Kroah-Hartman
2020-05-26 18:53 ` [PATCH 4.4 50/65] l2tp: hold tunnel while processing genl delete command Greg Kroah-Hartman
2020-05-26 18:53 ` [PATCH 4.4 51/65] l2tp: hold tunnel while handling genl tunnel updates Greg Kroah-Hartman
2020-05-26 18:53 ` [PATCH 4.4 52/65] l2tp: hold tunnel while handling genl TUNNEL_GET commands Greg Kroah-Hartman
2020-05-26 18:53 ` [PATCH 4.4 53/65] l2tp: hold tunnel used while creating sessions with netlink Greg Kroah-Hartman
2020-05-26 18:53 ` [PATCH 4.4 54/65] l2tp: prevent creation of sessions on terminated tunnels Greg Kroah-Hartman
2020-05-26 18:53 ` [PATCH 4.4 55/65] l2tp: pass tunnel pointer to ->session_create() Greg Kroah-Hartman
2020-05-26 18:53 ` [PATCH 4.4 56/65] l2tp: fix l2tp_eth module loading Greg Kroah-Hartman
2020-05-26 18:53 ` [PATCH 4.4 57/65] l2tp: dont register sessions in l2tp_session_create() Greg Kroah-Hartman
2020-05-26 18:53 ` [PATCH 4.4 58/65] l2tp: initialise l2tp_eth sessions before registering them Greg Kroah-Hartman
2020-05-26 18:53 ` [PATCH 4.4 59/65] l2tp: protect sock pointer of struct pppol2tp_session with RCU Greg Kroah-Hartman
2020-05-26 18:53 ` [PATCH 4.4 60/65] l2tp: initialise PPP sessions before registering them Greg Kroah-Hartman
2020-05-26 18:53 ` [PATCH 4.4 61/65] Revert "gfs2: Dont demote a glock until its revokes are written" Greg Kroah-Hartman
2020-05-26 18:53 ` [PATCH 4.4 62/65] staging: iio: ad2s1210: Fix SPI reading Greg Kroah-Hartman
2020-05-26 18:53 ` [PATCH 4.4 63/65] mei: release me_cl object reference Greg Kroah-Hartman
2020-05-26 18:53 ` [PATCH 4.4 64/65] iio: sca3000: Remove an erroneous get_device() Greg Kroah-Hartman
2020-05-26 18:53 ` [PATCH 4.4 65/65] l2tp: device MTU setup, tunnel socket needs a lock Greg Kroah-Hartman
2020-05-27 8:32 ` [PATCH 4.4 00/65] 4.4.225-rc1 review Jon Hunter
2020-05-27 8:52 ` Naresh Kamboju
2020-05-27 10:30 ` Chris Paterson
2020-05-27 13:50 ` Guenter Roeck
2020-05-27 17:16 ` shuah
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