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authorJens Axboe <axboe@kernel.dk>2019-11-07 12:27:19 -0700
committerJens Axboe <axboe@kernel.dk>2019-11-07 12:27:19 -0700
commit912c0a85911a6364ac127b6e1de8c2c7782db1bc (patch)
treef9092380a9688cf422c337802e8c51657851297c /kernel/stop_machine.c
parente876df1fe0ad1b191284ee6ed2db7960bd322d00 (diff)
parentb0814361a25cba73a224548843ed92d8ea78715a (diff)
Merge branch 'for-linus' into for-5.5/block
Pull on for-linus to resolve what otherwise would have been a conflict with the cgroups rstat patchset from Tejun. * for-linus: (942 commits) blkcg: make blkcg_print_stat() print stats only for online blkgs nvme: change nvme_passthru_cmd64 to explicitly mark rsvd nvme-multipath: fix crash in nvme_mpath_clear_ctrl_paths nvme-rdma: fix a segmentation fault during module unload iocost: don't nest spin_lock_irq in ioc_weight_write() io_uring: ensure we clear io_kiocb->result before each issue um-ubd: Entrust re-queue to the upper layers nvme-multipath: remove unused groups_only mode in ana log nvme-multipath: fix possible io hang after ctrl reconnect io_uring: don't touch ctx in setup after ring fd install io_uring: Fix leaked shadow_req Linux 5.4-rc5 riscv: cleanup do_trap_break nbd: verify socket is supported during setup ata: libahci_platform: Fix regulator_get_optional() misuse nbd: handle racing with error'ed out commands nbd: protect cmd->status with cmd->lock io_uring: fix bad inflight accounting for SETUP_IOPOLL|SETUP_SQTHREAD io_uring: used cached copies of sq->dropped and cq->overflow ARM: dts: stm32: relax qspi pins slew-rate for stm32mp157 ...
Diffstat (limited to 'kernel/stop_machine.c')
-rw-r--r--kernel/stop_machine.c10
1 files changed, 6 insertions, 4 deletions
diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c
index c7031a22aa7b..998d50ee2d9b 100644
--- a/kernel/stop_machine.c
+++ b/kernel/stop_machine.c
@@ -7,6 +7,7 @@
* Copyright (C) 2010 SUSE Linux Products GmbH
* Copyright (C) 2010 Tejun Heo <tj@kernel.org>
*/
+#include <linux/compiler.h>
#include <linux/completion.h>
#include <linux/cpu.h>
#include <linux/init.h>
@@ -167,7 +168,7 @@ static void set_state(struct multi_stop_data *msdata,
/* Reset ack counter. */
atomic_set(&msdata->thread_ack, msdata->num_threads);
smp_wmb();
- msdata->state = newstate;
+ WRITE_ONCE(msdata->state, newstate);
}
/* Last one to ack a state moves to the next state. */
@@ -186,7 +187,7 @@ void __weak stop_machine_yield(const struct cpumask *cpumask)
static int multi_cpu_stop(void *data)
{
struct multi_stop_data *msdata = data;
- enum multi_stop_state curstate = MULTI_STOP_NONE;
+ enum multi_stop_state newstate, curstate = MULTI_STOP_NONE;
int cpu = smp_processor_id(), err = 0;
const struct cpumask *cpumask;
unsigned long flags;
@@ -210,8 +211,9 @@ static int multi_cpu_stop(void *data)
do {
/* Chill out and ensure we re-read multi_stop_state. */
stop_machine_yield(cpumask);
- if (msdata->state != curstate) {
- curstate = msdata->state;
+ newstate = READ_ONCE(msdata->state);
+ if (newstate != curstate) {
+ curstate = newstate;
switch (curstate) {
case MULTI_STOP_DISABLE_IRQ:
local_irq_disable();