Commit c84a83e2 authored by Jens Axboe's avatar Jens Axboe

smp: don't warn about csd->flags having CSD_FLAG_LOCK cleared for !wait

blk-mq reuses the request potentially immediately, since the most
cache hot is always given out first. This means that rq->csd could
be reused between csd->func() being called and csd_unlock() being
called. This isn't a problem, since we never use wait == 1 for
the smp call function. Add CSD_FLAG_WAIT to be able to tell the
difference, retaining the warning for other cases.

Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent e3daab6c
...@@ -18,6 +18,7 @@ ...@@ -18,6 +18,7 @@
#ifdef CONFIG_USE_GENERIC_SMP_HELPERS #ifdef CONFIG_USE_GENERIC_SMP_HELPERS
enum { enum {
CSD_FLAG_LOCK = 0x01, CSD_FLAG_LOCK = 0x01,
CSD_FLAG_WAIT = 0x02,
}; };
struct call_function_data { struct call_function_data {
...@@ -124,7 +125,7 @@ static void csd_lock(struct call_single_data *csd) ...@@ -124,7 +125,7 @@ static void csd_lock(struct call_single_data *csd)
static void csd_unlock(struct call_single_data *csd) static void csd_unlock(struct call_single_data *csd)
{ {
WARN_ON(!(csd->flags & CSD_FLAG_LOCK)); WARN_ON((csd->flags & CSD_FLAG_WAIT) && !(csd->flags & CSD_FLAG_LOCK));
/* /*
* ensure we're all done before releasing data: * ensure we're all done before releasing data:
...@@ -146,6 +147,9 @@ void generic_exec_single(int cpu, struct call_single_data *csd, int wait) ...@@ -146,6 +147,9 @@ void generic_exec_single(int cpu, struct call_single_data *csd, int wait)
unsigned long flags; unsigned long flags;
int ipi; int ipi;
if (wait)
csd->flags |= CSD_FLAG_WAIT;
raw_spin_lock_irqsave(&dst->lock, flags); raw_spin_lock_irqsave(&dst->lock, flags);
ipi = list_empty(&dst->list); ipi = list_empty(&dst->list);
list_add_tail(&csd->list, &dst->list); list_add_tail(&csd->list, &dst->list);
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment