diff options
| author | Jens Axboe <axboe@kernel.dk> | 2013-05-17 09:58:43 +0200 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2013-10-25 12:55:59 +0200 |
| commit | c84a83e2aaab02a5ca64a982aa55342784934479 (patch) | |
| tree | 405880cd8121ba0fb1905549cc992071d27c6ca4 | |
| parent | smp: export __smp_call_function_single() (diff) | |
| download | linux-c84a83e2aaab02a5ca64a982aa55342784934479.tar.xz linux-c84a83e2aaab02a5ca64a982aa55342784934479.zip | |
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: Jens Axboe <axboe@kernel.dk>
| -rw-r--r-- | kernel/smp.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/kernel/smp.c b/kernel/smp.c index 46d3d0b48a8d..dbc3d42d2c68 100644 --- a/kernel/smp.c +++ b/kernel/smp.c @@ -18,6 +18,7 @@ #ifdef CONFIG_USE_GENERIC_SMP_HELPERS enum { CSD_FLAG_LOCK = 0x01, + CSD_FLAG_WAIT = 0x02, }; struct call_function_data { @@ -124,7 +125,7 @@ static void csd_lock(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: @@ -146,6 +147,9 @@ void generic_exec_single(int cpu, struct call_single_data *csd, int wait) unsigned long flags; int ipi; + if (wait) + csd->flags |= CSD_FLAG_WAIT; + raw_spin_lock_irqsave(&dst->lock, flags); ipi = list_empty(&dst->list); list_add_tail(&csd->list, &dst->list); |