Re: scsi-mq V2

From: Benjamin LaHaise
Date: Fri Jul 11 2014 - 10:55:30 EST

On Fri, Jul 11, 2014 at 02:33:12PM +0000, Elliott, Robert (Server Storage) wrote:
> That ran 9 total hours with no problem.
> Rather than revert in the bisect trees, I added just this single additional
> patch to the no-rebase tree, and the problem appeared:

Can you try the below totally untested patch instead? It looks like
put_reqs_available() is not irq-safe.

"Thought is the essence of where you are now."

diff --git a/fs/aio.c b/fs/aio.c
index 955947e..4b97180 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -830,16 +830,20 @@ void exit_aio(struct mm_struct *mm)
static void put_reqs_available(struct kioctx *ctx, unsigned nr)
struct kioctx_cpu *kcpu;
+ unsigned long flags;

kcpu = this_cpu_ptr(ctx->cpu);

+ local_irq_save(flags);
kcpu->reqs_available += nr;
while (kcpu->reqs_available >= ctx->req_batch * 2) {
kcpu->reqs_available -= ctx->req_batch;
atomic_add(ctx->req_batch, &ctx->reqs_available);

+ local_irq_restore(flags);

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at
Please read the FAQ at