RE: scsi-mq V2

[Elliott, Robert (Server Storage)]

> -----Original Message-----
> From: Christoph Hellwig [mailto:hch@xxxxxxxxxxxxx]
> Sent: Friday, 11 July, 2014 1:15 AM
> To: Elliott, Robert (Server Storage)
> Cc: Jeff Moyer; Christoph Hellwig; Jens Axboe; dgilbert@xxxxxxxxxxxx; James
> Bottomley; Bart Van Assche; Benjamin LaHaise; linux-scsi@xxxxxxxxxxxxxxx;
> linux-kernel@xxxxxxxxxxxxxxx
> Subject: Re: scsi-mq V2
> 
> On Fri, Jul 11, 2014 at 06:02:03AM +0000, Elliott, Robert (Server Storage)
> wrote:
> > Allowing longer run times before declaring success, the problem
> > does appear in all of the bisect trees.  I just let fio
> > continue to run for many minutes - no ^Cs necessary.
> >
> > no-rebase: good for > 45 minutes (I will leave that running for
> >   8 more hours)
> 
> Ok, thanks.  If it's still running tomorrow morning let's look into the
> aio reverts again.

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:


48a2e94154177286b3bcbed25ea802232527fa7c
aio: fix aio request leak when events are reaped by userspace

diff --git a/fs/aio.c b/fs/aio.c
index 4f078c0..e59bba8 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -1021,6 +1021,7 @@ void aio_complete(struct kiocb *iocb, long res, long res2)

        /* everything turned out well, dispose of the aiocb. */
        kiocb_free(iocb);
+       put_reqs_available(ctx, 1);     /* added by patch f8567 */

        /*
         * We have to order our ring_info tail store above and test
@@ -1101,7 +1102,7 @@ static long aio_read_events_ring(struct kioctx *ctx,

        pr_debug("%li  h%u t%u\n", ret, head, tail);

-       put_reqs_available(ctx, ret);
+       /* put_reqs_available(ctx, ret); removed by patch f8567 */
 out:
        mutex_unlock(&ctx->ring_lock);


---
Rob Elliott    HP Server Storage



--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/