RE: Drivers: scsi: FLUSH timeout

From: KY Srinivasan
Date: Fri Oct 04 2013 - 11:02:44 EST




> -----Original Message-----
> From: Eric Seppanen [mailto:eric@xxxxxxxxxxxxxxx]
> Sent: Thursday, October 03, 2013 1:49 PM
> To: Nicholas A. Bellinger
> Cc: KY Srinivasan; linux-kernel@xxxxxxxxxxxxxxx; devel@xxxxxxxxxxxxxxxxxxxxxx;
> linux-scsi@xxxxxxxxxxxxxxx
> Subject: Re: Drivers: scsi: FLUSH timeout
>
> On Thu, Oct 3, 2013 at 5:09 AM, Nicholas A. Bellinger
> <nab@xxxxxxxxxxxxxxx> wrote:
> >
> > On Wed, 2013-10-02 at 18:29 +0000, KY Srinivasan wrote:
> > > Ideally, I want this to be adjustable like the way we can change the I/O
> timeout.
> > > Since that has been attempted earlier and rejected (not clear what the
> reasons were),
> > > I was suggesting that we pick a larger number. James, let me know how I
> should proceed here.
> > >
> >
> > I think the objection was to making a module parameter for doing this
> > globally for all struct scsi_disk, and not the idea of making it
> > adjustable on an individual basis per-say..
> >
> > What about adding a /sys/class/scsi_disk/$HCTL/flush_timeout..?
>
> Do I/O timeouts and flush timeouts need to be independently adjusted?
> If you're having trouble with slow operations, it seems likely to be
> across the board.
>
> Flush timeout could be defined as 2x the read/write timeout. Any
> other command-specific timeouts could be scaled the same way.

I like this idea and would result in minimal changes. James, if it ok with you,
I could send you the patch.

Regards,

K. Y
--
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/