Re: [PATCH -mm 0/2] Use freezeable workqueues to avoidsuspend-related XFS corruptions

From: Nigel Cunningham
Date: Mon Nov 20 2006 - 17:40:20 EST


(Sorry to reply again)

On Tue, 2006-11-21 at 09:26 +1100, Nigel Cunningham wrote:
> Hi.
>
> On Mon, 2006-11-20 at 23:18 +0100, Rafael J. Wysocki wrote:
> > I think I/O can only be submitted from the process context. Thus if we freeze
> > all (and I mean _all_) threads that are used by filesystems, including worker
> > threads, we should effectively prevent fs-related I/O from being submitted
> > after tasks have been frozen.
>
> I know that will work. It's what I used to do before the switch to bdev
> freezing. I guess I need to look again at why I made the switch. Perhaps
> it was just because you guys gave freezing kthreads a bad wrap as too
> invasive or something. Bdev freezing is certainly fewer lines of code.

No, it looks like I wrongly believed that XFS was submitting I/O off a
timer, so that freezing kthreads wasn't enough. In that case, it looks
like freezing kthreads should be a good solution.

Regards,

Nigel

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