Re: PM / hibernate xfs lock up / xfs_reclaim_inodes_ag

[Nigel Cunningham <nigel@tuxonice.net>]

Hi.

On 27/07/11 20:33, Christoph Hellwig wrote:
> On Wed, Jul 27, 2011 at 11:35:13AM +0200, Rafael J. Wysocki wrote:
>> The Pavel's objection, if I remember it correctly, was that some
>> (or the majority of?) filesystems didn't implement the freezing operation,
>> so they would be more vulnerable to data loss in case of a failing hibernation
>> after this change.  However, that's better than actively causing pain to XFS
>> users.
> 
> The objection never made sense and only means he never read the code.
> freeze_super (or freeze_bdev back then) always does a sync_filesystem
> before even checking if we have a freeze method, and sync_filesystem is
> what we iterate over for each superblock in sync().

I've had freezing supers in TOI for a couple of years now and it has
only ever helped. To be honest, if you have a ton of dirty pages, it
does result in a big delay, but that's the worst of it.

Regards,

Nigel
-- 
Evolution (n): A hypothetical process whereby improbable
events occur with alarming frequency, order arises from chaos, and
no one is given credit.