On Thursday, August 25, 2011, Pavel Machek wrote: > Hi! > > > > > > The problem really isn't XFS specific, nor is it new - the fact is > > > > > that any filesystem that has registered a shrinker or can do async > > > > > work in the background post-sync is vulnerable to this problem. It's > > > > > > > > Should we avoid calling shrinkers while hibernating? > > > > > > If you like getting random OOM problems when hibernating, then go > > > for it. Besides, shrinkers are used for more than just filesystems, > > > so you might find you screw entire classes of users by doing this > > > (eg everyone using intel graphics and 3D). > > > > > > > Or put BUG_ON()s into filesystem shrinkers so that this can not > > > > happen? > > > > > > Definitely not. If your concern is filesystem shrinkers and you want > > > a large hammer to hit the problem with then do your hibernate > > > image allocation wih GFP_NOFS and the filesystem shrinkers will > > > abort without doing anything. > > > > I think we can do that, actually. > > I believe we should, yes. Question is if it helps much, because > various drivers (and userspace in case uswsusp?) will still trigger > GFP_KERNEL allocations. > > Something like this? > > --- snapshot.c.ofic 2011-08-25 15:48:41.000000000 +0200 > +++ snapshot.c 2011-08-25 15:49:07.000000000 +0200 > @@ -1107,7 +1107,7 @@ > > /* Helper functions used for the shrinking of memory. */ > > -#define GFP_IMAGE (GFP_KERNEL | __GFP_NOWARN) > +#define GFP_IMAGE (GFP_NODS | __GFP_NOWARN) Surely GFP_NOFS? > > /** > * preallocate_image_pages - Allocate a number of pages for hibernation image > > > -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
