On Mon 11-01-16 12:43:29, Johannes Weiner wrote: > On Mon, Jan 11, 2016 at 06:20:58PM +0100, Michal Hocko wrote: > > On Mon 11-01-16 12:00:47, Johannes Weiner wrote: > > > On Mon, Jan 11, 2016 at 02:07:16PM +0900, Tetsuo Handa wrote: > > > > After the OOM killer is disabled during suspend operation, > > > > any !__GFP_NOFAIL && __GFP_FS allocations are forced to fail. > > > > Thus, any !__GFP_NOFAIL && !__GFP_FS allocations should be > > > > forced to fail as well. > > > > > > > > Signed-off-by: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx> > > > > > > Why? We had to acknowledge that !__GFP_FS allocations can not fail > > > even when they can't invoke the OOM killer. They are NOFAIL. Just like > > > an explicit __GFP_NOFAIL they should trigger a warning when they occur > > > after the OOM killer has been disabled and then keep looping. > > > > They are more like GFP_KERNEL than GFP_NOFAIL IMO because unlike > > GFP_NOFAIL they are already allowed to fail due to fatal_signals_pending > > and this has been the case for a really long time. Even semantically > > they are basically GFP_KERNEL with FS recursion protection in majority > > cases. And I believe that we should allow them to fail long term after > > some FS (btrfs at least) catch up and start handling failures properly. > > I see, yeah that's probably a better way to look at it. > > Thanks! > > Scratch my objection to this patch then. But please do add to/update > that XXX comment above that line, or it'll be confusing. Hm? > > /* > * XXX: Page reclaim didn't yield anything, > * and the OOM killer can't be invoked, but > * keep looping as per tradition. Unless the > * system is trying to enter a quiescent state > * during suspend and the OOM killer has been > * shut off already. Give up like with other > * !__GFP_NOFAIL allocations in that case. > */ > *did_some_progress = !oom_killer_disabled; Yes this makes it more clear IMO. -- Michal Hocko SUSE Labs -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>