On Mon, Aug 26, 2024 at 09:18:01PM +0200, Michal Hocko wrote: > On Mon 26-08-24 18:49:23, Matthew Wilcox wrote: > > On Mon, Aug 26, 2024 at 06:51:55PM +0200, Michal Hocko wrote: > [...] > > > If a plan revert is preferably, I will go with it. > > > > There aren't any other users of PF_MEMALLOC_NOWARN and it definitely > > seems like something you want at a callsite rather than blanket for every > > allocation below this point. We don't seem to have many PF_ flags left, > > so let's not keep it around if there's no immediate plans for it. > > Good point. What about this? > --- > From 923cd429d4b1a3520c93bcf46611ae74a3158865 Mon Sep 17 00:00:00 2001 > From: Michal Hocko <mhocko@xxxxxxxx> > Date: Mon, 26 Aug 2024 21:15:02 +0200 > Subject: [PATCH] Revert "mm: introduce PF_MEMALLOC_NORECLAIM, > PF_MEMALLOC_NOWARN" > > This reverts commit eab0af905bfc3e9c05da2ca163d76a1513159aa4. > > There is no existing user of those flags. PF_MEMALLOC_NOWARN is > dangerous because a nested allocation context can use GFP_NOFAIL which > could cause unexpected failure. Such a code would be hard to maintain > because it could be deeper in the call chain. > > PF_MEMALLOC_NORECLAIM has been added even when it was pointed out [1] > that such a allocation contex is inherently unsafe if the context > doesn't fully control all allocations called from this context. > > While PF_MEMALLOC_NOWARN is not dangerous the way PF_MEMALLOC_NORECLAIM > is it doesn't have any user and as Matthew has pointed out we are > running out of those flags so better reclaim it without any real users. > > [1] https://lore.kernel.org/all/ZcM0xtlKbAOFjv5n@tiehlicka/ > > Signed-off-by: Michal Hocko <mhocko@xxxxxxxx> Looks good to me. Reviewed-by: Dave Chinner <dchinner@xxxxxxxxxx> -- Dave Chinner david@xxxxxxxxxxxxx
