| Message ID | 20240826085347.1152675-3-mhocko@kernel.org (mailing list archive) |
|---|---|
| State | Handled Elsewhere |
| Headers | show |
| Series | get rid of PF_MEMALLOC_NORECLAIM | expand |
On Mon, Aug 26, 2024 at 4:53 PM Michal Hocko <mhocko@kernel.org> wrote: > > From: Michal Hocko <mhocko@suse.com> > > There is no existing user of the flag and the flag 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. > > [1] https://lore.kernel.org/all/ZcM0xtlKbAOFjv5n@tiehlicka/ > > Signed-off-by: Michal Hocko <mhocko@suse.com> > --- > include/linux/sched.h | 1 - > include/linux/sched/mm.h | 7 ++----- > 2 files changed, 2 insertions(+), 6 deletions(-) > > diff --git a/include/linux/sched.h b/include/linux/sched.h > index f8d150343d42..72dad3a6317a 100644 > --- a/include/linux/sched.h > +++ b/include/linux/sched.h > @@ -1657,7 +1657,6 @@ extern struct pid *cad_pid; > * I am cleaning dirty pages from some other bdi. */ > #define PF_KTHREAD 0x00200000 /* I am a kernel thread */ > #define PF_RANDOMIZE 0x00400000 /* Randomize virtual address space */ > -#define PF_MEMALLOC_NORECLAIM 0x00800000 /* All allocation requests will clear __GFP_DIRECT_RECLAIM */ To maintain consistency with the other unused bits, it would be better to define PF__HOLE__00800000 instead. -- Regards Yafang
On Mon, Aug 26, 2024 at 10:47:13AM +0200, Michal Hocko wrote: > From: Michal Hocko <mhocko@suse.com> > > There is no existing user of the flag and the flag 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. Wouldn't a straight-up revert of eab0af905bfc be cleaner? Or is there a reason to keep PF_MEMALLOC_NOWARN?
On Mon 26-08-24 14:59:29, Matthew Wilcox wrote: > On Mon, Aug 26, 2024 at 10:47:13AM +0200, Michal Hocko wrote: > > From: Michal Hocko <mhocko@suse.com> > > > > There is no existing user of the flag and the flag 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. > > Wouldn't a straight-up revert of eab0af905bfc be cleaner? Or is there > a reason to keep PF_MEMALLOC_NOWARN? I wanted to make it PF_MEMALLOC_NORECLAIM specific. I do not have a strong case against PF_MEMALLOC_NOWARN TBH. It is a hack because the scope is claiming something about all allocations within the scope without necessarily knowing all of them (including potential future changes). But NOWARN is not really harmful so I do not care strongly. If a plan revert is preferably, I will go with it.
On Mon 26-08-24 21:48:34, Yafang Shao wrote: > On Mon, Aug 26, 2024 at 4:53 PM Michal Hocko <mhocko@kernel.org> wrote: > > > > From: Michal Hocko <mhocko@suse.com> > > > > There is no existing user of the flag and the flag 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. > > > > [1] https://lore.kernel.org/all/ZcM0xtlKbAOFjv5n@tiehlicka/ > > > > Signed-off-by: Michal Hocko <mhocko@suse.com> > > --- > > include/linux/sched.h | 1 - > > include/linux/sched/mm.h | 7 ++----- > > 2 files changed, 2 insertions(+), 6 deletions(-) > > > > diff --git a/include/linux/sched.h b/include/linux/sched.h > > index f8d150343d42..72dad3a6317a 100644 > > --- a/include/linux/sched.h > > +++ b/include/linux/sched.h > > @@ -1657,7 +1657,6 @@ extern struct pid *cad_pid; > > * I am cleaning dirty pages from some other bdi. */ > > #define PF_KTHREAD 0x00200000 /* I am a kernel thread */ > > #define PF_RANDOMIZE 0x00400000 /* Randomize virtual address space */ > > -#define PF_MEMALLOC_NORECLAIM 0x00800000 /* All allocation requests will clear __GFP_DIRECT_RECLAIM */ > > To maintain consistency with the other unused bits, it would be better > to define PF__HOLE__00800000 instead. OK
On Mon, Aug 26, 2024 at 06:51:55PM +0200, Michal Hocko wrote: > On Mon 26-08-24 14:59:29, Matthew Wilcox wrote: > > On Mon, Aug 26, 2024 at 10:47:13AM +0200, Michal Hocko wrote: > > > From: Michal Hocko <mhocko@suse.com> > > > > > > There is no existing user of the flag and the flag 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. > > > > Wouldn't a straight-up revert of eab0af905bfc be cleaner? Or is there > > a reason to keep PF_MEMALLOC_NOWARN? > > I wanted to make it PF_MEMALLOC_NORECLAIM specific. I do not have a > strong case against PF_MEMALLOC_NOWARN TBH. It is a hack because the > scope is claiming something about all allocations within the scope > without necessarily knowing all of them (including potential future > changes). But NOWARN is not really harmful so I do not care strongly. > > 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.
On Mon, Aug 26, 2024 at 10:47:13AM GMT, Michal Hocko wrote: > From: Michal Hocko <mhocko@suse.com> > > There is no existing user of the flag and the flag 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. I don't really buy the unsafety argument; if it applies to anything, it applies to GFP_NOFAIL - but we recently grew warnings about unsafe uses for it, so I don't see it as a great concern. GFP_NORECLAIM is frequently desirable as a hint about the latency requirements of a codepath; "don't try too hard, I've got fallbacks and I'm in a codepath where I don't want to block too long". I expect PF_MEMALLOC_NORECLAIM will find legitimate uses.
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@suse.com> 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@suse.com> --- include/linux/sched.h | 4 ++-- include/linux/sched/mm.h | 17 ++++------------- 2 files changed, 6 insertions(+), 15 deletions(-) diff --git a/include/linux/sched.h b/include/linux/sched.h index f8d150343d42..731ff1078c9e 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1657,8 +1657,8 @@ extern struct pid *cad_pid; * I am cleaning dirty pages from some other bdi. */ #define PF_KTHREAD 0x00200000 /* I am a kernel thread */ #define PF_RANDOMIZE 0x00400000 /* Randomize virtual address space */ -#define PF_MEMALLOC_NORECLAIM 0x00800000 /* All allocation requests will clear __GFP_DIRECT_RECLAIM */ -#define PF_MEMALLOC_NOWARN 0x01000000 /* All allocation requests will inherit __GFP_NOWARN */ +#define PF__HOLE__00800000 0x00800000 +#define PF__HOLE__01000000 0x01000000 #define PF__HOLE__02000000 0x02000000 #define PF_NO_SETAFFINITY 0x04000000 /* Userland is not allowed to meddle with cpus_mask */ #define PF_MCE_EARLY 0x08000000 /* Early kill for mce process policy */ diff --git a/include/linux/sched/mm.h b/include/linux/sched/mm.h index 91546493c43d..07c4fde32827 100644 --- a/include/linux/sched/mm.h +++ b/include/linux/sched/mm.h @@ -258,25 +258,16 @@ static inline gfp_t current_gfp_context(gfp_t flags) { unsigned int pflags = READ_ONCE(current->flags); - if (unlikely(pflags & (PF_MEMALLOC_NOIO | - PF_MEMALLOC_NOFS | - PF_MEMALLOC_NORECLAIM | - PF_MEMALLOC_NOWARN | - PF_MEMALLOC_PIN))) { + if (unlikely(pflags & (PF_MEMALLOC_NOIO | PF_MEMALLOC_NOFS | PF_MEMALLOC_PIN))) { /* - * Stronger flags before weaker flags: - * NORECLAIM implies NOIO, which in turn implies NOFS + * NOIO implies both NOIO and NOFS and it is a weaker context + * so always make sure it makes precedence */ - if (pflags & PF_MEMALLOC_NORECLAIM) - flags &= ~__GFP_DIRECT_RECLAIM; - else if (pflags & PF_MEMALLOC_NOIO) + if (pflags & PF_MEMALLOC_NOIO) flags &= ~(__GFP_IO | __GFP_FS); else if (pflags & PF_MEMALLOC_NOFS) flags &= ~__GFP_FS; - if (pflags & PF_MEMALLOC_NOWARN) - flags |= __GFP_NOWARN; - if (pflags & PF_MEMALLOC_PIN) flags &= ~__GFP_MOVABLE; }
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? Looks clean to me. Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org> > >From 923cd429d4b1a3520c93bcf46611ae74a3158865 Mon Sep 17 00:00:00 2001 > From: Michal Hocko <mhocko@suse.com> > 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@suse.com> > --- > include/linux/sched.h | 4 ++-- > include/linux/sched/mm.h | 17 ++++------------- > 2 files changed, 6 insertions(+), 15 deletions(-) > > diff --git a/include/linux/sched.h b/include/linux/sched.h > index f8d150343d42..731ff1078c9e 100644 > --- a/include/linux/sched.h > +++ b/include/linux/sched.h > @@ -1657,8 +1657,8 @@ extern struct pid *cad_pid; > * I am cleaning dirty pages from some other bdi. */ > #define PF_KTHREAD 0x00200000 /* I am a kernel thread */ > #define PF_RANDOMIZE 0x00400000 /* Randomize virtual address space */ > -#define PF_MEMALLOC_NORECLAIM 0x00800000 /* All allocation requests will clear __GFP_DIRECT_RECLAIM */ > -#define PF_MEMALLOC_NOWARN 0x01000000 /* All allocation requests will inherit __GFP_NOWARN */ > +#define PF__HOLE__00800000 0x00800000 > +#define PF__HOLE__01000000 0x01000000 > #define PF__HOLE__02000000 0x02000000 > #define PF_NO_SETAFFINITY 0x04000000 /* Userland is not allowed to meddle with cpus_mask */ > #define PF_MCE_EARLY 0x08000000 /* Early kill for mce process policy */ > diff --git a/include/linux/sched/mm.h b/include/linux/sched/mm.h > index 91546493c43d..07c4fde32827 100644 > --- a/include/linux/sched/mm.h > +++ b/include/linux/sched/mm.h > @@ -258,25 +258,16 @@ static inline gfp_t current_gfp_context(gfp_t flags) > { > unsigned int pflags = READ_ONCE(current->flags); > > - if (unlikely(pflags & (PF_MEMALLOC_NOIO | > - PF_MEMALLOC_NOFS | > - PF_MEMALLOC_NORECLAIM | > - PF_MEMALLOC_NOWARN | > - PF_MEMALLOC_PIN))) { > + if (unlikely(pflags & (PF_MEMALLOC_NOIO | PF_MEMALLOC_NOFS | PF_MEMALLOC_PIN))) { > /* > - * Stronger flags before weaker flags: > - * NORECLAIM implies NOIO, which in turn implies NOFS > + * NOIO implies both NOIO and NOFS and it is a weaker context > + * so always make sure it makes precedence > */ > - if (pflags & PF_MEMALLOC_NORECLAIM) > - flags &= ~__GFP_DIRECT_RECLAIM; > - else if (pflags & PF_MEMALLOC_NOIO) > + if (pflags & PF_MEMALLOC_NOIO) > flags &= ~(__GFP_IO | __GFP_FS); > else if (pflags & PF_MEMALLOC_NOFS) > flags &= ~__GFP_FS; > > - if (pflags & PF_MEMALLOC_NOWARN) > - flags |= __GFP_NOWARN; > - > if (pflags & PF_MEMALLOC_PIN) > flags &= ~__GFP_MOVABLE; > } > -- > 2.46.0 > > > -- > Michal Hocko > SUSE Labs
Looks good:
Reviewed-by: Christoph Hellwig <hch@lst.de>
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@suse.com> > 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@suse.com> Looks good to me. Reviewed-by: Dave Chinner <dchinner@redhat.com>
On 8/26/24 21:18, 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@suse.com> > 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@suse.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> > --- > include/linux/sched.h | 4 ++-- > include/linux/sched/mm.h | 17 ++++------------- > 2 files changed, 6 insertions(+), 15 deletions(-) > > diff --git a/include/linux/sched.h b/include/linux/sched.h > index f8d150343d42..731ff1078c9e 100644 > --- a/include/linux/sched.h > +++ b/include/linux/sched.h > @@ -1657,8 +1657,8 @@ extern struct pid *cad_pid; > * I am cleaning dirty pages from some other bdi. */ > #define PF_KTHREAD 0x00200000 /* I am a kernel thread */ > #define PF_RANDOMIZE 0x00400000 /* Randomize virtual address space */ > -#define PF_MEMALLOC_NORECLAIM 0x00800000 /* All allocation requests will clear __GFP_DIRECT_RECLAIM */ > -#define PF_MEMALLOC_NOWARN 0x01000000 /* All allocation requests will inherit __GFP_NOWARN */ > +#define PF__HOLE__00800000 0x00800000 > +#define PF__HOLE__01000000 0x01000000 > #define PF__HOLE__02000000 0x02000000 > #define PF_NO_SETAFFINITY 0x04000000 /* Userland is not allowed to meddle with cpus_mask */ > #define PF_MCE_EARLY 0x08000000 /* Early kill for mce process policy */ > diff --git a/include/linux/sched/mm.h b/include/linux/sched/mm.h > index 91546493c43d..07c4fde32827 100644 > --- a/include/linux/sched/mm.h > +++ b/include/linux/sched/mm.h > @@ -258,25 +258,16 @@ static inline gfp_t current_gfp_context(gfp_t flags) > { > unsigned int pflags = READ_ONCE(current->flags); > > - if (unlikely(pflags & (PF_MEMALLOC_NOIO | > - PF_MEMALLOC_NOFS | > - PF_MEMALLOC_NORECLAIM | > - PF_MEMALLOC_NOWARN | > - PF_MEMALLOC_PIN))) { > + if (unlikely(pflags & (PF_MEMALLOC_NOIO | PF_MEMALLOC_NOFS | PF_MEMALLOC_PIN))) { > /* > - * Stronger flags before weaker flags: > - * NORECLAIM implies NOIO, which in turn implies NOFS > + * NOIO implies both NOIO and NOFS and it is a weaker context > + * so always make sure it makes precedence > */ > - if (pflags & PF_MEMALLOC_NORECLAIM) > - flags &= ~__GFP_DIRECT_RECLAIM; > - else if (pflags & PF_MEMALLOC_NOIO) > + if (pflags & PF_MEMALLOC_NOIO) > flags &= ~(__GFP_IO | __GFP_FS); > else if (pflags & PF_MEMALLOC_NOFS) > flags &= ~__GFP_FS; > > - if (pflags & PF_MEMALLOC_NOWARN) > - flags |= __GFP_NOWARN; > - > if (pflags & PF_MEMALLOC_PIN) > flags &= ~__GFP_MOVABLE; > }
diff --git a/include/linux/sched.h b/include/linux/sched.h index f8d150343d42..72dad3a6317a 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1657,7 +1657,6 @@ extern struct pid *cad_pid; * I am cleaning dirty pages from some other bdi. */ #define PF_KTHREAD 0x00200000 /* I am a kernel thread */ #define PF_RANDOMIZE 0x00400000 /* Randomize virtual address space */ -#define PF_MEMALLOC_NORECLAIM 0x00800000 /* All allocation requests will clear __GFP_DIRECT_RECLAIM */ #define PF_MEMALLOC_NOWARN 0x01000000 /* All allocation requests will inherit __GFP_NOWARN */ #define PF__HOLE__02000000 0x02000000 #define PF_NO_SETAFFINITY 0x04000000 /* Userland is not allowed to meddle with cpus_mask */ diff --git a/include/linux/sched/mm.h b/include/linux/sched/mm.h index 91546493c43d..c49f2b24acb9 100644 --- a/include/linux/sched/mm.h +++ b/include/linux/sched/mm.h @@ -260,16 +260,13 @@ static inline gfp_t current_gfp_context(gfp_t flags) if (unlikely(pflags & (PF_MEMALLOC_NOIO | PF_MEMALLOC_NOFS | - PF_MEMALLOC_NORECLAIM | PF_MEMALLOC_NOWARN | PF_MEMALLOC_PIN))) { /* * Stronger flags before weaker flags: - * NORECLAIM implies NOIO, which in turn implies NOFS + * NOIO implies NOFS */ - if (pflags & PF_MEMALLOC_NORECLAIM) - flags &= ~__GFP_DIRECT_RECLAIM; - else if (pflags & PF_MEMALLOC_NOIO) + if (pflags & PF_MEMALLOC_NOIO) flags &= ~(__GFP_IO | __GFP_FS); else if (pflags & PF_MEMALLOC_NOFS) flags &= ~__GFP_FS;