| Message ID | 20230501165450.15352-10-surenb@google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Memory allocation profiling | expand |
On Mon, 1 May 2023 09:54:19 -0700 Suren Baghdasaryan <surenb@google.com> wrote: > Introduce __GFP_NO_OBJ_EXT flag in order to prevent recursive allocations > when allocating slabobj_ext on a slab. > > Signed-off-by: Suren Baghdasaryan <surenb@google.com> > --- > include/linux/gfp_types.h | 12 ++++++++++-- > 1 file changed, 10 insertions(+), 2 deletions(-) > > diff --git a/include/linux/gfp_types.h b/include/linux/gfp_types.h > index 6583a58670c5..aab1959130f9 100644 > --- a/include/linux/gfp_types.h > +++ b/include/linux/gfp_types.h > @@ -53,8 +53,13 @@ typedef unsigned int __bitwise gfp_t; > #define ___GFP_SKIP_ZERO 0 > #define ___GFP_SKIP_KASAN 0 > #endif > +#ifdef CONFIG_SLAB_OBJ_EXT > +#define ___GFP_NO_OBJ_EXT 0x4000000u > +#else > +#define ___GFP_NO_OBJ_EXT 0 > +#endif > #ifdef CONFIG_LOCKDEP > -#define ___GFP_NOLOCKDEP 0x4000000u > +#define ___GFP_NOLOCKDEP 0x8000000u So now we have two flags that depend on config options, but the first one is always allocated in fact. I wonder if you could use an enum to let the compiler allocate bits. Something similar to what Muchun Song did with section flags. See commit ed7802dd48f7a507213cbb95bb4c6f1fe134eb5d for reference. > #else > #define ___GFP_NOLOCKDEP 0 > #endif > @@ -99,12 +104,15 @@ typedef unsigned int __bitwise gfp_t; > * node with no fallbacks or placement policy enforcements. > * > * %__GFP_ACCOUNT causes the allocation to be accounted to kmemcg. > + * > + * %__GFP_NO_OBJ_EXT causes slab allocation to have no object > extension. */ > #define __GFP_RECLAIMABLE ((__force gfp_t)___GFP_RECLAIMABLE) > #define __GFP_WRITE ((__force gfp_t)___GFP_WRITE) > #define __GFP_HARDWALL ((__force gfp_t)___GFP_HARDWALL) > #define __GFP_THISNODE ((__force gfp_t)___GFP_THISNODE) > #define __GFP_ACCOUNT ((__force gfp_t)___GFP_ACCOUNT) > +#define __GFP_NO_OBJ_EXT ((__force gfp_t)___GFP_NO_OBJ_EXT) > > /** > * DOC: Watermark modifiers > @@ -249,7 +257,7 @@ typedef unsigned int __bitwise gfp_t; > #define __GFP_NOLOCKDEP ((__force gfp_t)___GFP_NOLOCKDEP) > > /* Room for N __GFP_FOO bits */ > -#define __GFP_BITS_SHIFT (26 + IS_ENABLED(CONFIG_LOCKDEP)) > +#define __GFP_BITS_SHIFT (27 + IS_ENABLED(CONFIG_LOCKDEP)) If the above suggestion is implemented, this could be changed to something like __GFP_LAST_BIT (the enum's last identifier). Petr T
On Tue, May 2, 2023 at 5:50 AM Petr Tesařík <petr@tesarici.cz> wrote: > > On Mon, 1 May 2023 09:54:19 -0700 > Suren Baghdasaryan <surenb@google.com> wrote: > > > Introduce __GFP_NO_OBJ_EXT flag in order to prevent recursive allocations > > when allocating slabobj_ext on a slab. > > > > Signed-off-by: Suren Baghdasaryan <surenb@google.com> > > --- > > include/linux/gfp_types.h | 12 ++++++++++-- > > 1 file changed, 10 insertions(+), 2 deletions(-) > > > > diff --git a/include/linux/gfp_types.h b/include/linux/gfp_types.h > > index 6583a58670c5..aab1959130f9 100644 > > --- a/include/linux/gfp_types.h > > +++ b/include/linux/gfp_types.h > > @@ -53,8 +53,13 @@ typedef unsigned int __bitwise gfp_t; > > #define ___GFP_SKIP_ZERO 0 > > #define ___GFP_SKIP_KASAN 0 > > #endif > > +#ifdef CONFIG_SLAB_OBJ_EXT > > +#define ___GFP_NO_OBJ_EXT 0x4000000u > > +#else > > +#define ___GFP_NO_OBJ_EXT 0 > > +#endif > > #ifdef CONFIG_LOCKDEP > > -#define ___GFP_NOLOCKDEP 0x4000000u > > +#define ___GFP_NOLOCKDEP 0x8000000u > > So now we have two flags that depend on config options, but the first > one is always allocated in fact. I wonder if you could use an enum to > let the compiler allocate bits. Something similar to what Muchun Song > did with section flags. > > See commit ed7802dd48f7a507213cbb95bb4c6f1fe134eb5d for reference. Thanks for the reference. I'll take a closer look and will try to clean it up. > > > #else > > #define ___GFP_NOLOCKDEP 0 > > #endif > > @@ -99,12 +104,15 @@ typedef unsigned int __bitwise gfp_t; > > * node with no fallbacks or placement policy enforcements. > > * > > * %__GFP_ACCOUNT causes the allocation to be accounted to kmemcg. > > + * > > + * %__GFP_NO_OBJ_EXT causes slab allocation to have no object > > extension. */ > > #define __GFP_RECLAIMABLE ((__force gfp_t)___GFP_RECLAIMABLE) > > #define __GFP_WRITE ((__force gfp_t)___GFP_WRITE) > > #define __GFP_HARDWALL ((__force gfp_t)___GFP_HARDWALL) > > #define __GFP_THISNODE ((__force gfp_t)___GFP_THISNODE) > > #define __GFP_ACCOUNT ((__force gfp_t)___GFP_ACCOUNT) > > +#define __GFP_NO_OBJ_EXT ((__force gfp_t)___GFP_NO_OBJ_EXT) > > > > /** > > * DOC: Watermark modifiers > > @@ -249,7 +257,7 @@ typedef unsigned int __bitwise gfp_t; > > #define __GFP_NOLOCKDEP ((__force gfp_t)___GFP_NOLOCKDEP) > > > > /* Room for N __GFP_FOO bits */ > > -#define __GFP_BITS_SHIFT (26 + IS_ENABLED(CONFIG_LOCKDEP)) > > +#define __GFP_BITS_SHIFT (27 + IS_ENABLED(CONFIG_LOCKDEP)) > > If the above suggestion is implemented, this could be changed to > something like __GFP_LAST_BIT (the enum's last identifier). Ack. Thanks for reviewing! Suren. > > Petr T
diff --git a/include/linux/gfp_types.h b/include/linux/gfp_types.h index 6583a58670c5..aab1959130f9 100644 --- a/include/linux/gfp_types.h +++ b/include/linux/gfp_types.h @@ -53,8 +53,13 @@ typedef unsigned int __bitwise gfp_t; #define ___GFP_SKIP_ZERO 0 #define ___GFP_SKIP_KASAN 0 #endif +#ifdef CONFIG_SLAB_OBJ_EXT +#define ___GFP_NO_OBJ_EXT 0x4000000u +#else +#define ___GFP_NO_OBJ_EXT 0 +#endif #ifdef CONFIG_LOCKDEP -#define ___GFP_NOLOCKDEP 0x4000000u +#define ___GFP_NOLOCKDEP 0x8000000u #else #define ___GFP_NOLOCKDEP 0 #endif @@ -99,12 +104,15 @@ typedef unsigned int __bitwise gfp_t; * node with no fallbacks or placement policy enforcements. * * %__GFP_ACCOUNT causes the allocation to be accounted to kmemcg. + * + * %__GFP_NO_OBJ_EXT causes slab allocation to have no object extension. */ #define __GFP_RECLAIMABLE ((__force gfp_t)___GFP_RECLAIMABLE) #define __GFP_WRITE ((__force gfp_t)___GFP_WRITE) #define __GFP_HARDWALL ((__force gfp_t)___GFP_HARDWALL) #define __GFP_THISNODE ((__force gfp_t)___GFP_THISNODE) #define __GFP_ACCOUNT ((__force gfp_t)___GFP_ACCOUNT) +#define __GFP_NO_OBJ_EXT ((__force gfp_t)___GFP_NO_OBJ_EXT) /** * DOC: Watermark modifiers @@ -249,7 +257,7 @@ typedef unsigned int __bitwise gfp_t; #define __GFP_NOLOCKDEP ((__force gfp_t)___GFP_NOLOCKDEP) /* Room for N __GFP_FOO bits */ -#define __GFP_BITS_SHIFT (26 + IS_ENABLED(CONFIG_LOCKDEP)) +#define __GFP_BITS_SHIFT (27 + IS_ENABLED(CONFIG_LOCKDEP)) #define __GFP_BITS_MASK ((__force gfp_t)((1 << __GFP_BITS_SHIFT) - 1)) /**
Introduce __GFP_NO_OBJ_EXT flag in order to prevent recursive allocations when allocating slabobj_ext on a slab. Signed-off-by: Suren Baghdasaryan <surenb@google.com> --- include/linux/gfp_types.h | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-)