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| author | Kees Cook <keescook@chromium.org> | 2021-04-01 16:23:43 -0700 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2021-04-08 14:05:19 +0200 |
| commit | 51cba1ebc60df9c4ce034a9f5441169c0d0956c0 (patch) | |
| tree | 9f3f79596f1922730ac3d2a90a47ad493484c75d /mm/slab.h | |
| parent | 0d66ccc1627013c95f1e7ef10b95b8451cd7834e (diff) | |
| download | linux-51cba1ebc60df9c4ce034a9f5441169c0d0956c0.tar.bz2 | |
init_on_alloc: Optimize static branches
The state of CONFIG_INIT_ON_ALLOC_DEFAULT_ON (and ...ON_FREE...) did not
change the assembly ordering of the static branches: they were always out
of line. Use the new jump_label macros to check the CONFIG settings to
default to the "expected" state, which slightly optimizes the resulting
assembly code.
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexander Potapenko <glider@google.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Link: https://lore.kernel.org/r/20210401232347.2791257-3-keescook@chromium.org
Diffstat (limited to 'mm/slab.h')
| -rw-r--r-- | mm/slab.h | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/mm/slab.h b/mm/slab.h index 076582f58f68..774c7221efdc 100644 --- a/mm/slab.h +++ b/mm/slab.h @@ -601,7 +601,8 @@ static inline void cache_random_seq_destroy(struct kmem_cache *cachep) { } static inline bool slab_want_init_on_alloc(gfp_t flags, struct kmem_cache *c) { - if (static_branch_unlikely(&init_on_alloc)) { + if (static_branch_maybe(CONFIG_INIT_ON_ALLOC_DEFAULT_ON, + &init_on_alloc)) { if (c->ctor) return false; if (c->flags & (SLAB_TYPESAFE_BY_RCU | SLAB_POISON)) @@ -613,7 +614,8 @@ static inline bool slab_want_init_on_alloc(gfp_t flags, struct kmem_cache *c) static inline bool slab_want_init_on_free(struct kmem_cache *c) { - if (static_branch_unlikely(&init_on_free)) + if (static_branch_maybe(CONFIG_INIT_ON_FREE_DEFAULT_ON, + &init_on_free)) return !(c->ctor || (c->flags & (SLAB_TYPESAFE_BY_RCU | SLAB_POISON))); return false; |