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| author | Vlastimil Babka <vbabka@suse.cz> | 2022-11-04 15:57:11 +0300 |
|---|---|---|
| committer | Vlastimil Babka <vbabka@suse.cz> | 2022-11-04 16:57:21 +0300 |
| commit | eb4940d4adf590590a9d0c47e38d2799c2ff9670 (patch) | |
| tree | 9148100bc1e80c34f412f48176e389e93416caa4 /mm | |
| parent | a207620123f27e6f63bab13b46b20e03a3deec8d (diff) | |
| download | linux-eb4940d4adf590590a9d0c47e38d2799c2ff9670.tar.xz | |
mm/slab: remove !CONFIG_TRACING variants of kmalloc_[node_]trace()
For !CONFIG_TRACING kernels, the kmalloc() implementation tries (in cases where
the allocation size is build-time constant) to save a function call, by
inlining kmalloc_trace() to a kmem_cache_alloc() call.
However since commit 6edf2576a6cc ("mm/slub: enable debugging memory wasting of
kmalloc") this path now fails to pass the original request size to be
eventually recorded (for kmalloc caches with debugging enabled).
We could adjust the code to call __kmem_cache_alloc_node() as the
CONFIG_TRACING variant, but that would as a result inline a call with 5
parameters, bloating the kmalloc() call sites. The cost of extra function
call (to kmalloc_trace()) seems like a lesser evil.
It also appears that the !CONFIG_TRACING variant is incompatible with upcoming
hardening efforts [1] so it's easier if we just remove it now. Kernels with no
tracing are rare these days and the benefit is dubious anyway.
[1] https://lore.kernel.org/linux-mm/20221101222520.never.109-kees@kernel.org/T/#m20ecf14390e406247bde0ea9cce368f469c539ed
Link: https://lore.kernel.org/all/097d8fba-bd10-a312-24a3-a4068c4f424c@suse.cz/
Suggested-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/slab_common.c | 2 |
1 files changed, 0 insertions, 2 deletions
diff --git a/mm/slab_common.c b/mm/slab_common.c index 74a991fd9d31..206e59051c1d 100644 --- a/mm/slab_common.c +++ b/mm/slab_common.c @@ -1040,7 +1040,6 @@ size_t __ksize(const void *object) return slab_ksize(folio_slab(folio)->slab_cache); } -#ifdef CONFIG_TRACING void *kmalloc_trace(struct kmem_cache *s, gfp_t gfpflags, size_t size) { void *ret = __kmem_cache_alloc_node(s, gfpflags, NUMA_NO_NODE, @@ -1064,7 +1063,6 @@ void *kmalloc_node_trace(struct kmem_cache *s, gfp_t gfpflags, return ret; } EXPORT_SYMBOL(kmalloc_node_trace); -#endif /* !CONFIG_TRACING */ #endif /* !CONFIG_SLOB */ gfp_t kmalloc_fix_flags(gfp_t flags) |