| Message ID | 20151104153910.GN7637@e104818-lin.cambridge.arm.com (mailing list archive) |
|---|---|
| State | Not Applicable |
| Delegated to: | Simon Horman |
| Headers | show |
On Wed, Nov 04, 2015 at 03:39:10PM +0000, Catalin Marinas wrote: > On Wed, Nov 04, 2015 at 09:28:34AM -0600, Christoph Lameter wrote: > > On Wed, 4 Nov 2015, Catalin Marinas wrote: > > > > > BTW, assuming L1_CACHE_BYTES is 512 (I don't ever see this happening but > > > just in theory), we potentially have the same issue. What would save us > > > is that INDEX_NODE would match the first "kmalloc-512" cache, so we have > > > it pre-populated. > > > > Ok maybe add some BUILD_BUG_ONs to ensure that builds fail until we have > > addressed that. > > A BUILD_BUG_ON should be fine. > > Thinking some more, I think if KMALLOC_MIN_SIZE is 128, there is no gain > with off-slab management since the freelist allocation would still be > 128 bytes. An alternative to reverting while still having a little > benefit of off-slab for 256 bytes objects (rather than 512 as we would > get with the revert): > > diff --git a/mm/slab.c b/mm/slab.c > index 4fcc5dd8d5a6..ac32b4a0f2ec 100644 > --- a/mm/slab.c > +++ b/mm/slab.c > @@ -2212,8 +2212,8 @@ __kmem_cache_create (struct kmem_cache *cachep, unsigned long flags) > * it too early on. Always use on-slab management when > * SLAB_NOLEAKTRACE to avoid recursive calls into kmemleak) > */ > - if ((size >= (PAGE_SIZE >> 5)) && !slab_early_init && > - !(flags & SLAB_NOLEAKTRACE)) > + if ((size >= (PAGE_SIZE >> 5)) && (size > KMALLOC_MIN_SIZE) && > + !slab_early_init && !(flags & SLAB_NOLEAKTRACE)) > /* > * Size is large, assume best to place the slab management obj > * off-slab (should allow better packing of objs). > > Whichever you prefer. Hello, I prefer this simple way. It looks like that it can solve the issue on any arbitrary configuration. Thanks. -- To unsubscribe from this list: send the line "unsubscribe linux-sh" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/mm/slab.c b/mm/slab.c index 4fcc5dd8d5a6..ac32b4a0f2ec 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -2212,8 +2212,8 @@ __kmem_cache_create (struct kmem_cache *cachep, unsigned long flags) * it too early on. Always use on-slab management when * SLAB_NOLEAKTRACE to avoid recursive calls into kmemleak) */ - if ((size >= (PAGE_SIZE >> 5)) && !slab_early_init && - !(flags & SLAB_NOLEAKTRACE)) + if ((size >= (PAGE_SIZE >> 5)) && (size > KMALLOC_MIN_SIZE) && + !slab_early_init && !(flags & SLAB_NOLEAKTRACE)) /* * Size is large, assume best to place the slab management obj * off-slab (should allow better packing of objs).