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authorJesper Dangaard Brouer <brouer@redhat.com>2015-09-05 01:45:31 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2015-09-05 02:54:41 +0300
commit2ae44005b678431a5c7a55dafcd09421ba3fadf0 (patch)
tree2611dbc3c9cb0e7e6d587e9a3c116e50718bfa71 /mm/slob.c
parentec6a90661a0d6ce1461d05c7a58a0a151154e14a (diff)
downloadlinux-2ae44005b678431a5c7a55dafcd09421ba3fadf0.tar.xz
slub: fix spelling succedd to succeed
With this patchset the SLUB allocator now has both bulk alloc and free implemented. This patchset mostly optimizes the "fastpath" where objects are available on the per CPU fastpath page. This mostly amortize the less-heavy none-locked cmpxchg_double used on fastpath. The "fallback" bulking (e.g __kmem_cache_free_bulk) provides a good basis for comparison. Measurements[1] of the fallback functions __kmem_cache_{free,alloc}_bulk have been copied from slab_common.c and forced "noinline" to force a function call like slab_common.c. Measurements on CPU CPU i7-4790K @ 4.00GHz Baseline normal fastpath (alloc+free cost): 42 cycles(tsc) 10.601 ns Measurements last-patch with disabled debugging: Bulk- fallback - this-patch 1 - 57 cycles(tsc) 14.448 ns - 44 cycles(tsc) 11.236 ns improved 22.8% 2 - 51 cycles(tsc) 12.768 ns - 28 cycles(tsc) 7.019 ns improved 45.1% 3 - 48 cycles(tsc) 12.232 ns - 22 cycles(tsc) 5.526 ns improved 54.2% 4 - 48 cycles(tsc) 12.025 ns - 19 cycles(tsc) 4.786 ns improved 60.4% 8 - 46 cycles(tsc) 11.558 ns - 18 cycles(tsc) 4.572 ns improved 60.9% 16 - 45 cycles(tsc) 11.458 ns - 18 cycles(tsc) 4.658 ns improved 60.0% 30 - 45 cycles(tsc) 11.499 ns - 18 cycles(tsc) 4.568 ns improved 60.0% 32 - 79 cycles(tsc) 19.917 ns - 65 cycles(tsc) 16.454 ns improved 17.7% 34 - 78 cycles(tsc) 19.655 ns - 63 cycles(tsc) 15.932 ns improved 19.2% 48 - 68 cycles(tsc) 17.049 ns - 50 cycles(tsc) 12.506 ns improved 26.5% 64 - 80 cycles(tsc) 20.009 ns - 63 cycles(tsc) 15.929 ns improved 21.3% 128 - 94 cycles(tsc) 23.749 ns - 86 cycles(tsc) 21.583 ns improved 8.5% 158 - 97 cycles(tsc) 24.299 ns - 90 cycles(tsc) 22.552 ns improved 7.2% 250 - 102 cycles(tsc) 25.681 ns - 98 cycles(tsc) 24.589 ns improved 3.9% Benchmarking shows impressive improvements in the "fastpath" with a small number of objects in the working set. Once the working set increases, resulting in activating the "slowpath" (that contains the heavier locked cmpxchg_double) the improvement decreases. I'm currently working on also optimizing the "slowpath" (as network stack use-case hits this), but this patchset should provide a good foundation for further improvements. Rest of my patch queue in this area needs some more work, but preliminary results are good. I'm attending Netfilter Workshop[2] next week, and I'll hopefully return working on further improvements in this area. This patch (of 6): s/succedd/succeed/ Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/slob.c')
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