Message-ID: <43A91C57.20102@cosmosbay.com>
Date: Wed, 21 Dec 2005 10:11:51 +0100
From: Eric Dumazet <dada1@cosmosbay.com>
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To: linux-kernel@vger.kernel.org
CC: Andi Kleen <ak@suse.de>
Subject: [POLL] SLAB : Are the 32 and 192 bytes caches really usefull on x86_64
 machines ?
References: <7vbqzadgmt.fsf@assigned-by-dhcp.cox.net>
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I wonder if the 32 and 192 bytes caches are worth to be declared in 
include/linux/kmalloc_sizes.h, at least on x86_64

(x86_64 : PAGE_SIZE = 4096, L1_CACHE_BYTES = 64)

On my machines, I can say that the 32 and 192 sizes could be avoided in favor 
in spending less cpu cycles in __find_general_cachep()

Could some of you post the result of the following command on your machines :

# grep "size-" /proc/slabinfo |grep -v DMA|cut -c1-40

size-131072            0      0 131072
size-65536             0      0  65536
size-32768             2      2  32768
size-16384             0      0  16384
size-8192             13     13   8192
size-4096            161    161   4096
size-2048          40564  42976   2048
size-1024            681    800   1024
size-512           19792  37168    512
size-256              81    105    256
size-192            1218   1280    192
size-64            31278  86907     64
size-128            5457  10380    128
size-32              594    784     32

Thank you

PS : I have no idea why the last lines (size-192, 64, 128, 32) are not ordered...

Eric
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