Re: [PATCH] slab+slob: dup name string
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On 05/23/2012 06:48 PM, Christoph Lameter wrote:
On Wed, 23 May 2012, James Bottomley wrote:So, why not simply patch slab to rely on the string lifetime being the cache lifetime (or beyond) and therefore not having it take a copy?Well thats they way it was for a long time. There must be some reason that someone started to add this copying business.... Pekka?
From git: commit 84c1cf62465e2fb0a692620dcfeb52323ab03d48 Author: Pekka Enberg <penberg@xxxxxxxxxx> Date: Tue Sep 14 23:21:12 2010 +0300 SLUB: Fix merged slab cache names As explained by Linus "I'm Proud to be an American" Torvalds: Looking at the merging code, I actually think it's totally buggy. If you have something like this: - load module A: create slab cache A - load module B: create slab cache B that can merge with A - unload module A - "cat /proc/slabinfo": BOOM. Oops. exactly because the name is not handled correctly, and you'll have module B holding open a slab cache that has a name pointer that points to module A that no longer exists.So if I understand it correctly, this is mostly because the name string outlives the cache in the slub case, because of merging ?
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