From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx102.postini.com [74.125.245.102]) by kanga.kvack.org (Postfix) with SMTP id E35876B0044 for ; Wed, 8 Aug 2012 17:03:22 -0400 (EDT) Message-Id: <20120808210129.987345284@linux.com> Date: Wed, 08 Aug 2012 16:01:29 -0500 From: Christoph Lameter Subject: Common11 [00/20] Sl[auo]b: Common code rework V11 Sender: owner-linux-mm@kvack.org List-ID: To: Joonsoo Kim Cc: Glauber Costa , Pekka Enberg , linux-mm@kvack.org, David Rientjes V10->V11 - Fix issues pointed out by Joonsoo and Glauber - Simplify Slab bootstrap further V9->V10 - Memory leak was a false alarm - Resequence patches to make it easier to apply. - Do more boot sequence consolidation in slab/slub. [We could still do much more like common kmalloc handling] - Fixes suggested by David and Glauber V8->V9: - Fix numerous things pointed out by Glauber. - Cleanup the way error handling works in the common kmem_cache_create() function. - General cleanup by breaking things up into multiple patches were necessary. V7->V8: - Do not use kfree for kmem_cache in slub. - Add more patches up to a common scheme for object alignment. V6->V7: - Omit pieces that were merged for 3.6 - Fix issues pointed out by Glauber. - Include the patches up to the point at which the slab name handling is unified V5->V6: - Patches against Pekka's for-next tree. - Go slow and cut down to just patches that are safe (there will likely be some churn already due to the mutex unification between slabs) - More to come next week when I have more time ( took me almost the whole week to catch up after being gone for awhile). V4->V5 - Rediff against current upstream + Pekka's cleanup branch. V3->V4: - Do not use the COMMON macro anymore. - Fixup various issues - No general sysfs support yet due to lockdep issues with keys in kmalloc'ed memory. V2->V3: - Incorporate more feedback from Joonsoo Kim and Glauber Costa - And a couple more patches to deal with slab duping and move more code to slab_common.c V1->V2: - Incorporate glommers feedback. - Add 2 more patches dealing with common code in kmem_cache_destroy This is a series of patches that extracts common functionality from slab allocators into a common code base. The intend is to standardize as much as possible of the allocator behavior while keeping the distinctive features of each allocator which are mostly due to their storage format and serialization approaches. This patchset makes a beginning by extracting common functionality in kmem_cache_create() and kmem_cache_destroy(). However, there are numerous other areas where such work could be beneficial: 1. Extract the sysfs support from SLUB and make it common. That way all allocators have a common sysfs API and are handleable in the same way regardless of the allocator chose. 2. Extract the error reporting and checking from SLUB and make it available for all allocators. This means that all allocators will gain the resiliency and error handling capabilties. 3. Extract the memory hotplug and cpu hotplug handling. It seems that SLAB may be more sophisticated here. Having common code here will make it easier to maintain the special code. 4. Extract the aliasing capability of SLUB. This will enable fast slab creation without creating too many additional slab caches. The arrays of caches of varying sizes in numerous subsystems do not cause the creation of numerous slab caches. Storage density is increased and the cache footprint is reduced. Ultimately it is to be hoped that the special code for each allocator shrinks to a mininum. This will also make it easier to make modification to allocators. In the far future one could envision that the current allocators will just become storage algorithms that can be chosen based on the need of the subsystem. F.e. Cpu cache dependend performance = Bonwick allocator (SLAB) Minimal cycle count and cache footprint = SLUB Maximum storage density = K&R allocator (SLOB) -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org