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2007-07-20mm: Remove slab destructors from kmem_cache_create().Paul Mundt
Slab destructors were no longer supported after Christoph's c59def9f222d44bb7e2f0a559f2906191a0862d7 change. They've been BUGs for both slab and slub, and slob never supported them either. This rips out support for the dtor pointer from kmem_cache_create() completely and fixes up every single callsite in the kernel (there were about 224, not including the slab allocator definitions themselves, or the documentation references). Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2007-07-17Slab allocators: Cleanup zeroing allocationsChristoph Lameter
It becomes now easy to support the zeroing allocs with generic inline functions in slab.h. Provide inline definitions to allow the continued use of kzalloc, kmem_cache_zalloc etc but remove other definitions of zeroing functions from the slab allocators and util.c. Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-17Slab allocators: support __GFP_ZERO in all allocatorsChristoph Lameter
A kernel convention for many allocators is that if __GFP_ZERO is passed to an allocator then the allocated memory should be zeroed. This is currently not supported by the slab allocators. The inconsistency makes it difficult to implement in derived allocators such as in the uncached allocator and the pool allocators. In addition the support zeroed allocations in the slab allocators does not have a consistent API. There are no zeroing allocator functions for NUMA node placement (kmalloc_node, kmem_cache_alloc_node). The zeroing allocations are only provided for default allocs (kzalloc, kmem_cache_zalloc_node). __GFP_ZERO will make zeroing universally available and does not require any addititional functions. So add the necessary logic to all slab allocators to support __GFP_ZERO. The code is added to the hot path. The gfp flags are on the stack and so the cacheline is readily available for checking if we want a zeroed object. Zeroing while allocating is now a frequent operation and we seem to be gradually approaching a 1-1 parity between zeroing and not zeroing allocs. The current tree has 3476 uses of kmalloc vs 2731 uses of kzalloc. Signed-off-by: Christoph Lameter <clameter@sgi.com> Acked-by: Pekka Enberg <penberg@cs.helsinki.fi> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-17Slab allocators: consistent ZERO_SIZE_PTR support and NULL result semanticsChristoph Lameter
Define ZERO_OR_NULL_PTR macro to be able to remove the checks from the allocators. Move ZERO_SIZE_PTR related stuff into slab.h. Make ZERO_SIZE_PTR work for all slab allocators and get rid of the WARN_ON_ONCE(size == 0) that is still remaining in SLAB. Make slub return NULL like the other allocators if a too large memory segment is requested via __kmalloc. Signed-off-by: Christoph Lameter <clameter@sgi.com> Acked-by: Pekka Enberg <penberg@cs.helsinki.fi> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-17Slab allocators: consolidate code for krealloc in mm/util.cChristoph Lameter
The size of a kmalloc object is readily available via ksize(). ksize is provided by all allocators and thus we can implement krealloc in a generic way. Implement krealloc in mm/util.c and drop slab specific implementations of krealloc. Signed-off-by: Christoph Lameter <clameter@sgi.com> Acked-by: Pekka Enberg <penberg@cs.helsinki.fi> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16slob: sparsemem supportPaul Mundt
Currently slob is disabled if we're using sparsemem, due to an earlier patch from Goto-san. Slob and static sparsemem work without any trouble as it is, and the only hiccup is a missing slab_is_available() in the case of sparsemem extreme. With this, we're rid of the last set of restrictions for slob usage. Signed-off-by: Paul Mundt <lethal@linux-sh.org> Acked-by: Pekka Enberg <penberg@cs.helsinki.fi> Acked-by: Matt Mackall <mpm@selenic.com> Cc: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16slob: initial NUMA supportPaul Mundt
This adds preliminary NUMA support to SLOB, primarily aimed at systems with small nodes (tested all the way down to a 128kB SRAM block), whether asymmetric or otherwise. We follow the same conventions as SLAB/SLUB, preferring current node placement for new pages, or with explicit placement, if a node has been specified. Presently on UP NUMA this has the side-effect of preferring node#0 allocations (since numa_node_id() == 0, though this could be reworked if we could hand off a pfn to determine node placement), so single-CPU NUMA systems will want to place smaller nodes further out in terms of node id. Once a page has been bound to a node (via explicit node id typing), we only do block allocations from partial free pages that have a matching node id in the page flags. The current implementation does have some scalability problems, in that all partial free pages are tracked in the global freelist (with contention due to the single spinlock). However, these are things that are being reworked for SMP scalability first, while things like per-node freelists can easily be built on top of this sort of functionality once it's been added. More background can be found in: http://marc.info/?l=linux-mm&m=118117916022379&w=2 http://marc.info/?l=linux-mm&m=118170446306199&w=2 http://marc.info/?l=linux-mm&m=118187859420048&w=2 and subsequent threads. Acked-by: Christoph Lameter <clameter@sgi.com> Acked-by: Matt Mackall <mpm@selenic.com> Signed-off-by: Paul Mundt <lethal@linux-sh.org> Acked-by: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16slob: improved alignment handlingNick Piggin
Remove the core slob allocator's minimum alignment restrictions, and instead introduce the alignment restrictions at the slab API layer. This lets us heed the ARCH_KMALLOC/SLAB_MINALIGN directives, and also use __alignof__ (unsigned long) for the default alignment (which should allow relaxed alignment architectures to take better advantage of SLOB's small minimum alignment). Signed-off-by: Nick Piggin <npiggin@suse.de> Acked-by: Matt Mackall <mpm@selenic.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16slob: remove bigblock trackingNick Piggin
Remove the bigblock lists in favour of using compound pages and going directly to the page allocator. Allocation size is stored in page->private, which also makes ksize more accurate than it previously was. Saves ~.5K of code, and 12-24 bytes overhead per >= PAGE_SIZE allocation. Signed-off-by: Nick Piggin <npiggin@suse.de> Acked-by: Matt Mackall <mpm@selenic.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16slob: rework freelist handlingNick Piggin
Improve slob by turning the freelist into a list of pages using struct page fields, then each page has a singly linked freelist of slob blocks via a pointer in the struct page. - The first benefit is that the slob freelists can be indexed by a smaller type (2 bytes, if the PAGE_SIZE is reasonable). - Next is that freeing is much quicker because it does not have to traverse the entire freelist. Allocation can be slightly faster too, because we can skip almost-full freelist pages completely. - Slob pages are then freed immediately when they become empty, rather than having a periodic timer try to free them. This gives efficiency and memory consumption improvement. Then, we don't encode seperate size and next fields into each slob block, rather we use the sign bit to distinguish between "size" or "next". Then size 1 blocks contain a "next" offset, and others contain the "size" in the first unit and "next" in the second unit. - This allows minimum slob allocation alignment to go from 8 bytes to 2 bytes on 32-bit and 12 bytes to 2 bytes on 64-bit. In practice, it is best to align them to word size, however some architectures (eg. cris) could gain space savings from turning off this extra alignment. Then, make kmalloc use its own slob_block at the front of the allocation in order to encode allocation size, rather than rely on not overwriting slob's existing header block. - This reduces kmalloc allocation overhead similarly to alignment reductions. - Decouples kmalloc layer from the slob allocator. Then, add a page flag specific to slob pages. - This means kfree of a page aligned slob block doesn't have to traverse the bigblock list. I would get benchmarks, but my test box's network doesn't come up with slob before this patch. I think something is timing out. Anyway, things are faster after the patch. Code size goes up about 1K, however dynamic memory usage _should_ be lower even on relatively small memory systems. Future todo item is to restore the cyclic free list search, rather than to always begin at the start. Signed-off-by: Nick Piggin <npiggin@suse.de> Acked-by: Matt Mackall <mpm@selenic.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-17Remove SLAB_CTOR_CONSTRUCTORChristoph Lameter
SLAB_CTOR_CONSTRUCTOR is always specified. No point in checking it. Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: David Howells <dhowells@redhat.com> Cc: Jens Axboe <jens.axboe@oracle.com> Cc: Steven French <sfrench@us.ibm.com> Cc: Michael Halcrow <mhalcrow@us.ibm.com> Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> Cc: Miklos Szeredi <miklos@szeredi.hu> Cc: Steven Whitehouse <swhiteho@redhat.com> Cc: Roman Zippel <zippel@linux-m68k.org> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Dave Kleikamp <shaggy@austin.ibm.com> Cc: Trond Myklebust <trond.myklebust@fys.uio.no> Cc: "J. Bruce Fields" <bfields@fieldses.org> Cc: Anton Altaparmakov <aia21@cantab.net> Cc: Mark Fasheh <mark.fasheh@oracle.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Jan Kara <jack@ucw.cz> Cc: David Chinner <dgc@sgi.com> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-17Slab allocators: Drop support for destructorsChristoph Lameter
There is no user of destructors left. There is no reason why we should keep checking for destructors calls in the slab allocators. The RFC for this patch was discussed at http://marc.info/?l=linux-kernel&m=117882364330705&w=2 Destructors were mainly used for list management which required them to take a spinlock. Taking a spinlock in a destructor is a bit risky since the slab allocators may run the destructors anytime they decide a slab is no longer needed. Patch drops destructor support. Any attempt to use a destructor will BUG(). Acked-by: Pekka Enberg <penberg@cs.helsinki.fi> Acked-by: Paul Mundt <lethal@linux-sh.org> Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-17slob: implement RCU freeingNick Piggin
The SLOB allocator should implement SLAB_DESTROY_BY_RCU correctly, because even on UP, RCU freeing semantics are not equivalent to simply freeing immediately. This also allows SLOB to be used on SMP. Signed-off-by: Nick Piggin <npiggin@suse.de> Acked-by: Matt Mackall <mpm@selenic.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-07slob: fix page order calculation on not 4KB pageAkinobu Mita
SLOB doesn't calculate correct page order when page size is not 4KB. This patch fixes it with using get_order() instead of find_order() which is SLOB version of get_order(). Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Acked-by: Matt Mackall <mpm@selenic.com> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-07slab allocators: Remove obsolete SLAB_MUST_HWCACHE_ALIGNChristoph Lameter
This patch was recently posted to lkml and acked by Pekka. The flag SLAB_MUST_HWCACHE_ALIGN is 1. Never checked by SLAB at all. 2. A duplicate of SLAB_HWCACHE_ALIGN for SLUB 3. Fulfills the role of SLAB_HWCACHE_ALIGN for SLOB. The only remaining use is in sparc64 and ppc64 and their use there reflects some earlier role that the slab flag once may have had. If its specified then SLAB_HWCACHE_ALIGN is also specified. The flag is confusing, inconsistent and has no purpose. Remove it. Acked-by: Pekka Enberg <penberg@cs.helsinki.fi> Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-07slob: handle SLAB_PANIC flagAkinobu Mita
kmem_cache_create() for slob doesn't handle SLAB_PANIC. Signed-off-by: Matt Mackall <mpm@selenic.com> Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-07slab: introduce kreallocPekka Enberg
This introduce krealloc() that reallocates memory while keeping the contents unchanged. The allocator avoids reallocation if the new size fits the currently used cache. I also added a simple non-optimized version for mm/slob.c for compatibility. [akpm@linux-foundation.org: fix warnings] Acked-by: Josef Sipek <jsipek@fsl.cs.sunysb.edu> Acked-by: Matt Mackall <mpm@selenic.com> Acked-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2006-12-30[PATCH] MM: SLOB is broken by recent cleanup of slab.hDimitri Gorokhovik
Recent cleanup of slab.h broke SLOB allocator: the routine kmem_cache_init has now the __init attribute for both slab.c and slob.c. This routine cannot be removed after init in the case of slob.c -- it serves as a timer callback. Provide a separate timer callback routine, call it once from kmem_cache_init, keep the __init attribute on the latter. Signed-off-by: Dimitri Gorokhovik <dimitri.gorokhovik@free.fr> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-13[PATCH] More slab.h cleanupsChristoph Lameter
More cleanups for slab.h 1. Remove tabs from weird locations as suggested by Pekka 2. Drop the check for NUMA and SLAB_DEBUG from the fallback section as suggested by Pekka. 3. Uses static inline for the fallback defs as also suggested by Pekka. 4. Make kmem_ptr_valid take a const * argument. 5. Separate the NUMA fallback definitions from the kmalloc_track fallback definitions. Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Pekka Enberg <penberg@cs.helsinki.fi> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-13[PATCH] Cleanup slab headers / API to allow easy addition of new slab allocatorsChristoph Lameter
This is a response to an earlier discussion on linux-mm about splitting slab.h components per allocator. Patch is against 2.6.19-git11. See http://marc.theaimsgroup.com/?l=linux-mm&m=116469577431008&w=2 This patch cleans up the slab header definitions. We define the common functions of slob and slab in slab.h and put the extra definitions needed for slab's kmalloc implementations in <linux/slab_def.h>. In order to get a greater set of common functions we add several empty functions to slob.c and also rename slob's kmalloc to __kmalloc. Slob does not need any special definitions since we introduce a fallback case. If there is no need for a slab implementation to provide its own kmalloc mess^H^H^Hacros then we simply fall back to __kmalloc functions. That is sufficient for SLOB. Sort the function in slab.h according to their functionality. First the functions operating on struct kmem_cache * then the kmalloc related functions followed by special debug and fallback definitions. Also redo a lot of comments. Signed-off-by: Christoph Lameter <clameter@sgi.com>? Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-27[PATCH] Make kmem_cache_destroy() return voidAlexey Dobriyan
un-, de-, -free, -destroy, -exit, etc functions should in general return void. Also, There is very little, say, filesystem driver code can do upon failed kmem_cache_destroy(). If it will be decided to BUG in this case, BUG should be put in generic code, instead. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-26[PATCH] ZVC: Support NR_SLAB_RECLAIMABLE / NR_SLAB_UNRECLAIMABLEChristoph Lameter
Remove the atomic counter for slab_reclaim_pages and replace the counter and NR_SLAB with two ZVC counter that account for unreclaimable and reclaimable slab pages: NR_SLAB_RECLAIMABLE and NR_SLAB_UNRECLAIMABLE. Change the check in vmscan.c to refer to to NR_SLAB_RECLAIMABLE. The intend seems to be to check for slab pages that could be freed. Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-26[PATCH] Extract the allocpercpu functions from the slab allocatorChristoph Lameter
The allocpercpu functions __alloc_percpu and __free_percpu() are heavily using the slab allocator. However, they are conceptually slab. This also simplifies SLOB (at this point slob may be broken in mm. This should fix it). Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Matt Mackall <mpm@selenic.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-30Remove obsolete #include <linux/config.h>Jörn Engel
Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de> Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-04-19[PATCH] mm/slob.c: for_each_possible_cpu(), not NR_CPUSJohn Hawkes
Convert for-loops that explicitly reference "NR_CPUS" into the potentially more efficient for_each_possible_cpu() construct. Signed-off-by: John Hawkes <hawkes@sgi.com> Cc: Matt Mackall <mpm@selenic.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-25[PATCH] slab: introduce kmem_cache_zalloc allocatorPekka Enberg
Introduce a memory-zeroing variant of kmem_cache_alloc. The allocator already exits in XFS and there are potential users for it so this patch makes the allocator available for the general public. Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-08[PATCH] SLOB=y && SMP=y fixIngo Molnar
fix CONFIG_SLOB=y (when CONFIG_SMP=y): get rid of the 'align' parameter from its __alloc_percpu() implementation. Boot-tested on x86. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08[PATCH] slob: introduce the SLOB allocatorMatt Mackall
configurable replacement for slab allocator This adds a CONFIG_SLAB option under CONFIG_EMBEDDED. When CONFIG_SLAB is disabled, the kernel falls back to using the 'SLOB' allocator. SLOB is a traditional K&R/UNIX allocator with a SLAB emulation layer, similar to the original Linux kmalloc allocator that SLAB replaced. It's signicantly smaller code and is more memory efficient. But like all similar allocators, it scales poorly and suffers from fragmentation more than SLAB, so it's only appropriate for small systems. It's been tested extensively in the Linux-tiny tree. I've also stress-tested it with make -j 8 compiles on a 3G SMP+PREEMPT box (not recommended). Here's a comparison for otherwise identical builds, showing SLOB saving nearly half a megabyte of RAM: $ size vmlinux* text data bss dec hex filename 3336372 529360 190812 4056544 3de5e0 vmlinux-slab 3323208 527948 190684 4041840 3dac70 vmlinux-slob $ size mm/{slab,slob}.o text data bss dec hex filename 13221 752 48 14021 36c5 mm/slab.o 1896 52 8 1956 7a4 mm/slob.o /proc/meminfo: SLAB SLOB delta MemTotal: 27964 kB 27980 kB +16 kB MemFree: 24596 kB 25092 kB +496 kB Buffers: 36 kB 36 kB 0 kB Cached: 1188 kB 1188 kB 0 kB SwapCached: 0 kB 0 kB 0 kB Active: 608 kB 600 kB -8 kB Inactive: 808 kB 812 kB +4 kB HighTotal: 0 kB 0 kB 0 kB HighFree: 0 kB 0 kB 0 kB LowTotal: 27964 kB 27980 kB +16 kB LowFree: 24596 kB 25092 kB +496 kB SwapTotal: 0 kB 0 kB 0 kB SwapFree: 0 kB 0 kB 0 kB Dirty: 4 kB 12 kB +8 kB Writeback: 0 kB 0 kB 0 kB Mapped: 560 kB 556 kB -4 kB Slab: 1756 kB 0 kB -1756 kB CommitLimit: 13980 kB 13988 kB +8 kB Committed_AS: 4208 kB 4208 kB 0 kB PageTables: 28 kB 28 kB 0 kB VmallocTotal: 1007312 kB 1007312 kB 0 kB VmallocUsed: 48 kB 48 kB 0 kB VmallocChunk: 1007264 kB 1007264 kB 0 kB (this work has been sponsored in part by CELF) From: Ingo Molnar <mingo@elte.hu> Fix 32-bitness bugs in mm/slob.c. Signed-off-by: Matt Mackall <mpm@selenic.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>