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2007-10-16Group short-lived and reclaimable kernel allocationsMel Gorman
This patch marks a number of allocations that are either short-lived such as network buffers or are reclaimable such as inode allocations. When something like updatedb is called, long-lived and unmovable kernel allocations tend to be spread throughout the address space which increases fragmentation. This patch groups these allocations together as much as possible by adding a new MIGRATE_TYPE. The MIGRATE_RECLAIMABLE type is for allocations that can be reclaimed on demand, but not moved. i.e. they can be migrated by deleting them and re-reading the information from elsewhere. Signed-off-by: Mel Gorman <mel@csn.ul.ie> Cc: Andy Whitcroft <apw@shadowen.org> Cc: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16Categorize GFP flagsChristoph Lameter
The function of GFP_LEVEL_MASK seems to be unclear. In order to clear up the mystery we get rid of it and replace GFP_LEVEL_MASK with 3 sets of GFP flags: GFP_RECLAIM_MASK Flags used to control page allocator reclaim behavior. GFP_CONSTRAINT_MASK Flags used to limit where allocations can occur. GFP_SLAB_BUG_MASK Flags that the slab allocator BUG()s on. These replace the uses of GFP_LEVEL mask in the slab allocators and in vmalloc.c. The use of the flags not included in these sets may occur as a result of a slab allocation standing in for a page allocation when constructing scatter gather lists. Extraneous flags are cleared and not passed through to the page allocator. __GFP_MOVABLE/RECLAIMABLE, __GFP_COLD and __GFP_COMP will now be ignored if passed to a slab allocator. Change the allocation of allocator meta data in SLAB and vmalloc to not pass through flags listed in GFP_CONSTRAINT_MASK. SLAB already removes the __GFP_THISNODE flag for such allocations. Generalize that to also cover vmalloc. The use of GFP_CONSTRAINT_MASK also includes __GFP_HARDWALL. The impact of allocator metadata placement on access latency to the cachelines of the object itself is minimal since metadata is only referenced on alloc and free. The attempt is still made to place the meta data optimally but we consistently allow fallback both in SLAB and vmalloc (SLUB does not need to allocate metadata like that). Allocator metadata may serve multiple in kernel users and thus should not be subject to the limitations arising from a single allocation context. [akpm@linux-foundation.org: fix fallback_alloc()] 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>
2007-10-16Memoryless nodes: Slab supportChristoph Lameter
Slab should not allocate control structures for nodes without memory. This may seem to work right now but its unreliable since not all allocations can fall back due to the use of GFP_THISNODE. Switching a few for_each_online_node's to N_NORMAL_MEMORY will allow us to only allocate for nodes that have regular memory. Signed-off-by: Christoph Lameter <clameter@sgi.com> Acked-by: Nishanth Aravamudan <nacc@us.ibm.com> Acked-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Acked-by: Bob Picco <bob.picco@hp.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Mel Gorman <mel@skynet.ie> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16Slab allocators: fail if ksize is called with a NULL parameterChristoph Lameter
A NULL pointer means that the object was not allocated. One cannot determine the size of an object that has not been allocated. Currently we return 0 but we really should BUG() on attempts to determine the size of something nonexistent. krealloc() interprets NULL to mean a zero sized object. Handle that separately in krealloc(). Signed-off-by: Christoph Lameter <clameter@sgi.com> Acked-by: Pekka Enberg <penberg@cs.helsinki.fi> Cc: Matt Mackall <mpm@selenic.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-08-22slab: skip calling cache_free_alien() when the platform is not numa capableSiddha, Suresh B
Skip calling cache_free_alien() when the platform is not numa capable. This will avoid cache misses that happen while accessing slabp (which is per page memory reference) to get nodeid. Instead use a global variable to skip the call, which is mostly likely to be present in the cache. This gives a 0.8% performance boost with the database oltp workload on a quad-core SMP platform and by any means the number is not small :) Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Acked-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-24slab: correctly handle __GFP_ZEROAndrew Morton
Use the correct local variable when calling into the page allocator. Local `flags' can have __GFP_ZERO set, which causes us to pass __GFP_ZERO into the page allocator, possibly from illegal contexts. The page allocator will later do prep_zero_page()->kmap_atomic(..., KM_USER0) from irq contexts and will then go BUG. Cc: Mike Galbraith <efault@gmx.de> Acked-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-20mm: 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>
2007-07-19Fix up non-NUMA SLAB configuration for zero-sized allocationsLinus Torvalds
I suspect Christoph tested his code only in the NUMA configuration, for the combination of SLAB+non-NUMA the zero-sized kmalloc's would not work. Of course, this would only trigger in configurations where those zero- sized allocations happen (not very common), so that may explain why it wasn't more widely noticed. Seen by by Andi Kleen under qemu, and there seems to be a report by Michael Tsirkin on it too. Cc: Andi Kleen <ak@suse.de> Cc: Roland Dreier <rdreier@cisco.com> Cc: Michael S. Tsirkin <mst@dev.mellanox.co.il> Cc: Pekka Enberg <penberg@cs.helsinki.fi> Cc: Christoph Lameter <clameter@sgi.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19FRV: work around a possible compiler bugDavid Howells
Work around a possible bug in the FRV compiler. What appears to be happening is that gcc resolves the __builtin_constant_p() in kmalloc() to true, but then fails to reduce the therefore constant conditions in the if-statements it guards to constant results. When compiling with -O2 or -Os, one single spurious error crops up in cpuup_callback() in mm/slab.c. This can be avoided by making the memsize variable const. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-17kallsyms: make KSYM_NAME_LEN include space for trailing '\0'Tejun Heo
KSYM_NAME_LEN is peculiar in that it does not include the space for the trailing '\0', forcing all users to use KSYM_NAME_LEN + 1 when allocating buffer. This is nonsense and error-prone. Moreover, when the caller forgets that it's very likely to subtly bite back by corrupting the stack because the last position of the buffer is always cleared to zero. This patch increments KSYM_NAME_LEN by one and updates code accordingly. * off-by-one bug in asm-powerpc/kprobes.h::kprobe_lookup_name() macro is fixed. * Where MODULE_NAME_LEN and KSYM_NAME_LEN were used together, MODULE_NAME_LEN was treated as if it didn't include space for the trailing '\0'. Fix it. Signed-off-by: Tejun Heo <htejun@gmail.com> Acked-by: Paulo Marques <pmarques@grupopie.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.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>
2007-07-16mm/slab.c: start_cpu_timer() should be __cpuinitAdrian Bunk
start_cpu_timer() should be __cpuinit (which also matches what it's callers are). __devinit didn't cause problems, it simply wasted a few bytes of memory for the common CONFIG_HOTPLUG_CPU=n case. Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16Make /proc/slabinfo use seq_list_xxx helpersPavel Emelianov
This entry prints a header in .start callback. This is OK, but the more elegant solution would be to move this into the .show callback and use seq_list_start_head() in .start one. I have left it as is in order to make the patch just switch to new API and noting more. [adobriyan@sw.ru: Wrong pointer was used as kmem_cache pointer] Signed-off-by: Pavel Emelianov <xemul@openvz.org> Cc: Christoph Lameter <clameter@sgi.com> Cc: Pekka Enberg <penberg@cs.helsinki.fi> Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-05Fix slab redzone alignmentDavid Woodhouse
Commit b46b8f19c9cd435ecac4d9d12b39d78c137ecd66 fixed a couple of bugs by switching the redzone to 64 bits. Unfortunately, it neglected to ensure that the _second_ redzone, after the slab object, is aligned correctly. This caused illegal instruction faults on sparc32, which for some reason not entirely clear to me are not trapped and fixed up. Two things need to be done to fix this: - increase the object size, rounding up to alignof(long long) so that the second redzone can be aligned correctly. - If SLAB_STORE_USER is set but alignof(long long)==8, allow a full 64 bits of space for the user word at the end of the buffer, even though we may not _use_ the whole 64 bits. This patch should be a no-op on any 64-bit architecture or any 32-bit architecture where alignof(long long) == 4. Of the others, it's tested on ppc32 by myself and a very similar patch was tested on sparc32 by Mark Fortescue, who reported the new problem. Also, fix the conditions for FORCED_DEBUG, which hadn't been adjusted to the new sizes. Again noticed by Mark. Signed-off-by: David Woodhouse <dwmw2@infradead.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-01SLAB: remove WARN_ON_ONCE for zero sized objects for 2.6.22 releaseChristoph Lameter
We agreed to remove the WARN_ON_ONCE before 2.6.22 is released. 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>
2007-06-08slab: fix alien cache handlingChristoph Lameter
cache_free_alien must be called regardless if we use alien caches or not. cache_free_alien() will do the right thing if there are no alien caches available. Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Paul Mundt <lethal@linux-sh.org> Acked-by: Pekka J Enberg <penberg@cs.helsinki.fi> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-19mm/slab: fix section mismatch warningSam Ravnborg
Use the new __init_refok marker to avoid the section mismatch warning from slab.c Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2007-05-17Slab allocators: define common size limitationsChristoph Lameter
Currently we have a maze of configuration variables that determine the maximum slab size. Worst of all it seems to vary between SLAB and SLUB. So define a common maximum size for kmalloc. For conveniences sake we use the maximum size ever supported which is 32 MB. We limit the maximum size to a lower limit if MAX_ORDER does not allow such large allocations. For many architectures this patch will have the effect of adding large kmalloc sizes. x86_64 adds 5 new kmalloc sizes. So a small amount of memory will be needed for these caches (contemporary SLAB has dynamically sizeable node and cpu structure so the waste is less than in the past) Most architectures will then be able to allocate object with sizes up to MAX_ORDER. We have had repeated breakage (in fact whenever we doubled the number of supported processors) on IA64 because one or the other struct grew beyond what the slab allocators supported. This will avoid future issues and f.e. avoid fixes for 2k and 4k cpu support. CONFIG_LARGE_ALLOCS is no longer necessary so drop it. It fixes sparc64 with SLAB. Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: "David S. Miller" <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-17Remove 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: warn on zero-length allocationsChristoph Lameter
slub warns on this, and we're working on making kmalloc(0) return NULL. Let's make slab warn as well so our testers detect such callers more rapidly. 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>
2007-05-17Slab 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>
2007-05-09Move remote node draining out of slab allocatorsChristoph Lameter
Currently the slab allocators contain callbacks into the page allocator to perform the draining of pagesets on remote nodes. This requires SLUB to have a whole subsystem in order to be compatible with SLAB. Moving node draining out of the slab allocators avoids a section of code in SLUB. Move the node draining so that is is done when the vm statistics are updated. At that point we are already touching all the cachelines with the pagesets of a processor. Add a expire counter there. If we have to update per zone or global vm statistics then assume that the pageset will require subsequent draining. The expire counter will be decremented on each vm stats update pass until it reaches zero. Then we will drain one batch from the pageset. The draining will cause vm counter updates which will then cause another expiration until the pcp is empty. So we will drain a batch every 3 seconds. Note that remote node draining is a somewhat esoteric feature that is required on large NUMA systems because otherwise significant portions of system memory can become trapped in pcp queues. The number of pcp is determined by the number of processors and nodes in a system. A system with 4 processors and 2 nodes has 8 pcps which is okay. But a system with 1024 processors and 512 nodes has 512k pcps with a high potential for large amount of memory being caught in them. 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>
2007-05-09vmstat: use our own timer eventsChristoph Lameter
vmstat is currently using the cache reaper to periodically bring the statistics up to date. The cache reaper does only exists in SLUB as a way to provide compatibility with SLAB. This patch removes the vmstat calls from the slab allocators and provides its own handling. The advantage is also that we can use a different frequency for the updates. Refreshing vm stats is a pretty fast job so we can run this every second and stagger this by only one tick. This will lead to some overlap in large systems. F.e a system running at 250 HZ with 1024 processors will have 4 vm updates occurring at once. However, the vm stats update only accesses per node information. It is only necessary to stagger the vm statistics updates per processor in each node. Vm counter updates occurring on distant nodes will not cause cacheline contention. We could implement an alternate approach that runs the first processor on each node at the second and then each of the other processor on a node on a subsequent tick. That may be useful to keep a large amount of the second free of timer activity. Maybe the timer folks will have some feedback on this one? [jirislaby@gmail.com: add missing break] Cc: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Jiri Slaby <jirislaby@gmail.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09Add suspend-related notifications for CPU hotplugRafael J. Wysocki
Since nonboot CPUs are now disabled after tasks and devices have been frozen and the CPU hotplug infrastructure is used for this purpose, we need special CPU hotplug notifications that will help the CPU-hotplug-aware subsystems distinguish normal CPU hotplug events from CPU hotplug events related to a system-wide suspend or resume operation in progress. This patch introduces such notifications and causes them to be used during suspend and resume transitions. It also changes all of the CPU-hotplug-aware subsystems to take these notifications into consideration (for now they are handled in the same way as the corresponding "normal" ones). [oleg@tv-sign.ru: cleanups] Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Cc: Gautham R Shenoy <ego@in.ibm.com> Cc: Pavel Machek <pavel@ucw.cz> Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09slab: shut down cache_reaper when cpu goes downChristoph Lameter
Shutdown the cache_reaper if the cpu is brought down and set the cache_reap.func to NULL. Otherwise hotplug shuts down the reaper for good. Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09slab: use CPU_LOCK_[ACQUIRE|RELEASE]Heiko Carstens
Looks like this was forgotten when CPU_LOCK_[ACQUIRE|RELEASE] was introduced. Cc: Pekka Enberg <penberg@cs.helsinki.fi> Cc: Srivatsa Vaddagiri <vatsa@in.ibm.com> Cc: Gautham Shenoy <ego@in.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09krealloc: fix kerneldoc commentsPekka J Enberg
No "blank" (or "*") line is allowed between the function name and lines for it parameter(s). Cc: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi> Cc: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08Fix race between cat /proc/slab_allocators and rmmodAlexey Dobriyan
Same story as with cat /proc/*/wchan race vs rmmod race, only /proc/slab_allocators want more info than just symbol name. Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08Increase slab redzone to 64bitsDavid Woodhouse
There are two problems with the existing redzone implementation. Firstly, it's causing misalignment of structures which contain a 64-bit integer, such as netfilter's 'struct ipt_entry' -- causing netfilter modules to fail to load because of the misalignment. (In particular, the first check in net/ipv4/netfilter/ip_tables.c::check_entry_size_and_hooks()) On ppc32 and sparc32, amongst others, __alignof__(uint64_t) == 8. With slab debugging, we use 32-bit redzones. And allocated slab objects aren't sufficiently aligned to hold a structure containing a uint64_t. By _just_ setting ARCH_KMALLOC_MINALIGN to __alignof__(u64) we'd disable redzone checks on those architectures. By using 64-bit redzones we avoid that loss of debugging, and also fix the other problem while we're at it. When investigating this, I noticed that on 64-bit platforms we're using a 32-bit value of RED_ACTIVE/RED_INACTIVE in the 64-bit memory location set aside for the redzone. Which means that the four bytes immediately before or after the allocated object at 0x00,0x00,0x00,0x00 for LE and BE machines, respectively. Which is probably not the most useful choice of poison value. One way to fix both of those at once is just to switch to 64-bit redzones in all cases. Signed-off-by: David Woodhouse <dwmw2@infradead.org> Acked-by: Pekka Enberg <penberg@cs.helsinki.fi> Cc: Christoph Lameter <clameter@engr.sgi.com> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-07Slab allocators: remove useless __GFP_NO_GROW flagChristoph Lameter
There is no user remaining and I have never seen any use of that flag. 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>
2007-05-07slab allocators: Remove SLAB_CTOR_ATOMICChristoph Lameter
SLAB_CTOR atomic is never used which is no surprise since I cannot imagine that one would want to do something serious in a constructor or destructor. In particular given that the slab allocators run with interrupts disabled. Actions in constructors and destructors are by their nature very limited and usually do not go beyond initializing variables and list operations. (The i386 pgd ctor and dtors do take a spinlock in constructor and destructor..... I think that is the furthest we go at this point.) There is no flag passed to the destructor so removing SLAB_CTOR_ATOMIC also establishes a certain symmetry. 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>
2007-05-07slab allocators: Remove SLAB_DEBUG_INITIAL flagChristoph Lameter
I have never seen a use of SLAB_DEBUG_INITIAL. It is only supported by SLAB. I think its purpose was to have a callback after an object has been freed to verify that the state is the constructor state again? The callback is performed before each freeing of an object. I would think that it is much easier to check the object state manually before the free. That also places the check near the code object manipulation of the object. Also the SLAB_DEBUG_INITIAL callback is only performed if the kernel was compiled with SLAB debugging on. If there would be code in a constructor handling SLAB_DEBUG_INITIAL then it would have to be conditional on SLAB_DEBUG otherwise it would just be dead code. But there is no such code in the kernel. I think SLUB_DEBUG_INITIAL is too problematic to make real use of, difficult to understand and there are easier ways to accomplish the same effect (i.e. add debug code before kfree). There is a related flag SLAB_CTOR_VERIFY that is frequently checked to be clear in fs inode caches. Remove the pointless checks (they would even be pointless without removeal of SLAB_DEBUG_INITIAL) from the fs constructors. This is the last slab flag that SLUB did not support. Remove the check for unimplemented flags from SLUB. 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>
2007-05-07fault injection: fix failslab with CONFIG_NUMAAkinobu Mita
Currently failslab injects failures into ____cache_alloc(). But with enabling CONFIG_NUMA it's not enough to let actual slab allocator functions (kmalloc, kmem_cache_alloc, ...) return NULL. This patch moves fault injection hook inside of __cache_alloc() and __cache_alloc_node(). These are lower call path than ____cache_alloc() and enable to inject faulures to slab allocators with CONFIG_NUMA. Acked-by: Pekka Enberg <penberg@cs.helsinki.fi> Signed-off-by: Akinobu Mita <akinobu.mita@gmail.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>
2007-05-07slab 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>
2007-05-07include KERN_* constant in printk() calls in mm/slab.cmatze
Signed-off-by: Matthias Kaehlcke <matthias.kaehlcke@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-07Add virt_to_head_page and consolidate code in slab and slubChristoph Lameter
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>
2007-05-07Make page->private usable in compound pagesChristoph Lameter
If we add a new flag so that we can distinguish between the first page and the tail pages then we can avoid to use page->private in the first page. page->private == page for the first page, so there is no real information in there. Freeing up page->private makes the use of compound pages more transparent. They become more usable like real pages. Right now we have to be careful f.e. if we are going beyond PAGE_SIZE allocations in the slab on i386 because we can then no longer use the private field. This is one of the issues that cause us not to support debugging for page size slabs in SLAB. Having page->private available for SLUB would allow more meta information in the page struct. I can probably avoid the 16 bit ints that I have in there right now. Also if page->private is available then a compound page may be equipped with buffer heads. This may free up the way for filesystems to support larger blocks than page size. We add PageTail as an alias of PageReclaim. Compound pages cannot currently be reclaimed. Because of the alias one needs to check PageCompound first. The RFC for the this approach was discussed at http://marc.info/?t=117574302800001&r=1&w=2 [nacc@us.ibm.com: fix hugetlbfs] Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-07slab: mark set_up_list3s() __initAndrew Morton
It is only ever used prior to free_initmem(). (It will cause a warning when we run the section checking, but that's a false-positive and it simply changes the source of an existing warning, which is also a false-positive) Cc: Christoph Lameter <clameter@engr.sgi.com> Cc: Pekka Enberg <penberg@cs.helsinki.fi> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-07slab: NUMA kmem_cache dietEric Dumazet
Some NUMA machines have a big MAX_NUMNODES (possibly 1024), but fewer possible nodes. This patch dynamically sizes the 'struct kmem_cache' to allocate only needed space. I moved nodelists[] field at the end of struct kmem_cache, and use the following computation in kmem_cache_init() cache_cache.buffer_size = offsetof(struct kmem_cache, nodelists) + nr_node_ids * sizeof(struct kmem_list3 *); On my two nodes x86_64 machine, kmem_cache.obj_size is now 192 instead of 704 (This is because on x86_64, MAX_NUMNODES is 64) On bigger NUMA setups, this might reduce the gfporder of "cache_cache" Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Cc: Pekka Enberg <penberg@cs.helsinki.fi> Cc: Andy Whitcroft <apw@shadowen.org> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-07SLAB: don't allocate empty shared cachesEric Dumazet
We can avoid allocating empty shared caches and avoid unecessary check of cache->limit. We save some memory. We avoid bringing into CPU cache unecessary cache lines. All accesses to l3->shared are already checking NULL pointers so this patch is safe. Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Acked-by: Pekka Enberg <penberg@cs.helsinki.fi> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-07SLAB: use num_possible_cpus() in enable_cpucache()Eric Dumazet
The existing comment in mm/slab.c is *perfect*, so I reproduce it : /* * CPU bound tasks (e.g. network routing) can exhibit cpu bound * allocation behaviour: Most allocs on one cpu, most free operations * on another cpu. For these cases, an efficient object passing between * cpus is necessary. This is provided by a shared array. The array * replaces Bonwick's magazine layer. * On uniprocessor, it's functionally equivalent (but less efficient) * to a larger limit. Thus disabled by default. */ As most shiped linux kernels are now compiled with CONFIG_SMP, there is no way a preprocessor #if can detect if the machine is UP or SMP. Better to use num_possible_cpus(). This means on UP we allocate a 'size=0 shared array', to be more efficient. Another patch can later avoid the allocations of 'empty shared arrays', to save some memory. Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Acked-by: Pekka Enberg <penberg@cs.helsinki.fi> Acked-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-07slab: ensure cache_alloc_refill terminatesPekka Enberg
If slab->inuse is corrupted, cache_alloc_refill can enter an infinite loop as detailed by Michael Richardson in the following post: <http://lkml.org/lkml/2007/2/16/292>. This adds a BUG_ON to catch those cases. Cc: Michael Richardson <mcr@sandelman.ca> 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>
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>
2007-05-02[PATCH] x86-64: skip cache_free_alien() on non NUMASiddha, Suresh B
Set use_alien_caches to 0 on non NUMA platforms. And avoid calling the cache_free_alien() when use_alien_caches is not set. This will avoid the cache miss that happens while dereferencing slabp to get nodeid. Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: Andi Kleen <ak@suse.de> Cc: Andi Kleen <andi@firstfloor.org> Cc: Eric Dumazet <dada1@cosmosbay.com> Cc: David Rientjes <rientjes@google.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2007-04-04[PATCH] SLAB: Mention slab name when listing corrupt objectsDavid Howells
Mention the slab name when listing corrupt objects. Although the function that released the memory is mentioned, that is frequently ambiguous as such functions often release several pieces of memory. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-03-01[PATCH] kernel-doc fixes for 2.6.20-git15 (non-drivers)Randy Dunlap
Fix kernel-doc warnings in 2.6.20-git15 (lib/, mm/, kernel/, include/). Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-20[PATCH] slab: reduce size of alien cache to cover only possible nodesChristoph Lameter
The alien cache is a per cpu per node array allocated for every slab on the system. Currently we size this array for all nodes that the kernel does support. For IA64 this is 1024 nodes. So we allocate an array with 1024 objects even if we only boot a system with 4 nodes. This patch uses "nr_node_ids" to determine the number of possible nodes supported by a hardware configuration and only allocates an alien cache sized for possible nodes. The initialization of nr_node_ids occurred too late relative to the bootstrap of the slab allocator and so I moved the setup_nr_node_ids() into free_area_init_nodes(). 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>