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* [PATCH] single bit flip detectorDave Jones2006-09-29
| | | | | | | | | | | | | | | | | | In cases where we detect a single bit has been flipped, we spew the usual slab corruption message, which users instantly think is a kernel bug. In a lot of cases, single bit errors are down to bad memory, or other hardware failure. This patch adds an extra line to the slab debug messages in those cases, in the hope that users will try memtest before they report a bug. 000: 6b 6b 6b 6b 6a 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b Single bit error detected. Possibly bad RAM. Run memtest86. [akpm@osdl.org: cleanups] Signed-off-by: Dave Jones <davej@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] GFP_THISNODE for the slab allocatorChristoph Lameter2006-09-27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch insures that the slab node lists in the NUMA case only contain slabs that belong to that specific node. All slab allocations use GFP_THISNODE when calling into the page allocator. If an allocation fails then we fall back in the slab allocator according to the zonelists appropriate for a certain context. This allows a replication of the behavior of alloc_pages and alloc_pages node in the slab layer. Currently allocations requested from the page allocator may be redirected via cpusets to other nodes. This results in remote pages on nodelists and that in turn results in interrupt latency issues during cache draining. Plus the slab is handing out memory as local when it is really remote. Fallback for slab memory allocations will occur within the slab allocator and not in the page allocator. This is necessary in order to be able to use the existing pools of objects on the nodes that we fall back to before adding more pages to a slab. The fallback function insures that the nodes we fall back to obey cpuset restrictions of the current context. We do not allocate objects from outside of the current cpuset context like before. Note that the implementation of locality constraints within the slab allocator requires importing logic from the page allocator. This is a mischmash that is not that great. Other allocators (uncached allocator, vmalloc, huge pages) face similar problems and have similar minimal reimplementations of the basic fallback logic of the page allocator. There is another way of implementing a slab by avoiding per node lists (see modular slab) but this wont work within the existing slab. V1->V2: - Use NUMA_BUILD to avoid #ifdef CONFIG_NUMA - Exploit GFP_THISNODE being 0 in the NON_NUMA case to avoid another #ifdef [akpm@osdl.org: build fix] Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] slab: fix kmalloc_node applying memory policies if nodeid == ↵Christoph Lameter2006-09-27
| | | | | | | | | | | | | | | | | | | | | | | | | | numa_node_id() kmalloc_node() falls back to ___cache_alloc() under certain conditions and at that point memory policies may be applied redirecting the allocation away from the current node. Therefore kmalloc_node(...,numa_node_id()) or kmalloc_node(...,-1) may not return memory from the local node. Fix this by doing the policy check in __cache_alloc() instead of ____cache_alloc(). This version here is a cleanup of Kiran's patch. - Tested on ia64. - Extra material removed. - Consolidate the exit path if alternate_node_alloc() returned an object. [akpm@osdl.org: warning fix] Signed-off-by: Alok N Kataria <alok.kataria@calsoftinc.com> Signed-off-by: Ravikiran Thirumalai <kiran@scalex86.org> Signed-off-by: Shai Fultheim <shai@scalex86.org> Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Make kmem_cache_destroy() return voidAlexey Dobriyan2006-09-27
| | | | | | | | | | | | | 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>
* [PATCH] ZVC: Support NR_SLAB_RECLAIMABLE / NR_SLAB_UNRECLAIMABLEChristoph Lameter2006-09-26
| | | | | | | | | | | | | 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>
* [PATCH] Extract the allocpercpu functions from the slab allocatorChristoph Lameter2006-09-26
| | | | | | | | | | | | 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>
* [PATCH] fix potential stack overflow in mm/slab.cSiddha, Suresh B2006-09-26
| | | | | | | | | On High end systems (1024 or so cpus) this can potentially cause stack overflow. Fix the stack usage. Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] slab: fix lockdep warningsRavikiran G Thirumalai2006-09-26
| | | | | | | | | | | | | | | | Place the alien array cache locks of on slab malloc slab caches on a seperate lockdep class. This avoids false positives from lockdep [akpm@osdl.org: build fix] Signed-off-by: Ravikiran Thirumalai <kiran@scalex86.org> Signed-off-by: Shai Fultheim <shai@scalex86.org> Cc: Thomas Gleixner <tglx@linutronix.de> Acked-by: Arjan van de Ven <arjan@linux.intel.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Pekka Enberg <penberg@cs.helsinki.fi> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] slab: do not panic when alloc_kmemlist fails and slab is upChristoph Lameter2006-09-26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It is fairly easy to get a system to oops by simply sizing a cache via /proc in such a way that one of the chaches (shared is easiest) becomes bigger than the maximum allowed slab allocation size. This occurs because enable_cpucache() fails if it cannot reallocate some caches. However, enable_cpucache() is used for multiple purposes: resizing caches, cache creation and bootstrap. If the slab is already up then we already have working caches. The resize can fail without a problem. We just need to return the proper error code. F.e. after this patch: # echo "size-64 10000 50 1000" >/proc/slabinfo -bash: echo: write error: Cannot allocate memory notice no OOPS. If we are doing a kmem_cache_create() then we also should not panic but return -ENOMEM. If on the other hand we do not have a fully bootstrapped slab allocator yet then we should indeed panic since we are unable to bring up the slab to its full functionality. Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Pekka Enberg <penberg@cs.helsinki.fi> Cc: Manfred Spraul <manfred@colorfullife.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] slab: extract __kmem_cache_destroy from kmem_cache_destroyChristoph Lameter2006-09-26
| | | | | | | | | | | The ability to free memory allocated to a slab cache is also useful if an error occurs during setup of a slab. So extract the function. Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Pekka Enberg <penberg@cs.helsinki.fi> Cc: Manfred Spraul <manfred@colorfullife.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] slab: optimize kmalloc_node the same way as kmallocChristoph Hellwig2006-09-26
| | | | | | | | [akpm@osdl.org: export fix] Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Add some comments to slab.cRavikiran G Thirumalai2006-09-26
| | | | | | | | | | | | | | | | Also, checks if we get a valid slabp_cache for off slab slab-descriptors. We should always get this. If we don't, then in that case we, will have to disable off-slab descriptors for this cache and do the calculations again. This is a rare case, so add a BUG_ON, for now, just in case. Signed-off-by: Alok N Kataria <alok.kataria@calsoftinc.com> Signed-off-by: Ravikiran Thirumalai <kiran@scalex86.org> Signed-off-by: Shai Fultheim <shai@scalex86.org> Cc: Pekka Enberg <penberg@cs.helsinki.fi> Cc: Manfred Spraul <manfred@colorfullife.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] slab: respect architecture and caller mandated alignmentPekka Enberg2006-09-26
| | | | | | | | | | | | | | | | | | As explained by Heiko, on s390 (32-bit) ARCH_KMALLOC_MINALIGN is set to eight because their common I/O layer allocates data structures that need to have an eight byte alignment. This does not work when CONFIG_SLAB_DEBUG is enabled because kmem_cache_create will override alignment to BYTES_PER_WORD which is four. So change kmem_cache_create to ensure cache alignment is always at minimum what the architecture or caller mandates even if slab debugging is enabled. Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Christoph Lameter <clameter@sgi.com> Signed-off-by: Manfred Spraul <manfred@colorfullife.com> 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>
* [PATCH] CPU hotplug compatible alloc_percpu()Martin Peschke2006-09-26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch splits alloc_percpu() up into two phases. Likewise for free_percpu(). This allows clients to limit initial allocations to online cpu's, and to populate or depopulate per-cpu data at run time as needed: struct my_struct *obj; /* initial allocation for online cpu's */ obj = percpu_alloc(sizeof(struct my_struct), GFP_KERNEL); ... /* populate per-cpu data for cpu coming online */ ptr = percpu_populate(obj, sizeof(struct my_struct), GFP_KERNEL, cpu); ... /* access per-cpu object */ ptr = percpu_ptr(obj, smp_processor_id()); ... /* depopulate per-cpu data for cpu going offline */ percpu_depopulate(obj, cpu); ... /* final removal */ percpu_free(obj); Signed-off-by: Martin Peschke <mp3@de.ibm.com> Cc: Paul Jackson <pj@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] mm/: make functions staticAdrian Bunk2006-09-26
| | | | | | | | | | | This patch makes the following needlessly global functions static: - slab.c: kmem_find_general_cachep() - swap.c: __page_cache_release() - vmalloc.c: __vmalloc_node() Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Fix kmem_cache_alloc() been documented twiceRolf Eike Beer2006-07-31
| | | | | | | | | kmem_cache_alloc() was documented twice, but kmem_cache_zalloc() never. Fix this obvious typo to get things right. Signed-off-by: Rolf Eike Beer <eike-kernel@sf-tec.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] cpu hotplug: replace __devinit* with __cpuinit* for cpu notificationsChandra Seetharaman2006-07-31
| | | | | | | | | | | | | | | | Few of the callback functions and notifier blocks that are associated with cpu notifications incorrectly have __devinit and __devinitdata. They should be __cpuinit and __cpuinitdata instead. It makes no functional difference but wastes text area when CONFIG_HOTPLUG is enabled and CONFIG_HOTPLUG_CPU is not. This patch fixes all those instances. Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com> Cc: Ashok Raj <ashok.raj@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] revert slab.c locking changeIngo Molnar2006-07-13
| | | | | | | | | | | | Chandra Seetharaman reported SLAB crashes caused by the slab.c lock annotation patch. There is only one chunk of that patch that has a material effect on the slab logic - this patch undoes that chunk. This was confirmed to fix the slab problem by Chandra. Signed-off-by: Ingo Molnar <mingo@elte.hu> Tested-by: Chandra Seetharaman <sekharan@us.ibm.com> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] lockdep: annotate mm/slab.cArjan van de Ven2006-07-13
| | | | | | | | | | | | | mm/slab.c uses nested locking when dealing with 'off-slab' caches, in that case it allocates the slab header from the (on-slab) kmalloc caches. Teach the lock validator about this by putting all on-slab caches into a separate class. this patch has no effect on non-lockdep kernels. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] lockdep: undo mm/slab.c annotationIngo Molnar2006-07-13
| | | | | | | | | undo existing mm/slab.c lock-validator annotations, in preparation of a new, less intrusive annotation patch. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] lockdep: annotate SLAB codeIngo Molnar2006-07-03
| | | | | | | | | | | | | | | | | | | Teach special (recursive) locking code to the lock validator. Has no effect on non-lockdep kernels. Fix initialize-locks-via-memcpy assumptions. Effects on non-lockdep kernels: the subclass nesting parameter is passed into cache_free_alien() and __cache_free(), and turns one internal kmem_cache_free() call into an open-coded __cache_free() call. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Cc: Pekka Enberg <penberg@cs.helsinki.fi> Cc: Christoph Lameter <clameter@engr.sgi.com> Cc: Manfred Spraul <manfred@colorfullife.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] slab: consolidate code to free slabs from freelistChristoph Lameter2006-06-30
| | | | | | | | | | | | | | | | | | | Post and discussion: http://marc.theaimsgroup.com/?t=115074342800003&r=1&w=2 Code in __shrink_node() duplicates code in cache_reap() Add a new function drain_freelist that removes slabs with objects that are already free and use that in various places. This eliminates the __node_shrink() function and provides the interrupt holdoff reduction from slab_free to code that used to call __node_shrink. [akpm@osdl.org: build fixes] 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>
* [PATCH] zoned vm counters: conversion of nr_slab to per zone counterChristoph Lameter2006-06-30
| | | | | | | | | | | | | - Allows reclaim to access counter without looping over processor counts. - Allows accurate statistics on how many pages are used in a zone by the slab. This may become useful to balance slab allocations over various zones. [akpm@osdl.org: bugfix] Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] zoned vm counters: basic ZVC (zoned vm counter) implementationChristoph Lameter2006-06-30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Per zone counter infrastructure The counters that we currently have for the VM are split per processor. The processor however has not much to do with the zone these pages belong to. We cannot tell f.e. how many ZONE_DMA pages are dirty. So we are blind to potentially inbalances in the usage of memory in various zones. F.e. in a NUMA system we cannot tell how many pages are dirty on a particular node. If we knew then we could put measures into the VM to balance the use of memory between different zones and different nodes in a NUMA system. For example it would be possible to limit the dirty pages per node so that fast local memory is kept available even if a process is dirtying huge amounts of pages. Another example is zone reclaim. We do not know how many unmapped pages exist per zone. So we just have to try to reclaim. If it is not working then we pause and try again later. It would be better if we knew when it makes sense to reclaim unmapped pages from a zone. This patchset allows the determination of the number of unmapped pages per zone. We can remove the zone reclaim interval with the counters introduced here. Futhermore the ability to have various usage statistics available will allow the development of new NUMA balancing algorithms that may be able to improve the decision making in the scheduler of when to move a process to another node and hopefully will also enable automatic page migration through a user space program that can analyse the memory load distribution and then rebalance memory use in order to increase performance. The counter framework here implements differential counters for each processor in struct zone. The differential counters are consolidated when a threshold is exceeded (like done in the current implementation for nr_pageache), when slab reaping occurs or when a consolidation function is called. Consolidation uses atomic operations and accumulates counters per zone in the zone structure and also globally in the vm_stat array. VM functions can access the counts by simply indexing a global or zone specific array. The arrangement of counters in an array also simplifies processing when output has to be generated for /proc/*. Counters can be updated by calling inc/dec_zone_page_state or _inc/dec_zone_page_state analogous to *_page_state. The second group of functions can be called if it is known that interrupts are disabled. Special optimized increment and decrement functions are provided. These can avoid certain checks and use increment or decrement instructions that an architecture may provide. We also add a new CONFIG_DMA_IS_NORMAL that signifies that an architecture can do DMA to all memory and therefore ZONE_NORMAL will not be populated. This is only currently set for IA64 SGI SN2 and currently only affects node_page_state(). In the best case node_page_state can be reduced to retrieving a single counter for the one zone on the node. [akpm@osdl.org: cleanups] [akpm@osdl.org: export vm_stat[] for filesystems] Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Trond Myklebust <trond.myklebust@fys.uio.no> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] pi-futex: rt mutex debugIngo Molnar2006-06-27
| | | | | | | | | | Runtime debugging functionality for rt-mutexes. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] pi-futex: introduce debug_check_no_locks_freed()Ingo Molnar2006-06-27
| | | | | | | | | | | Add debug_check_no_locks_freed(), as a central inline to add bad-lock-free-debugging functionality to. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] cpu hotplug: make cpu_notifier related notifier blocks __cpuinit onlyChandra Seetharaman2006-06-27
| | | | | | | | | | | | Make notifier_blocks associated with cpu_notifier as __cpuinitdata. __cpuinitdata makes sure that the data is init time only unless CONFIG_HOTPLUG_CPU is defined. Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com> Cc: Ashok Raj <ashok.raj@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] cpu hotplug: revert init patch submitted for 2.6.17Chandra Seetharaman2006-06-27
| | | | | | | | | | | | | | | | | | | | | In 2.6.17, there was a problem with cpu_notifiers and XFS. I provided a band-aid solution to solve that problem. In the process, i undid all the changes you both were making to ensure that these notifiers were available only at init time (unless CONFIG_HOTPLUG_CPU is defined). We deferred the real fix to 2.6.18. Here is a set of patches that fixes the XFS problem cleanly and makes the cpu notifiers available only at init time (unless CONFIG_HOTPLUG_CPU is defined). If CONFIG_HOTPLUG_CPU is defined then cpu notifiers are available at run time. This patch reverts the notifier_call changes made in 2.6.17 Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com> Cc: Ashok Raj <ashok.raj@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] add poison.h and patch primary usersRandy Dunlap2006-06-27
| | | | | | | | | | | | | | | | | Localize poison values into one header file for better documentation and easier/quicker debugging and so that the same values won't be used for multiple purposes. Use these constants in core arch., mm, driver, and fs code. Signed-off-by: Randy Dunlap <rdunlap@xenotime.net> Acked-by: Matt Mackall <mpm@selenic.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Andi Kleen <ak@muc.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] slab: kmalloc, kzalloc comments cleanup and fixPaul Drynoff2006-06-23
| | | | | | | | | | | | | | | | | | - Move comments for kmalloc to right place, currently it near __do_kmalloc - Comments for kzalloc - More detailed comments for kmalloc - Appearance of "kmalloc" and "kzalloc" man pages after "make mandocs" [rdunlap@xenotime.net: simplification] Signed-off-by: Paul Drynoff <pauldrynoff@gmail.com> Acked-by: Randy Dunlap <rdunlap@xenotime.net> Cc: Pekka Enberg <penberg@cs.helsinki.fi> Cc: Manfred Spraul <manfred@colorfullife.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] mm/slab.c: fix early init assumptionIngo Molnar2006-06-23
| | | | | | | | | | | | | | | | | | | | | | | The SLAB bootstrap code assumes that the first two kmalloc caches created (the INDEX_AC and INDEX_L3 kmalloc caches) wont be off-slab. But due to AC and L3 structure size increase in lockdep, one of them ended up being off-slab, and subsequently crashing with: Unable to handle kernel NULL pointer dereference at 0000000000000000 RIP: [<ffffffff80267478>] kmem_cache_alloc+0x26/0x7d The fix is to introduce a bootstrap flag and to use it to prevent off-slab caches being created so early during bootup. (The calculation for off-slab caches is quite complex so i didnt want to complicate things with introducing yet another INDEX_ calculation, the flag approach is simpler and smaller.) Signed-off-by: Ingo Molnar <mingo@elte.hu> Cc: Manfred Spraul <manfred@colorfullife.com> Cc: Pekka Enberg <penberg@cs.helsinki.fi> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] slab: verify pointers before freePekka Enberg2006-06-23
| | | | | | | | | | | | | | | | | | | | | | | | | Passing an invalid pointer to kfree() and kmem_cache_free() is likely to cause bad memory corruption or even take down the whole system because the bad pointer is likely reused immediately due to the per-CPU caches. Until now, we don't do any verification for this if CONFIG_DEBUG_SLAB is disabled. As suggested by Linus, add PageSlab check to page_to_cache() and page_to_slab() to verify pointers passed to kfree(). Also, move the stronger check from cache_free_debugcheck() to kmem_cache_free() to ensure the passed pointer actually belongs to the cache we're about to free the object. For page_to_cache() and page_to_slab(), the assertions should have virtually no extra cost (two instructions, no data cache pressure) and for kmem_cache_free() the overhead should be minimal. Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi> Cc: Manfred Spraul <manfred@colorfullife.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Cc: Linus Torvalds <torvalds@osdl.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] slab: redzone double-free detectionPekka Enberg2006-06-23
| | | | | | | | | | | | | | | | At present our slab debugging tells us that it detected a double-free or corruption - it does not distinguish between them. Sometimes it's useful to be able to differentiate between these two types of information. Add double-free detection to redzone verification when freeing an object. As explained by Manfred, when we are freeing an object, both redzones should be RED_ACTIVE. However, if both are RED_INACTIVE, we are trying to free an object that was already free'd. Signed-off-by: Manfred Spraul <manfred@colorfullife.com> 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>
* [PATCH] slab: stop using list_for_eachChristoph Hellwig2006-06-23
| | | | | | | | Use the _entry variant everywhere to clean the code up a tiny bit. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] slab: clean up kmem_getpagesChristoph Hellwig2006-06-23
| | | | | | | | | | | | | | The last ifdef addition hit the ugliness treshold on this functions, so: - rename the variable i to nr_pages so it's somewhat descriptive - remove the addr variable and do the page_address call at the very end - instead of ifdef'ing the whole alloc_pages_node call just make the __GFP_COMP addition to flags conditional - rewrite the __GFP_COMP comment to make sense Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] slab: page mapping cleanupPekka Enberg2006-06-23
| | | | | | | | | | | Clean up slab allocator page mapping a bit. The memory allocated for a slab is physically contiguous so it is okay to assume struct pages are too so kill the long-standing comment. Furthermore, rename set_slab_attr to slab_map_pages and add a comment explaining why its needed. 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>
* [PATCH] slab: extract cache_free_alien from __cache_freePekka Enberg2006-06-23
| | | | | | | | | | Move alien object freeing to cache_free_alien() to reduce #ifdef clutter in __cache_free(). Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi> Acked-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] slab.c: fix offslab_limit bugIngo Molnar2006-06-02
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | mm/slab.c's offlab_limit logic is totally broken. Firstly, "offslab_limit" is a global variable while it should either be calculated in situ or should be passed in as a parameter. Secondly, the more serious problem with it is that the condition for calculating it: if (!(OFF_SLAB(sizes->cs_cachep))) { offslab_limit = sizes->cs_size - sizeof(struct slab); offslab_limit /= sizeof(kmem_bufctl_t); is in total disconnect with the condition that makes use of it: /* More than offslab_limit objects will cause problems */ if ((flags & CFLGS_OFF_SLAB) && num > offslab_limit) break; but due to offslab_limit being a global variable this breakage was hidden. Up until lockdep came along and perturbed the slab sizes sufficiently so that the first off-slab cache would still see a (non-calculated) zero value for offslab_limit and would panic with: kmem_cache_create: couldn't create cache size-512. Call Trace: [<ffffffff8020a5b9>] show_trace+0x96/0x1c8 [<ffffffff8020a8f0>] dump_stack+0x13/0x15 [<ffffffff8022994f>] panic+0x39/0x21a [<ffffffff80270814>] kmem_cache_create+0x5a0/0x5d0 [<ffffffff80aced62>] kmem_cache_init+0x193/0x379 [<ffffffff80abf779>] start_kernel+0x17f/0x218 [<ffffffff80abf263>] _sinittext+0x263/0x26a Kernel panic - not syncing: kmem_cache_create(): failed to create slab `size-512' Paolo Ornati's config on x86_64 managed to trigger it. The fix is to move the calculation to the place that makes use of it. This also makes slab.o 54 bytes smaller. Btw., the check itself is quite silly. Its intention is to test whether the number of objects per slab would be higher than the number of slab control pointers possible. In theory it could be triggered: if someone tried to allocate 4-byte objects cache and explicitly requested with CFLGS_OFF_SLAB. So i kept the check. Out of historic interest i checked how old this bug was and it's ancient, 10 years old! It is the oldest hidden and then truly triggering bugs i ever saw being fixed in the kernel! Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] slab: Fix kmem_cache_destroy() on NUMARoland Dreier2006-05-16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With CONFIG_NUMA set, kmem_cache_destroy() may fail and say "Can't free all objects." The problem is caused by sequences such as the following (suppose we are on a NUMA machine with two nodes, 0 and 1): * Allocate an object from cache on node 0. * Free the object on node 1. The object is put into node 1's alien array_cache for node 0. * Call kmem_cache_destroy(), which ultimately ends up in __cache_shrink(). * __cache_shrink() does drain_cpu_caches(), which loops through all nodes. For each node it drains the shared array_cache and then handles the alien array_cache for the other node. However this means that node 0's shared array_cache will be drained, and then node 1 will move the contents of its alien[0] array_cache into that same shared array_cache. node 0's shared array_cache is never looked at again, so the objects left there will appear to be in use when __cache_shrink() calls __node_shrink() for node 0. So __node_shrink() will return 1 and kmem_cache_destroy() will fail. This patch fixes this by having drain_cpu_caches() do drain_alien_cache() on every node before it does drain_array() on the nodes' shared array_caches. The problem was originally reported by Or Gerlitz <ogerlitz@voltaire.com>. Signed-off-by: Roland Dreier <rolandd@cisco.com> Acked-by: Christoph Lameter <clameter@sgi.com> Acked-by: Pekka Enberg <penberg@cs.helsinki.fi> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] add slab_is_available() routine for boot codeMike Kravetz2006-05-15
| | | | | | | | | | slab_is_available() indicates slab based allocators are available for use. SPARSEMEM code needs to know this as it can be called at various times during the boot process. Signed-off-by: Mike Kravetz <kravetz@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] slab: fix crash on __drain_alien_cahce() during CPU Hotplugshin, jacob2006-04-28
| | | | | | | | transfer_objects should only be called when all of the cpus in the node are online. CPU_DEAD notifier callback marks l3->shared to NULL. Signed-off-by: Jacob Shin <jacob.shin@amd.com> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Remove __devinit and __cpuinit from notifier_call definitionsChandra Seetharaman2006-04-26
| | | | | | | | | | | | | Few of the notifier_chain_register() callers use __init in the definition of notifier_call. It is incorrect as the function definition should be available after the initializations (they do not unregister them during initializations). This patch fixes all such usages to _not_ have the notifier_call __init section. Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] nommu: use compound page in slab allocatorLuke Yang2006-04-11
| | | | | | | | | | | | | | The earlier patch to consolidate mmu and nommu page allocation and refcounting by using compound pages for nommu allocations had a bug: kmalloc slabs who's pages were initially allocated by a non-__GFP_COMP allocator could be passed into mm/nommu.c kmalloc allocations which really wanted __GFP_COMP underlying pages. Fix that by having nommu pass __GFP_COMP to all higher order slab allocations. Signed-off-by: Luke Yang <luke.adi@gmail.com> Acked-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] slab: add statistics for alien cache overflowsRavikiran G Thirumalai2006-04-11
| | | | | | | | | | | | Add a statistics counter which is incremented everytime the alien cache overflows. alien_cache limit is hardcoded to 12 right now. We can use this statistics to tune alien cache if needed in the future. Signed-off-by: Alok N Kataria <alokk@calsoftinc.com> Signed-off-by: Ravikiran Thirumalai <kiran@scalex86.org> Signed-off-by: Shai Fultheim <shai@scalex86.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] slab: allocate node local memory for off-slab slabmanagementRavikiran G Thirumalai2006-04-11
| | | | | | | | | | | Allocate off-slab slab descriptors from node local memory. Signed-off-by: Alok N Kataria <alokk@calsoftinc.com> Signed-off-by: Ravikiran Thirumalai <kiran@scalex86.org> Signed-off-by: Shai Fultheim <shai@scalex86.org> Acked-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* BUG_ON() Conversion in mm/slab.cEric Sesterhenn2006-04-02
| | | | | | | | this changes if() BUG(); constructs to BUG_ON() which is cleaner, contains unlikely() and can better optimized away. Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de> Signed-off-by: Adrian Bunk <bunk@stusta.de>
* [PATCH] for_each_possible_cpu: fixes for generic partKAMEZAWA Hiroyuki2006-03-28
| | | | | | | | replaces for_each_cpu with for_each_possible_cpu(). Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] slab: fix memory leak in alloc_kmemlistChristoph Lameter2006-03-25
| | | | | | | | | | | | | | | | | | | | | | | | | We have had this memory leak for a while now. The situation is complicated by the use of alloc_kmemlist() as a function to resize various caches by do_tune_cpucache(). What we do here is first of all make sure that we deallocate properly in the loop over all the nodes. If we are just resizing caches then we can simply return with -ENOMEM if an allocation fails. If the cache is new then we need to rollback and remove all earlier allocations. We detect that a cache is new by checking if the link to the global cache chain has been setup. This is a bit hackish .... (also fix up too overlong lines that I added in the last patch...) Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Jesper Juhl <jesper.juhl@gmail.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] alloc_kmemlist: Some cleanup in preparation for a real memory leak fixChristoph Lameter2006-03-25
| | | | | | | | | | | | | | | | | | | | Inspired by Jesper Juhl's patch from today 1. Get rid of err We do not set it to anything else but zero. 2. Drop the CONFIG_NUMA stuff. There are definitions for alloc_alien_cache and free_alien_cache() that do the right thing for the non NUMA case. 3. Better naming of variables. 4. Remove redundant cachep->nodelists[node] expressions. Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] slab: Bypass free lists for __drain_alien_cache()Christoph Lameter2006-03-25
| | | | | | | | | | | | | | | | | | __drain_alien_cache() currently drains objects by freeing them to the (remote) freelists of the original node. However, each node also has a shared list containing objects to be used on any processor of that node. We can avoid a number of remote node accesses by copying the pointers to the free objects directly into the remote shared array. And while we are at it: Skip alien draining if the alien cache spinlock is already taken. Kiran reported that this is a performance benefit. 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>
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