summaryrefslogtreecommitdiff
path: root/mm
AgeCommit message (Collapse)AuthorLines
2005-09-07[PATCH] introduce and use kzallocPekka J Enberg-12/+6
This patch introduces a kzalloc wrapper and converts kernel/ to use it. It saves a little program text. Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi> Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-07[PATCH] cpusets: confine oom_killer to mem_exclusive cpusetPaul Jackson-0/+5
Now the real motivation for this cpuset mem_exclusive patch series seems trivial. This patch keeps a task in or under one mem_exclusive cpuset from provoking an oom kill of a task under a non-overlapping mem_exclusive cpuset. Since only interrupt and GFP_ATOMIC allocations are allowed to escape mem_exclusive containment, there is little to gain from oom killing a task under a non-overlapping mem_exclusive cpuset, as almost all kernel and user memory allocation must come from disjoint memory nodes. This patch enables configuring a system so that a runaway job under one mem_exclusive cpuset cannot cause the killing of a job in another such cpuset that might be using very high compute and memory resources for a prolonged time. Signed-off-by: Paul Jackson <pj@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-07[PATCH] cpusets: formalize intermediate GFP_KERNEL containmentPaul Jackson-10/+14
This patch makes use of the previously underutilized cpuset flag 'mem_exclusive' to provide what amounts to another layer of memory placement resolution. With this patch, there are now the following four layers of memory placement available: 1) The whole system (interrupt and GFP_ATOMIC allocations can use this), 2) The nearest enclosing mem_exclusive cpuset (GFP_KERNEL allocations can use), 3) The current tasks cpuset (GFP_USER allocations constrained to here), and 4) Specific node placement, using mbind and set_mempolicy. These nest - each layer is a subset (same or within) of the previous. Layer (2) above is new, with this patch. The call used to check whether a zone (its node, actually) is in a cpuset (in its mems_allowed, actually) is extended to take a gfp_mask argument, and its logic is extended, in the case that __GFP_HARDWALL is not set in the flag bits, to look up the cpuset hierarchy for the nearest enclosing mem_exclusive cpuset, to determine if placement is allowed. The definition of GFP_USER, which used to be identical to GFP_KERNEL, is changed to also set the __GFP_HARDWALL bit, in the previous cpuset_gfp_hardwall_flag patch. GFP_ATOMIC and GFP_KERNEL allocations will stay within the current tasks cpuset, so long as any node therein is not too tight on memory, but will escape to the larger layer, if need be. The intended use is to allow something like a batch manager to handle several jobs, each job in its own cpuset, but using common kernel memory for caches and such. Swapper and oom_kill activity is also constrained to Layer (2). A task in or below one mem_exclusive cpuset should not cause swapping on nodes in another non-overlapping mem_exclusive cpuset, nor provoke oom_killing of a task in another such cpuset. Heavy use of kernel memory for i/o caching and such by one job should not impact the memory available to jobs in other non-overlapping mem_exclusive cpusets. This patch enables providing hardwall, inescapable cpusets for memory allocations of each job, while sharing kernel memory allocations between several jobs, in an enclosing mem_exclusive cpuset. Like Dinakar's patch earlier to enable administering sched domains using the cpu_exclusive flag, this patch also provides a useful meaning to a cpuset flag that had previously done nothing much useful other than restrict what cpuset configurations were allowed. Signed-off-by: Paul Jackson <pj@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-07[PATCH] cpusets: oom_kill tweaksPaul Jackson-26/+31
This patch series extends the use of the cpuset attribute 'mem_exclusive' to support cpuset configurations that: 1) allow GFP_KERNEL allocations to come from a potentially larger set of memory nodes than GFP_USER allocations, and 2) can constrain the oom killer to tasks running in cpusets in a specified subtree of the cpuset hierarchy. Here's an example usage scenario. For a few hours or more, a large NUMA system at a University is to be divided in two halves, with a bunch of student jobs running in half the system under some form of batch manager, and with a big research project running in the other half. Each of the student jobs is placed in a small cpuset, but should share the classic Unix time share facilities, such as buffered pages of files in /bin and /usr/lib. The big research project wants no interference whatsoever from the student jobs, and has highly tuned, unusual memory and i/o patterns that intend to make full use of all the main memory on the nodes available to it. In this example, we have two big sibling cpusets, one of which is further divided into a more dynamic set of child cpusets. We want kernel memory allocations constrained by the two big cpusets, and user allocations constrained by the smaller child cpusets where present. And we require that the oom killer not operate across the two halves of this system, or else the first time a student job runs amuck, the big research project will likely be first inline to get shot. Tweaking /proc/<pid>/oom_adj is not ideal -- if the big research project really does run amuck allocating memory, it should be shot, not some other task outside the research projects mem_exclusive cpuset. I propose to extend the use of the 'mem_exclusive' flag of cpusets to manage such scenarios. Let memory allocations for user space (GFP_USER) be constrained by a tasks current cpuset, but memory allocations for kernel space (GFP_KERNEL) by constrained by the nearest mem_exclusive ancestor of the current cpuset, even though kernel space allocations will still _prefer_ to remain within the current tasks cpuset, if memory is easily available. Let the oom killer be constrained to consider only tasks that are in overlapping mem_exclusive cpusets (it won't help much to kill a task that normally cannot allocate memory on any of the same nodes as the ones on which the current task can allocate.) The current constraints imposed on setting mem_exclusive are unchanged. A cpuset may only be mem_exclusive if its parent is also mem_exclusive, and a mem_exclusive cpuset may not overlap any of its siblings memory nodes. This patch was presented on linux-mm in early July 2005, though did not generate much feedback at that time. It has been built for a variety of arch's using cross tools, and built, booted and tested for function on SN2 (ia64). There are 4 patches in this set: 1) Some minor cleanup, and some improvements to the code layout of one routine to make subsequent patches cleaner. 2) Add another GFP flag - __GFP_HARDWALL. It marks memory requests for USER space, which are tightly confined by the current tasks cpuset. 3) Now memory requests (such as KERNEL) that not marked HARDWALL can if short on memory, look in the potentially larger pool of memory defined by the nearest mem_exclusive ancestor cpuset of the current tasks cpuset. 4) Finally, modify the oom killer to skip any task whose mem_exclusive cpuset doesn't overlap ours. Patch (1), the one time I looked on an SN2 (ia64) build, actually saved 32 bytes of kernel text space. Patch (2) has no affect on the size of kernel text space (it just adds a preprocessor flag). Patches (3) and (4) added about 600 bytes each of kernel text space, mostly in kernel/cpuset.c, which matters only if CONFIG_CPUSET is enabled. This patch: This patch applies a few comment and code cleanups to mm/oom_kill.c prior to applying a few small patches to improve cpuset management of memory placement. The comment changed in oom_kill.c was seriously misleading. The code layout change in select_bad_process() makes room for adding another condition on which a process can be spared the oom killer (see the subsequent cpuset_nodes_overlap patch for this addition). Also a couple typos and spellos that bugged me, while I was here. This patch should have no material affect. Signed-off-by: Paul Jackson <pj@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-07[PATCH] Additions to .data.read_mostly sectionRavikiran G Thirumalai-3/+3
Mark variables which are usually accessed for reads with __readmostly. Signed-off-by: Alok N Kataria <alokk@calsoftinc.com> Signed-off-by: Shai Fultheim <shai@scalex86.org> Signed-off-by: Ravikiran Thirumalai <kiran@scalex86.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-07[PATCH] readahead: reset cache_hit earlierSteven Pratt-0/+1
We don't reset the cache hit count until after readahead does a successful readahead. This seems to leave a corner case open where we miss in cache, but don't restart the readhead right away. Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-07[PATCH] remove misleading comment above sys_brkChristoph Hellwig-7/+0
Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-07[PATCH] More __read_mostly variablesChristoph Lameter-5/+5
Move some more frequently read variables that showed up during some of our performance tests as sometimes ending up in hot cachelines to the read_mostly section. Fix: Move the __read_mostly from before hpet_usec_quotient to follow the variable like the other uses of __read_mostly. Signed-off-by: Alok N Kataria <alokk@calsoftinc.com> Signed-off-by: Christoph Lameter <christoph@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>
2005-09-05[PATCH] Generic VFS fallback for security xattrsStephen Smalley-85/+0
This patch modifies the VFS setxattr, getxattr, and listxattr code to fall back to the security module for security xattrs if the filesystem does not support xattrs natively. This allows security modules to export the incore inode security label information to userspace even if the filesystem does not provide xattr storage, and eliminates the need to individually patch various pseudo filesystem types to provide such access. The patch removes the existing xattr code from devpts and tmpfs as it is then no longer needed. The patch restructures the code flow slightly to reduce duplication between the normal path and the fallback path, but this should only have one user-visible side effect - a program may get -EACCES rather than -EOPNOTSUPP if policy denied access but the filesystem didn't support the operation anyway. Note that the post_setxattr hook call is not needed in the fallback case, as the inode_setsecurity hook call handles the incore inode security state update directly. In contrast, we do call fsnotify in both cases. Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov> Acked-by: James Morris <jmorris@namei.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05[PATCH] VM: add page_state info to per-node meminfoMartin Hicks-5/+20
Add page_state info to the per-node meminfo file in sysfs. This is mostly just for informational purposes. The lack of this information was brought up recently during a discussion regarding pagecache clearing, and I put this patch together to test out one of the suggestions. It seems like interesting info to have, so I'm submitting the patch. Signed-off-by: Martin Hicks <mort@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05[PATCH] slab: removes local_irq_save()/local_irq_restore() pairManfred Spraul-11/+15
Proposed by and based on a patch from Eric Dumazet <dada1@cosmosbay.com>: This patch removes unnecessary critical section in ksize() function, as cli/sti are rather expensive on modern CPUS. It additionally adds a docbook entry for ksize() and further simplifies the code. Signed-Off-By: Manfred Spraul <manfred@colorfullife.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05[PATCH] mm/slab.c: prefetchw the start of new allocated objectsEric Dumazet-1/+3
Mostobjects returned by __cache_alloc() will be written by the caller, (but not all callers want to write all the object, but just at the begining) prefetchw() tells the modern CPU to think about the future writes, ie start some memory transactions in advance. Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05[PATCH] x86: ptep_clear optimizationZachary Amsden-2/+3
Add a new accessor for PTEs, which passes the full hint from the mmu_gather struct; this allows architectures with hardware pagetables to optimize away atomic PTE operations when destroying an address space. Removing the locked operation should allow better pipelining of memory access in this loop. I measured an average savings of 30-35 cycles per zap_pte_range on the first 500 destructions on Pentium-M, but I believe the optimization would win more on older processors which still assert the bus lock on xchg for an exclusive cacheline. Update: I made some new measurements, and this saves exactly 26 cycles over ptep_get_and_clear on Pentium M. On P4, with a PAE kernel, this saves 180 cycles per ptep_get_and_clear, for a whopping 92160 cycles savings for a full address space destruction. pte_clear_full is not yet used, but is provided for future optimizations (in particular, when running inside of a hypervisor that queues page table updates, the full hint allows us to avoid queueing unnecessary page table update for an address space in the process of being destroyed. This is not a huge win, but it does help a bit, and sets the stage for further hypervisor optimization of the mm layer on all architectures. Signed-off-by: Zachary Amsden <zach@vmware.com> Cc: Christoph Lameter <christoph@lameter.com> Cc: <linux-mm@kvack.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05[PATCH] sab: consolidate kmem_bufctl_tKyle Moffett-0/+1
This is used only in slab.c and each architecture gets to define whcih underlying type is to be used. Seems a bit silly - move it to slab.c and use the same type for all architectures: unsigned int. Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05[PATCH] hugetlb: move stale pte check into huge_pte_alloc()Adam Litke-2/+0
Initial Post (Wed, 17 Aug 2005) This patch moves the if (! pte_none(*pte)) hugetlb_clean_stale_pgtable(pte); logic into huge_pte_alloc() so all of its callers can be immune to the bug described by Kenneth Chen at http://lkml.org/lkml/2004/6/16/246 > It turns out there is a bug in hugetlb_prefault(): with 3 level page table, > huge_pte_alloc() might return a pmd that points to a PTE page. It happens > if the virtual address for hugetlb mmap is recycled from previously used > normal page mmap. free_pgtables() might not scrub the pmd entry on > munmap and hugetlb_prefault skips on any pmd presence regardless what type > it is. Unless I am missing something, it seems more correct to place the check inside huge_pte_alloc() to prevent a the same bug wherever a huge pte is allocated. It also allows checking for this condition when lazily faulting huge pages later in the series. Signed-off-by: Adam Litke <agl@us.ibm.com> Cc: <linux-mm@kvack.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05[PATCH] arm: allow for arch-specific IOREMAP_MAX_ORDERDeepak Saxena-2/+0
Version 6 of the ARM architecture introduces the concept of 16MB pages (supersections) and 36-bit (40-bit actually, but nobody uses this) physical addresses. 36-bit addressed memory and I/O and ARMv6 can only be mapped using supersections and the requirement on these is that both virtual and physical addresses be 16MB aligned. In trying to add support for ioremap() of 36-bit I/O, we run into the issue that get_vm_area() allows for a maximum of 512K alignment via the IOREMAP_MAX_ORDER constant. To work around this, we can: - Allocate a larger VM area than needed (size + (1ul << IOREMAP_MAX_ORDER)) and then align the pointer ourselves, but this ends up with 512K of wasted VM per ioremap(). - Provide a new __get_vm_area_aligned() API and make __get_vm_area() sit on top of this. I did this and it works but I don't like the idea adding another VM API just for this one case. - My preferred solution which is to allow the architecture to override the IOREMAP_MAX_ORDER constant with it's own version. Signed-off-by: Deepak Saxena <dsaxena@plexity.net> Cc: Russell King <rmk@arm.linux.org.uk> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05[PATCH] mm: remove implied vm_ops checkPaolo 'Blaisorblade' Giarrusso-1/+1
If !vma->vm-ops we already BUG above, so retesting it is useless. The compiler cannot optimize this because BUG is a macro and is not thus marked noreturn; that should possibly be fixed. Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05[PATCH] shmem_populate: avoid an useless check, and some commentsPaolo 'Blaisorblade' Giarrusso-1/+12
Either shmem_getpage returns a failure, or it found a page, or it was told it couldn't do any I/O. So it's useless to check nonblock in the else branch. We could add a BUG() there but I preferred to comment the offending function. This was taken out from one Ingo Molnar's old patch I'm resurrecting. Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Cc: Ingo Molnar <mingo@elte.hu> Cc: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05[PATCH] vm: slab.c spelling correctionMartin Hicks-1/+1
Fix a small spelling mistake. subtile->subtle Signed-off-by: Martin Hicks <mort@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05[PATCH] mm: fix madvise vma mergingHugh Dickins-4/+5
Better late than never, I've at last reviewed the madvise vma merging going into 2.6.13. Remove a pointless check and fix two little bugs - a simple test (with /proc/<pid>/maps hacked to show ReadHints) showed both mismerges in practice: though being madvise, neither was disastrous. 1. Correct placement of the success label in madvise_behavior: as in mprotect_fixup and mlock_fixup, it is necessary to update vm_flags when vma_merge succeeds (to handle the exceptional Case 8 noted in the comments above vma_merge itself). 2. Correct initial value of prev when starting part way into a vma: as in sys_mprotect and do_mlock, it needs to be set to vma in this case (vma_merge handles only that minimum of cases shown in its comments). 3. If find_vma_prev sets prev, then the vma it returns is prev->vm_next, so it's pointless to make that same assignment again in sys_madvise. Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05[PATCH] VM: zone reclaim atomic ops cleanupMartin Hicks-5/+6
Christoph Lameter and Marcelo Tosatti asked to get rid of the atomic_inc_and_test() to cleanup the atomic ops in the zone reclaim code. Signed-off-by: Martin Hicks <mort@sgi.com> Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05[PATCH] VM: add capabilites check to set_zone_reclaimMartin Hicks-0/+3
Add a capability check to sys_set_zone_reclaim(). This syscall is not something that should be available to a user. Signed-off-by: Martin Hicks <mort@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05[PATCH] mm: remove atomicNick Piggin-1/+1
This bitop does not need to be atomic because it is performed when there will be no references to the page (ie. the page is being freed). Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05[PATCH] mm: remap ZERO_PAGE mappingsNick Piggin-0/+4
filemap_xip's nopage routine maps the ZERO_PAGE into readonly mappings, if it has no data page to map there: then if the hole in the file is later filled, __xip_unmap uses an rmap technique to replace the ZERO_PAGEs mapped for that offset by the newly allocated file page, so that established mappings will see the newly written data. However, on MIPS (alone) there's not one but as many as eight ZERO_PAGEs, chosen for coloring by user virtual address; and if mremap has meanwhile been used to move a mapping containing a ZERO_PAGE, it will generally not match the ZERO_PAGE(address) __xip_unmap is looking for. To maintain XIP's established mappings correctly on MIPS, we need Nick's fix to mremap's move_one_page (originally presented as an optimization), to replace the ZERO_PAGE appropriate to the old address by the ZERO_PAGE appropriate to the new address. (But when I first saw this, I was thinking the ZERO_PAGEs themselves would get corrupted, very bad. Now I think it's the other way round, that the established mappings will fail to see the newly written data: incorrect, but not corrupting everything else. Whether filemap_xip's technique is generally safe, I'd hesitate to say in a hurry: it's interesting, but we've never tried to do that in tmpfs.) Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05[PATCH] mm: cleanup rmapNick Piggin-5/+1
Thanks to Bill Irwin for pointing this out. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05[PATCH] mm: micro-optimise rmapNick Piggin-10/+11
Microoptimise page_add_anon_rmap. Although these expressions are used only in the taken branch of the if() statement, the compiler can't reorder them inside because atomic_inc_and_test is a barrier. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05[PATCH] mm: comment rmapNick Piggin-0/+2
Just be clear that VM_RESERVED pages here are a bug, and the test is not there because they are expected. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05[PATCH] /proc/<pid>/numa_maps to show on which nodes pages resideChristoph Lameter-6/+6
This patch was recently discussed on linux-mm: http://marc.theaimsgroup.com/?t=112085728500002&r=1&w=2 I inherited a large code base from Ray for page migration. There was a small patch in there that I find to be very useful since it allows the display of the locality of the pages in use by a process. I reworked that patch and came up with a /proc/<pid>/numa_maps that gives more information about the vma's of a process. numa_maps is indexes by the start address found in /proc/<pid>/maps. F.e. with this patch you can see the page use of the "getty" process: margin:/proc/12008 # cat maps 00000000-00004000 r--p 00000000 00:00 0 2000000000000000-200000000002c000 r-xp 00000000 08:04 516 /lib/ld-2.3.3.so 2000000000038000-2000000000040000 rw-p 00028000 08:04 516 /lib/ld-2.3.3.so 2000000000040000-2000000000044000 rw-p 2000000000040000 00:00 0 2000000000058000-2000000000260000 r-xp 00000000 08:04 54707842 /lib/tls/libc.so.6.1 2000000000260000-2000000000268000 ---p 00208000 08:04 54707842 /lib/tls/libc.so.6.1 2000000000268000-2000000000274000 rw-p 00200000 08:04 54707842 /lib/tls/libc.so.6.1 2000000000274000-2000000000280000 rw-p 2000000000274000 00:00 0 2000000000280000-20000000002b4000 r--p 00000000 08:04 9126923 /usr/lib/locale/en_US.utf8/LC_CTYPE 2000000000300000-2000000000308000 r--s 00000000 08:04 60071467 /usr/lib/gconv/gconv-modules.cache 2000000000318000-2000000000328000 rw-p 2000000000318000 00:00 0 4000000000000000-4000000000008000 r-xp 00000000 08:04 29576399 /sbin/mingetty 6000000000004000-6000000000008000 rw-p 00004000 08:04 29576399 /sbin/mingetty 6000000000008000-600000000002c000 rw-p 6000000000008000 00:00 0 [heap] 60000fff7fffc000-60000fff80000000 rw-p 60000fff7fffc000 00:00 0 60000ffffff44000-60000ffffff98000 rw-p 60000ffffff44000 00:00 0 [stack] a000000000000000-a000000000020000 ---p 00000000 00:00 0 [vdso] cat numa_maps 2000000000000000 default MaxRef=43 Pages=11 Mapped=11 N0=4 N1=3 N2=2 N3=2 2000000000038000 default MaxRef=1 Pages=2 Mapped=2 Anon=2 N0=2 2000000000040000 default MaxRef=1 Pages=1 Mapped=1 Anon=1 N0=1 2000000000058000 default MaxRef=43 Pages=61 Mapped=61 N0=14 N1=15 N2=16 N3=16 2000000000268000 default MaxRef=1 Pages=2 Mapped=2 Anon=2 N0=2 2000000000274000 default MaxRef=1 Pages=3 Mapped=3 Anon=3 N0=3 2000000000280000 default MaxRef=8 Pages=3 Mapped=3 N0=3 2000000000300000 default MaxRef=8 Pages=2 Mapped=2 N0=2 2000000000318000 default MaxRef=1 Pages=1 Mapped=1 Anon=1 N2=1 4000000000000000 default MaxRef=6 Pages=2 Mapped=2 N1=2 6000000000004000 default MaxRef=1 Pages=1 Mapped=1 Anon=1 N0=1 6000000000008000 default MaxRef=1 Pages=1 Mapped=1 Anon=1 N0=1 60000fff7fffc000 default MaxRef=1 Pages=1 Mapped=1 Anon=1 N0=1 60000ffffff44000 default MaxRef=1 Pages=1 Mapped=1 Anon=1 N0=1 getty uses ld.so. The first vma is the code segment which is used by 43 other processes and the pages are evenly distributed over the 4 nodes. The second vma is the process specific data portion for ld.so. This is only one page. The display format is: <startaddress> Links to information in /proc/<pid>/map <memory policy> This can be "default" "interleave={}", "prefer=<node>" or "bind={<zones>}" MaxRef= <maximum reference to a page in this vma> Pages= <Nr of pages in use> Mapped= <Nr of pages with mapcount > Anon= <nr of anonymous pages> Nx= <Nr of pages on Node x> The content of the proc-file is self-evident. If this would be tied into the sparsemem system then the contents of this file would not be too useful. Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05[PATCH] rmap: don't test rssHugh Dickins-6/+1
Remove the three get_mm_counter(mm, rss) tests from rmap.c: there was a time when testing rss was important to avoid a particular race between dup_mmap and the anonmm rmap; but now it's just a rather silly pseudo- optimization, made even more obscure by the get_mm_counter macro. Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05[PATCH] delete from_swap_cache BUG_ONsHugh Dickins-5/+1
Three of the four BUG_ONs in delete_from_swap_cache are immediately repeated in __delete_from_swap_cache: delete those and add the one. But perhaps mm/ is altogether overprovisioned with historic BUGs? Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05[PATCH] swap: swap_lock replace list+deviceHugh Dickins-78/+57
The idea of a swap_device_lock per device, and a swap_list_lock over them all, is appealing; but in practice almost every holder of swap_device_lock must already hold swap_list_lock, which defeats the purpose of the split. The only exceptions have been swap_duplicate, valid_swaphandles and an untrodden path in try_to_unuse (plus a few places added in this series). valid_swaphandles doesn't show up high in profiles, but swap_duplicate does demand attention. However, with the hold time in get_swap_pages so much reduced, I've not yet found a load and set of swap device priorities to show even swap_duplicate benefitting from the split. Certainly the split is mere overhead in the common case of a single swap device. So, replace swap_list_lock and swap_device_lock by spinlock_t swap_lock (generally we seem to prefer an _ in the name, and not hide in a macro). If someone can show a regression in swap_duplicate, then probably we should add a hashlock for the swap_map entries alone (shorts being anatomic), so as to help the case of the single swap device too. Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05[PATCH] swap: scan_swap_map latency breaksHugh Dickins-2/+12
The get_swap_page/scan_swap_map latency can be so bad that even those without preemption configured deserve relief: periodically cond_resched. Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05[PATCH] swap: scan_swap_map drop swap_device_lockHugh Dickins-7/+35
get_swap_page has often shown up on latency traces, doing lengthy scans while holding two spinlocks. swap_list_lock is already dropped, now scan_swap_map drop swap_device_lock before scanning the swap_map. While scanning for an empty cluster, don't worry that racing tasks may allocate what was free and free what was allocated; but when allocating an entry, check it's still free after retaking the lock. Avoid dropping the lock in the expected common path. No barriers beyond the locks, just let the cookie crumble; highest_bit limit is volatile, but benign. Guard against swapoff: must check SWP_WRITEOK before allocating, must raise SWP_SCANNING reference count while in scan_swap_map, swapoff wait for that to fall - just use schedule_timeout, we don't want to burden scan_swap_map itself, and it's very unlikely that anyone can really still be in scan_swap_map once swapoff gets this far. Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05[PATCH] swap: scan_swap_map restyledHugh Dickins-45/+48
Rewrite scan_swap_map to allocate in just the same way as before (taking the next free entry SWAPFILE_CLUSTER-1 times, then restarting at the lowest wholly empty cluster, falling back to lowest entry if none), but with a view towards dropping the lock in the next patch. Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05[PATCH] swap: get_swap_page drop swap_list_lockHugh Dickins-39/+36
Rewrite get_swap_page to allocate in just the same sequence as before, but without holding swap_list_lock across its scan_swap_map. Decrement nr_swap_pages and update swap_list.next in advance, while still holding swap_list_lock. Skip full devices by testing highest_bit. Swapoff hold swap_device_lock as well as swap_list_lock to clear SWP_WRITEOK. Reduces lock contention when there are parallel swap devices of the same priority. Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05[PATCH] swap: freeing update swap_list.nextHugh Dickins-2/+2
This makes negligible difference in practice: but swap_list.next should not be updated to a higher prio in the general helper swap_info_get, but rather in swap_entry_free; and then only in the case when entry is actually freed. Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05[PATCH] swap: swap unsigned int consistencyHugh Dickins-9/+10
The swap header's unsigned int last_page determines the range of swap pages, but swap_info has been using int or unsigned long in some cases: use unsigned int throughout (except, in several places a local unsigned long is useful to avoid overflows when adding). Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Jens Axboe <axboe@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05[PATCH] swap: show span of swap extentsHugh Dickins-14/+30
The "Adding %dk swap" message shows the number of swap extents, as a guide to how fragmented the swapfile may be. But a useful further guide is what total extent they span across (sometimes scarily large). And there's no need to keep nr_extents in swap_info: it's unused after the initial message, so save a little space by keeping it on stack. Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05[PATCH] swap: swap extent list is orderedHugh Dickins-18/+9
There are several comments that swap's extent_list.prev points to the lowest extent: that's not so, it's extent_list.next which points to it, as you'd expect. And a couple of loops in add_swap_extent which go all the way through the list, when they should just add to the other end. Fix those up, and let map_swap_page search the list forwards: profiles shows it to be twice as quick that way - because prefetch works better on how the structs are typically kmalloc'ed? or because usually more is written to than read from swap, and swap is allocated ascendingly? Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05[PATCH] swap: move destroy_swap_extents callsHugh Dickins-2/+2
sys_swapon's call to destroy_swap_extents on failure is made after the final swap_list_unlock, which is faintly unsafe: another sys_swapon might already be setting up that swap_info_struct. Calling it earlier, before taking swap_list_lock, is safe. sys_swapoff's call to destroy_swap_extents was safe, but likewise move it earlier, before taking the locks (once try_to_unuse has completed, nothing can be needing the swap extents). Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05[PATCH] swap: correct swapfile nr_good_pagesHugh Dickins-9/+16
If a regular swapfile lies on a filesystem whose blocksize is less than PAGE_SIZE, then setup_swap_extents may have to cut the number of usable swap pages; but sys_swapon's nr_good_pages was not expecting that. Also, setup_swap_extents takes no account of badpages listed in the swap header: not worth doing so, but ensure nr_badpages is 0 for a regular swapfile. Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05[PATCH] swap: update swapfile i_sem commentHugh Dickins-1/+1
Update swap extents comment: nowadays we guard with S_SWAPFILE not i_sem. Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05[PATCH] sparsemem extreme: hotplug preparationDave Hansen-12/+41
This splits up sparse_index_alloc() into two pieces. This is needed because we'll allocate the memory for the second level in a different place from where we actually consume it to keep the allocation from happening underneath a lock Signed-off-by: Dave Hansen <haveblue@us.ibm.com> Signed-off-by: Bob Picco <bob.picco@hp.com> Cc: Andy Whitcroft <apw@shadowen.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05[PATCH] sparsemem extreme implementationBob Picco-12/+33
With cleanups from Dave Hansen <haveblue@us.ibm.com> SPARSEMEM_EXTREME makes mem_section a one dimensional array of pointers to mem_sections. This two level layout scheme is able to achieve smaller memory requirements for SPARSEMEM with the tradeoff of an additional shift and load when fetching the memory section. The current SPARSEMEM implementation is a one dimensional array of mem_sections which is the default SPARSEMEM configuration. The patch attempts isolates the implementation details of the physical layout of the sparsemem section array. SPARSEMEM_EXTREME requires bootmem to be functioning at the time of memory_present() calls. This is not always feasible, so architectures which do not need it may allocate everything statically by using SPARSEMEM_STATIC. Signed-off-by: Andy Whitcroft <apw@shadowen.org> Signed-off-by: Bob Picco <bob.picco@hp.com> Signed-off-by: Dave Hansen <haveblue@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05[PATCH] SPARSEMEM EXTREMEBob Picco-6/+41
A new option for SPARSEMEM is ARCH_SPARSEMEM_EXTREME. Architecture platforms with a very sparse physical address space would likely want to select this option. For those architecture platforms that don't select the option, the code generated is equivalent to SPARSEMEM currently in -mm. I'll be posting a patch on ia64 ml which uses this new SPARSEMEM feature. ARCH_SPARSEMEM_EXTREME makes mem_section a one dimensional array of pointers to mem_sections. This two level layout scheme is able to achieve smaller memory requirements for SPARSEMEM with the tradeoff of an additional shift and load when fetching the memory section. The current SPARSEMEM -mm implementation is a one dimensional array of mem_sections which is the default SPARSEMEM configuration. The patch attempts isolates the implementation details of the physical layout of the sparsemem section array. ARCH_SPARSEMEM_EXTREME depends on 64BIT and is by default boolean false. I've boot tested under aim load ia64 configured for ARCH_SPARSEMEM_EXTREME. I've also boot tested a 4 way Opteron machine with !ARCH_SPARSEMEM_EXTREME and tested with aim. Signed-off-by: Andy Whitcroft <apw@shadowen.org> Signed-off-by: Bob Picco <bob.picco@hp.com> Signed-off-by: Dave Hansen <haveblue@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-08-29[PATCH] Lazy page table copies in fork()Nick Piggin-0/+11
Defer copying of ptes until fault time when it is possible to reconstruct the pte from backing store. Idea from Andi Kleen and Nick Piggin. Thanks to input from Rik van Riel and Linus and to Hugh for correcting my blundering. Ray Fucillo <fucillo@intersystems.com> reports: "I applied this latest patch to a 2.6.12 kernel and found that it does resolve the problem. Prior to the patch on this machine, I was seeing about 23ms spent in fork for ever 100MB of shared memory segment. After applying the patch, fork is taking about 1ms regardless of the shared memory size." Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-08-19Fix nasty ncpfs symlink handling bug.Linus Torvalds-11/+6
This bug could cause oopses and page state corruption, because ncpfs used the generic page-cache symlink handlign functions. But those functions only work if the page cache is guaranteed to be "stable", ie a page that was installed when the symlink walk was started has to still be installed in the page cache at the end of the walk. We could have fixed ncpfs to not use the generic helper routines, but it is in many ways much cleaner to instead improve on the symlink walking helper routines so that they don't require that absolute stability. We do this by allowing "follow_link()" to return a error-pointer as a cookie, which is fed back to the cleanup "put_link()" routine. This also simplifies NFS symlink handling. Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-08-05[PATCH] Fix hugepage crash on failing mmap()David Gibson-1/+10
This patch fixes a crash in the hugepage code. unmap_hugepage_area() was assuming that (due to prefault) PTEs must exist for all the area in question. However, this may not be the case, if mmap() encounters an error before the prefault and calls unmap_region() to clean up any partial mapping. Depending on the hugepage configuration, this crash can be triggered by an unpriveleged user. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Cc: William Lee Irwin III <wli@holomorphy.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-08-04[PATCH] __vm_enough_memory() signedness fixSimon Derr-2/+10
We have found what seems to be a small bug in __vm_enough_memory() when sysctl_overcommit_memory is set to OVERCOMMIT_NEVER. When this bug occurs the systems fails to boot, with /sbin/init whining about fork() returning ENOMEM. We hunted down the problem to this: The deferred update mecanism used in vm_acct_memory(), on a SMP system, allows the vm_committed_space counter to have a negative value. This should not be a problem since this counter is known to be inaccurate. But in __vm_enough_memory() this counter is compared to the `allowed' variable, which is an unsigned long. This comparison is broken since it will consider the negative values of vm_committed_space to be huge positive values, resulting in a memory allocation failure. Signed-off-by: <Jean-Marc.Saffroy@ext.bull.net> Signed-off-by: <Simon.Derr@bull.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-08-04[PATCH] fix VmSize and VmData after mremapHugh Dickins-1/+1
mremap's move_vma is applying __vm_stat_account to the old vma which may have already been freed: move it to just before the do_munmap. mremapping to and fro with CONFIG_DEBUG_SLAB=y showed /proc/<pid>/status VmSize and VmData wrapping just like in kernel bugzilla #4842, and fixed by this patch - worth including in 2.6.13, though not yet confirmed that it fixes that specific report from Frank van Maarseveen. Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>