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* [PATCH] fix alloc_large_system_hash() roundupJohn Hawkes2006-03-25
| | | | | | | | | | | | | | The "rounded up to nearest power of 2 in size" algorithm in alloc_large_system_hash is not correct. As coded, it takes an otherwise acceptable power-of-2 value and doubles it. For example, we see the error if we boot with thash_entries=2097152 which produces a hash table with 4194304 entries. Signed-off-by: John Hawkes <hawkes@sgi.com> Cc: Roland Dreier <rdreier@cisco.com> Cc: "Chen, Kenneth W" <kenneth.w.chen@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] find_task_by_pid() needs tasklist_lockAndrew Morton2006-03-25
| | | | | | | | | | | | | | | | | | | | A couple of places are forgetting to take it. The kswapd case is probably unimportant. keventd_create_kthread() was racy. The whole thing is a bit flakey: you start a kernel thread, get its pid from kernel_thread() then look up its task_struct. a) It assumes that pid recycling takes a "long" time. b) We get a task_struct but no reference was taken on it. The owner of the kswapd and kthread task_struct*'s must assume that the new thread won't exit unexpectedly. Because if it does, they're left holding dead memory and any attempt to control or stop that task will crash. Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] quieten zone_pcp_initAnton Blanchard2006-03-25
| | | | | | | | | | | | | | | | In zone_pcp_init we print out all zones even if they are empty: On node 0 totalpages: 245760 DMA zone: 245760 pages, LIFO batch:31 DMA32 zone: 0 pages, LIFO batch:0 Normal zone: 0 pages, LIFO batch:0 HighMem zone: 0 pages, LIFO batch:0 To conserve dmesg space why not print only the non zero zones. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] mm: make page migration dependent on swap and NUMAChristoph Lameter2006-03-25
| | | | | | | | | | The page migration code could function without NUMA but we currently have no users for the non-NUMA case. Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Adrian Bunk <bunk@stusta.de> 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>
* [PATCH] slab: add transfer_objects() functionChristoph Lameter2006-03-25
| | | | | | | | | | | | | slabr_objects() can be used to transfer objects between various object caches of the slab allocator. It is currently only used during __cache_alloc() to retrieve elements from the shared array. We will be using it soon to transfer elements from the alien caches to the remote shared array. 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] mm: use kmem_cache_zallocPekka Enberg2006-03-25
| | | | | | | | Convert mm/ to use the new kmem_cache_zalloc allocator. 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: optimize constant-size kzalloc callsPekka Enberg2006-03-25
| | | | | | | | | | As suggested by Eric Dumazet, optimize kzalloc() calls that pass a compile-time constant size. Please note that the patch increases kernel text slightly (~200 bytes for defconfig on x86). 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: introduce kmem_cache_zalloc allocatorPekka Enberg2006-03-25
| | | | | | | | | | Introduce a memory-zeroing variant of kmem_cache_alloc. The allocator already exits in XFS and there are potential users for it so this patch makes the allocator available for the general public. Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] slab: implement /proc/slab_allocatorsAl Viro2006-03-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Implement /proc/slab_allocators. It produces output like: idr_layer_cache: 80 idr_pre_get+0x33/0x4e buffer_head: 2555 alloc_buffer_head+0x20/0x75 mm_struct: 9 mm_alloc+0x1e/0x42 mm_struct: 20 dup_mm+0x36/0x370 vm_area_struct: 384 dup_mm+0x18f/0x370 vm_area_struct: 151 do_mmap_pgoff+0x2e0/0x7c3 vm_area_struct: 1 split_vma+0x5a/0x10e vm_area_struct: 11 do_brk+0x206/0x2e2 vm_area_struct: 2 copy_vma+0xda/0x142 vm_area_struct: 9 setup_arg_pages+0x99/0x214 fs_cache: 8 copy_fs_struct+0x21/0x133 fs_cache: 29 copy_process+0xf38/0x10e3 files_cache: 30 alloc_files+0x1b/0xcf signal_cache: 81 copy_process+0xbaa/0x10e3 sighand_cache: 77 copy_process+0xe65/0x10e3 sighand_cache: 1 de_thread+0x4d/0x5f8 anon_vma: 241 anon_vma_prepare+0xd9/0xf3 size-2048: 1 add_sect_attrs+0x5f/0x145 size-2048: 2 journal_init_revoke+0x99/0x302 size-2048: 2 journal_init_revoke+0x137/0x302 size-2048: 2 journal_init_inode+0xf9/0x1c4 Cc: Manfred Spraul <manfred@colorfullife.com> Cc: Alexander Nyberg <alexn@telia.com> Cc: Pekka Enberg <penberg@cs.helsinki.fi> Cc: Christoph Lameter <clameter@engr.sgi.com> Cc: Ravikiran Thirumalai <kiran@scalex86.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> DESC slab-leaks3-locking-fix EDESC From: Andrew Morton <akpm@osdl.org> Update for slab-remove-cachep-spinlock.patch Cc: Al Viro <viro@ftp.linux.org.uk> Cc: Manfred Spraul <manfred@colorfullife.com> Cc: Alexander Nyberg <alexn@telia.com> Cc: Pekka Enberg <penberg@cs.helsinki.fi> Cc: Christoph Lameter <clameter@engr.sgi.com> Cc: Ravikiran Thirumalai <kiran@scalex86.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] strndup_user()Davi Arnaut2006-03-24
| | | | | | | | | | | This patch series creates a strndup_user() function to easy copying C strings from userspace. Also we avoid common pitfalls like userspace modifying the final \0 after the strlen_user(). Signed-off-by: Davi Arnaut <davi.arnaut@gmail.com> Cc: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] msync(): use do_fsync()Andrew Morton2006-03-24
| | | | | | | | | No need to duplicate all that code. Cc: Hugh Dickins <hugh@veritas.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] msync: fix return valueAndrew Morton2006-03-24
| | | | | | | | | | | | | | | | | | | | | | msync() does a strange thing. Essentially: vma = find_vma(); for ( ; ; ) { if (!vma) return -ENOMEM; ... vma = vma->vm_next; } so an msync() request which starts within or before a valid VMA and which ends within or beyond the final VMA will incorrectly return -ENOMEM. Fix. Cc: Hugh Dickins <hugh@veritas.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] msync(MS_SYNC): don't hold mmap_sem while syncingAndrew Morton2006-03-24
| | | | | | | | | | It seems bad to hold mmap_sem while performing synchronous disk I/O. Alter the msync(MS_SYNC) code so that the lock is released while we sync the file. Cc: Hugh Dickins <hugh@veritas.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] msync(): perform dirty page levellingAndrew Morton2006-03-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It seems sensible to perform dirty page throttling in msync: as the application dirties pages we can kick off pdflush early, or even force the msync() caller to perform writeout, or even throttle the msync() caller. The main effect of this is to start disk writeback earlier if we've just discovered that a large amount of pagecache has been dirtied. (Otherwise it wouldn't happen for up to five seconds, next time pdflush wakes up). It also will cause the page-dirtying process to get panalised for dirtying those pages rather than whacking someone else with the problem. We should do this for munmap() and possibly even exit(), too. We drop the mmap_sem while performing the dirty page balancing. It doesn't seem right to hold mmap_sem for that long. Note that this patch only affects MS_ASYNC. MS_SYNC will be syncing all the dirty pages anyway. We note that msync(MS_SYNC) does a full-file-sync inside mmap_sem, and always has. We can fix that up... The patch also tightens up the mmap_sem coverage in sys_msync(): no point in taking it while we perform the incoming arg checking. Cc: Hugh Dickins <hugh@veritas.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] set_page_dirty() return value fixesAndrew Morton2006-03-24
| | | | | | | | | | | | We need set_page_dirty() to return true if it actually transitioned the page from a clean to dirty state. This wasn't right in a couple of places. Do a kernel-wide audit, fix things up. This leaves open the possibility of returning a negative errno from set_page_dirty() sometime in the future. But we don't do that at present. Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] balance_dirty_pages_ratelimited: take nr_pages argAndrew Morton2006-03-24
| | | | | | | | Modify balance_dirty_pages_ratelimited() so that it can take a number-of-pages-which-I-just-dirtied argument. For msync(). Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] fadvise(): write commandsAndrew Morton2006-03-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add two new linux-specific fadvise extensions(): LINUX_FADV_ASYNC_WRITE: start async writeout of any dirty pages between file offsets `offset' and `offset+len'. Any pages which are currently under writeout are skipped, whether or not they are dirty. LINUX_FADV_WRITE_WAIT: wait upon writeout of any dirty pages between file offsets `offset' and `offset+len'. By combining these two operations the application may do several things: LINUX_FADV_ASYNC_WRITE: push some or all of the dirty pages at the disk. LINUX_FADV_WRITE_WAIT, LINUX_FADV_ASYNC_WRITE: push all of the currently dirty pages at the disk. LINUX_FADV_WRITE_WAIT, LINUX_FADV_ASYNC_WRITE, LINUX_FADV_WRITE_WAIT: push all of the currently dirty pages at the disk, wait until they have been written. It should be noted that none of these operations write out the file's metadata. So unless the application is strictly performing overwrites of already-instantiated disk blocks, there are no guarantees here that the data will be available after a crash. To complete this suite of operations I guess we should have a "sync file metadata only" operation. This gives applications access to all the building blocks needed for all sorts of sync operations. But sync-metadata doesn't fit well with the fadvise() interface. Probably it should be a new syscall: sys_fmetadatasync(). The patch also diddles with the meaning of `endbyte' in sys_fadvise64_64(). It is made to represent that last affected byte in the file (ie: it is inclusive). Generally, all these byterange and pagerange functions are inclusive so we can easily represent EOF with -1. As Ulrich notes, these two functions are somewhat abusive of the fadvise() concept, which appears to be "set the future policy for this fd". But these commands are a perfect fit with the fadvise() impementation, and several of the existing fadvise() commands are synchronous and don't affect future policy either. I think we can live with the slight incongruity. Cc: Michael Kerrisk <mtk-manpages@gmx.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] filemap_fdatawrite_range() api: clarify -end parameterAndrew Morton2006-03-24
| | | | | | | | | I had trouble understanding working out whether filemap_fdatawrite_range()'s `end' parameter describes the last-byte-to-be-written or the last-plus-one. Clarify that in comments. Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] cpuset: memory_spread_slab drop useless PF_SPREAD_PAGE checkPaul Jackson2006-03-24
| | | | | | | | | | | | | | | | | | | The hook in the slab cache allocation path to handle cpuset memory spreading for tasks in cpusets with 'memory_spread_slab' enabled has a modest performance bug. The hook calls into the memory spreading handler alternate_node_alloc() if either of 'memory_spread_slab' or 'memory_spread_page' is enabled, even though the handler does nothing (albeit harmlessly) for the page case Fix - drop PF_SPREAD_PAGE from the set of flag bits that are used to trigger a call to alternate_node_alloc(). The page case is handled by separate hooks -- see the calls conditioned on cpuset_do_page_mem_spread() in mm/filemap.c Signed-off-by: Paul Jackson <pj@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] cpuset memory spread slab cache optimizationsPaul Jackson2006-03-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | The hooks in the slab cache allocator code path for support of NUMA mempolicies and cpuset memory spreading are in an important code path. Many systems will use neither feature. This patch optimizes those hooks down to a single check of some bits in the current tasks task_struct flags. For non NUMA systems, this hook and related code is already ifdef'd out. The optimization is done by using another task flag, set if the task is using a non-default NUMA mempolicy. Taking this flag bit along with the PF_SPREAD_PAGE and PF_SPREAD_SLAB flag bits added earlier in this 'cpuset memory spreading' patch set, one can check for the combination of any of these special case memory placement mechanisms with a single test of the current tasks task_struct flags. This patch also tightens up the code, to save a few bytes of kernel text space, and moves some of it out of line. Due to the nested inlines called from multiple places, we were ending up with three copies of this code, which once we get off the main code path (for local node allocation) seems a bit wasteful of instruction memory. Signed-off-by: Paul Jackson <pj@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] cpuset memory spread slab cache implementationPaul Jackson2006-03-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Provide the slab cache infrastructure to support cpuset memory spreading. See the previous patches, cpuset_mem_spread, for an explanation of cpuset memory spreading. This patch provides a slab cache SLAB_MEM_SPREAD flag. If set in the kmem_cache_create() call defining a slab cache, then any task marked with the process state flag PF_MEMSPREAD will spread memory page allocations for that cache over all the allowed nodes, instead of preferring the local (faulting) node. On systems not configured with CONFIG_NUMA, this results in no change to the page allocation code path for slab caches. On systems with cpusets configured in the kernel, but the "memory_spread" cpuset option not enabled for the current tasks cpuset, this adds a call to a cpuset routine and failed bit test of the processor state flag PF_SPREAD_SLAB. For tasks so marked, a second inline test is done for the slab cache flag SLAB_MEM_SPREAD, and if that is set and if the allocation is not in_interrupt(), this adds a call to to a cpuset routine that computes which of the tasks mems_allowed nodes should be preferred for this allocation. ==> This patch adds another hook into the performance critical code path to allocating objects from the slab cache, in the ____cache_alloc() chunk, below. The next patch optimizes this hook, reducing the impact of the combined mempolicy plus memory spreading hooks on this critical code path to a single check against the tasks task_struct flags word. This patch provides the generic slab flags and logic needed to apply memory spreading to a particular slab. A subsequent patch will mark a few specific slab caches for this placement policy. Signed-off-by: Paul Jackson <pj@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] cpuset memory spread page cache implementation and hooksPaul Jackson2006-03-24
| | | | | | | | | | | | | | | | | | | | | | | | Change the page cache allocation calls to support cpuset memory spreading. See the previous patch, cpuset_mem_spread, for an explanation of cpuset memory spreading. On systems without cpusets configured in the kernel, this is no change. On systems with cpusets configured in the kernel, but the "memory_spread" cpuset option not enabled for the current tasks cpuset, this adds a call to a cpuset routine and failed bit test of the processor state flag PF_SPREAD_PAGE. On tasks in cpusets with "memory_spread" enabled, this adds a call to a cpuset routine that computes which of the tasks mems_allowed nodes should be preferred for this allocation. If memory spreading applies to a particular allocation, then any other NUMA mempolicy does not apply. Signed-off-by: Paul Jackson <pj@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] cpusets: only wakeup kswapd for zones in the current cpusetChristoph Lameter2006-03-24
| | | | | | | | | | | If we get under some memory pressure in a cpuset (we only scan zones that are in the cpuset for memory) then kswapd is woken up for all zones. This patch only wakes up kswapd in zones that are part of the current cpuset. Signed-off-by: Christoph Lameter <clameter@sgi.com> Acked-by: Paul Jackson <pj@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Represent laptop_mode as jiffies internallyBart Samwel2006-03-24
| | | | | | | | | | | | | Make that the internal value for /proc/sys/vm/laptop_mode is stored as jiffies instead of seconds. Let the sysctl interface do the conversions, instead of doing on-the-fly conversions every time the value is used. Add a description of the fact that laptop_mode doubles as a flag and a timeout to the comment above the laptop_mode variable. Signed-off-by: Bart Samwel <bart@samwel.tk> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Represent dirty_*_centisecs as jiffies internallyBart Samwel2006-03-24
| | | | | | | | | | | | | | | | | | | | | Make that the internal values for: /proc/sys/vm/dirty_writeback_centisecs /proc/sys/vm/dirty_expire_centisecs are stored as jiffies instead of centiseconds. Let the sysctl interface do the conversions with full precision using clock_t_to_jiffies, instead of doing overflow-sensitive on-the-fly conversions every time the values are used. Cons: apparent precision loss if HZ is not a multiple of 100, because of conversion back and forth. This is a common problem for all sysctl values that use proc_dointvec_userhz_jiffies. (There is only one other in-tree use, in net/core/neighbour.c.) Signed-off-by: Bart Samwel <bart@samwel.tk> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Block queue IO tracing support (blktrace) as of 2006-03-23Jens Axboe2006-03-23
| | | | Signed-off-by: Jens Axboe <axboe@suse.de>
* [PATCH] ext3_readdir: use generic readaheadAndrew Morton2006-03-23
| | | | | | | | | | | | | | | | | | | | | | Linus points out that ext3_readdir's readahead only cuts in when ext3_readdir() is operating at the very start of the directory. So for large directories we end up performing no readahead at all and we suck. So take it all out and use the core VM's page_cache_readahead(). This means that ext3 directory reads will use all of readahead's dynamic sizing goop. Note that we're using the directory's filp->f_ra to hold the readahead state, but readahead is actually being performed against the underlying blockdev's address_space. Fortunately the readahead code is all set up to handle this. Tested with printk. It works. I was struggling to find a real workload which actually cared. (The patch also exports page_cache_readahead() to GPL modules) Cc: "Stephen C. Tweedie" <sct@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] swsusp: userland interfaceRafael J. Wysocki2006-03-23
| | | | | | | | | | | | | | | | | | | | | | | | | This patch introduces a user space interface for swsusp. The interface is based on a special character device, called the snapshot device, that allows user space processes to perform suspend and resume-related operations with the help of some ioctls and the read()/write() functions.  Additionally it allows these processes to allocate free swap pages from a selected swap partition, called the resume partition, so that they know which sectors of the resume partition are available to them. The interface uses the same low-level system memory snapshot-handling functions that are used by the built-it swap-writing/reading code of swsusp. The interface documentation is included in the patch. The patch assumes that the major and minor numbers of the snapshot device will be 10 (ie. misc device) and 231, the registration of which has already been requested. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] swsusp: low level interfaceRafael J. Wysocki2006-03-23
| | | | | | | | | | | | | | | | | | Introduce the low level interface that can be used for handling the snapshot of the system memory by the in-kernel swap-writing/reading code of swsusp and the userland interface code (to be introduced shortly). Also change the way in which swsusp records the allocated swap pages and, consequently, simplifies the in-kernel swap-writing/reading code (this is necessary for the userland interface too). To this end, it introduces two helper functions in mm/swapfile.c, so that the swsusp code does not refer directly to the swap internals. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Pavel Machek <pavel@ucw.cz> 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] page migration reorgChristoph Lameter2006-03-22
| | | | | | | | | | | | | | | | | | | | | | Centralize the page migration functions in anticipation of additional tinkering. Creates a new file mm/migrate.c 1. Extract buffer_migrate_page() from fs/buffer.c 2. Extract central migration code from vmscan.c 3. Extract some components from mempolicy.c 4. Export pageout() and remove_from_swap() from vmscan.c 5. Make it possible to configure NUMA systems without page migration and non-NUMA systems with page migration. I had to so some #ifdeffing in mempolicy.c that may need a cleanup. 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] mm: slab cache interleave rotor fixPaul Jackson2006-03-22
| | | | | | | | | | | | | The alien cache rotor in mm/slab.c assumes that the first online node is node 0. Eventually for some archs, especially with hotplug, this will no longer be true. Fix the interleave rotor to handle the general case of node numbering. Signed-off-by: Paul Jackson <pj@sgi.com> Acked-by: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] mm: hugetlb alloc_fresh_huge_page bogus node loop fixPaul Jackson2006-03-22
| | | | | | | | | | | Fix bogus node loop in hugetlb.c alloc_fresh_huge_page(), which was assuming that nodes are numbered contiguously from 0 to num_online_nodes(). Once the hotplug folks get this far, that will be false. Signed-off-by: Paul Jackson <pj@sgi.com> Acked-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] fix swap cluster offsetAkinobu Mita2006-03-22
| | | | | | | | | | When we've allocated SWAPFILE_CLUSTER pages, ->cluster_next should be the first index of swap cluster. But current code probably sets it wrong offset. Signed-off-by: Akinobu Mita <mita@miraclelinux.com> Acked-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] drain_node_pages: interrupt latency reduction / optimizationChristoph Lameter2006-03-22
| | | | | | | | | | | | | | | | 1. Only disable interrupts if there is actually something to free 2. Only dirty the pcp cacheline if we actually freed something. 3. Disable interrupts for each single pcp and not for cleaning all the pcps in all zones of a node. drain_node_pages is called every 2 seconds from cache_reap. This fix should avoid most disabling of interrupts. 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 drain_array() so that it works correctly with the shared_arrayChristoph Lameter2006-03-22
| | | | | | | | | | | | | | | The list_lock also protects the shared array and we call drain_array() with the shared array. Therefore we cannot go as far as I wanted to but have to take the lock in a way so that it also protects the array_cache in drain_pages. (Note: maybe we should make the array_cache locking more consistent? I.e. always take the array cache lock for shared arrays and disable interrupts for the per cpu arrays?) 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: remove drain_array_lockedChristoph Lameter2006-03-22
| | | | | | | | | Remove drain_array_locked and use that opportunity to limit the time the l3 lock is taken further. 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: make drain_array more universal by adding more parametersChristoph Lameter2006-03-22
| | | | | | | | | | | And a parameter to drain_array to control the freeing of all objects and then use drain_array() to replace instances of drain_array_locked with drain_array. Doing so will avoid taking locks in those locations if the arrays are empty. 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: cache_reap(): further reduction in interrupt holdoffChristoph Lameter2006-03-22
| | | | | | | | | | | | | | | | | | | | | | | | | cache_reap takes the l3->list_lock (disabling interrupts) unconditionally and then does a few checks and maybe does some cleanup. This patch makes cache_reap() only take the lock if there is work to do and then the lock is taken and released for each cleaning action. The checking of when to do the next reaping is done without any locking and becomes racy. Should not matter since reaping can also be skipped if the slab mutex cannot be acquired. The same is true for the touched processing. If we get this wrong once in awhile then we will mistakenly clean or not clean the shared cache. This will impact performance slightly. Note that the additional drain_array() function introduced here will fall out in a subsequent patch since array cleaning will now be very similar from all callers. 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] mm: make shrink_all_memory try harderRafael J. Wysocki2006-03-22
| | | | | | | | | | Make shrink_all_memory() repeat the attempts to free more memory if there seems to be no pages to free. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Cc: Pavel Machek <pavel@ucw.cz> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] optimize follow_hugetlb_pageChen, Kenneth W2006-03-22
| | | | | | | | | | | | | | | | | | | | | | | follow_hugetlb_page() walks a range of user virtual address and then fills in list of struct page * into an array that is passed from the argument list. It also gets a reference count via get_page(). For compound page, get_page() actually traverse back to head page via page_private() macro and then adds a reference count to the head page. Since we are doing a virt to pte look up, kernel already has a struct page pointer into the head page. So instead of traverse into the small unit page struct and then follow a link back to the head page, optimize that with incrementing the reference count directly on the head page. The benefit is that we don't take a cache miss on accessing page struct for the corresponding user address and more importantly, not to pollute the cache with a "not very useful" round trip of pointer chasing. This adds a moderate performance gain on an I/O intensive database transaction workload. Signed-off-by: Ken Chen <kenneth.w.chen@intel.com> Cc: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] hugepage: Fix hugepage logic in free_pgtables() harderDavid Gibson2006-03-22
| | | | | | | | | | | | | | | | | | | | | | Turns out the hugepage logic in free_pgtables() was doubly broken. The loop coalescing multiple normal page VMAs into one call to free_pgd_range() had an off by one error, which could mean it would coalesce one hugepage VMA into the same bundle (checking 'vma' not 'next' in the loop). I transferred this bug into the new is_vm_hugetlb_page() based version. Here's the fix. This one didn't bite on powerpc previously for the same reason the is_hugepage_only_range() problem didn't: powerpc's hugetlb_free_pgd_range() is identical to free_pgd_range(). It didn't bite on ia64 because the hugepage region is distant enough from any other region that the separated PMD_SIZE distance test would always prevent coalescing the two together. No libhugetlbfs testsuite regressions (ppc64, POWER5). Signed-off-by: David Gibson <dwg@au1.ibm.com> Cc: William Lee Irwin III <wli@holomorphy.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] hugepage: Fix hugepage logic in free_pgtables()David Gibson2006-03-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | free_pgtables() has special logic to call hugetlb_free_pgd_range() instead of the normal free_pgd_range() on hugepage VMAs. However, the test it uses to do so is incorrect: it calls is_hugepage_only_range on a hugepage sized range at the start of the vma. is_hugepage_only_range() will return true if the given range has any intersection with a hugepage address region, and in this case the given region need not be hugepage aligned. So, for example, this test can return true if called on, say, a 4k VMA immediately preceding a (nicely aligned) hugepage VMA. At present we get away with this because the powerpc version of hugetlb_free_pgd_range() is just a call to free_pgd_range(). On ia64 (the only other arch with a non-trivial is_hugepage_only_range()) we get away with it for a different reason; the hugepage area is not contiguous with the rest of the user address space, and VMAs are not permitted in between, so the test can't return a false positive there. Nonetheless this should be fixed. We do that in the patch below by replacing the is_hugepage_only_range() test with an explicit test of the VMA using is_vm_hugetlb_page(). This in turn changes behaviour for platforms where is_hugepage_only_range() returns false always (everything except powerpc and ia64). We address this by ensuring that hugetlb_free_pgd_range() is defined to be identical to free_pgd_range() (instead of a no-op) on everything except ia64. Even so, it will prevent some otherwise possible coalescing of calls down to free_pgd_range(). Since this only happens for hugepage VMAs, removing this small optimization seems unlikely to cause any trouble. This patch causes no regressions on the libhugetlbfs testsuite - ppc64 POWER5 (8-way), ppc64 G5 (2-way) and i386 Pentium M (UP). Signed-off-by: David Gibson <dwg@au1.ibm.com> Cc: William Lee Irwin III <wli@holomorphy.com> Acked-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] hugepage: Make {alloc,free}_huge_page() localDavid Gibson2006-03-22
| | | | | | | | | | | | | | | | | Originally, mm/hugetlb.c just handled the hugepage physical allocation path and its {alloc,free}_huge_page() functions were used from the arch specific hugepage code. These days those functions are only used with mm/hugetlb.c itself. Therefore, this patch makes them static and removes their prototypes from hugetlb.h. This requires a small rearrangement of code in mm/hugetlb.c to avoid a forward declaration. This patch causes no regressions on the libhugetlbfs testsuite (ppc64, POWER5). Signed-off-by: David Gibson <dwg@au1.ibm.com> Cc: William Lee Irwin III <wli@holomorphy.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] hugepage: Strict page reservation for hugepage inodesDavid Gibson2006-03-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | These days, hugepages are demand-allocated at first fault time. There's a somewhat dubious (and racy) heuristic when making a new mmap() to check if there are enough available hugepages to fully satisfy that mapping. A particularly obvious case where the heuristic breaks down is where a process maps its hugepages not as a single chunk, but as a bunch of individually mmap()ed (or shmat()ed) blocks without touching and instantiating the pages in between allocations. In this case the size of each block is compared against the total number of available hugepages. It's thus easy for the process to become overcommitted, because each block mapping will succeed, although the total number of hugepages required by all blocks exceeds the number available. In particular, this defeats such a program which will detect a mapping failure and adjust its hugepage usage downward accordingly. The patch below addresses this problem, by strictly reserving a number of physical hugepages for hugepage inodes which have been mapped, but not instatiated. MAP_SHARED mappings are thus "safe" - they will fail on mmap(), not later with an OOM SIGKILL. MAP_PRIVATE mappings can still trigger an OOM. (Actually SHARED mappings can technically still OOM, but only if the sysadmin explicitly reduces the hugepage pool between mapping and instantiation) This patch appears to address the problem at hand - it allows DB2 to start correctly, for instance, which previously suffered the failure described above. This patch causes no regressions on the libhugetblfs testsuite, and makes a test (designed to catch this problem) pass which previously failed (ppc64, POWER5). Signed-off-by: David Gibson <dwg@au1.ibm.com> Cc: William Lee Irwin III <wli@holomorphy.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] hugepage: serialize hugepage allocation and instantiationDavid Gibson2006-03-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, no lock or mutex is held between allocating a hugepage and inserting it into the pagetables / page cache. When we do go to insert the page into pagetables or page cache, we recheck and may free the newly allocated hugepage. However, since the number of hugepages in the system is strictly limited, and it's usualy to want to use all of them, this can still lead to spurious allocation failures. For example, suppose two processes are both mapping (MAP_SHARED) the same hugepage file, large enough to consume the entire available hugepage pool. If they race instantiating the last page in the mapping, they will both attempt to allocate the last available hugepage. One will fail, of course, returning OOM from the fault and thus causing the process to be killed, despite the fact that the entire mapping can, in fact, be instantiated. The patch fixes this race by the simple method of adding a (sleeping) mutex to serialize the hugepage fault path between allocation and insertion into pagetables and/or page cache. It would be possible to avoid the serialization by catching the allocation failures, waiting on some condition, then rechecking to see if someone else has instantiated the page for us. Given the likely frequency of hugepage instantiations, it seems very doubtful it's worth the extra complexity. This patch causes no regression on the libhugetlbfs testsuite, and one test, which can trigger this race now passes where it previously failed. Actually, the test still sometimes fails, though less often and only as a shmat() failure, rather processes getting OOM killed by the VM. The dodgy heuristic tests in fs/hugetlbfs/inode.c for whether there's enough hugepage space aren't protected by the new mutex, and would be ugly to do so, so there's still a race there. Another patch to replace those tests with something saner for this reason as well as others coming... Signed-off-by: David Gibson <dwg@au1.ibm.com> Cc: William Lee Irwin III <wli@holomorphy.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] hugepage: Small fixes to hugepage clear/copy pathDavid Gibson2006-03-22
| | | | | | | | | | | | | | | | | | | | | | | | Move the loops used in mm/hugetlb.c to clear and copy hugepages to their own functions for clarity. As we do so, we add some checks of need_resched - we are, after all copying megabytes of memory here. We also add might_sleep() accordingly. We generally dropped locks around the clear and copy, already but not everyone has PREEMPT enabled, so we should still be checking explicitly. For this to work, we need to remove the clear_huge_page() from alloc_huge_page(), which is called with the page_table_lock held in the COW path. We move the clear_huge_page() to just after the alloc_huge_page() in the hugepage no-page path. In the COW path, the new page is about to be copied over, so clearing it was just a waste of time anyway. So as a side effect we also fix the fact that we held the page_table_lock for far too long in this path by calling alloc_huge_page() under it. It causes no regressions on the libhugetlbfs testsuite (ppc64, POWER5). Signed-off-by: David Gibson <dwg@au1.ibm.com> Cc: William Lee Irwin III <wli@holomorphy.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Enable mprotect on huge pagesZhang, Yanmin2006-03-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 2.6.16-rc3 uses hugetlb on-demand paging, but it doesn_t support hugetlb mprotect. From: David Gibson <david@gibson.dropbear.id.au> Remove a test from the mprotect() path which checks that the mprotect()ed range on a hugepage VMA is hugepage aligned (yes, really, the sense of is_aligned_hugepage_range() is the opposite of what you'd guess :-/). In fact, we don't need this test. If the given addresses match the beginning/end of a hugepage VMA they must already be suitably aligned. If they don't, then mprotect_fixup() will attempt to split the VMA. The very first test in split_vma() will check for a badly aligned address on a hugepage VMA and return -EINVAL if necessary. From: "Chen, Kenneth W" <kenneth.w.chen@intel.com> On i386 and x86-64, pte flag _PAGE_PSE collides with _PAGE_PROTNONE. The identify of hugetlb pte is lost when changing page protection via mprotect. A page fault occurs later will trigger a bug check in huge_pte_alloc(). The fix is to always make new pte a hugetlb pte and also to clean up legacy code where _PAGE_PRESENT is forced on in the pre-faulting day. Signed-off-by: Zhang Yanmin <yanmin.zhang@intel.com> Cc: David Gibson <david@gibson.dropbear.id.au> Cc: "David S. Miller" <davem@davemloft.net> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: William Lee Irwin III <wli@holomorphy.com> Signed-off-by: Ken Chen <kenneth.w.chen@intel.com> Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com> Cc: Andi Kleen <ak@muc.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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