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2006-01-08[PATCH] fadvise: return ESPIPE on FIFO/pipeValentine Barshak
The patch makes posix_fadvise return ESPIPE on FIFO/pipe in order to be fully POSIX-compliant. Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08[PATCH] Fix and add EXPORT_SYMBOL(filemap_write_and_wait)OGAWA Hirofumi
This patch add EXPORT_SYMBOL(filemap_write_and_wait) and use it. See mm/filemap.c: And changes the filemap_write_and_wait() and filemap_write_and_wait_range(). Current filemap_write_and_wait() doesn't wait if filemap_fdatawrite() returns error. However, even if filemap_fdatawrite() returned an error, it may have submitted the partially data pages to the device. (e.g. in the case of -ENOSPC) <quotation> Andrew Morton writes, If filemap_fdatawrite() returns an error, this might be due to some I/O problem: dead disk, unplugged cable, etc. Given the generally crappy quality of the kernel's handling of such exceptions, there's a good chance that the filemap_fdatawait() will get stuck in D state forever. </quotation> So, this patch doesn't wait if filemap_fdatawrite() returns the -EIO. Trond, could you please review the nfs part? Especially I'm not sure, nfs must use the "filemap_fdatawrite(inode->i_mapping) == 0", or not. Acked-by: Trond Myklebust <trond.myklebust@fys.uio.no> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08[PATCH] export/change sync_page_range/_nolock()OGAWA Hirofumi
This exports/changes the sync_page_range/_nolock(). The fatfs needs sync_page_range/_nolock() for expanding truncate, and changes "size_t count" to "loff_t count". Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08[PATCH] cpuset: rebind vma mempolicies fixPaul Jackson
Fix more of longstanding bug in cpuset/mempolicy interaction. NUMA mempolicies (mm/mempolicy.c) are constrained by the current tasks cpuset to just the Memory Nodes allowed by that cpuset. The kernel maintains internal state for each mempolicy, tracking what nodes are used for the MPOL_INTERLEAVE, MPOL_BIND or MPOL_PREFERRED policies. When a tasks cpuset memory placement changes, whether because the cpuset changed, or because the task was attached to a different cpuset, then the tasks mempolicies have to be rebound to the new cpuset placement, so as to preserve the cpuset-relative numbering of the nodes in that policy. An earlier fix handled such mempolicy rebinding for mempolicies attached to a task. This fix rebinds mempolicies attached to vma's (address ranges in a tasks address space.) Due to the need to hold the task->mm->mmap_sem semaphore while updating vma's, the rebinding of vma mempolicies has to be done when the cpuset memory placement is changed, at which time mmap_sem can be safely acquired. The tasks mempolicy is rebound later, when the task next attempts to allocate memory and notices that its task->cpuset_mems_generation is out-of-date with its cpusets mems_generation. Because walking the tasklist to find all tasks attached to a changing cpuset requires holding tasklist_lock, a spinlock, one cannot update the vma's of the affected tasks while doing the tasklist scan. In general, one cannot acquire a semaphore (which can sleep) while already holding a spinlock (such as tasklist_lock). So a list of mm references has to be built up during the tasklist scan, then the tasklist lock dropped, then for each mm, its mmap_sem acquired, and the vma's in that mm rebound. Once the tasklist lock is dropped, affected tasks may fork new tasks, before their mm's are rebound. A kernel global 'cpuset_being_rebound' is set to point to the cpuset being rebound (there can only be one; cpuset modifications are done under a global 'manage_sem' semaphore), and the mpol_copy code that is used to copy a tasks mempolicies during fork catches such forking tasks, and ensures their children are also rebound. When a task is moved to a different cpuset, it is easier, as there is only one task involved. It's mm->vma's are scanned, using the same mpol_rebind_policy() as used above. It may happen that both the mpol_copy hook and the update done via the tasklist scan update the same mm twice. This is ok, as the mempolicies of each vma in an mm keep track of what mems_allowed they are relative to, and safely no-op a second request to rebind to the same nodes. Signed-off-by: Paul Jackson <pj@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08[PATCH] cpuset: numa_policy_rebind cleanupPaul Jackson
Cleanup, reorganize and make more robust the mempolicy.c code to rebind mempolicies relative to the containing cpuset after a tasks memory placement changes. The real motivator for this cleanup patch is to lay more groundwork for the upcoming patch to correctly rebind NUMA mempolicies that are attached to vma's after the containing cpuset memory placement changes. NUMA mempolicies are constrained by the cpuset their task is a member of. When either (1) a task is moved to a different cpuset, or (2) the 'mems' mems_allowed of a cpuset is changed, then the NUMA mempolicies have embedded node numbers (for MPOL_BIND, MPOL_INTERLEAVE and MPOL_PREFERRED) that need to be recalculated, relative to their new cpuset placement. The old code used an unreliable method of determining what was the old mems_allowed constraining the mempolicy. It just looked at the tasks mems_allowed value. This sort of worked with the present code, that just rebinds the -task- mempolicy, and leaves any -vma- mempolicies broken, referring to the old nodes. But in an upcoming patch, the vma mempolicies will be rebound as well. Then the order in which the various task and vma mempolicies are updated will no longer be deterministic, and one can no longer count on the task->mems_allowed holding the old value for as long as needed. It's not even clear if the current code was guaranteed to work reliably for task mempolicies. So I added a mems_allowed field to each mempolicy, stating exactly what mems_allowed the policy is relative to, and updated synchronously and reliably anytime that the mempolicy is rebound. Also removed a useless wrapper routine, numa_policy_rebind(), and had its caller, cpuset_update_task_memory_state(), call directly to the rewritten policy_rebind() routine, and made that rebind routine extern instead of static, and added a "mpol_" prefix to its name, making it mpol_rebind_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>
2006-01-08[PATCH] cpuset: implement cpuset_mems_allowedPaul Jackson
Provide a cpuset_mems_allowed() method, which the sys_migrate_pages() code needed, to obtain the mems_allowed vector of a cpuset, and replaced the workaround in sys_migrate_pages() to call this new method. Signed-off-by: Paul Jackson <pj@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08[PATCH] cpuset: combine refresh_mems and update_memsPaul Jackson
The important code paths through alloc_pages_current() and alloc_page_vma(), by which most kernel page allocations go, both called cpuset_update_current_mems_allowed(), which in turn called refresh_mems(). -Both- of these latter two routines did a tasklock, got the tasks cpuset pointer, and checked for out of date cpuset->mems_generation. That was a silly duplication of code and waste of CPU cycles on an important code path. Consolidated those two routines into a single routine, called cpuset_update_task_memory_state(), since it updates more than just mems_allowed. Changed all callers of either routine to call the new consolidated routine. Signed-off-by: Paul Jackson <pj@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08[PATCH] cpuset: memory pressure meterPaul Jackson
Provide a simple per-cpuset metric of memory pressure, tracking the -rate- that the tasks in a cpuset call try_to_free_pages(), the synchronous (direct) memory reclaim code. This enables batch managers monitoring jobs running in dedicated cpusets to efficiently detect what level of memory pressure that job is causing. This is useful both on tightly managed systems running a wide mix of submitted jobs, which may choose to terminate or reprioritize jobs that are trying to use more memory than allowed on the nodes assigned them, and with tightly coupled, long running, massively parallel scientific computing jobs that will dramatically fail to meet required performance goals if they start to use more memory than allowed to them. This patch just provides a very economical way for the batch manager to monitor a cpuset for signs of memory pressure. It's up to the batch manager or other user code to decide what to do about it and take action. ==> Unless this feature is enabled by writing "1" to the special file /dev/cpuset/memory_pressure_enabled, the hook in the rebalance code of __alloc_pages() for this metric reduces to simply noticing that the cpuset_memory_pressure_enabled flag is zero. So only systems that enable this feature will compute the metric. Why a per-cpuset, running average: Because this meter is per-cpuset, rather than per-task or mm, the system load imposed by a batch scheduler monitoring this metric is sharply reduced on large systems, because a scan of the tasklist can be avoided on each set of queries. Because this meter is a running average, instead of an accumulating counter, a batch scheduler can detect memory pressure with a single read, instead of having to read and accumulate results for a period of time. Because this meter is per-cpuset rather than per-task or mm, the batch scheduler can obtain the key information, memory pressure in a cpuset, with a single read, rather than having to query and accumulate results over all the (dynamically changing) set of tasks in the cpuset. A per-cpuset simple digital filter (requires a spinlock and 3 words of data per-cpuset) is kept, and updated by any task attached to that cpuset, if it enters the synchronous (direct) page reclaim code. A per-cpuset file provides an integer number representing the recent (half-life of 10 seconds) rate of direct page reclaims caused by the tasks in the cpuset, in units of reclaims attempted per second, times 1000. Signed-off-by: Paul Jackson <pj@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08[PATCH] cpuset: mempolicy one more nodemask conversionPaul Jackson
Finish converting mm/mempolicy.c from bitmaps to nodemasks. The previous conversion had left one routine using bitmaps, since it involved a corresponding change to kernel/cpuset.c Fix that interface by replacing with a simple macro that calls nodes_subset(), or if !CONFIG_CPUSET, returns (1). Signed-off-by: Paul Jackson <pj@sgi.com> Cc: Christoph Lameter <christoph@lameter.com> Cc: Andi Kleen <ak@muc.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08[PATCH] slob: introduce the SLOB allocatorMatt Mackall
configurable replacement for slab allocator This adds a CONFIG_SLAB option under CONFIG_EMBEDDED. When CONFIG_SLAB is disabled, the kernel falls back to using the 'SLOB' allocator. SLOB is a traditional K&R/UNIX allocator with a SLAB emulation layer, similar to the original Linux kmalloc allocator that SLAB replaced. It's signicantly smaller code and is more memory efficient. But like all similar allocators, it scales poorly and suffers from fragmentation more than SLAB, so it's only appropriate for small systems. It's been tested extensively in the Linux-tiny tree. I've also stress-tested it with make -j 8 compiles on a 3G SMP+PREEMPT box (not recommended). Here's a comparison for otherwise identical builds, showing SLOB saving nearly half a megabyte of RAM: $ size vmlinux* text data bss dec hex filename 3336372 529360 190812 4056544 3de5e0 vmlinux-slab 3323208 527948 190684 4041840 3dac70 vmlinux-slob $ size mm/{slab,slob}.o text data bss dec hex filename 13221 752 48 14021 36c5 mm/slab.o 1896 52 8 1956 7a4 mm/slob.o /proc/meminfo: SLAB SLOB delta MemTotal: 27964 kB 27980 kB +16 kB MemFree: 24596 kB 25092 kB +496 kB Buffers: 36 kB 36 kB 0 kB Cached: 1188 kB 1188 kB 0 kB SwapCached: 0 kB 0 kB 0 kB Active: 608 kB 600 kB -8 kB Inactive: 808 kB 812 kB +4 kB HighTotal: 0 kB 0 kB 0 kB HighFree: 0 kB 0 kB 0 kB LowTotal: 27964 kB 27980 kB +16 kB LowFree: 24596 kB 25092 kB +496 kB SwapTotal: 0 kB 0 kB 0 kB SwapFree: 0 kB 0 kB 0 kB Dirty: 4 kB 12 kB +8 kB Writeback: 0 kB 0 kB 0 kB Mapped: 560 kB 556 kB -4 kB Slab: 1756 kB 0 kB -1756 kB CommitLimit: 13980 kB 13988 kB +8 kB Committed_AS: 4208 kB 4208 kB 0 kB PageTables: 28 kB 28 kB 0 kB VmallocTotal: 1007312 kB 1007312 kB 0 kB VmallocUsed: 48 kB 48 kB 0 kB VmallocChunk: 1007264 kB 1007264 kB 0 kB (this work has been sponsored in part by CELF) From: Ingo Molnar <mingo@elte.hu> Fix 32-bitness bugs in mm/slob.c. Signed-off-by: Matt Mackall <mpm@selenic.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08[PATCH] slob: introduce mm/util.c for shared functionsMatt Mackall
Add mm/util.c for functions common between SLAB and SLOB. Signed-off-by: Matt Mackall <mpm@selenic.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08[PATCH] Change maxaligned_in_smp alignemnt macros to internodealigned_in_smp ↵Ravikiran G Thirumalai
macros ____cacheline_maxaligned_in_smp is currently used to align critical structures and avoid false sharing. It uses per-arch L1_CACHE_SHIFT_MAX and people find L1_CACHE_SHIFT_MAX useless. However, we have been using ____cacheline_maxaligned_in_smp to align structures on the internode cacheline size. As per Andi's suggestion, following patch kills ____cacheline_maxaligned_in_smp and introduces INTERNODE_CACHE_SHIFT, which defaults to L1_CACHE_SHIFT for all arches. Arches needing L3/Internode cacheline alignment can define INTERNODE_CACHE_SHIFT in the arch asm/cache.h. Patch replaces ____cacheline_maxaligned_in_smp with ____cacheline_internodealigned_in_smp With this patch, L1_CACHE_SHIFT_MAX can be killed Signed-off-by: Ravikiran Thirumalai <kiran@scalex86.org> Signed-off-by: Shai Fultheim <shai@scalex86.org> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08[PATCH] Optimise oom kill of current taskKirill Korotaev
When oom_killer kills current there's no need to call schedule_timeout_interruptible() since task must die ASAP. Signed-Off-By: Pavel Emelianov <xemul@sw.ru> Signed-Off-By: Kirill Korotaev <dev@openvz.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08[PATCH] Move page migration related functions near do_migrate_pages()Christoph Lameter
Group page migration functions in mempolicy.c Add a forward declaration for migrate_page_add (like gather_stats()) and use our new found mobility to group all page migration related function around do_migrate_pages(). Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Andi Kleen <ak@muc.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08[PATCH] mempolicies: unexport get_vma_policy()Christoph Lameter
Since the numa_maps functionality is now in mempolicy.c we no longer need to export get_vma_policy(). Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Andi Kleen <ak@muc.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08[PATCH] Drop page table lock before calling migrate_page_add()Christoph Lameter
migrate_page_add cannot be called with a spinlock held (calls isolate_lru_page which calles schedule_on_each_cpu). Drop ptl lock in check_pte_range before calling migrate_page_add(). Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08[PATCH] Fold numa_maps into mempolicies.cChristoph Lameter
First discussed at http://marc.theaimsgroup.com/?t=113149255100001&r=1&w=2 - Use the check_range() in mempolicy.c to gather statistics. - Improve the numa_maps code in general and fix some comments. Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Andi Kleen <ak@muc.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08[PATCH] mempolicies: private pointer in check_range and MPOL_MF_INVERTChristoph Lameter
This was was first posted at http://marc.theaimsgroup.com/?l=linux-mm&m=113149240227584&w=2 (Part of this functionality is also contained in the direct migration pathset. The functionality here is more generic and independent of that patchset.) - Add internal flags MPOL_MF_INVERT to control check_range() behavior. - Replace the pagelist passed through by check_range by a general private pointer that may be used for other purposes. (The following patches will use that to merge numa_maps into mempolicy.c and to better group the page migration code in the policy layer) - Improve some comments. Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Andi Kleen <ak@muc.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08[PATCH] rmap: additional diagnostics in page_remove_rmap()Dave Jones
We seem to be hitting this assertion failure too often for it to be hardware bugs. 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>
2006-01-08[PATCH] mm: clean up local variablesTobias Klauser
Clean up a local variable with the same name as a variable in a larger block. Also move a variable into the block where it's actually used. Spotted by http://linuxicc.sourceforge.net/ Signed-off-by: Tobias Klauser <tklauser@nuerscht.ch> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08[PATCH] mm: make hugepages obey cpusets.Christoph Lameter
See http://marc.theaimsgroup.com/?l=linux-kernel&m=113167000201265&w=2 http://marc.theaimsgroup.com/?l=linux-mm&m=113167267527312&w=2 Make hugepages obey cpusets. Signed-off-by: Christoph Lameter <clameter@sgi.com> Acked-by: William Irwin <wli@holomorphy.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08[PATCH] SwapMig: Switch error handling in migrate_pages to use -ExxChristoph Lameter
Use -Exxx instead of numeric return codes and cleanup the code in migrate_pages() using -Exx error codes. Consolidate successful migration handling Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08[PATCH] SwapMig: Extend parameters for migrate_pages()Christoph Lameter
Extend the parameters of migrate_pages() to allow the caller control over the fate of successfully migrated or impossible to migrate pages. Swap migration and direct migration will have the same interface after this patch so that patches can be independently applied to the policy layer and the core migration code. Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Andi Kleen <ak@muc.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08[PATCH] SwapMig: Drop unused pages immediatelyChristoph Lameter
Drop unused pages immediately If a page is encountered that is only referenced by the migration code then there is no reason to swap or migrate the page. Release the page by calling move_to_lru(). Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08[PATCH] SwapMig: add_to_swap() avoid atomic allocationsChristoph Lameter
Add gfp_mask to add_to_swap add_to_swap does allocations with GFP_ATOMIC in order not to interfere with swapping. During migration we may have use add_to_swap extensively which may lead to out of memory errors. This patch makes add_to_swap take a parameter that specifies the gfp mask. The page migration code can then make add_to_swap use GFP_KERNEL. Signed-off-by: Hirokazu Takahashi <taka@valinux.co.jp> Signed-off-by: Dave Hansen <haveblue@us.ibm.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>
2006-01-08[PATCH] SwapMig: CONFIG_MIGRATION fixesChristoph Lameter
Move move_to_lru, putback_lru_pages and isolate_lru in section surrounded by CONFIG_MIGRATION saving some codesize for single processor kernels. Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08[PATCH] Swap Migration V5: sys_migrate_pages interfaceChristoph Lameter
sys_migrate_pages implementation using swap based page migration This is the original API proposed by Ray Bryant in his posts during the first half of 2005 on linux-mm@kvack.org and linux-kernel@vger.kernel.org. The intent of sys_migrate is to migrate memory of a process. A process may have migrated to another node. Memory was allocated optimally for the prior context. sys_migrate_pages allows to shift the memory to the new node. sys_migrate_pages is also useful if the processes available memory nodes have changed through cpuset operations to manually move the processes memory. Paul Jackson is working on an automated mechanism that will allow an automatic migration if the cpuset of a process is changed. However, a user may decide to manually control the migration. This implementation is put into the policy layer since it uses concepts and functions that are also needed for mbind and friends. The patch also provides a do_migrate_pages function that may be useful for cpusets to automatically move memory. sys_migrate_pages does not modify policies in contrast to Ray's implementation. The current code here is based on the swap based page migration capability and thus is not able to preserve the physical layout relative to it containing nodeset (which may be a cpuset). When direct page migration becomes available then the implementation needs to be changed to do a isomorphic move of pages between different nodesets. The current implementation simply evicts all pages in source nodeset that are not in the target nodeset. Patch supports ia64, i386 and x86_64. Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08[PATCH] Swap Migration V5: MPOL_MF_MOVE interfaceChristoph Lameter
Add page migration support via swap to the NUMA policy layer This patch adds page migration support to the NUMA policy layer. An additional flag MPOL_MF_MOVE is introduced for mbind. If MPOL_MF_MOVE is specified then pages that do not conform to the memory policy will be evicted from memory. When they get pages back in new pages will be allocated following the numa policy. Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08[PATCH] Swap Migration V5: Add CONFIG_MIGRATION for page migration supportChristoph Lameter
Include page migration if the system is NUMA or having a memory model that allows distinct areas of memory (SPARSEMEM, DISCONTIGMEM). And: - Only include lru_add_drain_per_cpu if building for an SMP system. Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08[PATCH] Swap Migration V5: migrate_pages() functionChristoph Lameter
This adds the basic page migration function with a minimal implementation that only allows the eviction of pages to swap space. Page eviction and migration may be useful to migrate pages, to suspend programs or for remapping single pages (useful for faulty pages or pages with soft ECC failures) The process is as follows: The function wanting to migrate pages must first build a list of pages to be migrated or evicted and take them off the lru lists via isolate_lru_page(). isolate_lru_page determines that a page is freeable based on the LRU bit set. Then the actual migration or swapout can happen by calling migrate_pages(). migrate_pages does its best to migrate or swapout the pages and does multiple passes over the list. Some pages may only be swappable if they are not dirty. migrate_pages may start writing out dirty pages in the initial passes over the pages. However, migrate_pages may not be able to migrate or evict all pages for a variety of reasons. The remaining pages may be returned to the LRU lists using putback_lru_pages(). Changelog V4->V5: - Use the lru caches to return pages to the LRU Changelog V3->V4: - Restructure code so that applying patches to support full migration does require minimal changes. Rename swapout_pages() to migrate_pages(). Changelog V2->V3: - Extract common code from shrink_list() and swapout_pages() Signed-off-by: Mike Kravetz <kravetz@us.ibm.com> Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: "Michael Kerrisk" <mtk-manpages@gmx.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08[PATCH] Swap Migration V5: PF_SWAPWRITE to allow writing to swapChristoph Lameter
Add PF_SWAPWRITE to control a processes permission to write to swap. - Use PF_SWAPWRITE in may_write_to_queue() instead of checking for kswapd and pdflush - Set PF_SWAPWRITE flag for kswapd and pdflush Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08[PATCH] Swap Migration V5: LRU operationsChristoph Lameter
This is the start of the `swap migration' patch series. Swap migration allows the moving of the physical location of pages between nodes in a numa system while the process is running. This means that the virtual addresses that the process sees do not change. However, the system rearranges the physical location of those pages. The main intent of page migration patches here is to reduce the latency of memory access by moving pages near to the processor where the process accessing that memory is running. The patchset allows a process to manually relocate the node on which its pages are located through the MF_MOVE and MF_MOVE_ALL options while setting a new memory policy. The pages of process can also be relocated from another process using the sys_migrate_pages() function call. Requires CAP_SYS_ADMIN. The migrate_pages function call takes two sets of nodes and moves pages of a process that are located on the from nodes to the destination nodes. Manual migration is very useful if for example the scheduler has relocated a process to a processor on a distant node. A batch scheduler or an administrator can detect the situation and move the pages of the process nearer to the new processor. sys_migrate_pages() could be used on non-numa machines as well, to force all of a particualr process's pages out to swap, if someone thinks that's useful. Larger installations usually partition the system using cpusets into sections of nodes. Paul has equipped cpusets with the ability to move pages when a task is moved to another cpuset. This allows automatic control over locality of a process. If a task is moved to a new cpuset then also all its pages are moved with it so that the performance of the process does not sink dramatically (as is the case today). Swap migration works by simply evicting the page. The pages must be faulted back in. The pages are then typically reallocated by the system near the node where the process is executing. For swap migration the destination of the move is controlled by the allocation policy. Cpusets set the allocation policy before calling sys_migrate_pages() in order to move the pages as intended. No allocation policy changes are performed for sys_migrate_pages(). This means that the pages may not faulted in to the specified nodes if no allocation policy was set by other means. The pages will just end up near the node where the fault occurred. There's another patch series in the pipeline which implements "direct migration". The direct migration patchset extends the migration functionality to avoid going through swap. The destination node of the relation is controllable during the actual moving of pages. The crutch of using the allocation policy to relocate is not necessary and the pages are moved directly to the target. Its also faster since swap is not used. And sys_migrate_pages() can then move pages directly to the specified node. Implement functions to isolate pages from the LRU and put them back later. This patch: An earlier implementation was provided by Hirokazu Takahashi <taka@valinux.co.jp> and IWAMOTO Toshihiro <iwamoto@valinux.co.jp> for the memory hotplug project. From: Magnus This breaks out isolate_lru_page() and putpack_lru_page(). Needed for swap migration. Signed-off-by: Magnus Damm <magnus.damm@gmail.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>
2006-01-08[PATCH] mm: free_pages optNick Piggin
Try to streamline free_pages_bulk by ensuring callers don't pass in a 'count' that exceeds the list size. Some cleanups: Rename __free_pages_bulk to __free_one_page. Put the page list manipulation from __free_pages_ok into free_one_page. Make __free_pages_ok static. Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08[PATCH] mm: cleanup zone_pcpNick Piggin
Use zone_pcp everywhere even though NUMA code "knows" the internal details of the zone. Stop other people trying to copy, and it looks nicer. Also, only print the pagesets of online cpus in zoneinfo. Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: "Seth, Rohit" <rohit.seth@intel.com> Cc: Christoph Lameter <christoph@lameter.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08[PATCH] Make high and batch sizes of per_cpu_pagelists configurableRohit Seth
As recently there has been lot of traffic on the right values for batch and high water marks for per_cpu_pagelists. This patch makes these two variables configurable through /proc interface. A new tunable /proc/sys/vm/percpu_pagelist_fraction is added. This entry controls the fraction of pages at most in each zone that are allocated for each per cpu page list. The min value for this is 8. It means that we don't allow more than 1/8th of pages in each zone to be allocated in any single per_cpu_pagelist. The batch value of each per cpu pagelist is also updated as a result. It is set to pcp->high/4. The upper limit of batch is (PAGE_SHIFT * 8) Signed-off-by: Rohit Seth <rohit.seth@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08[PATCH] drop-pagecacheAndrew Morton
Add /proc/sys/vm/drop_caches. When written to, this will cause the kernel to discard as much pagecache and/or reclaimable slab objects as it can. THis operation requires root permissions. It won't drop dirty data, so the user should run `sync' first. Caveats: a) Holds inode_lock for exorbitant amounts of time. b) Needs to be taught about NUMA nodes: propagate these all the way through so the discarding can be controlled on a per-node basis. This is a debugging feature: useful for getting consistent results between filesystem benchmarks. We could possibly put it under a config option, but it's less than 300 bytes. Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08[PATCH] slab: remove nested #ifdef CONFIG_NUMAChristoph Lameter
For some reason there is an #ifdef CONFIG_NUMA within another #ifdef CONFIG_NUMA in the page allocator. Remove innermost #ifdef CONFIG_NUMA Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08[PATCH] slab: fix code formattingPekka Enberg
The slab allocator code is inconsistent in coding style and messy. For this patch, I ran Lindent for mm/slab.c and fixed up goofs by hand. Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08[PATCH] slab: extract slab order calculation to separate functionPekka Enberg
This patch moves the ugly loop that determines the 'optimal' size (page order) of cache slabs from kmem_cache_create() to a separate function and cleans it up a bit. Thanks to Matthew Wilcox for the help with this patch. Signed-off-by: Matthew Dobson <colpatch@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08[PATCH] slab: extract slabinfo header printing to separate functionPekka Enberg
This patch extracts slabinfo header printing to a separate function print_slabinfo_header() to make s_start() more readable. Signed-off-by: Matthew Dobson <colpatch@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08[PATCH] slab: remove unused align parameter from alloc_percpuPekka Enberg
__alloc_percpu and alloc_percpu both take an 'align' argument which is completely ignored. snmp6_mib_init() in net/ipv6/af_inet6.c attempts to use it, but it will be ignored. Therefore, remove the 'align' argument and fixup the lone caller. Signed-off-by: Matthew Dobson <colpatch@us.ibm.com> Acked-by: Manfred Spraul <manfred@colorfullife.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08[PATCH] revert "mm: page_state fixes"Andrew Morton
Hugh says: page_alloc_cpu_notify() specifically contains code to /* Add dead cpu's page_states to our own. */ which handles this more efficiently. 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>
2006-01-06identify multipage ->writepages() callsAndrew Morton
NFS needs to be able to distinguish between single-page ->writepage() calls and multipage ->writepages() calls. For the single-page writepage calls NFS can kick off the I/O within the context of ->writepage(). For multipage ->writepages calls, nfs_writepage() will leave the I/O pending and nfs_writepages() will kick off the I/O when it all has been queued up within NFS. Cc: Trond Myklebust <trond.myklebust@fys.uio.no> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2006-01-06[PATCH] mm: add a new function (needed for swap suspend)Rafael J. Wysocki
This adds the function get_swap_page_of_type() allowing us to specify an index in swap_info[] and select a swap_info_struct structure to be used for allocating a swap page. This function (or another one of similar functionality) will be necessary for implementing the image-writing part of swsusp in the user space.  It can also be used for simplifying the current in-kernel implementation of the image-writing part of swsusp. 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>
2006-01-06[PATCH] allow flatmem to be disabled when only sparsemem is implementedAnton Blanchard
On architectures that implement sparsemem but not discontigmem we want to be able to hide the flatmem option in some cases. On ppc64 for example, when we select NUMA we must not select flatmem. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Andy Whitcroft <apw@shadowen.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-06[PATCH] NOMMU: Make SYSV IPC SHM use ramfs facilities on NOMMUDavid Howells
The attached patch makes the SYSV IPC shared memory facilities use the new ramfs facilities on a no-MMU kernel. The following changes are made: (1) There are now shmem_mmap() and shmem_get_unmapped_area() functions to allow the IPC SHM facilities to commune with the tiny-shmem and shmem code. (2) ramfs files now need resizing using do_truncate() rather than by modifying the inode size directly (see shmem_file_setup()). This causes ramfs to attempt to bind a block of pages of sufficient size to the inode. (3) CONFIG_SYSVIPC is no longer contingent on CONFIG_MMU. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-06[PATCH] mm: page_state optNick Piggin
Optimise page_state manipulations by introducing interrupt unsafe accessors to page_state fields. Callers must provide their own locking (either disable interrupts or not update from interrupt context). Switch over the hot callsites that can easily be moved under interrupts off sections. Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-06[PATCH] build_zonelists_node(): rename argsChristoph Lameter
Give j and r meaningful names. Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-06[PATCH] Fix zone policy determinationChristoph Lameter
The use k in the inner loop means that the highest zone nr is always used if any zone of a node is populated. This means that the policy zone is not correctly determined on arches that do no use HIGHMEM like ia64. Change the loop to decrement k which also simplifies the BUG_ON. Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-06[PATCH] mm: move determination of policy_zone into page allocatorChristoph Lameter
Currently the function to build a zonelist for a BIND policy has the side effect to set the policy_zone. This seems to be a bit strange. policy zone seems to not be initialized elsewhere and therefore 0. Do we police ZONE_DMA if no bind policy has been used yet? This patch moves the determination of the zone to apply policies to into the page allocator. We determine the zone while building the zonelist for nodes. Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>