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* mm: remove likely() from mapping_unevictable()Steven Rostedt2011-01-131-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The mapping_unevictable() has a likely() around the mapping parameter. This mapping parameter comes from page_mapping() which has an unlikely() that the page will be set as PAGE_MAPPING_ANON, and if so, it will return NULL. One would think that this unlikely() means that the mapping returned by page_mapping() would not be NULL, but where page_mapping() is used just above mapping_unevictable(), that unlikely() is incorrect most of the time. This means that the "likely(mapping)" in mapping_unevictable() is incorrect most of the time. Running the annotated branch profiler on my main box which runs firefox, evolution, xchat and is part of my distcc farm, I had this: correct incorrect % Function File Line ------- --------- - -------- ---- ---- 12872836 1269443893 98 mapping_unevictable pagemap.h 51 35935762 1270265395 97 page_mapping mm.h 659 1306198001 143659 0 page_mapping mm.h 657 203131478 121586 0 page_mapping mm.h 657 5415491 1116 0 page_mapping mm.h 657 74899487 1116 0 page_mapping mm.h 657 203132845 224 0 page_mapping mm.h 659 5415464 27 0 page_mapping mm.h 659 13552 0 0 page_mapping mm.h 657 13552 0 0 page_mapping mm.h 659 242630 0 0 page_mapping mm.h 657 242630 0 0 page_mapping mm.h 659 74899487 0 0 page_mapping mm.h 659 The page_mapping() is a static inline, which is why it shows up multiple times. The mapping_unevictable() is also a static inline but seems to be used only once in my setup. The unlikely in page_mapping() was correct a total of 1909540379 times and incorrect 1270533123 times, with a 39% being incorrect. Perhaps this is enough to remove the unlikely from page_mapping() as well. Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Acked-by: Nick Piggin <npiggin@kernel.dk> Acked-by: Rik van Riel <riel@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: retry page fault when blocking on disk transferMichel Lespinasse2010-10-261-0/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This change reduces mmap_sem hold times that are caused by waiting for disk transfers when accessing file mapped VMAs. It introduces the VM_FAULT_ALLOW_RETRY flag, which indicates that the call site wants mmap_sem to be released if blocking on a pending disk transfer. In that case, filemap_fault() returns the VM_FAULT_RETRY status bit and do_page_fault() will then re-acquire mmap_sem and retry the page fault. It is expected that the retry will hit the same page which will now be cached, and thus it will complete with a low mmap_sem hold time. Tests: - microbenchmark: thread A mmaps a large file and does random read accesses to the mmaped area - achieves about 55 iterations/s. Thread B does mmap/munmap in a loop at a separate location - achieves 55 iterations/s before, 15000 iterations/s after. - We are seeing related effects in some applications in house, which show significant performance regressions when running without this change. [akpm@linux-foundation.org: fix warning & crash] Signed-off-by: Michel Lespinasse <walken@google.com> Acked-by: Rik van Riel <riel@redhat.com> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Reviewed-by: Wu Fengguang <fengguang.wu@intel.com> Cc: Ying Han <yinghan@google.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Acked-by: "H. Peter Anvin" <hpa@zytor.com> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'hwpoison' of ↵Linus Torvalds2010-08-121-1/+8
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-mce-2.6 * 'hwpoison' of git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-mce-2.6: hugetlb: add missing unlock in avoidcopy path in hugetlb_cow() hwpoison: rename CONFIG HWPOISON, hugetlb: support hwpoison injection for hugepage HWPOISON, hugetlb: detect hwpoison in hugetlb code HWPOISON, hugetlb: isolate corrupted hugepage HWPOISON, hugetlb: maintain mce_bad_pages in handling hugepage error HWPOISON, hugetlb: set/clear PG_hwpoison bits on hugepage HWPOISON, hugetlb: enable error handling path for hugepage hugetlb, rmap: add reverse mapping for hugepage hugetlb: move definition of is_vm_hugetlb_page() to hugepage_inline.h Fix up trivial conflicts in mm/memory-failure.c
| * hugetlb, rmap: add reverse mapping for hugepageNaoya Horiguchi2010-08-111-1/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds reverse mapping feature for hugepage by introducing mapcount for shared/private-mapped hugepage and anon_vma for private-mapped hugepage. While hugepage is not currently swappable, reverse mapping can be useful for memory error handler. Without this patch, memory error handler cannot identify processes using the bad hugepage nor unmap it from them. That is: - for shared hugepage: we can collect processes using a hugepage through pagecache, but can not unmap the hugepage because of the lack of mapcount. - for privately mapped hugepage: we can neither collect processes nor unmap the hugepage. This patch solves these problems. This patch include the bug fix given by commit 23be7468e8, so reverts it. Dependency: "hugetlb: move definition of is_vm_hugetlb_page() to hugepage_inline.h" ChangeLog since May 24. - create hugetlb_inline.h and move is_vm_hugetlb_index() in it. - move functions setting up anon_vma for hugepage into mm/rmap.c. ChangeLog since May 13. - rebased to 2.6.34 - fix logic error (in case that private mapping and shared mapping coexist) - move is_vm_hugetlb_page() into include/linux/mm.h to use this function from linear_page_index() - define and use linear_hugepage_index() instead of compound_order() - use page_move_anon_rmap() in hugetlb_cow() - copy exclusive switch of __set_page_anon_rmap() into hugepage counterpart. - revert commit 24be7468 completely Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Larry Woodman <lwoodman@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com> Acked-by: Fengguang Wu <fengguang.wu@intel.com> Acked-by: Mel Gorman <mel@csn.ul.ie> Signed-off-by: Andi Kleen <ak@linux.intel.com>
| * hugetlb: move definition of is_vm_hugetlb_page() to hugepage_inline.hNaoya Horiguchi2010-08-111-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | is_vm_hugetlb_page() is a widely used inline function to insert hooks into hugetlb code. But we can't use it in pagemap.h because of circular dependency of the header files. This patch removes this limitation. Acked-by: Mel Gorman <mel@csn.ul.ie> Acked-by: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: Andi Kleen <ak@linux.intel.com>
* | gcc-4.6: pagemap: avoid unused-but-set variableAndi Kleen2010-08-091-1/+3
|/ | | | | | | | Avoid quite a lot of warnings in header files in a gcc 4.6 -Wall builds Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: add new 'read_cache_page_gfp()' helper functionLinus Torvalds2010-01-271-0/+2
| | | | | | | | | | | | | | | | | | | | It's a simplified 'read_cache_page()' which takes a page allocation flag, so that different paths can control how aggressive the memory allocations are that populate a address space. In particular, the intel GPU object mapping code wants to be able to do a certain amount of own internal memory management by automatically shrinking the address space when memory starts getting tight. This allows it to dynamically use different memory allocation policies on a per-allocation basis, rather than depend on the (static) address space gfp policy. The actual new function is a one-liner, but re-organizing the helper functions to the point where you can do this with a single line of code is what most of the patch is all about. Tested-by: Chris Wilson <chris@chris-wilson.co.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* rcu: Expunge lingering references to CONFIG_CLASSIC_RCU, optimize on !SMPPaul E. McKenney2009-08-221-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | A couple of references to CONFIG_CLASSIC_RCU have survived. Although these are harmless, it is past time for them to go. The one in hardirq.h is strictly a readability problem. The two in pagemap.h appear to disable a !SMP performance optimization (which this patch re-enables). This does raise the issue as to whether pagemap.h should really be referring to the CPU implementation. Long term, I intend to make the RCU implementation driven by CONFIG_PREEMPT, at which point these should change from defined(CONFIG_TREE_RCU) to !defined(CONFIG_PREEMPT). In the meantime, is there something else that could be done in pagemap.h? Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: akpm@linux-foundation.org Cc: mathieu.desnoyers@polymtl.ca Cc: josht@linux.vnet.ibm.com Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org LKML-Reference: <20090822050851.GA8414@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* mm: remove CONFIG_UNEVICTABLE_LRU config optionKOSAKI Motohiro2009-06-161-12/+0
| | | | | | | | | | | | | | | | Currently, nobody wants to turn UNEVICTABLE_LRU off. Thus this configurability is unnecessary. Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Andi Kleen <andi@firstfloor.org> Acked-by: Minchan Kim <minchan.kim@gmail.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Matt Mackall <mpm@selenic.com> Cc: Rik van Riel <riel@redhat.com> Cc: Lee Schermerhorn <lee.schermerhorn@hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* CacheFiles: Permit the page lock state to be monitoredDavid Howells2009-04-031-0/+5
| | | | | | | | | | | | | | | Add a function to install a monitor on the page lock waitqueue for a particular page, thus allowing the page being unlocked to be detected. This is used by CacheFiles to detect read completion on a page in the backing filesystem so that it can then copy the data to the waiting netfs page. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Steve Dickson <steved@redhat.com> Acked-by: Trond Myklebust <Trond.Myklebust@netapp.com> Acked-by: Rik van Riel <riel@redhat.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Tested-by: Daire Byrne <Daire.Byrne@framestore.com>
* mm: define a UNIQUE value for AS_UNEVICTABLE flagLee Schermerhorn2009-04-021-4/+8
| | | | | | | | | | | | | | | | | | | A new "address_space flag"--AS_MM_ALL_LOCKS--was defined to use the next available AS flag while the Unevictable LRU was under development. The Unevictable LRU was using the same flag and "no one" noticed. Current mainline, since 2.6.28, has same value for two symbolic flag names. So, define a unique flag value for AS_UNEVICTABLE--up close to the other flags, [at the cost of an additional #ifdef] so we'll notice next time. Note that #ifdef is not actually required, if we don't mind having the unused flag value defined. Replace #defines with an enum. Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: <stable@kernel.org> [2.6.28.x, 2.6.29.x] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fs: symlink write_begin allocation context fixNick Piggin2009-01-041-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With the write_begin/write_end aops, page_symlink was broken because it could no longer pass a GFP_NOFS type mask into the point where the allocations happened. They are done in write_begin, which would always assume that the filesystem can be entered from reclaim. This bug could cause filesystem deadlocks. The funny thing with having a gfp_t mask there is that it doesn't really allow the caller to arbitrarily tinker with the context in which it can be called. It couldn't ever be GFP_ATOMIC, for example, because it needs to take the page lock. The only thing any callers care about is __GFP_FS anyway, so turn that into a single flag. Add a new flag for write_begin, AOP_FLAG_NOFS. Filesystems can now act on this flag in their write_begin function. Change __grab_cache_page to accept a nofs argument as well, to honour that flag (while we're there, change the name to grab_cache_page_write_begin which is more instructive and does away with random leading underscores). This is really a more flexible way to go in the end anyway -- if a filesystem happens to want any extra allocations aside from the pagecache ones in ints write_begin function, it may now use GFP_KERNEL (rather than GFP_NOFS) for common case allocations (eg. ocfs2_alloc_write_ctxt, for a random example). [kosaki.motohiro@jp.fujitsu.com: fix ubifs] [kosaki.motohiro@jp.fujitsu.com: fix fuse] Signed-off-by: Nick Piggin <npiggin@suse.de> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: <stable@kernel.org> [2.6.28.x] Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> [ Cleaned up the calling convention: just pass in the AOP flags untouched to the grab_cache_page_write_begin() function. That just simplifies everybody, and may even allow future expansion of the logic. - Linus ] Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: page lock use lock bitopsNick Piggin2008-10-201-1/+1
| | | | | | | | | | | | trylock_page, unlock_page open and close a critical section. Hence, we can use the lock bitops to get the desired memory ordering. Also, mark trylock as likely to succeed (and remove the annotation from callers). Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: pagecache insertion fewer atomicsNick Piggin2008-10-201-7/+7
| | | | | | | | | | | | Setting and clearing the page locked when inserting it into swapcache / pagecache when it has no other references can use non-atomic page flags operations because no other CPU may be operating on it at this time. This saves one atomic operation when inserting a page into pagecache. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* SHM_LOCKED pages are unevictableLee Schermerhorn2008-10-201-3/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Shmem segments locked into memory via shmctl(SHM_LOCKED) should not be kept on the normal LRU, since scanning them is a waste of time and might throw off kswapd's balancing algorithms. Place them on the unevictable LRU list instead. Use the AS_UNEVICTABLE flag to mark address_space of SHM_LOCKed shared memory regions as unevictable. Then these pages will be culled off the normal LRU lists during vmscan. Add new wrapper function to clear the mapping's unevictable state when/if shared memory segment is munlocked. Add 'scan_mapping_unevictable_page()' to mm/vmscan.c to scan all pages in the shmem segment's mapping [struct address_space] for evictability now that they're no longer locked. If so, move them to the appropriate zone lru list. Changes depend on [CONFIG_]UNEVICTABLE_LRU. [kosaki.motohiro@jp.fujitsu.com: revert shm change] Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Signed-off-by: Rik van Riel <riel@redhat.com> Signed-off-by: Kosaki Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Ramfs and Ram Disk pages are unevictableLee Schermerhorn2008-10-201-0/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Christoph Lameter pointed out that ram disk pages also clutter the LRU lists. When vmscan finds them dirty and tries to clean them, the ram disk writeback function just redirties the page so that it goes back onto the active list. Round and round she goes... With the ram disk driver [rd.c] replaced by the newer 'brd.c', this is no longer the case, as ram disk pages are no longer maintained on the lru. [This makes them unmigratable for defrag or memory hot remove, but that can be addressed by a separate patch series.] However, the ramfs pages behave like ram disk pages used to, so: Define new address_space flag [shares address_space flags member with mapping's gfp mask] to indicate that the address space contains all unevictable pages. This will provide for efficient testing of ramfs pages in page_evictable(). Also provide wrapper functions to set/test the unevictable state to minimize #ifdefs in ramfs driver and any other users of this facility. Set the unevictable state on address_space structures for new ramfs inodes. Test the unevictable state in page_evictable() to cull unevictable pages. These changes depend on [CONFIG_]UNEVICTABLE_LRU. [riel@redhat.com: undo the brd.c part] Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Signed-off-by: Rik van Riel <riel@redhat.com> Debugged-by: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: rename page trylockNick Piggin2008-08-041-26/+41
| | | | | | | | | | | | | | | Converting page lock to new locking bitops requires a change of page flag operation naming, so we might as well convert it to something nicer (!TestSetPageLocked_Lock => trylock_page, SetPageLocked => set_page_locked). This also facilitates lockdeping of page lock. Signed-off-by: Nick Piggin <npiggin@suse.de> Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* powerpc/mm: Lockless get_user_pages_fast() for 64-bit (v3)Nick Piggin2008-07-301-0/+23
| | | | | | | | | | | | | Implement lockless get_user_pages_fast for 64-bit powerpc. Page table existence is guaranteed with RCU, and speculative page references are used to take a reference to the pages without having a prior existence guarantee on them. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* mmu-notifiers: add mm_take_all_locks() operationAndrea Arcangeli2008-07-281-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | mm_take_all_locks holds off reclaim from an entire mm_struct. This allows mmu notifiers to register into the mm at any time with the guarantee that no mmu operation is in progress on the mm. This operation locks against the VM for all pte/vma/mm related operations that could ever happen on a certain mm. This includes vmtruncate, try_to_unmap, and all page faults. The caller must take the mmap_sem in write mode before calling mm_take_all_locks(). The caller isn't allowed to release the mmap_sem until mm_drop_all_locks() returns. mmap_sem in write mode is required in order to block all operations that could modify pagetables and free pages without need of altering the vma layout (for example populate_range() with nonlinear vmas). It's also needed in write mode to avoid new anon_vmas to be associated with existing vmas. A single task can't take more than one mm_take_all_locks() in a row or it would deadlock. mm_take_all_locks() and mm_drop_all_locks are expensive operations that may have to take thousand of locks. mm_take_all_locks() can fail if it's interrupted by signals. When mmu_notifier_register returns, we must be sure that the driver is notified if some task is in the middle of a vmtruncate for the 'mm' where the mmu notifier was registered (mmu_notifier_invalidate_range_start/end is run around the vmtruncation but mmu_notifier_register can run after mmu_notifier_invalidate_range_start and before mmu_notifier_invalidate_range_end). Same problem for rmap paths. And we've to remove page pinning to avoid replicating the tlb_gather logic inside KVM (and GRU doesn't work well with page pinning regardless of needing tlb_gather), so without mm_take_all_locks when vmtruncate frees the page, kvm would have no way to notice that it mapped into sptes a page that is going into the freelist without a chance of any further mmu_notifier notification. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Andrea Arcangeli <andrea@qumranet.com> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Jack Steiner <steiner@sgi.com> Cc: Robin Holt <holt@sgi.com> Cc: Nick Piggin <npiggin@suse.de> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Kanoj Sarcar <kanojsarcar@yahoo.com> Cc: Roland Dreier <rdreier@cisco.com> Cc: Steve Wise <swise@opengridcomputing.com> Cc: Avi Kivity <avi@qumranet.com> Cc: Hugh Dickins <hugh@veritas.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Anthony Liguori <aliguori@us.ibm.com> Cc: Chris Wright <chrisw@redhat.com> Cc: Marcelo Tosatti <marcelo@kvack.org> Cc: Eric Dumazet <dada1@cosmosbay.com> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Cc: Izik Eidus <izike@qumranet.com> Cc: Anthony Liguori <aliguori@us.ibm.com> Cc: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: speculative page referencesNick Piggin2008-07-261-1/+110
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If we can be sure that elevating the page_count on a pagecache page will pin it, we can speculatively run this operation, and subsequently check to see if we hit the right page rather than relying on holding a lock or otherwise pinning a reference to the page. This can be done if get_page/put_page behaves consistently throughout the whole tree (ie. if we "get" the page after it has been used for something else, we must be able to free it with a put_page). Actually, there is a period where the count behaves differently: when the page is free or if it is a constituent page of a compound page. We need an atomic_inc_not_zero operation to ensure we don't try to grab the page in either case. This patch introduces the core locking protocol to the pagecache (ie. adds page_cache_get_speculative, and tweaks some update-side code to make it work). Thanks to Hugh for pointing out an improvement to the algorithm setting page_count to zero when we have control of all references, in order to hold off speculative getters. [kamezawa.hiroyu@jp.fujitsu.com: fix migration_entry_wait()] [hugh@veritas.com: fix add_to_page_cache] [akpm@linux-foundation.org: repair a comment] Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: Jeff Garzik <jeff@garzik.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Hugh Dickins <hugh@veritas.com> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Reviewed-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Hugh Dickins <hugh@veritas.com> Acked-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mapping_set_error: add unlikely()Andrew Morton2008-07-241-1/+1
| | | | | | | | | This is called on a per-page basis and in the vast majority of cases `error' is zero. Cc: Guillaume Chazarain <guichaz@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* include/linux: Remove all users of FASTCALL() macroHarvey Harrison2008-02-131-5/+5
| | | | | | | | | FASTCALL() is always expanded to empty, remove it. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Add lock_page_killableMatthew Wilcox2007-12-061-0/+14
| | | | | | This routine is like lock_page, but can be interrupted by a fatal signal Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
* fs: introduce write_begin, write_end, and perform_write aopsNick Piggin2007-10-161-0/+2
| | | | | | | | | | | | | | | These are intended to replace prepare_write and commit_write with more flexible alternatives that are also able to avoid the buffered write deadlock problems efficiently (which prepare_write is unable to do). [mark.fasheh@oracle.com: API design contributions, code review and fixes] [akpm@linux-foundation.org: various fixes] [dmonakhov@sw.ru: new aop block_write_begin fix] Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com> Signed-off-by: Dmitriy Monakhov <dmonakhov@openvz.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: fix pagecache write deadlocksNick Piggin2007-10-161-2/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Modify the core write() code so that it won't take a pagefault while holding a lock on the pagecache page. There are a number of different deadlocks possible if we try to do such a thing: 1. generic_buffered_write 2. lock_page 3. prepare_write 4. unlock_page+vmtruncate 5. copy_from_user 6. mmap_sem(r) 7. handle_mm_fault 8. lock_page (filemap_nopage) 9. commit_write 10. unlock_page a. sys_munmap / sys_mlock / others b. mmap_sem(w) c. make_pages_present d. get_user_pages e. handle_mm_fault f. lock_page (filemap_nopage) 2,8 - recursive deadlock if page is same 2,8;2,8 - ABBA deadlock is page is different 2,6;b,f - ABBA deadlock if page is same The solution is as follows: 1. If we find the destination page is uptodate, continue as normal, but use atomic usercopies which do not take pagefaults and do not zero the uncopied tail of the destination. The destination is already uptodate, so we can commit_write the full length even if there was a partial copy: it does not matter that the tail was not modified, because if it is dirtied and written back to disk it will not cause any problems (uptodate *means* that the destination page is as new or newer than the copy on disk). 1a. The above requires that fault_in_pages_readable correctly returns access information, because atomic usercopies cannot distinguish between non-present pages in a readable mapping, from lack of a readable mapping. 2. If we find the destination page is non uptodate, unlock it (this could be made slightly more optimal), then allocate a temporary page to copy the source data into. Relock the destination page and continue with the copy. However, instead of a usercopy (which might take a fault), copy the data from the pinned temporary page via the kernel address space. (also, rename maxlen to seglen, because it was confusing) This increases the CPU/memory copy cost by almost 50% on the affected workloads. That will be solved by introducing a new set of pagecache write aops in a subsequent patch. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* filemap: convert some unsigned long to pgoff_tFengguang Wu2007-10-161-11/+12
| | | | | | | | | Convert some 'unsigned long' to pgoff_t. Signed-off-by: Fengguang Wu <wfg@mail.ustc.edu.cn> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Factor outstanding I/O error handlingGuillaume Chazarain2007-05-081-0/+11
| | | | | | | | | | Cleanup: setting an outstanding error on a mapping was open coded too many times. Factor it out in mapping_set_error(). Signed-off-by: Guillaume Chazarain <guichaz@yahoo.fr> Cc: Steven Whitehouse <swhiteho@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: make read_cache_page synchronousNick Piggin2007-05-071-0/+11
| | | | | | | | | | | | | | | | Ensure pages are uptodate after returning from read_cache_page, which allows us to cut out most of the filesystem-internal PageUptodate calls. I didn't have a great look down the call chains, but this appears to fixes 7 possible use-before uptodate in hfs, 2 in hfsplus, 1 in jfs, a few in ecryptfs, 1 in jffs2, and a possible cleared data overwritten with readpage in block2mtd. All depending on whether the filler is async and/or can return with a !uptodate page. Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] mm: remove find_trylock_pageNick Piggin2007-02-091-2/+0
| | | | | | | | Remove find_trylock_page as per the removal schedule. Signed-off-by: Nick Piggin <npiggin@suse.de> [ Let's see if anybody screams ] Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] mm: clean up pagecache allocationNick Piggin2006-10-281-5/+9
| | | | | | | | | | | | | | - Consolidate page_cache_alloc - Fix splice: only the pagecache pages and filesystem data need to use mapping_gfp_mask. - Fix grab_cache_page_nowait: same as splice, also honour NUMA placement. Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: Jens Axboe <jens.axboe@oracle.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] mm: non syncing lock_page()Nick Piggin2006-09-261-0/+15
| | | | | | | | | | | | | | | | | | | | | lock_page needs the caller to have a reference on the page->mapping inode due to sync_page, ergo set_page_dirty_lock is obviously buggy according to its comments. Solve it by introducing a new lock_page_nosync which does not do a sync_page. akpm: unpleasant solution to an unpleasant problem. If it goes wrong it could cause great slowdowns while the lock_page() caller waits for kblockd to perform the unplug. And if a filesystem has special sync_page() requirements (none presently do), permanent hangs are possible. otoh, set_page_dirty_lock() is usually (always?) called against userspace pages. They are always up-to-date, so there shouldn't be any pending read I/O against these pages. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] zoned vm counters: conversion of nr_pagecache to per zone counterChristoph Lameter2006-06-301-45/+0
| | | | | | | | | | | | | | | | | | Currently a single atomic variable is used to establish the size of the page cache in the whole machine. The zoned VM counters have the same method of implementation as the nr_pagecache code but also allow the determination of the pagecache size per zone. Remove the special implementation for nr_pagecache and make it a zoned counter named NR_FILE_PAGES. Updates of the page cache counters are always performed with interrupts off. We can therefore use the __ variant here. Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Trond Myklebust <trond.myklebust@fys.uio.no> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] read_mapping_page for address spacePekka Enberg2006-06-231-0/+7
| | | | | | | | | | Add read_mapping_page() which is used for callers that pass mapping->a_ops->readpage as the filler for read_cache_page. This removes some duplication from filesystem code. 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] Add find_get_pages_contig(): contiguous variant of find_get_pages()Jens Axboe2006-04-271-0/+2
| | | | | | | find_get_pages_contig() will break out if we hit a hole in the page cache. From Andrew Morton, small modifications and documentation by me. Signed-off-by: Jens Axboe <axboe@suse.de>
* [PATCH] mm: schedule find_trylock_page() removalNick Piggin2006-03-311-2/+2
| | | | | | | | | | | | find_trylock_page() is an odd interface in that it doesn't take a reference like the others. Now that XFS no longer uses it, and its last remaining caller actually wants an elevated refcount, opencode that callsite and schedule find_trylock_page() for removal. Signed-off-by: Nick Piggin <npiggin@suse.de> Acked-by: Hugh Dickins <hugh@veritas.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 Jackson2006-03-241-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | 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] mm: gfp_noreclaim cleanupPaul Jackson2005-11-131-2/+2
| | | | | | | | | | Remove last remnant of the defunct early reclaim page logic, the no longer used __GFP_NORECLAIM flag bit. Signed-off-by: Paul Jackson <pj@sgi.com> Acked-by: Martin Hicks <mort@bork.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] gfp_t: the restAl Viro2005-10-281-3/+4
| | | | | | | zone handling, mapping->flags handling Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] gfp_t: mm/* (easy parts)Al Viro2005-10-281-3/+3
| | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] gfp flags annotations - part 1Al Viro2005-10-081-1/+1
| | | | | | | | | | | | - added typedef unsigned int __nocast gfp_t; - replaced __nocast uses for gfp flags with gfp_t - it gives exactly the same warnings as far as sparse is concerned, doesn't change generated code (from gcc point of view we replaced unsigned int with typedef) and documents what's going on far better. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] VM: add __GFP_NORECLAIMMartin Hicks2005-06-211-2/+2
| | | | | | | | | | | | | | When using the early zone reclaim, it was noticed that allocating new pages that should be spread across the whole system caused eviction of local pages. This adds a new GFP flag to prevent early reclaim from happening during certain allocation attempts. The example that is implemented here is for page cache pages. We want page cache pages to be spread across the whole system, and we don't want page cache pages to evict other pages to get local memory. Signed-off-by: Martin Hicks <mort@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* Linux-2.6.12-rc2v2.6.12-rc2Linus Torvalds2005-04-161-0/+246
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
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