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2008-10-20swap: cull unevictable pages in fault pathLee Schermerhorn
In the fault paths that install new anonymous pages, check whether the page is evictable or not using lru_cache_add_active_or_unevictable(). If the page is evictable, just add it to the active lru list [via the pagevec cache], else add it to the unevictable list. This "proactive" culling in the fault path mimics the handling of mlocked pages in Nick Piggin's series to keep mlocked pages off the lru lists. Notes: 1) This patch is optional--e.g., if one is concerned about the additional test in the fault path. We can defer the moving of nonreclaimable pages until when vmscan [shrink_*_list()] encounters them. Vmscan will only need to handle such pages once, but if there are a lot of them it could impact system performance. 2) The 'vma' argument to page_evictable() is require to notice that we're faulting a page into an mlock()ed vma w/o having to scan the page's rmap in the fault path. Culling mlock()ed anon pages is currently the only reason for this patch. 3) We can't cull swap pages in read_swap_cache_async() because the vma argument doesn't necessarily correspond to the swap cache offset passed in by swapin_readahead(). This could [did!] result in mlocking pages in non-VM_LOCKED vmas if [when] we tried to cull in this path. 4) Move set_pte_at() to after where we add page to lru to keep it hidden from other tasks that might walk the page table. We already do it in this order in do_anonymous() page. And, these are COW'd anon pages. Is this safe? [riel@redhat.com: undo an overzealous code cleanup] 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>
2008-10-20mlock: mlocked pages are unevictableNick Piggin
Make sure that mlocked pages also live on the unevictable LRU, so kswapd will not scan them over and over again. This is achieved through various strategies: 1) add yet another page flag--PG_mlocked--to indicate that the page is locked for efficient testing in vmscan and, optionally, fault path. This allows early culling of unevictable pages, preventing them from getting to page_referenced()/try_to_unmap(). Also allows separate accounting of mlock'd pages, as Nick's original patch did. Note: Nick's original mlock patch used a PG_mlocked flag. I had removed this in favor of the PG_unevictable flag + an mlock_count [new page struct member]. I restored the PG_mlocked flag to eliminate the new count field. 2) add the mlock/unevictable infrastructure to mm/mlock.c, with internal APIs in mm/internal.h. This is a rework of Nick's original patch to these files, taking into account that mlocked pages are now kept on unevictable LRU list. 3) update vmscan.c:page_evictable() to check PageMlocked() and, if vma passed in, the vm_flags. Note that the vma will only be passed in for new pages in the fault path; and then only if the "cull unevictable pages in fault path" patch is included. 4) add try_to_unlock() to rmap.c to walk a page's rmap and ClearPageMlocked() if no other vmas have it mlocked. Reuses as much of try_to_unmap() as possible. This effectively replaces the use of one of the lru list links as an mlock count. If this mechanism let's pages in mlocked vmas leak through w/o PG_mlocked set [I don't know that it does], we should catch them later in try_to_unmap(). One hopes this will be rare, as it will be relatively expensive. Original mm/internal.h, mm/rmap.c and mm/mlock.c changes: Signed-off-by: Nick Piggin <npiggin@suse.de> splitlru: introduce __get_user_pages(): New munlock processing need to GUP_FLAGS_IGNORE_VMA_PERMISSIONS. because current get_user_pages() can't grab PROT_NONE pages theresore it cause PROT_NONE pages can't munlock. [akpm@linux-foundation.org: fix this for pagemap-pass-mm-into-pagewalkers.patch] [akpm@linux-foundation.org: untangle patch interdependencies] [akpm@linux-foundation.org: fix things after out-of-order merging] [hugh@veritas.com: fix page-flags mess] [lee.schermerhorn@hp.com: fix munlock page table walk - now requires 'mm'] [kosaki.motohiro@jp.fujitsu.com: build fix] [kosaki.motohiro@jp.fujitsu.com: fix truncate race and sevaral comments] [kosaki.motohiro@jp.fujitsu.com: splitlru: introduce __get_user_pages()] Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Rik van Riel <riel@redhat.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Nick Piggin <npiggin@suse.de> Cc: Dave Hansen <dave@linux.vnet.ibm.com> Cc: Matt Mackall <mpm@selenic.com> Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-20Unevictable LRU InfrastructureLee Schermerhorn
When the system contains lots of mlocked or otherwise unevictable pages, the pageout code (kswapd) can spend lots of time scanning over these pages. Worse still, the presence of lots of unevictable pages can confuse kswapd into thinking that more aggressive pageout modes are required, resulting in all kinds of bad behaviour. Infrastructure to manage pages excluded from reclaim--i.e., hidden from vmscan. Based on a patch by Larry Woodman of Red Hat. Reworked to maintain "unevictable" pages on a separate per-zone LRU list, to "hide" them from vmscan. Kosaki Motohiro added the support for the memory controller unevictable lru list. Pages on the unevictable list have both PG_unevictable and PG_lru set. Thus, PG_unevictable is analogous to and mutually exclusive with PG_active--it specifies which LRU list the page is on. The unevictable infrastructure is enabled by a new mm Kconfig option [CONFIG_]UNEVICTABLE_LRU. A new function 'page_evictable(page, vma)' in vmscan.c tests whether or not a page may be evictable. Subsequent patches will add the various !evictable tests. We'll want to keep these tests light-weight for use in shrink_active_list() and, possibly, the fault path. To avoid races between tasks putting pages [back] onto an LRU list and tasks that might be moving the page from non-evictable to evictable state, the new function 'putback_lru_page()' -- inverse to 'isolate_lru_page()' -- tests the "evictability" of a page after placing it on the LRU, before dropping the reference. If the page has become unevictable, putback_lru_page() will redo the 'putback', thus moving the page to the unevictable list. This way, we avoid "stranding" evictable pages on the unevictable list. [akpm@linux-foundation.org: fix fallout from out-of-order merge] [riel@redhat.com: fix UNEVICTABLE_LRU and !PROC_PAGE_MONITOR build] [nishimura@mxp.nes.nec.co.jp: remove redundant mapping check] [kosaki.motohiro@jp.fujitsu.com: unevictable-lru-infrastructure: putback_lru_page()/unevictable page handling rework] [kosaki.motohiro@jp.fujitsu.com: kill unnecessary lock_page() in vmscan.c] [kosaki.motohiro@jp.fujitsu.com: revert migration change of unevictable lru infrastructure] [kosaki.motohiro@jp.fujitsu.com: revert to unevictable-lru-infrastructure-kconfig-fix.patch] [kosaki.motohiro@jp.fujitsu.com: restore patch failure of vmstat-unevictable-and-mlocked-pages-vm-events.patch] 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> Debugged-by: Benjamin Kidwell <benjkidwell@yahoo.com> Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-20vmscan: split LRU lists into anon & file setsRik van Riel
Split the LRU lists in two, one set for pages that are backed by real file systems ("file") and one for pages that are backed by memory and swap ("anon"). The latter includes tmpfs. The advantage of doing this is that the VM will not have to scan over lots of anonymous pages (which we generally do not want to swap out), just to find the page cache pages that it should evict. This patch has the infrastructure and a basic policy to balance how much we scan the anon lists and how much we scan the file lists. The big policy changes are in separate patches. [lee.schermerhorn@hp.com: collect lru meminfo statistics from correct offset] [kosaki.motohiro@jp.fujitsu.com: prevent incorrect oom under split_lru] [kosaki.motohiro@jp.fujitsu.com: fix pagevec_move_tail() doesn't treat unevictable page] [hugh@veritas.com: memcg swapbacked pages active] [hugh@veritas.com: splitlru: BDI_CAP_SWAP_BACKED] [akpm@linux-foundation.org: fix /proc/vmstat units] [nishimura@mxp.nes.nec.co.jp: memcg: fix handling of shmem migration] [kosaki.motohiro@jp.fujitsu.com: adjust Quicklists field of /proc/meminfo] [kosaki.motohiro@jp.fujitsu.com: fix style issue of get_scan_ratio()] Signed-off-by: Rik van Riel <riel@redhat.com> Signed-off-by: Lee Schermerhorn <Lee.Schermerhorn@hp.com> Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-20vmscan: free swap space on swap-in/activationRik van Riel
If vm_swap_full() (swap space more than 50% full), the system will free swap space at swapin time. With this patch, the system will also free the swap space in the pageout code, when we decide that the page is not a candidate for swapout (and just wasting swap space). Signed-off-by: Rik van Riel <riel@redhat.com> Signed-off-by: Lee Schermerhorn <Lee.Schermerhorn@hp.com> Signed-off-by: MinChan Kim <minchan.kim@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-20swap: use an array for the LRU pagevecsKOSAKI Motohiro
Turn the pagevecs into an array just like the LRUs. This significantly cleans up the source code and reduces the size of the kernel by about 13kB after all the LRU lists have been created further down in the split VM patch series. 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>
2008-10-20vmscan: Use an indexed array for LRU variablesChristoph Lameter
Currently we are defining explicit variables for the inactive and active list. An indexed array can be more generic and avoid repeating similar code in several places in the reclaim code. We are saving a few bytes in terms of code size: Before: text data bss dec hex filename 4097753 573120 4092484 8763357 85b7dd vmlinux After: text data bss dec hex filename 4097729 573120 4092484 8763333 85b7c5 vmlinux Having an easy way to add new lru lists may ease future work on the reclaim code. Signed-off-by: Rik van Riel <riel@redhat.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Signed-off-by: Christoph Lameter <cl@linux-foundation.org> 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>
2008-08-04mm: rename page trylockNick Piggin
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>
2008-07-30swap: update function comment of release_pagesFernando Luis Vazquez Cao
Signed-off-by: Fernando Luis Vazquez Cao <fernando@oss.ntt.co.jp> Cc: Hugh Dickins <hugh@veritas.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> 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>
2008-07-24mm: remove initialization of static per-cpu variablesVegard Nossum
This was required by some old, no-longer-used gcc on sparc. Signed-off-by: Vegard Nossum <vegard.nossum@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-24mm: fix atomic_t overflow in vmAlan Cox
The atomic_t type is 32bit but a 64bit system can have more than 2^32 pages of virtual address space available. Without this we overflow on ludicrously large mappings Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28mm: rotate_reclaimable_page() cleanupMiklos Szeredi
Clean up messy conditional calling of test_clear_page_writeback() from both rotate_reclaimable_page() and end_page_writeback(). The only user of rotate_reclaimable_page() is end_page_writeback() so this is OK. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-19mm: fix various kernel-doc commentsRandy Dunlap
Fix various kernel-doc notation in mm/: filemap.c: add function short description; convert 2 to kernel-doc fremap.c: change parameter 'prot' to @prot pagewalk.c: change "-" in function parameters to ":" slab.c: fix short description of kmem_ptr_validate() swap.c: fix description & parameters of put_pages_list() swap_state.c: fix function parameters vmalloc.c: change "@returns" to "Returns:" since that is not a parameter Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-04memcg: move_lists on page not page_cgroupHugh Dickins
Each caller of mem_cgroup_move_lists is having to use page_get_page_cgroup: it's more convenient if it acts upon the page itself not the page_cgroup; and in a later patch this becomes important to handle within memcontrol.c. Signed-off-by: Hugh Dickins <hugh@veritas.com> Cc: David Rientjes <rientjes@google.com> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hirokazu Takahashi <taka@valinux.co.jp> Cc: YAMAMOTO Takashi <yamamoto@valinux.co.jp> Cc: Paul Menage <menage@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-07Memory controller: add per cgroup LRU and reclaimBalbir Singh
Add the page_cgroup to the per cgroup LRU. The reclaim algorithm has been modified to make the isolate_lru_pages() as a pluggable component. The scan_control data structure now accepts the cgroup on behalf of which reclaims are carried out. try_to_free_pages() has been extended to become cgroup aware. [akpm@linux-foundation.org: fix warning] [Lee.Schermerhorn@hp.com: initialize all scan_control's isolate_pages member] [bunk@kernel.org: make do_try_to_free_pages() static] [hugh@veritas.com: memcgroup: fix try_to_free order] [kamezawa.hiroyu@jp.fujitsu.com: this unlock_page_cgroup() is unnecessary] Signed-off-by: Pavel Emelianov <xemul@openvz.org> Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Paul Menage <menage@google.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Kirill Korotaev <dev@sw.ru> Cc: Herbert Poetzl <herbert@13thfloor.at> Cc: David Rientjes <rientjes@google.com> Cc: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-05mm: remove fastcall from mm/Harvey Harrison
fastcall is always defined to be 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>
2007-10-20spelling fixes: mm/Simon Arlott
Spelling fixes in mm/. Signed-off-by: Simon Arlott <simon@fire.lp0.eu> Signed-off-by: Adrian Bunk <bunk@kernel.org>
2007-10-17mm: bdi init hooksPeter Zijlstra
provide BDI constructor/destructor hooks [akpm@linux-foundation.org: compile fix] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16mm: use pagevec to rotate reclaimable pageHisashi Hifumi
While running some memory intensive load, system response deteriorated just after swap-out started. The cause of this problem is that when a PG_reclaim page is moved to the tail of the inactive LRU list in rotate_reclaimable_page(), lru_lock spin lock is acquired every page writeback . This deteriorates system performance and makes interrupt hold off time longer when swap-out started. Following patch solves this problem. I use pagevec in rotating reclaimable pages to mitigate LRU spin lock contention and reduce interrupt hold off time. I did a test that allocating and touching pages in multiple processes, and pinging to the test machine in flooding mode to measure response under memory intensive load. The test result is: -2.6.23-rc5 --- testmachine ping statistics --- 3000 packets transmitted, 3000 received, 0% packet loss, time 53222ms rtt min/avg/max/mdev = 0.074/0.652/172.228/7.176 ms, pipe 11, ipg/ewma 17.746/0.092 ms -2.6.23-rc5-patched --- testmachine ping statistics --- 3000 packets transmitted, 3000 received, 0% packet loss, time 51924ms rtt min/avg/max/mdev = 0.072/0.108/3.884/0.114 ms, pipe 2, ipg/ewma 17.314/0.091 ms Max round-trip-time was improved. The test machine spec is that 4CPU(3.16GHz, Hyper-threading enabled) 8GB memory , 8GB swap. I did ping test again to observe performance deterioration caused by taking a ref. -2.6.23-rc6-with-modifiedpatch --- testmachine ping statistics --- 3000 packets transmitted, 3000 received, 0% packet loss, time 53386ms rtt min/avg/max/mdev = 0.074/0.110/4.716/0.147 ms, pipe 2, ipg/ewma 17.801/0.129 ms The result for my original patch is as follows. -2.6.23-rc5-with-originalpatch --- testmachine ping statistics --- 3000 packets transmitted, 3000 received, 0% packet loss, time 51924ms rtt min/avg/max/mdev = 0.072/0.108/3.884/0.114 ms, pipe 2, ipg/ewma 17.314/0.091 ms The influence to response was small. [akpm@linux-foundation.org: fix uninitalised var warning] [hugh@veritas.com: fix locking] [randy.dunlap@oracle.com: fix function declaration] [hugh@veritas.com: fix BUG at include/linux/mm.h:220!] [hugh@veritas.com: kill redundancy in rotate_reclaimable_page] [hugh@veritas.com: move_tail_pages into lru_add_drain] Signed-off-by: Hisashi Hifumi <hifumi.hisashi@oss.ntt.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16Clean up duplicate includes in mm/Jesper Juhl
This patch cleans up duplicate includes in mm/ Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com> Acked-by: Paul Mundt <lethal@linux-sh.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09Add suspend-related notifications for CPU hotplugRafael J. Wysocki
Since nonboot CPUs are now disabled after tasks and devices have been frozen and the CPU hotplug infrastructure is used for this purpose, we need special CPU hotplug notifications that will help the CPU-hotplug-aware subsystems distinguish normal CPU hotplug events from CPU hotplug events related to a system-wide suspend or resume operation in progress. This patch introduces such notifications and causes them to be used during suspend and resume transitions. It also changes all of the CPU-hotplug-aware subsystems to take these notifications into consideration (for now they are handled in the same way as the corresponding "normal" ones). [oleg@tv-sign.ru: cleanups] Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Cc: Gautham R Shenoy <ego@in.ibm.com> Cc: Pavel Machek <pavel@ucw.cz> Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-07Make page->private usable in compound pagesChristoph Lameter
If we add a new flag so that we can distinguish between the first page and the tail pages then we can avoid to use page->private in the first page. page->private == page for the first page, so there is no real information in there. Freeing up page->private makes the use of compound pages more transparent. They become more usable like real pages. Right now we have to be careful f.e. if we are going beyond PAGE_SIZE allocations in the slab on i386 because we can then no longer use the private field. This is one of the issues that cause us not to support debugging for page size slabs in SLAB. Having page->private available for SLUB would allow more meta information in the page struct. I can probably avoid the 16 bit ints that I have in there right now. Also if page->private is available then a compound page may be equipped with buffer heads. This may free up the way for filesystems to support larger blocks than page size. We add PageTail as an alias of PageReclaim. Compound pages cannot currently be reclaimed. Because of the alias one needs to check PageCompound first. The RFC for the this approach was discussed at http://marc.info/?t=117574302800001&r=1&w=2 [nacc@us.ibm.com: fix hugetlbfs] Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2006-12-07[PATCH] hotplug CPU: clean up hotcpu_notifier() useIngo Molnar
There was lots of #ifdef noise in the kernel due to hotcpu_notifier(fn, prio) not correctly marking 'fn' as used in the !HOTPLUG_CPU case, and thus generating compiler warnings of unused symbols, hence forcing people to add #ifdefs. the compiler can skip truly unused functions just fine: text data bss dec hex filename 1624412 728710 3674856 6027978 5bfaca vmlinux.before 1624412 728710 3674856 6027978 5bfaca vmlinux.after [akpm@osdl.org: topology.c fix] Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-07[PATCH] mm: make compound page destructor handling explicitAndy Whitcroft
Currently we we use the lru head link of the second page of a compound page to hold its destructor. This was ok when it was purely an internal implmentation detail. However, hugetlbfs overrides this destructor violating the layering. Abstract this out as explicit calls, also introduce a type for the callback function allowing them to be type checked. For each callback we pre-declare the function, causing a type error on definition rather than on use elsewhere. [akpm@osdl.org: cleanups] Signed-off-by: Andy Whitcroft <apw@shadowen.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-11-22WorkStruct: make allyesconfigDavid Howells
Fix up for make allyesconfig. Signed-Off-By: David Howells <dhowells@redhat.com>
2006-09-26[PATCH] mm/: make functions staticAdrian Bunk
This patch makes the following needlessly global functions static: - slab.c: kmem_find_general_cachep() - swap.c: __page_cache_release() - vmalloc.c: __vmalloc_node() Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-26[PATCH] mm: VM_BUG_ONNick Piggin
Introduce a VM_BUG_ON, which is turned on with CONFIG_DEBUG_VM. Use this in the lightweight, inline refcounting functions; PageLRU and PageActive checks in vmscan, because they're pretty well confined to vmscan. And in page allocate/free fastpaths which can be the hottest parts of the kernel for kbuilds. Unlike BUG_ON, VM_BUG_ON must not be used to execute statements with side-effects, and should not be used outside core mm code. Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: Hugh Dickins <hugh@veritas.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-08-14[PATCH] fuse: fix error case in fuse_readpagesAlexander Zarochentsev
Don't let fuse_readpages leave the @pages list not empty when exiting on error. [akpm@osdl.org: kernel-doc fixes] Signed-off-by: Alexander Zarochentsev <zam@namesys.com> Signed-off-by: Miklos Szeredi <miklos@szeredi.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-06-30[PATCH] Light weight event countersChristoph Lameter
The remaining counters in page_state after the zoned VM counter patches have been applied are all just for show in /proc/vmstat. They have no essential function for the VM. We use a simple increment of per cpu variables. In order to avoid the most severe races we disable preempt. Preempt does not prevent the race between an increment and an interrupt handler incrementing the same statistics counter. However, that race is exceedingly rare, we may only loose one increment or so and there is no requirement (at least not in kernel) that the vm event counters have to be accurate. In the non preempt case this results in a simple increment for each counter. For many architectures this will be reduced by the compiler to a single instruction. This single instruction is atomic for i386 and x86_64. And therefore even the rare race condition in an interrupt is avoided for both architectures in most cases. The patchset also adds an off switch for embedded systems that allows a building of linux kernels without these counters. The implementation of these counters is through inline code that hopefully results in only a single instruction increment instruction being emitted (i386, x86_64) or in the increment being hidden though instruction concurrency (EPIC architectures such as ia64 can get that done). Benefits: - VM event counter operations usually reduce to a single inline instruction on i386 and x86_64. - No interrupt disable, only preempt disable for the preempt case. Preempt disable can also be avoided by moving the counter into a spinlock. - Handling is similar to zoned VM counters. - Simple and easily extendable. - Can be omitted to reduce memory use for embedded use. References: RFC http://marc.theaimsgroup.com/?l=linux-kernel&m=113512330605497&w=2 RFC http://marc.theaimsgroup.com/?l=linux-kernel&m=114988082814934&w=2 local_t http://marc.theaimsgroup.com/?l=linux-kernel&m=114991748606690&w=2 V2 http://marc.theaimsgroup.com/?t=115014808400007&r=1&w=2 V3 http://marc.theaimsgroup.com/?l=linux-kernel&m=115024767022346&w=2 V4 http://marc.theaimsgroup.com/?l=linux-kernel&m=115047968808926&w=2 Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26[PATCH] core: use list_move()Akinobu Mita
This patch converts the combination of list_del(A) and list_add(A, B) to list_move(A, B). Cc: Greg Kroah-Hartman <gregkh@suse.de> Cc: Ram Pai <linuxram@us.ibm.com> Signed-off-by: Akinobu Mita <mita@miraclelinux.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23[PATCH] percpu_counters: create lib/percpu_counter.cRavikiran G Thirumalai
- Move percpu_counter routines from mm/swap.c to lib/percpu_counter.c Signed-off-by: Ravikiran Thirumalai <kiran@scalex86.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-28[PATCH] for_each_possible_cpu: fixes for generic partKAMEZAWA Hiroyuki
replaces for_each_cpu with for_each_possible_cpu(). Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-22[PATCH] mm: less atomic opsNick Piggin
In the page release paths, we can be sure that nobody will mess with our page->flags because the refcount has dropped to 0. So no need for atomic operations here. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-22[PATCH] mm: PageActive no testsetNick Piggin
PG_active is protected by zone->lru_lock, it does not need TestSet/TestClear operations. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-22[PATCH] mm: PageLRU no testsetNick Piggin
PG_lru is protected by zone->lru_lock. It does not need TestSet/TestClear operations. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-22[PATCH] mm: never ClearPageLRU released pagesNick Piggin
If vmscan finds a zero refcount page on the lru list, never ClearPageLRU it. This means the release code need not hold ->lru_lock to stabilise PageLRU, so that lock may be skipped entirely when releasing !PageLRU pages (because we know PageLRU won't have been temporarily cleared by vmscan, which was previously guaranteed by holding the lock to synchronise against vmscan). Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-17[PATCH] fix race in pagevec_strip?Christoph Lameter
We can call try_to_release_page() with PagePrivate off and a valid page->mapping This may cause all sorts of trouble for the filesystem *_releasepage() handlers. XFS bombs out in that case. Lock the page before checking for page private. Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-08[PATCH] percpu_counter_sum()Andrew Morton
Implement percpu_counter_sum(). This is a more accurate but slower version of percpu_counter_read_positive(). We need this for Alex's speedup-ext3_statfs patch and for the nr_file accounting fix. Otherwise these things would be too inaccurate on large CPU counts. Cc: Ravikiran G Thirumalai <kiran@scalex86.org> Cc: Alex Tomas <alex@clusterfs.com> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-14[PATCH] compound page: use page[1].lruHugh Dickins
If a compound page has its own put_page_testzero destructor (the only current example is free_huge_page), that is noted in page[1].mapping of the compound page. But that's rather a poor place to keep it: functions which call set_page_dirty_lock after get_user_pages (e.g. Infiniband's __ib_umem_release) ought to be checking first, otherwise set_page_dirty is liable to crash on what's not the address of a struct address_space. And now I'm about to make that worse: it turns out that every compound page needs a destructor, so we can no longer rely on hugetlb pages going their own special way, to avoid further problems of page->mapping reuse. For example, not many people know that: on 50% of i386 -Os builds, the first tail page of a compound page purports to be PageAnon (when its destructor has an odd address), which surprises page_add_file_rmap. Keep the compound page destructor in page[1].lru.next instead. And to free up the common pairing of mapping and index, also move compound page order from index to lru.prev. Slab reuses page->lru too: but if we ever need slab to use compound pages, it can easily stack its use above this. (akpm: decoded version of the above: the tail pages of a compound page now have ->mapping==NULL, so there's no need for the set_page_dirty[_lock]() caller to check that they're not compund pages before doing the dirty). Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-07[PATCH] mm: compound release fixNick Piggin
Compound pages on SMP systems can now often be freed from pagetables via the release_pages path. This uses put_page_testzero which does not handle compound pages at all. Releasing constituent pages from process mappings decrements their count to a large negative number and leaks the reference at the head page - net result is a memory leak. The problem was hidden because the debug check in put_page_testzero itself actually did take compound pages into consideration. Fix the bug and the debug check. 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>
2006-01-18[PATCH] mm: migration page refcounting fixNick Piggin
Migration code currently does not take a reference to target page properly, so between unlocking the pte and trying to take a new reference to the page with isolate_lru_page, anything could happen to it. Fix this by holding the pte lock until we get a chance to elevate the refcount. Other small cleanups while we're here. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-11[XFS] Export pagevec_lookup for use on the XFS page writeout path,Christoph Hellwig
for dealing with delayed allocate and unwritten extents (as well). Signed-off-by: Christoph Hellwig <hch@sgi.com> Signed-off-by: Nathan Scott <nathans@sgi.com>
2006-01-06[PATCH] consolidate lru_add_drain() and lru_drain_cache()Andrew Morton
Cc: Christoph Lameter <clameter@engr.sgi.com> Cc: Rajesh Shah <rajesh.shah@intel.com> Cc: Li Shaohua <shaohua.li@intel.com> Cc: Srivatsa Vaddagiri <vatsa@in.ibm.com> Cc: Ashok Raj <ashok.raj@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-22[PATCH] unpaged: unifdefed PageCompoundHugh Dickins
It looks like snd_xxx is not the only nopage to be using PageReserved as a way of holding a high-order page together: which no longer works, but is masked by our failure to free from VM_RESERVED areas. We cannot fix that bug without first substituting another way to hold the high-order page together, while farming out the 0-order pages from within it. That's just what PageCompound is designed for, but it's been kept under CONFIG_HUGETLB_PAGE. Remove the #ifdefs: which saves some space (out- of-line put_page), doesn't slow down what most needs to be fast (already using hugetlb), and unifies the way we handle high-order pages. Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-07[PATCH] mm/swap.c: unexport vm_acct_memoryAdrian Bunk
I didn't find any possible modular usage in the kernel. Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-01Export __pagevec_release and pagevec_lookup_tagSteve French
These are needed to implement cifs_writepages Signed-off-by: Dave Kleikamp <shaggy@austin.ibm.com> Signed-off-by: Steve French <sfrench@us.ibm.com>
2005-10-30[PATCH] vm: remove redundant assignment from __pagevec_release_nonlru()Tejun Heo
This patch removes redundant assignment from __pagevec_release_nonlru(). pages_to_free.cold is set to pvec->cold by pagevec_init() call right above the assignment. Signed-off-by: Tejun Heo <htejun@gmail.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-29[PATCH] mm: split page table lockHugh Dickins
Christoph Lameter demonstrated very poor scalability on the SGI 512-way, with a many-threaded application which concurrently initializes different parts of a large anonymous area. This patch corrects that, by using a separate spinlock per page table page, to guard the page table entries in that page, instead of using the mm's single page_table_lock. (But even then, page_table_lock is still used to guard page table allocation, and anon_vma allocation.) In this implementation, the spinlock is tucked inside the struct page of the page table page: with a BUILD_BUG_ON in case it overflows - which it would in the case of 32-bit PA-RISC with spinlock debugging enabled. Splitting the lock is not quite for free: another cacheline access. Ideally, I suppose we would use split ptlock only for multi-threaded processes on multi-cpu machines; but deciding that dynamically would have its own costs. So for now enable it by config, at some number of cpus - since the Kconfig language doesn't support inequalities, let preprocessor compare that with NR_CPUS. But I don't think it's worth being user-configurable: for good testing of both split and unsplit configs, split now at 4 cpus, and perhaps change that to 8 later. There is a benefit even for singly threaded processes: kswapd can be attacking one part of the mm while another part is busy faulting. Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-29[PATCH] core remove PageReservedNick Piggin
Remove PageReserved() calls from core code by tightening VM_RESERVED handling in mm/ to cover PageReserved functionality. PageReserved special casing is removed from get_page and put_page. All setting and clearing of PageReserved is retained, and it is now flagged in the page_alloc checks to help ensure we don't introduce any refcount based freeing of Reserved pages. MAP_PRIVATE, PROT_WRITE of VM_RESERVED regions is tentatively being deprecated. We never completely handled it correctly anyway, and is be reintroduced in future if required (Hugh has a proof of concept). Once PageReserved() calls are removed from kernel/power/swsusp.c, and all arch/ and driver code, the Set and Clear calls, and the PG_reserved bit can be trivially removed. Last real user of PageReserved is swsusp, which uses PageReserved to determine whether a struct page points to valid memory or not. This still needs to be addressed (a generic page_is_ram() should work). A last caveat: the ZERO_PAGE is now refcounted and managed with rmap (and thus mapcounted and count towards shared rss). These writes to the struct page could cause excessive cacheline bouncing on big systems. There are a number of ways this could be addressed if it is an issue. Signed-off-by: Nick Piggin <npiggin@suse.de> Refcount bug fix for filemap_xip.c Signed-off-by: Carsten Otte <cotte@de.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-04-16Linux-2.6.12-rc2Linus Torvalds
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!