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2008-10-12Merge branches 'x86/xen', 'x86/build', 'x86/microcode', 'x86/mm-debug-v2', ↵Ingo Molnar
'x86/memory-corruption-check', 'x86/early-printk', 'x86/xsave', 'x86/ptrace-v2', 'x86/quirks', 'x86/setup', 'x86/spinlocks' and 'x86/signal' into x86/core-v2
2008-10-11Merge phase #2 (PAT updates) of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'x86-v28-for-linus-phase2-B' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (27 commits) x86, cpa: make the kernel physical mapping initialization a two pass sequence, fix x86, pat: cleanups x86: fix pagetable init 64-bit breakage x86: track memtype for RAM in page struct x86, cpa: srlz cpa(), global flush tlb after splitting big page and before doing cpa x86, cpa: remove cpa pool code x86, cpa: no need to check alias for __set_pages_p/__set_pages_np x86, cpa: dont use large pages for kernel identity mapping with DEBUG_PAGEALLOC x86, cpa: make the kernel physical mapping initialization a two pass sequence x86, cpa: remove USER permission from the very early identity mapping attribute x86, cpa: rename PTE attribute macros for kernel direct mapping in early boot x86: make sure the CPA test code's use of _PAGE_UNUSED1 is obvious linux-next: fix x86 tree build failure x86: have set_memory_array_{uc,wb} coalesce memtypes, fix agp: enable optimized agp_alloc_pages methods x86: have set_memory_array_{uc,wb} coalesce memtypes. x86: {reverve,free}_memtype() take a physical address x86: fix pageattr-test agp: add agp_generic_destroy_pages() agp: generic_alloc_pages() ...
2008-10-10Merge branch 'for-2.6.28' of git://git.kernel.dk/linux-2.6-blockLinus Torvalds
* 'for-2.6.28' of git://git.kernel.dk/linux-2.6-block: (132 commits) doc/cdrom: Trvial documentation error, file not present block_dev: fix kernel-doc in new functions block: add some comments around the bio read-write flags block: mark bio_split_pool static block: Find bio sector offset given idx and offset block: gendisk integrity wrapper block: Switch blk_integrity_compare from bdev to gendisk block: Fix double put in blk_integrity_unregister block: Introduce integrity data ownership flag block: revert part of d7533ad0e132f92e75c1b2eb7c26387b25a583c1 bio.h: Remove unused conditional code block: remove end_{queued|dequeued}_request() block: change elevator to use __blk_end_request() gdrom: change to use __blk_end_request() memstick: change to use __blk_end_request() virtio_blk: change to use __blk_end_request() blktrace: use BLKTRACE_BDEV_SIZE as the name size for setup structure block: add lld busy state exporting interface block: Fix blk_start_queueing() to not kick a stopped queue include blktrace_api.h in headers_install ...
2008-10-10Merge branch 'linus' into x86/pat2Ingo Molnar
Conflicts: arch/x86/mm/init_64.c
2008-10-09SLOB: fix bogus ksize calculation fixMatt Mackall
This fixes the previous fix, which was completely wrong on closer inspection. This version has been manually tested with a user-space test harness and generates sane values. A nearly identical patch has been boot-tested. The problem arose from changing how kmalloc/kfree handled alignment padding without updating ksize to match. This brings it in sync. Signed-off-by: Matt Mackall <mpm@selenic.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-09highmem: use bio_has_data() in the bounce pathJens Axboe
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-10-07SLOB: fix bogus ksize calculationMatt Mackall
SLOB's ksize calculation was braindamaged and generally harmlessly underreported the allocation size. But for very small buffers, it could in fact overreport them, leading code depending on krealloc to overrun the allocation and trample other data. Signed-off-by: Matt Mackall <mpm@selenic.com> Tested-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-02mm: handle initialising compound pages at orders greater than MAX_ORDERAndy Whitcroft
When we initialise a compound page we initialise the page flags and head page pointer for all base pages spanned by that page. When we initialise a gigantic page (a page of order greater than or equal to MAX_ORDER) we have to initialise more than MAX_ORDER_NR_PAGES pages. Currently we assume that all elements of the mem_map in this page are contigious in memory. However this is only guarenteed out to MAX_ORDER_NR_PAGES pages, and with SPARSEMEM enabled they will not be contigious. This leads us to walk off the end of the first section and scribble on everything which follows, BAD. When we reach a MAX_ORDER_NR_PAGES boundary we much locate the next section of the mem_map. As gigantic pages can only be maximally aligned we know this will occur at exact multiple of MAX_ORDER_NR_PAGES pages from the start of the page. This is a bug fix for the gigantic page support in hugetlbfs. Credit to Mel Gorman for spotting the issue. Signed-off-by: Andy Whitcroft <apw@shadowen.org> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Jon Tollefson <kniht@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-02mm: tiny-shmem nommu fixNick Piggin
The previous patch db203d53d474aa068984e409d807628f5841da1b ("mm: tiny-shmem fix lock ordering: mmap_sem vs i_mutex") to fix the lock ordering in tiny-shmem breaks shared anonymous and IPC memory on NOMMU architectures because it was using the expanding truncate to signal ramfs to allocate a physically contiguous RAM backing the inode (otherwise it is unusable for "memory mapping" it to userspace). However do_truncate is what caused the lock ordering error, due to it taking i_mutex. In this case, we can actually just call ramfs directly to allocate memory for the mapping, rather than go via truncate. Acked-by: David Howells <dhowells@redhat.com> Acked-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: Matt Mackall <mpm@selenic.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-02memory hotplug: missing zone->lock in test_pages_isolated()Gerald Schaefer
__test_page_isolated_in_pageblock() in mm/page_isolation.c has a comment saying that the caller must hold zone->lock. But the only caller of that function, test_pages_isolated(), does not hold zone->lock and the lock is also not acquired anywhere before. This patch adds the missing zone->lock to test_pages_isolated(). We reproducibly run into BUG_ON(!PageBuddy(page)) in __offline_isolated_pages() during memory hotplug stress test, see trace below. This patch fixes that problem, it would be good if we could have it in 2.6.27. kernel BUG at /home/autobuild/BUILD/linux-2.6.26-20080909/mm/page_alloc.c:4561! illegal operation: 0001 [#1] PREEMPT SMP Modules linked in: dm_multipath sunrpc bonding qeth_l3 dm_mod qeth ccwgroup vmur CPU: 1 Not tainted 2.6.26-29.x.20080909-s390default #1 Process memory_loop_all (pid: 10025, task: 2f444028, ksp: 2b10dd28) Krnl PSW : 040c0000 801727ea (__offline_isolated_pages+0x18e/0x1c4) R:0 T:1 IO:0 EX:0 Key:0 M:1 W:0 P:0 AS:0 CC:0 PM:0 Krnl GPRS: 00000000 7e27fc00 00000000 7e27fc00 00000000 00000400 00014000 7e27fc01 00606f00 7e27fc00 00013fe0 2b10dd28 00000005 80172662 801727b2 2b10dd28 Krnl Code: 801727de: 5810900c l %r1,12(%r9) 801727e2: a7f4ffb3 brc 15,80172748 801727e6: a7f40001 brc 15,801727e8 >801727ea: a7f4ffbc brc 15,80172762 801727ee: a7f40001 brc 15,801727f0 801727f2: a7f4ffaf brc 15,80172750 801727f6: 0707 bcr 0,%r7 801727f8: 0017 unknown Call Trace: ([<0000000000172772>] __offline_isolated_pages+0x116/0x1c4) [<00000000001953a2>] offline_isolated_pages_cb+0x22/0x34 [<000000000013164c>] walk_memory_resource+0xcc/0x11c [<000000000019520e>] offline_pages+0x36a/0x498 [<00000000001004d6>] remove_memory+0x36/0x44 [<000000000028fb06>] memory_block_change_state+0x112/0x150 [<000000000028ffb8>] store_mem_state+0x90/0xe4 [<0000000000289c00>] sysdev_store+0x34/0x40 [<00000000001ee048>] sysfs_write_file+0xd0/0x178 [<000000000019b1a8>] vfs_write+0x74/0x118 [<000000000019b9ae>] sys_write+0x46/0x7c [<000000000011160e>] sysc_do_restart+0x12/0x16 [<0000000077f3e8ca>] 0x77f3e8ca Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Acked-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>
2008-09-29mm owner: fix race between swapoff and exitBalbir Singh
There's a race between mm->owner assignment and swapoff, more easily seen when task slab poisoning is turned on. The condition occurs when try_to_unuse() runs in parallel with an exiting task. A similar race can occur with callers of get_task_mm(), such as /proc/<pid>/<mmstats> or ptrace or page migration. CPU0 CPU1 try_to_unuse looks at mm = task0->mm increments mm->mm_users task 0 exits mm->owner needs to be updated, but no new owner is found (mm_users > 1, but no other task has task->mm = task0->mm) mm_update_next_owner() leaves mmput(mm) decrements mm->mm_users task0 freed dereferencing mm->owner fails The fix is to notify the subsystem via mm_owner_changed callback(), if no new owner is found, by specifying the new task as NULL. Jiri Slaby: mm->owner was set to NULL prior to calling cgroup_mm_owner_callbacks(), but must be set after that, so as not to pass NULL as old owner causing oops. Daisuke Nishimura: mm_update_next_owner() may set mm->owner to NULL, but mem_cgroup_from_task() and its callers need to take account of this situation to avoid oops. Hugh Dickins: Lockdep warning and hang below exec_mmap() when testing these patches. exit_mm() up_reads mmap_sem before calling mm_update_next_owner(), so exec_mmap() now needs to do the same. And with that repositioning, there's now no point in mm_need_new_owner() allowing for NULL mm. Reported-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Jiri Slaby <jirislaby@gmail.com> Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Signed-off-by: Hugh Dickins <hugh@veritas.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Paul Menage <menage@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-09-23memcg: check under limit at shrink_usageDaisuke Nishimura
Current memory cgroup(both in mainline and -mm) doesn't account swap caches as memory(swap cache support is dropped temporarily now). So try_to_free_mem_cgroup_pages doesn't reflect the count of pages that have been moved to swap cache. But this makes mem_cgroup_shrink_usage fail easily if most of the pages are anon/shmem, and then shmem_getpage returns -ENOMEM and the process will be killed. This patch adds res_counter_check_under_limit to avoid these cases. BTW, even if swap cache support is enabled again, if a process is moved to another cgroup, which has been just made, between precharge and shrink_usage in shmem_getpage, shrink_usage may fail just because there is no pages to reclaim. So this change would make sense anyway. Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-09-23mm: tiny-shmem fix lock ordering: mmap_sem vs i_mutexNick Piggin
tiny-shmem calls do_truncate in shmem_file_setup. do_truncate takes i_mutex, and shmem_file_setup is called with mmap_sem held. However i_mutex nests outside mmap_sem. Copy the code in shmem.c to avoid this problem. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Nick Piggin <npiggin@suse.de> Reported-and-tested-by: Ingo Molnar <mingo@elte.hu> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Matt Mackall <mpm@selenic.com> Cc: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-09-15slub: fixed uninitialized counter in struct kmem_cache_nodeSalman Qazi
Initialized total objects atomic for the node in init_kmem_cache_node. The uninitialized value was ruining the stats in /proc/slabinfo. Acked-by: Christoph Lameter <cl@linux-foundation.org> Signed-off-by: Salman Qazi <sqazi@google.com> Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
2008-09-14Merge commit 'v2.6.27-rc6' into x86/patIngo Molnar
2008-09-13mm: mark the correct zone as full when scanning zonelistsMel Gorman
The iterator for_each_zone_zonelist() uses a struct zoneref *z cursor when scanning zonelists to keep track of where in the zonelist it is. The zoneref that is returned corresponds to the the next zone that is to be scanned, not the current one. It was intended to be treated as an opaque list. When the page allocator is scanning a zonelist, it marks elements in the zonelist corresponding to zones that are temporarily full. As the zonelist is being updated, it uses the cursor here; if (NUMA_BUILD) zlc_mark_zone_full(zonelist, z); This is intended to prevent rescanning in the near future but the zoneref cursor does not correspond to the zone that has been found to be full. This is an easy misunderstanding to make so this patch corrects the problem by changing zoneref cursor to be the current zone being scanned instead of the next one. Signed-off-by: Mel Gorman <mel@csn.ul.ie> Cc: Andy Whitcroft <apw@shadowen.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: <stable@kernel.org> [2.6.26.x] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-09-03mmap: fix petty bug in anonymous shared mmap offset handlingTejun Heo
Anonymous mappings should ignore offset but shared anonymous mapping forgot to clear it and makes the following legit test program trigger SIGBUS. #include <sys/mman.h> #include <stdio.h> #include <errno.h> #define PAGE_SIZE 4096 int main(void) { char *p; int i; p = mmap(NULL, 2 * PAGE_SIZE, PROT_READ|PROT_WRITE, MAP_SHARED|MAP_ANONYMOUS, -1, PAGE_SIZE); if (p == MAP_FAILED) { perror("mmap"); return 1; } for (i = 0; i < 2; i++) { printf("page %d\n", i); p[i * 4096] = i; } return 0; } Fix it. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Hugh Dickins <hugh@veritas.com> Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-09-02mm: size of quicklists shouldn't be proportional to the number of CPUsKOSAKI Motohiro
Quicklists store pages for each CPU as caches. (Each CPU can cache node_free_pages/16 pages) It is used for page table cache. exit() will increase the cache size, while fork() consumes it. So for example if an apache-style application runs (one parent and many child model), one CPU process will fork() while another CPU will process the middleware work and exit(). At that time, the CPU on which the parent runs doesn't have page table cache at all. Others (on which children runs) have maximum caches. QList_max = (#ofCPUs - 1) x Free / 16 => QList_max / (Free + QList_max) = (#ofCPUs - 1) / (16 + #ofCPUs - 1) So, How much quicklist memory is used in the maximum case? This is proposional to # of CPUs because the limit of per cpu quicklist cache doesn't see the number of cpus. Above calculation mean Number of CPUs per node 2 4 8 16 ============================== ==================== QList_max / (Free + QList_max) 5.8% 16% 30% 48% Wow! Quicklist can spend about 50% memory at worst case. My demonstration program is here -------------------------------------------------------------------------------- #define _GNU_SOURCE #include <stdio.h> #include <errno.h> #include <stdlib.h> #include <string.h> #include <sched.h> #include <unistd.h> #include <sys/mman.h> #include <sys/wait.h> #define BUFFSIZE 512 int max_cpu(void) /* get max number of logical cpus from /proc/cpuinfo */ { FILE *fd; char *ret, buffer[BUFFSIZE]; int cpu = 1; fd = fopen("/proc/cpuinfo", "r"); if (fd == NULL) { perror("fopen(/proc/cpuinfo)"); exit(EXIT_FAILURE); } while (1) { ret = fgets(buffer, BUFFSIZE, fd); if (ret == NULL) break; if (!strncmp(buffer, "processor", 9)) cpu = atoi(strchr(buffer, ':') + 2); } fclose(fd); return cpu; } void cpu_bind(int cpu) /* bind current process to one cpu */ { cpu_set_t mask; int ret; CPU_ZERO(&mask); CPU_SET(cpu, &mask); ret = sched_setaffinity(0, sizeof(mask), &mask); if (ret == -1) { perror("sched_setaffinity()"); exit(EXIT_FAILURE); } sched_yield(); /* not necessary */ } #define MMAP_SIZE (10 * 1024 * 1024) /* 10 MB */ #define FORK_INTERVAL 1 /* 1 second */ main(int argc, char *argv[]) { int cpu_max, nextcpu; long pagesize; pid_t pid; /* set max number of logical cpu */ if (argc > 1) cpu_max = atoi(argv[1]) - 1; else cpu_max = max_cpu(); /* get the page size */ pagesize = sysconf(_SC_PAGESIZE); if (pagesize == -1) { perror("sysconf(_SC_PAGESIZE)"); exit(EXIT_FAILURE); } /* prepare parent process */ cpu_bind(0); nextcpu = cpu_max; loop: /* select destination cpu for child process by round-robin rule */ if (++nextcpu > cpu_max) nextcpu = 1; pid = fork(); if (pid == 0) { /* child action */ char *p; int i; /* consume page tables */ p = mmap(0, MMAP_SIZE, PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, 0, 0); i = MMAP_SIZE / pagesize; while (i-- > 0) { *p = 1; p += pagesize; } /* move to other cpu */ cpu_bind(nextcpu); /* printf("a child moved to cpu%d after mmap().\n", nextcpu); fflush(stdout); */ /* back page tables to pgtable_quicklist */ exit(0); } else if (pid > 0) { /* parent action */ sleep(FORK_INTERVAL); waitpid(pid, NULL, WNOHANG); } goto loop; } ---------------------------------------- When above program which does task migration runs, my 8GB box spends 800MB of memory for quicklist. This is not memory leak but doesn't seem good. % cat /proc/meminfo MemTotal: 7701568 kB MemFree: 4724672 kB (snip) Quicklists: 844800 kB because - My machine spec is number of numa node: 2 number of cpus: 8 (4CPU x2 node) total mem: 8GB (4GB x2 node) free mem: about 5GB - Then, 4.7GB x 16% ~= 880MB. So, Quicklist can use 800MB. So, if following spec machine run that program CPUs: 64 (8cpu x 8node) Mem: 1TB (128GB x8node) Then, quicklist can waste 300GB (= 1TB x 30%). It is too large. So, I don't like cache policies which is proportional to # of cpus. My patch changes the number of caches from: per-cpu-cache-amount = memory_on_node / 16 to per-cpu-cache-amount = memory_on_node / 16 / number_of_cpus_on_node. Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Keiichiro Tokunaga <tokunaga.keiich@jp.fujitsu.com> Acked-by: Christoph Lameter <cl@linux-foundation.org> Tested-by: David Miller <davem@davemloft.net> Acked-by: Mike Travis <travis@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-09-02mm/bootmem: silence section mismatch warning - ↵Marcin Slusarz
contig_page_data/bootmem_node_data WARNING: vmlinux.o(.data+0x1f5c0): Section mismatch in reference from the variable contig_page_data to the variable .init.data:bootmem_node_data The variable contig_page_data references the variable __initdata bootmem_node_data If the reference is valid then annotate the variable with __init* (see linux/init.h) or name the variable: *driver, *_template, *_timer, *_sht, *_ops, *_probe, *_probe_one, *_console, Signed-off-by: Marcin Slusarz <marcin.slusarz@gmail.com> Cc: Johannes Weiner <hannes@saeurebad.de> Cc: Sean MacLennan <smaclennan@pikatech.com> Cc: Sam Ravnborg <sam@ravnborg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-09-02VFS: fix dio write returning EIO when try_to_release_page failsHisashi Hifumi
Dio write returns EIO when try_to_release_page fails because bh is still referenced. The patch commit 3f31fddfa26b7594b44ff2b34f9a04ba409e0f91 Author: Mingming Cao <cmm@us.ibm.com> Date: Fri Jul 25 01:46:22 2008 -0700 jbd: fix race between free buffer and commit transaction was merged into 2.6.27-rc1, but I noticed that this patch is not enough to fix the race. I did fsstress test heavily to 2.6.27-rc1, and found that dio write still sometimes got EIO through this test. The patch above fixed race between freeing buffer(dio) and committing transaction(jbd) but I discovered that there is another race, freeing buffer(dio) and ext3/4_ordered_writepage. : background_writeout() ->write_cache_pages() ->ext3_ordered_writepage() walk_page_buffers() -> take a bh ref block_write_full_page() -> unlock_page : <- end_page_writeback : <- race! (dio write->try_to_release_page fails) walk_page_buffers() ->release a bh ref ext3_ordered_writepage holds bh ref and does unlock_page remaining taking a bh ref, so this causes the race and failure of try_to_release_page. To fix this race, I used the approach of falling back to buffered writes if try_to_release_page() fails on a page. [akpm@linux-foundation.org: cleanups] Signed-off-by: Hisashi Hifumi <hifumi.hisashi@oss.ntt.co.jp> Cc: Chris Mason <chris.mason@oracle.com> Cc: Jan Kara <jack@suse.cz> Cc: Mingming Cao <cmm@us.ibm.com> Cc: Zach Brown <zach.brown@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-09-02mm: make setup_zone_migrate_reserve() aware of overlapping nodesAdam Litke
I have gotten to the root cause of the hugetlb badness I reported back on August 15th. My system has the following memory topology (note the overlapping node): Node 0 Memory: 0x8000000-0x44000000 Node 1 Memory: 0x0-0x8000000 0x44000000-0x80000000 setup_zone_migrate_reserve() scans the address range 0x0-0x8000000 looking for a pageblock to move onto the MIGRATE_RESERVE list. Finding no candidates, it happily continues the scan into 0x8000000-0x44000000. When a pageblock is found, the pages are moved to the MIGRATE_RESERVE list on the wrong zone. Oops. setup_zone_migrate_reserve() should skip pageblocks in overlapping nodes. Signed-off-by: Adam Litke <agl@us.ibm.com> Acked-by: Mel Gorman <mel@csn.ul.ie> Cc: Dave Hansen <dave@linux.vnet.ibm.com> Cc: Nishanth Aravamudan <nacc@us.ibm.com> Cc: Andy Whitcroft <apw@shadowen.org> Cc: <stable@kernel.org> [2.6.25.x, 2.6.26.x] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-09-02Remove '#include <stddef.h>' from mm/page_isolation.cDavid Woodhouse
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2008-08-28Merge master.kernel.org:/home/rmk/linux-2.6-armLinus Torvalds
* master.kernel.org:/home/rmk/linux-2.6-arm: [ARM] 5226/1: remove unmatched comment end. [ARM] Skip memory holes in FLATMEM when reading /proc/pagetypeinfo [ARM] use bcd2bin/bin2bcd [ARM] use the new byteorder headers [ARM] OMAP: Fix 2430 SMC91x ethernet IRQ [ARM] OMAP: Add and update OMAP default configuration files [ARM] OMAP: Change mailing list for OMAP in MAINTAINERS [ARM] S3C2443: Fix the S3C2443 clock register definitions [ARM] JIVE: Fix the spi bus numbering [ARM] S3C24XX: pwm.c: stop debugging output [ARM] S3C24XX: Fix sparse warnings in pwm.c [ARM] S3C24XX: Fix spare errors in pwm-clock driver [ARM] S3C24XX: Fix sparse warnings in arch/arm/plat-s3c24xx/gpiolib.c [ARM] S3C24XX: Fix nor-simtec driver sparse errors [ARM] 5225/1: zaurus: Register I2C controller for audio codecs [ARM] orion5x: update defconfig to v2.6.27-rc4 [ARM] Orion: register UART1 on QNAP TS-209 and TS-409 [ARM] Orion: activate lm75 driver on DNS-323 [ARM] Orion: fix MAC detection on QNAP TS-209 and TS-409 [ARM] Orion: Fix boot crash on Kurobox Pro
2008-08-27Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6: slub: Disable NUMA remote node defragmentation by default
2008-08-27[ARM] Skip memory holes in FLATMEM when reading /proc/pagetypeinfoMel Gorman
Ordinarily, memory holes in flatmem still have a valid memmap and is safe to use. However, an architecture (ARM) frees up the memmap backing memory holes on the assumption it is never used. /proc/pagetypeinfo reads the whole range of pages in a zone believing that the memmap is valid and that pfn_valid will return false if it is not. On ARM, freeing the memmap breaks the page->zone linkages even though pfn_valid() returns true and the kernel can oops shortly afterwards due to accessing a bogus struct zone *. This patch lets architectures say when FLATMEM can have holes in the memmap. Rather than an expensive check for valid memory, /proc/pagetypeinfo will confirm that the page linkages are still valid by checking page->zone is still the expected zone. The lookup of page_zone is safe as there is a limited range of memory that is accessed when calling page_zone. Even if page_zone happens to return the correct zone, the impact is that the counters in /proc/pagetypeinfo are slightly off but fragmentation monitoring is unlikely to be relevant on an embedded system. Reported-by: H Hartley Sweeten <hsweeten@visionengravers.com> Signed-off-by: Mel Gorman <mel@csn.ul.ie> Tested-by: H Hartley Sweeten <hsweeten@visionengravers.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-08-22Merge branch 'x86/urgent' into x86/patIngo Molnar
Conflicts: arch/x86/mm/pageattr.c Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-20mm: xip/ext2 fix block allocation raceNick Piggin
XIP can call into get_xip_mem concurrently with the same file,offset with create=1. This usually maps down to get_block, which expects the page lock to prevent such a situation. This causes ext2 to explode for one reason or another. Serialise those calls for the moment. For common usages today, I suspect get_xip_mem rarely is called to create new blocks. In future as XIP technologies evolve we might need to look at which operations require scalability, and rework the locking to suit. Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: Jared Hulbert <jaredeh@gmail.com> Acked-by: Carsten Otte <cotte@freenet.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>
2008-08-20mm: xip fix fault vs sparse page invalidate raceNick Piggin
XIP has a race between sparse pages being inserted into page tables, and sparse pages being zapped when its time to put a non-sparse page in. What can happen is that a process can be left with a dangling sparse page in a MAP_SHARED mapping, while the rest of the world sees the non-sparse version. Ie. data corruption. Guard these operations with a seqlock, making fault-in-sparse-pages the slowpath, and try-to-unmap-sparse-pages the fastpath. Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: Jared Hulbert <jaredeh@gmail.com> Acked-by: Carsten Otte <cotte@freenet.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>
2008-08-20mm: dirty page tracking race fixNick Piggin
There is a race with dirty page accounting where a page may not properly be accounted for. clear_page_dirty_for_io() calls page_mkclean; then TestClearPageDirty. page_mkclean walks the rmaps for that page, and for each one it cleans and write protects the pte if it was dirty. It uses page_check_address to find the pte. That function has a shortcut to avoid the ptl if the pte is not present. Unfortunately, the pte can be switched to not-present then back to present by other code while holding the page table lock -- this should not be a signal for page_mkclean to ignore that pte, because it may be dirty. For example, powerpc64's set_pte_at will clear a previously present pte before setting it to the desired value. There may also be other code in core mm or in arch which do similar things. The consequence of the bug is loss of data integrity due to msync, and loss of dirty page accounting accuracy. XIP's __xip_unmap could easily also be unreliable (depending on the exact XIP locking scheme), which can lead to data corruption. Fix this by having an option to always take ptl to check the pte in page_check_address. It's possible to retain this optimization for page_referenced and try_to_unmap. Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: Jared Hulbert <jaredeh@gmail.com> Cc: Carsten Otte <cotte@freenet.de> Cc: Hugh Dickins <hugh@veritas.com> Acked-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>
2008-08-20bootmem: fix aligning of node-relative indexes and offsetsJohannes Weiner
Absolute alignment requirements may never be applied to node-relative offsets. Andreas Herrmann spotted this flaw when a bootmem allocation on an unaligned node was itself not aligned because the combination of an unaligned node with an aligned offset into that node is not garuanteed to be aligned itself. This patch introduces two helper functions that align a node-relative index or offset with respect to the node's starting address so that the absolute PFN or virtual address that results from combining the two satisfies the requested alignment. Then all the broken ALIGN()s in alloc_bootmem_core() are replaced by these helpers. Signed-off-by: Johannes Weiner <hannes@saeurebad.de> Reported-by: Andreas Herrmann <andreas.herrmann3@amd.com> Debugged-by: Andreas Herrmann <andreas.herrmann3@amd.com> Reviewed-by: Andreas Herrmann <andreas.herrmann3@amd.com> Tested-by: Andreas Herrmann <andreas.herrmann3@amd.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-08-20mm: mminit_loglevel cannot be __meminitdata anymoreMarcin Slusarz
mminit_loglevel is now used from mminit_verify_zonelist <- build_all_zonelists <- 1. online_pages <- memory_block_action <- memory_block_change_state <- store_mem_state (sys handler) 2. numa_zonelist_order_handler (proc handler) so it cannot be annotated __meminit - drop it fixes following section mismatch warning: WARNING: vmlinux.o(.text+0x71628): Section mismatch in reference from the function mminit_verify_zonelist() to the variable .meminit.data:mminit_loglevel The function mminit_verify_zonelist() references the variable __meminitdata mminit_loglevel. This is often because mminit_verify_zonelist lacks a __meminitdata annotation or the annotation of mminit_loglevel is wrong. Signed-off-by: Marcin Slusarz <marcin.slusarz@gmail.com> Acked-by: Mel Gorman <mel@csn.ul.ie> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-08-20mm: show free swap as signedHugh Dickins
Adjust <Alt><SysRq>m show_swap_cache_info() to show "Free swap" as a signed long: the signed format is preferable, because during swapoff nr_swap_pages can legitimately go negative, so makes more sense thus (it used to be shown redundantly, once as signed and once as unsigned). Signed-off-by: Hugh Dickins <hugh@veritas.com> Reviewed-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>
2008-08-20mm: page_remove_rmap comments on PageAnonHugh Dickins
Add a comment to s390's page_test_dirty/page_clear_dirty/page_set_dirty dance in page_remove_rmap(): I was wrong to think the PageSwapCache test could be avoided, and would like a comment in there to remind me. And mention s390, to help us remember that this block is not really common. Also move down the "It would be tidy to reset PageAnon" comment: it does not belong to s390's block, and it would be unwise to reset PageAnon before we're done with testing it. Signed-off-by: Hugh Dickins <hugh@veritas.com> Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-08-20slub: Disable NUMA remote node defragmentation by defaultChristoph Lameter
Switch remote node defragmentation off by default. The current settings can cause excessive node local allocations with hackbench: SLAB: % cat /proc/meminfo MemTotal: 7701760 kB MemFree: 5940096 kB Slab: 123840 kB SLUB: % cat /proc/meminfo MemTotal: 7701376 kB MemFree: 4740928 kB Slab: 1591680 kB [Note: this feature is not related to slab defragmentation.] You can find the original discussion here: http://lkml.org/lkml/2008/8/4/308 Reported-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Tested-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Christoph Lameter <cl@linux-foundation.org> Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
2008-08-15Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6: security: Fix setting of PF_SUPERPRIV by __capable()
2008-08-15bootmem allocator: alloc_bootmem_core(): page-align the end offsetMikulas Patocka
This is the minimal sequence that jams the allocator: void *p, *q, *r; p = alloc_bootmem(PAGE_SIZE); q = alloc_bootmem(64); free_bootmem(p, PAGE_SIZE); p = alloc_bootmem(PAGE_SIZE); r = alloc_bootmem(64); after this sequence (assuming that the allocator was empty or page-aligned before), pointer "q" will be equal to pointer "r". What's hapenning inside the allocator: p = alloc_bootmem(PAGE_SIZE); in allocator: last_end_off == PAGE_SIZE, bitmap contains bits 10000... q = alloc_bootmem(64); in allocator: last_end_off == PAGE_SIZE + 64, bitmap contains 11000... free_bootmem(p, PAGE_SIZE); in allocator: last_end_off == PAGE_SIZE + 64, bitmap contains 01000... p = alloc_bootmem(PAGE_SIZE); in allocator: last_end_off == PAGE_SIZE, bitmap contains 11000... r = alloc_bootmem(64); and now: it finds bit "2", as a place where to allocate (sidx) it hits the condition if (bdata->last_end_off && PFN_DOWN(bdata->last_end_off) + 1 == sidx)) start_off = ALIGN(bdata->last_end_off, align); -you can see that the condition is true, so it assigns start_off = ALIGN(bdata->last_end_off, align); (that is PAGE_SIZE) and allocates over already allocated block. With the patch it tries to continue at the end of previous allocation only if the previous allocation ended in the middle of the page. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Acked-by: Johannes Weiner <hannes@saeurebad.de> Cc: David Miller <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-08-15x86, pat: avoid highmem cache attribute aliasingNick Piggin
Highmem code can leave ptes and tlb entries around for a given page even after kunmap, and after it has been freed. >From what I can gather, the PAT code may change the cache attributes of arbitrary physical addresses (ie. including highmem pages), which would result in aliases in the case that it operates on one of these lazy tlb highmem pages. Flushing kmaps should solve the problem. I've also just added code for conditional flushing if we haven't got any dangling highmem aliases -- this should help performance if we change page attributes frequently or systems that aren't using much highmem pages (eg. if < 4G RAM). Should be turned into 2 patches, but just for RFC... Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-14security: Fix setting of PF_SUPERPRIV by __capable()David Howells
Fix the setting of PF_SUPERPRIV by __capable() as it could corrupt the flags the target process if that is not the current process and it is trying to change its own flags in a different way at the same time. __capable() is using neither atomic ops nor locking to protect t->flags. This patch removes __capable() and introduces has_capability() that doesn't set PF_SUPERPRIV on the process being queried. This patch further splits security_ptrace() in two: (1) security_ptrace_may_access(). This passes judgement on whether one process may access another only (PTRACE_MODE_ATTACH for ptrace() and PTRACE_MODE_READ for /proc), and takes a pointer to the child process. current is the parent. (2) security_ptrace_traceme(). This passes judgement on PTRACE_TRACEME only, and takes only a pointer to the parent process. current is the child. In Smack and commoncap, this uses has_capability() to determine whether the parent will be permitted to use PTRACE_ATTACH if normal checks fail. This does not set PF_SUPERPRIV. Two of the instances of __capable() actually only act on current, and so have been changed to calls to capable(). Of the places that were using __capable(): (1) The OOM killer calls __capable() thrice when weighing the killability of a process. All of these now use has_capability(). (2) cap_ptrace() and smack_ptrace() were using __capable() to check to see whether the parent was allowed to trace any process. As mentioned above, these have been split. For PTRACE_ATTACH and /proc, capable() is now used, and for PTRACE_TRACEME, has_capability() is used. (3) cap_safe_nice() only ever saw current, so now uses capable(). (4) smack_setprocattr() rejected accesses to tasks other than current just after calling __capable(), so the order of these two tests have been switched and capable() is used instead. (5) In smack_file_send_sigiotask(), we need to allow privileged processes to receive SIGIO on files they're manipulating. (6) In smack_task_wait(), we let a process wait for a privileged process, whether or not the process doing the waiting is privileged. I've tested this with the LTP SELinux and syscalls testscripts. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Serge Hallyn <serue@us.ibm.com> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Acked-by: Andrew G. Morgan <morgan@kernel.org> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: James Morris <jmorris@namei.org>
2008-08-12mm/sparse.c: removed duplicated includeHuang Weiyi
Signed-off-by: Huang Weiyi <weiyi.huang@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-08-12do_migrate_pages(): remove unused variableMinChan Kim
Signed-off-by: MinChan Kim <minchan.kim@gmail.com> Acked-by: Christoph Lameter <cl@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-08-12allocate structures for reservation tracking in hugetlbfs outside of ↵Andy Whitcroft
spinlocks v2 [Andrew this should replace the previous version which did not check the returns from the region prepare for errors. This has been tested by us and Gerald and it looks good. Bah, while reviewing the locking based on your previous email I spotted that we need to check the return from the vma_needs_reservation call for allocation errors. Here is an updated patch to correct this. This passes testing here.] Signed-off-by: Andy Whitcroft <apw@shadowen.org> Tested-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Cc: Mel Gorman <mel@csn.ul.ie> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-08-12hugetlbfs: allocate structures for reservation tracking outside of spinlocksAndy Whitcroft
In the normal case, hugetlbfs reserves hugepages at map time so that the pages exist for future faults. A struct file_region is used to track when reservations have been consumed and where. These file_regions are allocated as necessary with kmalloc() which can sleep with the mm->page_table_lock held. This is wrong and triggers may-sleep warning when PREEMPT is enabled. Updates to the underlying file_region are done in two phases. The first phase prepares the region for the change, allocating any necessary memory, without actually making the change. The second phase actually commits the change. This patch makes use of this by checking the reservations before the page_table_lock is taken; triggering any necessary allocations. This may then be safely repeated within the locks without any allocations being required. Credit to Mel Gorman for diagnosing this failure and initial versions of the patch. Signed-off-by: Andy Whitcroft <apw@shadowen.org> Tested-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Cc: Mel Gorman <mel@csn.ul.ie> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-08-12memcg: fix oops in mem_cgroup_shrink_usageHugh Dickins
Got an oops in mem_cgroup_shrink_usage() when testing loop over tmpfs: yes, of course, loop0 has no mm: other entry points check but this didn't. Signed-off-by: Hugh Dickins <hugh@veritas.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-08-12page allocator: use no-panic variant of alloc_bootmem() in ↵Jan Beulich
alloc_large_system_hash() .. since a failed allocation is being (initially) handled gracefully, and panic()-ed upon failure explicitly in the function if retries with smaller sizes failed. Signed-off-by: Jan Beulich <jbeulich@novell.com> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-08-12hugetlb: call arch_prepare_hugepage() for surplus pagesGerald Schaefer
The s390 software large page emulation implements shared page tables by using page->index of the first tail page from a compound large page to store page table information. This is set up in arch_prepare_hugepage(), which is called from alloc_fresh_huge_page_node(). A similar call to arch_prepare_hugepage() is missing for surplus large pages that are allocated in alloc_buddy_huge_page(), which breaks the software emulation mode for (surplus) large pages on s390. This patch adds the missing call to arch_prepare_hugepage(). It will have no effect on other architectures where arch_prepare_hugepage() is a nop. Also, use the correct order in the error path in alloc_fresh_huge_page_node(). Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Acked-by: Nick Piggin <npiggin@suse.de> Acked-by: Adam Litke <agl@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-08-12Merge git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linusLinus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus: fix spinlock recursion in hvc_console stop_machine: remove unused variable modules: extend initcall_debug functionality to the module loader export virtio_rng.h lguest: use get_user_pages_fast() instead of get_user_pages() mm: Make generic weak get_user_pages_fast and EXPORT_GPL it lguest: don't set MAC address for guest unless specified
2008-08-12mm: Make generic weak get_user_pages_fast and EXPORT_GPL itRusty Russell
Out of line get_user_pages_fast fallback implementation, make it a weak symbol, get rid of CONFIG_HAVE_GET_USER_PAGES_FAST. Export the symbol to modules so lguest can use it. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-08-11Merge branch 'core-fixes-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: lockdep: fix debug_lock_alloc lockdep: increase MAX_LOCKDEP_KEYS generic-ipi: fix stack and rcu interaction bug in smp_call_function_mask() lockdep: fix overflow in the hlock shrinkage code lockdep: rename map_[acquire|release]() => lock_map_[acquire|release]() lockdep: handle chains involving classes defined in modules mm: fix mm_take_all_locks() locking order lockdep: annotate mm_take_all_locks() lockdep: spin_lock_nest_lock() lockdep: lock protection locks lockdep: map_acquire lockdep: shrink held_lock structure lockdep: re-annotate scheduler runqueues lockdep: lock_set_subclass - reset a held lock's subclass lockdep: change scheduler annotation debug_locks: set oops_in_progress if we will log messages. lockdep: fix combinatorial explosion in lock subgraph traversal
2008-08-12Merge branch 'core/locking' into core/urgentIngo Molnar
2008-08-11mm: fix mm_take_all_locks() locking orderPeter Zijlstra
Lockdep spotted: ======================================================= [ INFO: possible circular locking dependency detected ] 2.6.27-rc1 #270 ------------------------------------------------------- qemu-kvm/2033 is trying to acquire lock: (&inode->i_data.i_mmap_lock){----}, at: [<ffffffff802996cc>] mm_take_all_locks+0xc2/0xea but task is already holding lock: (&anon_vma->lock){----}, at: [<ffffffff8029967a>] mm_take_all_locks+0x70/0xea which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&anon_vma->lock){----}: [<ffffffff8025cd37>] __lock_acquire+0x11be/0x14d2 [<ffffffff8025d0a9>] lock_acquire+0x5e/0x7a [<ffffffff804c655b>] _spin_lock+0x3b/0x47 [<ffffffff8029a2ef>] vma_adjust+0x200/0x444 [<ffffffff8029a662>] split_vma+0x12f/0x146 [<ffffffff8029bc60>] mprotect_fixup+0x13c/0x536 [<ffffffff8029c203>] sys_mprotect+0x1a9/0x21e [<ffffffff8020c0db>] system_call_fastpath+0x16/0x1b [<ffffffffffffffff>] 0xffffffffffffffff -> #0 (&inode->i_data.i_mmap_lock){----}: [<ffffffff8025ca54>] __lock_acquire+0xedb/0x14d2 [<ffffffff8025d397>] lock_release_non_nested+0x1c2/0x219 [<ffffffff8025d515>] lock_release+0x127/0x14a [<ffffffff804c6403>] _spin_unlock+0x1e/0x50 [<ffffffff802995d9>] mm_drop_all_locks+0x7f/0xb0 [<ffffffff802a965d>] do_mmu_notifier_register+0xe2/0x112 [<ffffffff802a96a8>] mmu_notifier_register+0xe/0x10 [<ffffffffa0043b6b>] kvm_dev_ioctl+0x11e/0x287 [kvm] [<ffffffff802bd0ca>] vfs_ioctl+0x2a/0x78 [<ffffffff802bd36f>] do_vfs_ioctl+0x257/0x274 [<ffffffff802bd3e1>] sys_ioctl+0x55/0x78 [<ffffffff8020c0db>] system_call_fastpath+0x16/0x1b [<ffffffffffffffff>] 0xffffffffffffffff other info that might help us debug this: 5 locks held by qemu-kvm/2033: #0: (&mm->mmap_sem){----}, at: [<ffffffff802a95d0>] do_mmu_notifier_register+0x55/0x112 #1: (mm_all_locks_mutex){--..}, at: [<ffffffff8029963e>] mm_take_all_locks+0x34/0xea #2: (&anon_vma->lock){----}, at: [<ffffffff8029967a>] mm_take_all_locks+0x70/0xea #3: (&anon_vma->lock){----}, at: [<ffffffff8029967a>] mm_take_all_locks+0x70/0xea #4: (&anon_vma->lock){----}, at: [<ffffffff8029967a>] mm_take_all_locks+0x70/0xea stack backtrace: Pid: 2033, comm: qemu-kvm Not tainted 2.6.27-rc1 #270 Call Trace: [<ffffffff8025b7c7>] print_circular_bug_tail+0xb8/0xc3 [<ffffffff8025ca54>] __lock_acquire+0xedb/0x14d2 [<ffffffff80259bb1>] ? add_lock_to_list+0x7e/0xad [<ffffffff8029967a>] ? mm_take_all_locks+0x70/0xea [<ffffffff8029967a>] ? mm_take_all_locks+0x70/0xea [<ffffffff8025d397>] lock_release_non_nested+0x1c2/0x219 [<ffffffff802996cc>] ? mm_take_all_locks+0xc2/0xea [<ffffffff802996cc>] ? mm_take_all_locks+0xc2/0xea [<ffffffff8025b202>] ? trace_hardirqs_on_caller+0x4d/0x115 [<ffffffff802995d9>] ? mm_drop_all_locks+0x7f/0xb0 [<ffffffff8025d515>] lock_release+0x127/0x14a [<ffffffff804c6403>] _spin_unlock+0x1e/0x50 [<ffffffff802995d9>] mm_drop_all_locks+0x7f/0xb0 [<ffffffff802a965d>] do_mmu_notifier_register+0xe2/0x112 [<ffffffff802a96a8>] mmu_notifier_register+0xe/0x10 [<ffffffffa0043b6b>] kvm_dev_ioctl+0x11e/0x287 [kvm] [<ffffffff8033f9f2>] ? file_has_perm+0x83/0x8e [<ffffffff802bd0ca>] vfs_ioctl+0x2a/0x78 [<ffffffff802bd36f>] do_vfs_ioctl+0x257/0x274 [<ffffffff802bd3e1>] sys_ioctl+0x55/0x78 [<ffffffff8020c0db>] system_call_fastpath+0x16/0x1b Which the locking hierarchy in mm/rmap.c confirms as valid. Fix this by first taking all the mapping->i_mmap_lock instances and then take all anon_vma->lock instances. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>