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2011-04-14mm/thp: use conventional format for boolean attributesBen Hutchings
The conventional format for boolean attributes in sysfs is numeric ("0" or "1" followed by new-line). Any boolean attribute can then be read and written using a generic function. Using the strings "yes [no]", "[yes] no" (read), "yes" and "no" (write) will frustrate this. [akpm@linux-foundation.org: use kstrtoul()] [akpm@linux-foundation.org: test_bit() doesn't return 1/0, per Neil] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Johannes Weiner <jweiner@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Hugh Dickins <hughd@google.com> Tested-by: David Rientjes <rientjes@google.com> Cc: NeilBrown <neilb@suse.de> Cc: <stable@kernel.org> [2.6.38.x] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-04-14oom-kill: remove boost_dying_task_prio()KOSAKI Motohiro
This is an almost-revert of commit 93b43fa ("oom: give the dying task a higher priority"). That commit dramatically improved oom killer logic when a fork-bomb occurs. But I've found that it has nasty corner case. Now cpu cgroup has strange default RT runtime. It's 0! That said, if a process under cpu cgroup promote RT scheduling class, the process never run at all. If an admin inserts a !RT process into a cpu cgroup by setting rtruntime=0, usually it runs perfectly because a !RT task isn't affected by the rtruntime knob. But if it promotes an RT task via an explicit setscheduler() syscall or an OOM, the task can't run at all. In short, the oom killer doesn't work at all if admins are using cpu cgroup and don't touch the rtruntime knob. Eventually, kernel may hang up when oom kill occur. I and the original author Luis agreed to disable this logic. Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Acked-by: Luis Claudio R. Goncalves <lclaudio@uudg.org> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Acked-by: David Rientjes <rientjes@google.com> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-04-14vmscan: all_unreclaimable() use zone->all_unreclaimable as a nameKOSAKI Motohiro
all_unreclaimable check in direct reclaim has been introduced at 2.6.19 by following commit. 2006 Sep 25; commit 408d8544; oom: use unreclaimable info And it went through strange history. firstly, following commit broke the logic unintentionally. 2008 Apr 29; commit a41f24ea; page allocator: smarter retry of costly-order allocations Two years later, I've found obvious meaningless code fragment and restored original intention by following commit. 2010 Jun 04; commit bb21c7ce; vmscan: fix do_try_to_free_pages() return value when priority==0 But, the logic didn't works when 32bit highmem system goes hibernation and Minchan slightly changed the algorithm and fixed it . 2010 Sep 22: commit d1908362: vmscan: check all_unreclaimable in direct reclaim path But, recently, Andrey Vagin found the new corner case. Look, struct zone { .. int all_unreclaimable; .. unsigned long pages_scanned; .. } zone->all_unreclaimable and zone->pages_scanned are neigher atomic variables nor protected by lock. Therefore zones can become a state of zone->page_scanned=0 and zone->all_unreclaimable=1. In this case, current all_unreclaimable() return false even though zone->all_unreclaimabe=1. This resulted in the kernel hanging up when executing a loop of the form 1. fork 2. mmap 3. touch memory 4. read memory 5. munmmap as described in http://www.gossamer-threads.com/lists/linux/kernel/1348725#1348725 Is this ignorable minor issue? No. Unfortunately, x86 has very small dma zone and it become zone->all_unreclamble=1 easily. and if it become all_unreclaimable=1, it never restore all_unreclaimable=0. Why? if all_unreclaimable=1, vmscan only try DEF_PRIORITY reclaim and a-few-lru-pages>>DEF_PRIORITY always makes 0. that mean no page scan at all! Eventually, oom-killer never works on such systems. That said, we can't use zone->pages_scanned for this purpose. This patch restore all_unreclaimable() use zone->all_unreclaimable as old. and in addition, to add oom_killer_disabled check to avoid reintroduce the issue of commit d1908362 ("vmscan: check all_unreclaimable in direct reclaim path"). Reported-by: Andrey Vagin <avagin@openvz.org> Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Nick Piggin <npiggin@kernel.dk> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: David Rientjes <rientjes@google.com> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-04-14mm: check that we have the right vma in __access_remote_vm()Michael Ellerman
In __access_remote_vm() we need to check that we have found the right vma, not the following vma before we try to access it. Otherwise we might call the vma's access routine with an address which does not fall inside the vma. It was discovered on a current kernel but with an unreleased driver, from memory it was strace leading to a kernel bad access, but it obviously depends on what the access implementation does. Looking at other access implementations I only see: $ git grep -A 5 vm_operations|grep access arch/powerpc/platforms/cell/spufs/file.c- .access = spufs_mem_mmap_access, arch/x86/pci/i386.c- .access = generic_access_phys, drivers/char/mem.c- .access = generic_access_phys fs/sysfs/bin.c- .access = bin_access, The spufs one looks like it might behave badly given the wrong vma, it assumes vma->vm_file->private_data is a spu_context, and looks like it would probably blow up pretty quickly if it wasn't. generic_access_phys() only uses the vma to check vm_flags and get the mm, and then walks page tables using the address. So it should bail on the vm_flags check, or at worst let you access some other VM_IO mapping. And bin_access() just proxies to another access implementation. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-04-14brk: COMPAT_BRK: fix detection of randomized brkJiri Kosina
5520e89 ("brk: fix min_brk lower bound computation for COMPAT_BRK") tried to get the whole logic of brk randomization for legacy (libc5-based) applications finally right. It turns out that the way to detect whether brk has actually been randomized in the end or not introduced by that patch still doesn't work for those binaries, as reported by Geert: : /sbin/init from my old m68k ramdisk exists prematurely. : : Before the patch: : : | brk(0x80005c8e) = 0x80006000 : : After the patch: : : | brk(0x80005c8e) = 0x80005c8e : : Old libc5 considers brk() to have failed if the return value is not : identical to the requested value. I don't like it, but currently see no better option than a bit flag in task_struct to catch the CONFIG_COMPAT_BRK && randomize_va_space == 2 case. Signed-off-by: Jiri Kosina <jkosina@suse.cz> Tested-by: Geert Uytterhoeven <geert@linux-m68k.org> Reported-by: Geert Uytterhoeven <geert@linux-m68k.org> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-04-14tmpfs: fix off-by-one in max_blocks checksHugh Dickins
If you fill up a tmpfs, df was showing tmpfs 460800 - - - /tmp because of an off-by-one in the max_blocks checks. Fix it so df shows tmpfs 460800 460800 0 100% /tmp Signed-off-by: Hugh Dickins <hughd@google.com> Cc: Tim Chen <tim.c.chen@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-04-14mm: add VM counters for transparent hugepagesAndi Kleen
I found it difficult to make sense of transparent huge pages without having any counters for its actions. Add some counters to vmstat for allocation of transparent hugepages and fallback to smaller pages. Optional patch, but useful for development and understanding the system. Contains improvements from Andrea Arcangeli and Johannes Weiner [akpm@linux-foundation.org: coding-style fixes] [hannes@cmpxchg.org: fix vmstat_text[] entries] Signed-off-by: Andi Kleen <ak@linux.intel.com> Acked-by: Andrea Arcangeli <aarcange@redhat.com> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-04-14vmstat: update comment regarding stat_thresholdChristoph Lameter
Signed-off-by: Christoph Lameter <cl@linux.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-04-14mm/page_alloc.c: silence build_all_zonelists() section mismatchPaul Mundt
The memory hotplug case involves calling to build_all_zonelists() which in turns calls in to setup_zone_pageset(). The latter is marked __meminit while build_all_zonelists() itself has no particular annotation. build_all_zonelists() is only handed a non-NULL pointer in the case of memory hotplug through an existing __meminit path, so the setup_zone_pageset() reference is always safe. The options as such are either to flag build_all_zonelists() as __ref (as per __build_all_zonelists()), or to simply discard the __meminit annotation from setup_zone_pageset(). Signed-off-by: Paul Mundt <lethal@linux-sh.org> Acked-by: Mel Gorman <mel@csn.ul.ie> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-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>
2011-04-14mm: optimize pfn calculation in online_page()Daniel Kiper
If CONFIG_FLATMEM is enabled pfn is calculated in online_page() more than once. It is possible to optimize that and use value established at beginning of that function. Signed-off-by: Daniel Kiper <dkiper@net-space.pl> Acked-by: Dave Hansen <dave@linux.vnet.ibm.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Christoph Lameter <cl@linux.com> Acked-by: David Rientjes <rientjes@google.com> Reviewed-by: Jesper Juhl <jj@chaosbits.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-04-13vm: fix vm_pgoff wrap in stack expansionLinus Torvalds
Commit 982134ba6261 ("mm: avoid wrapping vm_pgoff in mremap()") fixed the case of a expanding mapping causing vm_pgoff wrapping when you used mremap. But there was another case where we expand mappings hiding in plain sight: the automatic stack expansion. This fixes that case too. This one also found by Robert Święcki, using his nasty system call fuzzer tool. Good job. Reported-and-tested-by: Robert Święcki <robert@swiecki.net> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-04-12vm: fix mlock() on stack guard pageLinus Torvalds
Commit 53a7706d5ed8 ("mlock: do not hold mmap_sem for extended periods of time") changed mlock() to care about the exact number of pages that __get_user_pages() had brought it. Before, it would only care about errors. And that doesn't work, because we also handled one page specially in __mlock_vma_pages_range(), namely the stack guard page. So when that case was handled, the number of pages that the function returned was off by one. In particular, it could be zero, and then the caller would end up not making any progress at all. Rather than try to fix up that off-by-one error for the mlock case specially, this just moves the logic to handle the stack guard page into__get_user_pages() itself, thus making all the counts come out right automatically. Reported-by: Robert Święcki <robert@swiecki.net> Cc: Hugh Dickins <hughd@google.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-04-07Merge branch 'for-linus2' of git://git.profusion.mobi/users/lucas/linux-2.6Linus Torvalds
* 'for-linus2' of git://git.profusion.mobi/users/lucas/linux-2.6: Fix common misspellings
2011-04-07mm: avoid wrapping vm_pgoff in mremap()Linus Torvalds
The normal mmap paths all avoid creating a mapping where the pgoff inside the mapping could wrap around due to overflow. However, an expanding mremap() can take such a non-wrapping mapping and make it bigger and cause a wrapping condition. Noticed by Robert Swiecki when running a system call fuzzer, where it caused a BUG_ON() due to terminally confusing the vma_prio_tree code. A vma dumping patch by Hugh then pinpointed the crazy wrapped case. Reported-and-tested-by: Robert Swiecki <robert@swiecki.net> Acked-by: Hugh Dickins <hughd@google.com> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-31Fix common misspellingsLucas De Marchi
Fixes generated by 'codespell' and manually reviewed. Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
2011-03-29Merge branch 'frv' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-2.6-frv * 'frv' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-2.6-frv: FRV: Use generic show_interrupts() FRV: Convert genirq namespace frv: Select GENERIC_HARDIRQS_NO_DEPRECATED frv: Convert cpu irq_chip to new functions frv: Convert mb93493 irq_chip to new functions frv: Convert mb93093 irq_chip to new function frv: Convert mb93091 irq_chip to new functions frv: Fix typo from __do_IRQ overhaul frv: Remove stale irq_chip.end FRV: Do some cleanups FRV: Missing node arg in alloc_thread_info_node() macro NOMMU: implement access_remote_vm NOMMU: support SMP dynamic percpu_alloc NOMMU: percpu should use is_vmalloc_addr().
2011-03-29NOMMU: implement access_remote_vmMike Frysinger
Recent vm changes brought in a new function which the core procfs code utilizes. So implement it for nommu systems too to avoid link failures. Signed-off-by: Mike Frysinger <vapier@gentoo.org> Signed-off-by: David Howells <dhowells@redhat.com> Tested-by: Simon Horman <horms@verge.net.au> Tested-by: Ithamar Adema <ithamar.adema@team-embedded.nl> Acked-by: Greg Ungerer <gerg@uclinux.org>
2011-03-28NOMMU: percpu should use is_vmalloc_addr().David Howells
per_cpu_ptr_to_phys() uses VMALLOC_START and VMALLOC_END to determine if an address is in the vmalloc() region or not. This is incorrect on NOMMU as there is no real vmalloc() capability (vmalloc() is emulated by kmalloc()). The correct way to do this is to use is_vmalloc_addr(). This encapsulates the vmalloc() region test in MMU mode and just returns 0 in NOMMU mode. On FRV in NOMMU mode, the percpu compilation fails without this patch: mm/percpu.c: In function 'per_cpu_ptr_to_phys': mm/percpu.c:1011: error: 'VMALLOC_START' undeclared (first use in this function) mm/percpu.c:1011: error: (Each undeclared identifier is reported only once mm/percpu.c:1011: error: for each function it appears in.) mm/percpu.c:1012: error: 'VMALLOC_END' undeclared (first use in this function) mm/percpu.c:1018: warning: control reaches end of non-void function Signed-off-by: David Howells <dhowells@redhat.com>
2011-03-27mm: fix memory.c incorrect kernel-docRandy Dunlap
Fix mm/memory.c incorrect kernel-doc function notation: Warning(mm/memory.c:3718): Cannot understand * @access_remote_vm - access another process' address space on line 3718 - I thought it was a doc line Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-24Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: fs: simplify iget & friends fs: pull inode->i_lock up out of writeback_single_inode fs: rename inode_lock to inode_hash_lock fs: move i_wb_list out from under inode_lock fs: move i_sb_list out from under inode_lock fs: remove inode_lock from iput_final and prune_icache fs: Lock the inode LRU list separately fs: factor inode disposal fs: protect inode->i_state with inode->i_lock autofs4: Do not potentially dereference NULL pointer returned by fget() in autofs_dev_ioctl_setpipefd() autofs4 - remove autofs4_lock autofs4 - fix d_manage() return on rcu-walk autofs4 - fix autofs4_expire_indirect() traversal autofs4 - fix dentry leak in autofs4_expire_direct() autofs4 - reinstate last used update on access vfs - check non-mountpoint dentry might block in __follow_mount_rcu()
2011-03-24fs: move i_wb_list out from under inode_lockDave Chinner
Protect the inode writeback list with a new global lock inode_wb_list_lock and use it to protect the list manipulations and traversals. This lock replaces the inode_lock as the inodes on the list can be validity checked while holding the inode->i_lock and hence the inode_lock is no longer needed to protect the list. Signed-off-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-03-24fs: protect inode->i_state with inode->i_lockDave Chinner
Protect inode state transitions and validity checks with the inode->i_lock. This enables us to make inode state transitions independently of the inode_lock and is the first step to peeling away the inode_lock from the code. This requires that __iget() is done atomically with i_state checks during list traversals so that we don't race with another thread marking the inode I_FREEING between the state check and grabbing the reference. Also remove the unlock_new_inode() memory barrier optimisation required to avoid taking the inode_lock when clearing I_NEW. Simplify the code by simply taking the inode->i_lock around the state change and wakeup. Because the wakeup is no longer tricky, remove the wake_up_inode() function and open code the wakeup where necessary. Signed-off-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-03-24Merge branch 'slab/urgent' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6 * 'slab/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6: SLUB: Write to per cpu data when allocating it slub: Fix debugobjects with lockless fastpath
2011-03-24lib, arch: add filter argument to show_mem and fix private implementationsDavid Rientjes
Commit ddd588b5dd55 ("oom: suppress nodes that are not allowed from meminfo on oom kill") moved lib/show_mem.o out of lib/lib.a, which resulted in build warnings on all architectures that implement their own versions of show_mem(): lib/lib.a(show_mem.o): In function `show_mem': show_mem.c:(.text+0x1f4): multiple definition of `show_mem' arch/sparc/mm/built-in.o:(.text+0xd70): first defined here The fix is to remove __show_mem() and add its argument to show_mem() in all implementations to prevent this breakage. Architectures that implement their own show_mem() actually don't do anything with the argument yet, but they could be made to filter nodes that aren't allowed in the current context in the future just like the generic implementation. Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Reported-by: James Bottomley <James.Bottomley@hansenpartnership.com> Suggested-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: David Rientjes <rientjes@google.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-24SLUB: Write to per cpu data when allocating itChristoph Lameter
It turns out that the cmpxchg16b emulation has to access vmalloced percpu memory with interrupts disabled. If the memory has never been touched before then the fault necessary to establish the mapping will not to occur and the kernel will fail on boot. Fix that by reusing the CONFIG_PREEMPT code that writes the cpu number into a field on every cpu. Writing to the per cpu area before causes the mapping to be established before we get to a cmpxchg16b emulation. Tested-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Christoph Lameter <cl@linux.com> Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-03-24slub: Fix debugobjects with lockless fastpathThomas Gleixner
On Thu, 24 Mar 2011, Ingo Molnar wrote: > RIP: 0010:[<ffffffff810570a9>] [<ffffffff810570a9>] get_next_timer_interrupt+0x119/0x260 That's a typical timer crash, but you were unable to debug it with debugobjects because commit d3f661d6 broke those. Cc: Christoph Lameter <cl@linux.com> Tested-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-03-24Merge branch 'for-2.6.39/core' of git://git.kernel.dk/linux-2.6-blockLinus Torvalds
* 'for-2.6.39/core' of git://git.kernel.dk/linux-2.6-block: (65 commits) Documentation/iostats.txt: bit-size reference etc. cfq-iosched: removing unnecessary think time checking cfq-iosched: Don't clear queue stats when preempt. blk-throttle: Reset group slice when limits are changed blk-cgroup: Only give unaccounted_time under debug cfq-iosched: Don't set active queue in preempt block: fix non-atomic access to genhd inflight structures block: attempt to merge with existing requests on plug flush block: NULL dereference on error path in __blkdev_get() cfq-iosched: Don't update group weights when on service tree fs: assign sb->s_bdi to default_backing_dev_info if the bdi is going away block: Require subsystems to explicitly allocate bio_set integrity mempool jbd2: finish conversion from WRITE_SYNC_PLUG to WRITE_SYNC and explicit plugging jbd: finish conversion from WRITE_SYNC_PLUG to WRITE_SYNC and explicit plugging fs: make fsync_buffers_list() plug mm: make generic_writepages() use plugging blk-cgroup: Add unaccounted time to timeslice_used. block: fixup plugging stubs for !CONFIG_BLOCK block: remove obsolete comments for blkdev_issue_zeroout. blktrace: Use rq->cmd_flags directly in blk_add_trace_rq. ... Fix up conflicts in fs/{aio.c,super.c}
2011-03-23Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: deal with races in /proc/*/{syscall,stack,personality} proc: enable writing to /proc/pid/mem proc: make check_mem_permission() return an mm_struct on success proc: hold cred_guard_mutex in check_mem_permission() proc: disable mem_write after exec mm: implement access_remote_vm mm: factor out main logic of access_process_vm mm: use mm_struct to resolve gate vma's in __get_user_pages mm: arch: rename in_gate_area_no_task to in_gate_area_no_mm mm: arch: make in_gate_area take an mm_struct instead of a task_struct mm: arch: make get_gate_vma take an mm_struct instead of a task_struct x86: mark associated mm when running a task in 32 bit compatibility mode x86: add context tag to mark mm when running a task in 32-bit compatibility mode auxv: require the target to be tracable (or yourself) close race in /proc/*/environ report errors in /proc/*/*map* sanely pagemap: close races with suid execve make sessionid permissions in /proc/*/task/* match those in /proc/* fix leaks in path_lookupat() Fix up trivial conflicts in fs/proc/base.c
2011-03-23crash_dump: export is_kdump_kernel to modules, consolidate elfcorehdr_addr, ↵Olaf Hering
setup_elfcorehdr and saved_max_pfn The Xen PV drivers in a crashed HVM guest can not connect to the dom0 backend drivers because both frontend and backend drivers are still in connected state. To run the connection reset function only in case of a crashdump, the is_kdump_kernel() function needs to be available for the PV driver modules. Consolidate elfcorehdr_addr, setup_elfcorehdr and saved_max_pfn into kernel/crash_dump.c Also export elfcorehdr_addr to make is_kdump_kernel() usable for modules. Leave 'elfcorehdr' as early_param(). This changes powerpc from __setup() to early_param(). It adds an address range check from x86 also on ia64 and powerpc. [akpm@linux-foundation.org: additional #includes] [akpm@linux-foundation.org: remove elfcorehdr_addr export] [akpm@linux-foundation.org: fix for Tejun's mm/nobootmem.c changes] Signed-off-by: Olaf Hering <olaf@aepfle.de> Cc: Russell King <rmk@arm.linux.org.uk> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-23memcg: give current access to memory reserves if it's trying to dieDavid Rientjes
When a memcg is oom and current has already received a SIGKILL, then give it access to memory reserves with a higher scheduling priority so that it may quickly exit and free its memory. This is identical to the global oom killer and is done even before checking for panic_on_oom: a pending SIGKILL here while panic_on_oom is selected is guaranteed to have come from userspace; the thread only needs access to memory reserves to exit and thus we don't unnecessarily panic the machine until the kernel has no last resort to free memory. Signed-off-by: David Rientjes <rientjes@google.com> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> 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>
2011-03-23memcg: fix leak on wrong LRU with FUSEKAMEZAWA Hiroyuki
fs/fuse/dev.c::fuse_try_move_page() does (1) remove a page by ->steal() (2) re-add the page to page cache (3) link the page to LRU if it was not on LRU at (1) This implies the page is _on_ LRU when it's added to radix-tree. So, the page is added to memory cgroup while it's on LRU. because LRU is lazy and no one flushs it. This is the same behavior as SwapCache and needs special care as - remove page from LRU before overwrite pc->mem_cgroup. - add page to LRU after overwrite pc->mem_cgroup. And we need to taking care of pagevec. If PageLRU(page) is set before we add PCG_USED bit, the page will not be added to memcg's LRU (in short period). So, regardlress of PageLRU(page) value before commit_charge(), we need to check PageLRU(page) after commit_charge(). Addresses https://bugzilla.kernel.org/show_bug.cgi?id=30432 Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Miklos Szeredi <miklos@szeredi.hu> Cc: Balbir Singh <balbir@in.ibm.com> Reported-by: Daniel Poelzleithner <poelzi@poelzi.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-23memcg: page_cgroup array is never stored on reserved pagesMichal Hocko
KAMEZAWA Hiroyuki noted that free_pages_cgroup doesn't have to check for PageReserved because we never store the array on reserved pages (neither alloc_pages_exact nor vmalloc use those pages). So we can replace the check by a BUG_ON. Signed-off-by: Michal Hocko <mhocko@suse.cz> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Balbir Singh <balbir@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-23page_cgroup: reduce allocation overhead for page_cgroup array for ↵Michal Hocko
CONFIG_SPARSEMEM Currently we are allocating a single page_cgroup array per memory section (stored in mem_section->base) when CONFIG_SPARSEMEM is selected. This is correct but memory inefficient solution because the allocated memory (unless we fall back to vmalloc) is not kmalloc friendly: - 32b - 16384 entries (20B per entry) fit into 327680B so the 524288B slab cache is used - 32b with PAE - 131072 entries with 2621440B fit into 4194304B - 64b - 32768 entries (40B per entry) fit into 2097152 cache This is ~37% wasted space per memory section and it sumps up for the whole memory. On a x86_64 machine it is something like 6MB per 1GB of RAM. We can reduce the internal fragmentation by using alloc_pages_exact which allocates PAGE_SIZE aligned blocks so we will get down to <4kB wasted memory per section which is much better. We still need a fallback to vmalloc because we have no guarantees that we will have a continuous memory of that size (order-10) later on during the hotplug events. [hannes@cmpxchg.org: do not define unused free_page_cgroup() without memory hotplug] Signed-off-by: Michal Hocko <mhocko@suse.cz> Cc: Dave Hansen <dave@linux.vnet.ibm.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Balbir Singh <balbir@in.ibm.com> Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-23mm/memcontrol.c: suppress uninitialized-var warning with older gcc'sAndrew Morton
mm/memcontrol.c: In function 'mem_cgroup_force_empty': mm/memcontrol.c:2280: warning: 'flags' may be used uninitialized in this function It's a false positive. Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Greg Thelen <gthelen@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: 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>
2011-03-23memcg: use native word page statistics countersJohannes Weiner
The statistic counters are in units of pages, there is no reason to make them 64-bit wide on 32-bit machines. Make them native words. Since they are signed, this leaves 31 bit on 32-bit machines, which can represent roughly 8TB assuming a page size of 4k. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Greg Thelen <gthelen@google.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: 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>
2011-03-23memcg: break out event counters from other statsJohannes Weiner
For increasing and decreasing per-cpu cgroup usage counters it makes sense to use signed types, as single per-cpu values might go negative during updates. But this is not the case for only-ever-increasing event counters. All the counters have been signed 64-bit so far, which was enough to count events even with the sign bit wasted. This patch: - divides s64 counters into signed usage counters and unsigned monotonically increasing event counters. - converts unsigned event counters into 'unsigned long' rather than 'u64'. This matches the type used by the /proc/vmstat event counters. The next patch narrows the signed usage counters type (on 32-bit CPUs, that is). Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Greg Thelen <gthelen@google.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: 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>
2011-03-23memcg: unify charge/uncharge quantities to units of pagesJohannes Weiner
There is no clear pattern when we pass a page count and when we pass a byte count that is a multiple of PAGE_SIZE. We never charge or uncharge subpage quantities, so convert it all to page counts. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: 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>
2011-03-23memcg: convert uncharge batching from bytes to page granularityJohannes Weiner
We never uncharge subpage quantities. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: 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>
2011-03-23memcg: convert per-cpu stock from bytes to page granularityJohannes Weiner
We never keep subpage quantities in the per-cpu stock. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: 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>
2011-03-23memcg: keep only one charge cancelling functionJohannes Weiner
We have two charge cancelling functions: one takes a page count, the other a page size. The second one just divides the parameter by PAGE_SIZE and then calls the first one. This is trivial, no need for an extra function. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: 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>
2011-03-23memcg: remove memcg->reclaim_param_lockJohannes Weiner
The reclaim_param_lock is only taken around single reads and writes to integer variables and is thus superfluous. Drop it. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Reviewed-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>
2011-03-23memcg: charged pages always have valid per-memcg zone infoJohannes Weiner
page_cgroup_zoneinfo() will never return NULL for a charged page, remove the check for it in mem_cgroup_get_reclaim_stat_from_page(). Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Reviewed-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>
2011-03-23memcg: remove direct page_cgroup-to-page pointerJohannes Weiner
In struct page_cgroup, we have a full word for flags but only a few are reserved. Use the remaining upper bits to encode, depending on configuration, the node or the section, to enable page_cgroup-to-page lookups without a direct pointer. This saves a full word for every page in a system with memory cgroups enabled. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Minchan Kim <minchan.kim@gmail.com> Cc: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-23memcg: condense page_cgroup-to-page lookup pointsJohannes Weiner
The per-cgroup LRU lists string up 'struct page_cgroup's. To get from those structures to the page they represent, a lookup is required. Currently, the lookup is done through a direct pointer in struct page_cgroup, so a lot of functions down the callchain do this lookup by themselves instead of receiving the page pointer from their callers. The next patch removes this pointer, however, and the lookup is no longer that straight-forward. In preparation for that, this patch only leaves the non-optional lookups when coming directly from the LRU list and passes the page down the stack. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Minchan Kim <minchan.kim@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-23memcg: fold __mem_cgroup_move_account into callerJohannes Weiner
It is one logical function, no need to have it split up. Also, get rid of some checks from the inner function that ensured the sanity of the outer function. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Minchan Kim <minchan.kim@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-23memcg: change page_cgroup_zoneinfo signatureJohannes Weiner
Instead of passing a whole struct page_cgroup to this function, let it take only what it really needs from it: the struct mem_cgroup and the page. This has the advantage that reading pc->mem_cgroup is now done at the same place where the ordering rules for this pointer are enforced and explained. It is also in preparation for removing the pc->page backpointer. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Minchan Kim <minchan.kim@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-23memcg: no uncharged pages reach page_cgroup_zoneinfoJohannes Weiner
This patch series removes the direct page pointer from struct page_cgroup, which saves 20% of per-page memcg memory overhead (Fedora and Ubuntu enable memcg per default, openSUSE apparently too). The node id or section number is encoded in the remaining free bits of pc->flags which allows calculating the corresponding page without the extra pointer. I ran, what I think is, a worst-case microbenchmark that just cats a large sparse file to /dev/null, because it means that walking the LRU list on behalf of per-cgroup reclaim and looking up pages from page_cgroups is happening constantly and at a high rate. But it made no measurable difference. A profile reported a 0.11% share of the new lookup_cgroup_page() function in this benchmark. This patch: All callsites check PCG_USED before passing pc->mem_cgroup, so the latter is never NULL. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Minchan Kim <minchan.kim@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-23memcg: add memcg sanity checks at allocating and freeing pagesDaisuke Nishimura
Add checks at allocating or freeing a page whether the page is used (iow, charged) from the view point of memcg. This check may be useful in debugging a problem and we did similar checks before the commit 52d4b9ac(memcg: allocate all page_cgroup at boot). This patch adds some overheads at allocating or freeing memory, so it's enabled only when CONFIG_DEBUG_VM is enabled. Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Minchan Kim <minchan.kim@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-23memcg: remove NULL check from lookup_page_cgroup() resultJohannes Weiner
The page_cgroup array is set up before even fork is initialized. I seriously doubt that this code executes before the array is alloc'd. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Minchan Kim <minchan.kim@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-23memcg: remove impossible conditional when committingJohannes Weiner
No callsite ever passes a NULL pointer for a struct mem_cgroup * to the committing function. There is no need to check for it. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Minchan Kim <minchan.kim@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>