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* atomic: move atomic_add_unless to generic codeArun Sharma2011-07-2626-102/+109
| | | | | | | | | | | | | | This is in preparation for more generic atomic primitives based on __atomic_add_unless. Signed-off-by: Arun Sharma <asharma@fb.com> Signed-off-by: Hans-Christian Egtvedt <hans-christian.egtvedt@atmel.com> Reviewed-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: David Miller <davem@davemloft.net> Acked-by: Mike Frysinger <vapier@gentoo.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* atomic: use <linux/atomic.h>Arun Sharma2011-07-26439-448/+427
| | | | | | | | | | | | | | This allows us to move duplicated code in <asm/atomic.h> (atomic_inc_not_zero() for now) to <linux/atomic.h> Signed-off-by: Arun Sharma <asharma@fb.com> Reviewed-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: David Miller <davem@davemloft.net> Cc: Eric Dumazet <eric.dumazet@gmail.com> Acked-by: Mike Frysinger <vapier@gentoo.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* asm-generic: add another generic ext2 atomic bitopsAkinobu Mita2011-07-2615-59/+28
| | | | | | | | | | | | | | | The majority of architectures implement ext2 atomic bitops as test_and_{set,clear}_bit() without spinlock. This adds this type of generic implementation in ext2-atomic-setbit.h and use it wherever possible. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Suggested-by: Andreas Dilger <adilger@dilger.ca> Suggested-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fail_make_request: cleanup should_fail_requestAkinobu Mita2011-07-261-14/+12
| | | | | | | | | | | This changes should_fail_request() to more usable wrapper function of should_fail(). It can avoid putting #ifdef CONFIG_FAIL_MAKE_REQUEST in the middle of a function. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fail_page_alloc: simplify debugfs initializationAkinobu Mita2011-07-261-31/+16
| | | | | | | | | | Now cleanup_fault_attr_dentries() recursively removes a directory, So we can simplify the error handling in the initialization code and no need to hold dentry structs for each debugfs file. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* failslab: simplify debugfs initializationAkinobu Mita2011-07-261-21/+10
| | | | | | | | | | | | | Now cleanup_fault_attr_dentries() recursively removes a directory, So we can simplify the error handling in the initialization code and no need to hold dentry structs for each debugfs file. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Pekka Enberg <penberg@kernel.org> Cc: Matt Mackall <mpm@selenic.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fault-injection: use debugfs_remove_recursiveAkinobu Mita2011-07-264-107/+30
| | | | | | | | | Use debugfs_remove_recursive() to simplify initialization and deinitialization of fault injection debugfs files. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fault-injection: cleanup simple attribute of stacktrace_depthAkinobu Mita2011-07-261-15/+15
| | | | | | | | | | | | Minor cosmetic changes for simple attribute of stacktrace_depth: - use min_t() - reduce #ifdef by moving a function - do not use partly capitalized function name Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fault-injection: remove nonexistent function externAkinobu Mita2011-07-261-1/+0
| | | | | | | | should_fail_srandom() does not exist. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fault-injection: do not include unneeded headerAkinobu Mita2011-07-261-1/+0
| | | | | | | | No need to include linux/kallsyms.h. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ramoops: make record_size a module parameterSergiu Iordache2011-07-262-10/+28
| | | | | | | | | | | | | | | The size of the dump is currently set using the RECORD_SIZE macro which is set to a page size. This patch makes the record size a module parameter and allows it to be set through platform data as well to allow larger dumps if needed. Signed-off-by: Sergiu Iordache <sergiu@chromium.org> Acked-by: Marco Stornelli <marco.stornelli@gmail.com> Cc: "Ahmed S. Darwish" <darwish.07@gmail.com> Cc: Artem Bityutskiy <Artem.Bityutskiy@nokia.com> Cc: Kyungmin Park <kyungmin.park@samsung.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ramoops: move dump_oops into platform dataSergiu Iordache2011-07-262-1/+5
| | | | | | | | | | | | | | | | The platform driver currently allows setting the mem_size and mem_address. ince dump_oops is also a module parameter it would be more consistent if it could be set through platform data as well. Signed-off-by: Sergiu Iordache <sergiu@chromium.org> Acked-by: Marco Stornelli <marco.stornelli@gmail.com> Cc: "Ahmed S. Darwish" <darwish.07@gmail.com> Cc: Artem Bityutskiy <Artem.Bityutskiy@nokia.com> Cc: Kyungmin Park <kyungmin.park@samsung.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ramoops: add new line to each printMarco Stornelli2011-07-261-6/+9
| | | | | | | | | | | | Add new line to each print. Signed-off-by: Marco Stornelli <marco.stornelli@gmail.com> Reported-by: Stevie Trujillo <stevie.trujillo@gmail.com> Cc: Kyungmin Park <kyungmin.park@samsung.com> Cc: Américo Wang <xiyou.wangcong@gmail.com> Cc: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ramoops: use module parameters instead of platform data if not availableMarco Stornelli2011-07-261-12/+35
| | | | | | | | | | | | | | | | Use generic module parameters instead of platform data, if platform data are not available. This limitation has been introduced with commit c3b92ce9e75 ("ramoops: use the platform data structure instead of module params"). [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Marco Stornelli <marco.stornelli@gmail.com> Cc: Kyungmin Park <kyungmin.park@samsung.com> Cc: Américo Wang <xiyou.wangcong@gmail.com> Reported-by: Stevie Trujillo <stevie.trujillo@gmail.com> Cc: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Vmware balloon: switch to using sysem-wide freezable workqueueDmitry Torokhov2011-07-261-20/+11
| | | | | | | | | | | | With the arrival of concurrency-managed workqueues there is no need for our driver to use dedicated workqueue; system-wide one should suffice just fine. [akpm@linux-foundation.org: fix comment layout & grammar] Signed-off-by: Dmitry Torokhov <dtor@vmware.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* drivers/w1/slaves/w1_therm.c: add support for DS28EA00Christian Glindkamp2011-07-262-0/+10
| | | | | | | Signed-off-by: Christian Glindkamp <christian.glindkamp@taskit.de> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* panic, vt: do not force oops output when panic_timeout < 0Mandeep Singh Baines2011-07-261-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Don't force output if you intend to reboot immediately. In this patch, I'm disabling the functionality enabled by vc->vc_panic_force_write if panic_timeout < 0 (i.e. no timeout). vc_panic_force_write is only enabled for fb video consoles if the FBINFO_CAN_FORCE_OUTPUT flag is set. For our application, we're using ram_oops to preserved the panic in memory. We want to reliably, and as fast as possible, machine_restart. The vc_panic_force_write flag results in a bunch of graphics driver code to be invoked which slows down restart and decreases reliability. Since we're already storing the panic in RAM and are going to reboot immediately, there is no benefit in mode switching back to the vc in order to display the panic output. The log buffer will get flushed by the console_unblank() call so remote management consoles should see all output. Signed-off-by: Mandeep Singh Baines <msb@chromium.org> Cc: Huang Ying <ying.huang@intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Hugh Dickins <hughd@google.com> Cc: Olaf Hering <olaf@aepfle.de> Cc: Jesse Barnes <jbarnes@virtuousgeek.org> Cc: Dave Airlie <airlied@gmail.com> Cc: Greg Kroah-Hartman <gregkh@suse.de> Acked-by: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* panic: panic=-1 for immediate rebootHugh Dickins2011-07-262-1/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When a kernel BUG or oops occurs, ChromeOS intends to panic and immediately reboot, with stacktrace and other messages preserved in RAM across reboot. But the longer we delay, the more likely the user is to poweroff and lose the info. panic_timeout (seconds before rebooting) is set by panic= boot option or sysctl or /proc/sys/kernel/panic; but 0 means wait forever, so at present we have to delay at least 1 second. Let a negative number mean reboot immediately (with the small cosmetic benefit of suppressing that newline-less "Rebooting in %d seconds.." message). Signed-off-by: Hugh Dickins <hughd@chromium.org> Signed-off-by: Mandeep Singh Baines <msb@chromium.org> Cc: Huang Ying <ying.huang@intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Hugh Dickins <hughd@google.com> Cc: Olaf Hering <olaf@aepfle.de> Cc: Jesse Barnes <jbarnes@virtuousgeek.org> Cc: Dave Airlie <airlied@gmail.com> Cc: Greg Kroah-Hartman <gregkh@suse.de> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Documentation/DMA-API-HOWTO.txt: fix misleading exampleMichal Miroslaw2011-07-261-6/+6
| | | | | | | | | See: DMA-API.txt, part Id, DMA_FROM_DEVICE description. Signed-off-by: Michal Miroslaw <mirq-linux@rere.qmqm.pl> Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* include/linux/dma-mapping.h: remove DMA_xxBIT_MASK macrosWANG Cong2011-07-262-28/+0
| | | | | | | | | | | git grep shows there are no users in tree, so we can remove them safely. Signed-off-by: WANG Cong <xiyou.wangcong@gmail.com> Acked-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Acked-by: Jiri Slaby <jslaby@suse.cz> Acked-by: Vinod Koul <vinod.koul@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* gcov: disable CONSTRUCTORS for UMLVitaliy Ivanov2011-07-261-1/+1
| | | | | | | | | | | | | | | Selecting GCOV for UML causing configuration mismatch: warning: (GCOV_KERNEL) selects CONSTRUCTORS which has unmet direct dependencies (!UML) Constructors are not needed for UML. Signed-off-by: Vitaliy Ivanov <vitalivanov@gmail.com> Cc: Peter Oberparleiter <oberpar@linux.vnet.ibm.com> Acked-by: Richard Weinberger <richard@nod.at> Acked-by: WANG Cong <xiyou.wangcong@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* drivers/edac/mpc85xx_edac.c: correct offset_in_page mask bits in ↵Kai.Jiang2011-07-261-2/+2
| | | | | | | | | | | | | | | | | edac_mc_handle_ce() Parameter offset_in_page in edac_mc_handle_ce() should mask the higher bits above the page size, not the lower bits. The original input sometimes causes a crash. Signed-off-by: Kai.Jiang <Kai.Jiang@freescale.com> Signed-off-by: Shaohui Xie <Shaohui.Xie@freescale.com> Cc: Anton Vorontsov <avorontsov@mvista.com> Cc: Grant Likely <grant.likely@secretlab.ca> Cc: "David S. Miller" <davem@davemloft.net> Cc: Kumar Gala <galak@kernel.crashing.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ipc: introduce shm_rmid_forced sysctlVasiliy Kulikov2011-07-266-4/+163
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add support for the shm_rmid_forced sysctl. If set to 1, all shared memory objects in current ipc namespace will be automatically forced to use IPC_RMID. The POSIX way of handling shmem allows one to create shm objects and call shmdt(), leaving shm object associated with no process, thus consuming memory not counted via rlimits. With shm_rmid_forced=1 the shared memory object is counted at least for one process, so OOM killer may effectively kill the fat process holding the shared memory. It obviously breaks POSIX - some programs relying on the feature would stop working. So set shm_rmid_forced=1 only if you're sure nobody uses "orphaned" memory. Use shm_rmid_forced=0 by default for compatability reasons. The feature was previously impemented in -ow as a configure option. [akpm@linux-foundation.org: fix documentation, per Randy] [akpm@linux-foundation.org: fix warning] [akpm@linux-foundation.org: readability/conventionality tweaks] [akpm@linux-foundation.org: fix shm_rmid_forced/shm_forced_rmid confusion, use standard comment layout] Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Cc: Randy Dunlap <rdunlap@xenotime.net> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: "Serge E. Hallyn" <serge.hallyn@canonical.com> Cc: Daniel Lezcano <daniel.lezcano@free.fr> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Tejun Heo <tj@kernel.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Solar Designer <solar@openwall.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ipc/mqueue.c: fix mq_open() return valueJiri Slaby2011-07-261-5/+7
| | | | | | | | | | | | | | | | | | | | | | We return ENOMEM from mqueue_get_inode even when we have enough memory. Namely in case the system rlimit of mqueue was reached. This error propagates to mq_queue and user sees the error unexpectedly. So fix this up to properly return EMFILE as described in the manpage: EMFILE The process already has the maximum number of files and message queues open. instead of: ENOMEM Insufficient memory. With the previous patch we just switch to ERR_PTR/PTR_ERR/IS_ERR error handling here. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Manfred Spraul <manfred@colorfullife.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ipc/mqueue.c: refactor failure handlingJiri Slaby2011-07-261-56/+57
| | | | | | | | | | | | | | | If new_inode fails to allocate an inode we need only to return with NULL. But now we test the opposite and have all the work in a nested block. So do the opposite to save one indentation level (and remove unnecessary line breaks). This is only a preparation/cleanup for the next patch where we fix up return values from mqueue_get_inode. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Manfred Spraul <manfred@colorfullife.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* cpumask: add cpumask_var_t documentationKOSAKI Motohiro2011-07-261-0/+14
| | | | | | | | | | cpumask_var_t has one notable difference from cpumask_t. Add the explanation. Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Thiago Farina <tfransosi@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* cpumask: alloc_cpumask_var() use NUMA_NO_NODEKOSAKI Motohiro2011-07-261-1/+1
| | | | | | | | | | NUMA_NO_NODE and numa_node_id() have different meanings. NUMA_NO_NODE is obviously the recommended fallback. Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Christoph Lameter <cl@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* cpumask: convert for_each_cpumask() with for_each_cpu()KOSAKI Motohiro2011-07-261-1/+1
| | | | | | | | Adapt new API fashion. 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>
* fs/exec.c:acct_arg_size(): ptl is no longer needed for add_mm_counter()Oleg Nesterov2011-07-261-7/+0
| | | | | | | | | | | | | acct_arg_size() takes ->page_table_lock around add_mm_counter() if !SPLIT_RSS_COUNTING. This is not needed after commit 172703b08cd0 ("mm: delete non-atomic mm counter implementation"). Signed-off-by: Oleg Nesterov <oleg@redhat.com> Reviewed-by: Matt Fleming <matt.fleming@linux.intel.com> Cc: Dave Hansen <dave@linux.vnet.ibm.com> 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>
* exec: do not retry load_binary method if CONFIG_MODULES=nTetsuo Handa2011-07-261-2/+4
| | | | | | | | | | | If CONFIG_MODULES=n, it makes no sense to retry the list of binary formats handler because the list will not be modified by request_module(). Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Richard Weinberger <richard@nod.at> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* exec: do not call request_module() twice from search_binary_handler()Tetsuo Handa2011-07-261-0/+2
| | | | | | | | | | | | | | | | | | | | | Currently, search_binary_handler() tries to load binary loader module using request_module() if a loader for the requested program is not yet loaded. But second attempt of request_module() does not affect the result of search_binary_handler(). If request_module() triggered recursion, calling request_module() twice causes 2 to the power of MAX_KMOD_CONCURRENT (= 50) repetitions. It is not an infinite loop but is sufficient for users to consider as a hang up. Therefore, this patch changes not to call request_module() twice, making 1 to the power of MAX_KMOD_CONCURRENT repetitions in case of recursion. Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Reported-by: Richard Weinberger <richard@nod.at> Tested-by: Richard Weinberger <richard@nod.at> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fs/exec.c: use BUILD_BUG_ON for VM_STACK_FLAGS & VM_STACK_INCOMPLETE_SETUPMichal Hocko2011-07-261-1/+1
| | | | | | | | | | | | | | Commit a8bef8ff6ea1 ("mm: migration: avoid race between shift_arg_pages() and rmap_walk() during migration by not migrating temporary stacks") introduced a BUG_ON() to ensure that VM_STACK_FLAGS and VM_STACK_INCOMPLETE_SETUP do not overlap. The check is a compile time one, so BUILD_BUG_ON is more appropriate. Signed-off-by: Michal Hocko <mhocko@suse.cz> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Richard Weinberger <richard@nod.at> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* kernel/fork.c: fix a few coding style issuesDaniel Rebelo de Oliveira2011-07-261-35/+48
| | | | | | Signed-off-by: Daniel Rebelo de Oliveira <psykon@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* proc: fix a race in do_io_accounting()Vasiliy Kulikov2011-07-261-3/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | If an inode's mode permits opening /proc/PID/io and the resulting file descriptor is kept across execve() of a setuid or similar binary, the ptrace_may_access() check tries to prevent using this fd against the task with escalated privileges. Unfortunately, there is a race in the check against execve(). If execve() is processed after the ptrace check, but before the actual io information gathering, io statistics will be gathered from the privileged process. At least in theory this might lead to gathering sensible information (like ssh/ftp password length) that wouldn't be available otherwise. Holding task->signal->cred_guard_mutex while gathering the io information should protect against the race. The order of locking is similar to the one inside of ptrace_attach(): first goes cred_guard_mutex, then lock_task_sighand(). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* procfs: return ENOENT on opening a being-removed proc entryDaisuke Ogino2011-07-261-1/+1
| | | | | | | | | | | | | | Change the return value to ENOENT. This return value is then returned when opening the proc entry that have been removed. For example, open("/proc/bus/pci/XX/YY") when the corresponding device is being hot-removed. Signed-off-by: Daisuke Ogino <ogino.daisuke@jp.fujitsu.com> Cc: Jesse Barnes <jbarnes@virtuousgeek.org> Acked-by: Alexey Dobriyan <adobriyan@gmail.com> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* h8300/m68k/xtensa: __FD_ISSET should return 0/1Andrew Morton2011-07-263-3/+3
| | | | | | | | | | | | Harmonise these return values with other architectures. In some cases this affects all compilers and in other cases non-gcc compilers only. Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Chris Zankel <chris@zankel.net> Cc: Ulrich Drepper <drepper@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* do_coredump: fix the "ispipe" error checkOleg Nesterov2011-07-261-6/+6
| | | | | | | | | | | | | do_coredump() assumes that if format_corename() fails it should return -ENOMEM. This is not true, for example cn_print_exe_file() can propagate the error from d_path. Even if it was true, this is too fragile. Change the code to check "ispipe < 0". Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Jiri Slaby <jslaby@suse.cz> Reviewed-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* coredump: escape / in hostname and commJiri Slaby2011-07-261-8/+23
| | | | | | | | | | | | | | | | | | | Change every occurence of / in comm and hostname to !. If the process changes its name to contain /, the core is not dumped (if the directory tree doesn't exist like that). The same with hostname being something like myhost/3. Fix this behaviour by using the escape loop used in %E. (We extract it to a separate function.) Now both with comm == myprocess/1 and hostname == myhost/1, the core is dumped like (kernel.core_pattern='core.%p.%e.%h): core.2349.myprocess!1.myhost!1 Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andi Kleen <andi@firstfloor.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* coredump: use task comm instead of (unknown)Jiri Slaby2011-07-261-1/+1
| | | | | | | | | | | | | | | | If we don't know the file corresponding to the binary (i.e. exe_file is unknown), use "task->comm (path unknown)" instead of simple "(unknown)" as suggested by ak. The fallback is the same as %e except it will append "(path unknown)". Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andi Kleen <andi@firstfloor.org> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ptrace: unify show_regs() prototypeMike Frysinger2011-07-2621-28/+0
| | | | | | | | | [ poleg@redhat.com: no need to declare show_regs() in ptrace.h, sched.h does this ] Signed-off-by: Mike Frysinger <vapier@gentoo.org> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* cpusets: randomize node rotor used in cpuset_mem_spread_node()Michal Hocko2011-07-266-1/+43
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ This patch has already been accepted as commit 0ac0c0d0f837 but later reverted (commit 35926ff5fba8) because it itroduced arch specific __node_random which was defined only for x86 code so it broke other archs. This is a followup without any arch specific code. Other than that there are no functional changes.] Some workloads that create a large number of small files tend to assign too many pages to node 0 (multi-node systems). Part of the reason is that the rotor (in cpuset_mem_spread_node()) used to assign nodes starts at node 0 for newly created tasks. This patch changes the rotor to be initialized to a random node number of the cpuset. [akpm@linux-foundation.org: fix layout] [Lee.Schermerhorn@hp.com: Define stub numa_random() for !NUMA configuration] [mhocko@suse.cz: Make it arch independent] [akpm@linux-foundation.org: fix CONFIG_NUMA=y, MAX_NUMNODES>1 build] Signed-off-by: Jack Steiner <steiner@sgi.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Signed-off-by: Michal Hocko <mhocko@suse.cz> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Pekka Enberg <penberg@cs.helsinki.fi> Cc: Paul Menage <menage@google.com> Cc: Jack Steiner <steiner@sgi.com> Cc: Robin Holt <holt@sgi.com> Cc: David Rientjes <rientjes@google.com> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: David Rientjes <rientjes@google.com> Cc: Jack Steiner <steiner@sgi.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Paul Menage <menage@google.com> Cc: Pekka Enberg <penberg@cs.helsinki.fi> Cc: Robin Holt <holt@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* memcg: get rid of percpu_charge_mutex lockMichal Hocko2011-07-261-10/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | percpu_charge_mutex protects from multiple simultaneous per-cpu charge caches draining because we might end up having too many work items. At least this was the case until commit 26fe61684449 ("memcg: fix percpu cached charge draining frequency") when we introduced a more targeted draining for async mode. Now that also sync draining is targeted we can safely remove mutex because we will not send more work than the current number of CPUs. FLUSHING_CACHED_CHARGE protects from sending the same work multiple times and stock->nr_pages == 0 protects from pointless sending a work if there is obviously nothing to be done. This is of course racy but we can live with it as the race window is really small (we would have to see FLUSHING_CACHED_CHARGE cleared while nr_pages would be still non-zero). The only remaining place where we can race is synchronous mode when we rely on FLUSHING_CACHED_CHARGE test which might have been set by other drainer on the same group but we should wait in that case as well. Signed-off-by: Michal Hocko <mhocko@suse.cz> Cc: Balbir Singh <bsingharora@gmail.com> 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>
* memcg: add mem_cgroup_same_or_subtree() helperMichal Hocko2011-07-261-25/+26
| | | | | | | | | | | | We are checking whether a given two groups are same or at least in the same subtree of a hierarchy at several places. Let's make a helper for it to make code easier to read. Signed-off-by: Michal Hocko <mhocko@suse.cz> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Balbir Singh <bsingharora@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* memcg: unify sync and async per-cpu charge cache drainingMichal Hocko2011-07-261-14/+34
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently we have two ways how to drain per-CPU caches for charges. drain_all_stock_sync will synchronously drain all caches while drain_all_stock_async will asynchronously drain only those that refer to a given memory cgroup or its subtree in hierarchy. Targeted async draining has been introduced by 26fe6168 (memcg: fix percpu cached charge draining frequency) to reduce the cpu workers number. sync draining is currently triggered only from mem_cgroup_force_empty which is triggered only by userspace (mem_cgroup_force_empty_write) or when a cgroup is removed (mem_cgroup_pre_destroy). Although these are not usually frequent operations it still makes some sense to do targeted draining as well, especially if the box has many CPUs. This patch unifies both methods to use the single code (drain_all_stock) which relies on the original async implementation and just adds flush_work to wait on all caches that are still under work for the sync mode. We are using FLUSHING_CACHED_CHARGE bit check to prevent from waiting on a work that we haven't triggered. Please note that both sync and async functions are currently protected by percpu_charge_mutex so we cannot race with other drainers. Signed-off-by: Michal Hocko <mhocko@suse.cz> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Balbir Singh <bsingharora@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* memcg: do not try to drain per-cpu caches without pagesMichal Hocko2011-07-261-6/+7
| | | | | | | | | | | | | | | | | | | | drain_all_stock_async tries to optimize a work to be done on the work queue by excluding any work for the current CPU because it assumes that the context we are called from already tried to charge from that cache and it's failed so it must be empty already. While the assumption is correct we can optimize it even more by checking the current number of pages in the cache. This will also reduce a work on other CPUs with an empty stock. For the current CPU we can simply call drain_local_stock rather than deferring it to the work queue. [kamezawa.hiroyu@jp.fujitsu.com: use drain_local_stock for current CPU optimization] Signed-off-by: Michal Hocko <mhocko@suse.cz> 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>
* memcg: add memory.vmscan_statKAMEZAWA Hiroyuki2011-07-265-18/+303
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The commit log of 0ae5e89c60c9 ("memcg: count the soft_limit reclaim in...") says it adds scanning stats to memory.stat file. But it doesn't because we considered we needed to make a concensus for such new APIs. This patch is a trial to add memory.scan_stat. This shows - the number of scanned pages(total, anon, file) - the number of rotated pages(total, anon, file) - the number of freed pages(total, anon, file) - the number of elaplsed time (including sleep/pause time) for both of direct/soft reclaim. The biggest difference with oringinal Ying's one is that this file can be reset by some write, as # echo 0 ...../memory.scan_stat Example of output is here. This is a result after make -j 6 kernel under 300M limit. [kamezawa@bluextal ~]$ cat /cgroup/memory/A/memory.scan_stat [kamezawa@bluextal ~]$ cat /cgroup/memory/A/memory.vmscan_stat scanned_pages_by_limit 9471864 scanned_anon_pages_by_limit 6640629 scanned_file_pages_by_limit 2831235 rotated_pages_by_limit 4243974 rotated_anon_pages_by_limit 3971968 rotated_file_pages_by_limit 272006 freed_pages_by_limit 2318492 freed_anon_pages_by_limit 962052 freed_file_pages_by_limit 1356440 elapsed_ns_by_limit 351386416101 scanned_pages_by_system 0 scanned_anon_pages_by_system 0 scanned_file_pages_by_system 0 rotated_pages_by_system 0 rotated_anon_pages_by_system 0 rotated_file_pages_by_system 0 freed_pages_by_system 0 freed_anon_pages_by_system 0 freed_file_pages_by_system 0 elapsed_ns_by_system 0 scanned_pages_by_limit_under_hierarchy 9471864 scanned_anon_pages_by_limit_under_hierarchy 6640629 scanned_file_pages_by_limit_under_hierarchy 2831235 rotated_pages_by_limit_under_hierarchy 4243974 rotated_anon_pages_by_limit_under_hierarchy 3971968 rotated_file_pages_by_limit_under_hierarchy 272006 freed_pages_by_limit_under_hierarchy 2318492 freed_anon_pages_by_limit_under_hierarchy 962052 freed_file_pages_by_limit_under_hierarchy 1356440 elapsed_ns_by_limit_under_hierarchy 351386416101 scanned_pages_by_system_under_hierarchy 0 scanned_anon_pages_by_system_under_hierarchy 0 scanned_file_pages_by_system_under_hierarchy 0 rotated_pages_by_system_under_hierarchy 0 rotated_anon_pages_by_system_under_hierarchy 0 rotated_file_pages_by_system_under_hierarchy 0 freed_pages_by_system_under_hierarchy 0 freed_anon_pages_by_system_under_hierarchy 0 freed_file_pages_by_system_under_hierarchy 0 elapsed_ns_by_system_under_hierarchy 0 total_xxxx is for hierarchy management. This will be useful for further memcg developments and need to be developped before we do some complicated rework on LRU/softlimit management. This patch adds a new struct memcg_scanrecord into scan_control struct. sc->nr_scanned at el is not designed for exporting information. For example, nr_scanned is reset frequentrly and incremented +2 at scanning mapped pages. To avoid complexity, I added a new param in scan_control which is for exporting scanning score. Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Michal Hocko <mhocko@suse.cz> Cc: Ying Han <yinghan@google.com> Cc: Andrew Bresticker <abrestic@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* memcg: fix behavior of mem_cgroup_resize_limit()Daisuke Nishimura2011-07-261-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | Commit 22a668d7c3ef ("memcg: fix behavior under memory.limit equals to memsw.limit") introduced "memsw_is_minimum" flag, which becomes true when mem_limit == memsw_limit. The flag is checked at the beginning of reclaim, and "noswap" is set if the flag is true, because using swap is meaningless in this case. This works well in most cases, but when we try to shrink mem_limit, which is the same as memsw_limit now, we might fail to shrink mem_limit because swap doesn't used. This patch fixes this behavior by: - check MEM_CGROUP_RECLAIM_SHRINK at the begining of reclaim - If it is set, don't set "noswap" flag even if memsw_is_minimum is true. Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Balbir Singh <bsingharora@gmail.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Ying Han <yinghan@google.com> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* memcg: fix vmscan count in small memcgsKAMEZAWA Hiroyuki2011-07-261-6/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 246e87a93934 ("memcg: fix get_scan_count() for small targets") fixes the memcg/kswapd behavior against small targets and prevent vmscan priority too high. But the implementation is too naive and adds another problem to small memcg. It always force scan to 32 pages of file/anon and doesn't handle swappiness and other rotate_info. It makes vmscan to scan anon LRU regardless of swappiness and make reclaim bad. This patch fixes it by adjusting scanning count with regard to swappiness at el. At a test "cat 1G file under 300M limit." (swappiness=20) before patch scanned_pages_by_limit 360919 scanned_anon_pages_by_limit 180469 scanned_file_pages_by_limit 180450 rotated_pages_by_limit 31 rotated_anon_pages_by_limit 25 rotated_file_pages_by_limit 6 freed_pages_by_limit 180458 freed_anon_pages_by_limit 19 freed_file_pages_by_limit 180439 elapsed_ns_by_limit 429758872 after patch scanned_pages_by_limit 180674 scanned_anon_pages_by_limit 24 scanned_file_pages_by_limit 180650 rotated_pages_by_limit 35 rotated_anon_pages_by_limit 24 rotated_file_pages_by_limit 11 freed_pages_by_limit 180634 freed_anon_pages_by_limit 0 freed_file_pages_by_limit 180634 elapsed_ns_by_limit 367119089 scanned_pages_by_system 0 the numbers of scanning anon are decreased(as expected), and elapsed time reduced. By this patch, small memcgs will work better. (*) Because the amount of file-cache is much bigger than anon, recalaim_stat's rotate-scan counter make scanning files more. Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Michal Hocko <mhocko@suse.cz> Cc: Ying Han <yinghan@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* memcg: change memcg_oom_mutex to spinlockMichal Hocko2011-07-261-11/+11
| | | | | | | | | | | | | | | | | | | memcg_oom_mutex is used to protect memcg OOM path and eventfd interface for oom_control. None of the critical sections which it protects sleep (eventfd_signal works from atomic context and the rest are simple linked list resp. oom_lock atomic operations). Mutex is also too heavyweight for those code paths because it triggers a lot of scheduling. It also makes makes convoying effects more visible when we have a big number of oom killing because we take the lock mutliple times during mem_cgroup_handle_oom so we have multiple places where many processes can sleep. Signed-off-by: Michal Hocko <mhocko@suse.cz> Cc: Balbir Singh <bsingharora@gmail.com> 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>
* memcg: make oom_lock 0 and 1 based rather than counterMichal Hocko2011-07-261-16/+70
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 867578cb ("memcg: fix oom kill behavior") introduced a oom_lock counter which is incremented by mem_cgroup_oom_lock when we are about to handle memcg OOM situation. mem_cgroup_handle_oom falls back to a sleep if oom_lock > 1 to prevent from multiple oom kills at the same time. The counter is then decremented by mem_cgroup_oom_unlock called from the same function. This works correctly but it can lead to serious starvations when we have many processes triggering OOM and many CPUs available for them (I have tested with 16 CPUs). Consider a process (call it A) which gets the oom_lock (the first one that got to mem_cgroup_handle_oom and grabbed memcg_oom_mutex) and other processes that are blocked on the mutex. While A releases the mutex and calls mem_cgroup_out_of_memory others will wake up (one after another) and increase the counter and fall into sleep (memcg_oom_waitq). Once A finishes mem_cgroup_out_of_memory it takes the mutex again and decreases oom_lock and wakes other tasks (if releasing memory by somebody else - e.g. killed process - hasn't done it yet). A testcase would look like: Assume malloc XXX is a program allocating XXX Megabytes of memory which touches all allocated pages in a tight loop # swapoff SWAP_DEVICE # cgcreate -g memory:A # cgset -r memory.oom_control=0 A # cgset -r memory.limit_in_bytes= 200M # for i in `seq 100` # do # cgexec -g memory:A malloc 10 & # done The main problem here is that all processes still race for the mutex and there is no guarantee that we will get counter back to 0 for those that got back to mem_cgroup_handle_oom. In the end the whole convoy in/decreases the counter but we do not get to 1 that would enable killing so nothing useful can be done. The time is basically unbounded because it highly depends on scheduling and ordering on mutex (I have seen this taking hours...). This patch replaces the counter by a simple {un}lock semantic. As mem_cgroup_oom_{un}lock works on the a subtree of a hierarchy we have to make sure that nobody else races with us which is guaranteed by the memcg_oom_mutex. We have to be careful while locking subtrees because we can encounter a subtree which is already locked: hierarchy: A / \ B \ /\ \ C D E B - C - D tree might be already locked. While we want to enable locking E subtree because OOM situations cannot influence each other we definitely do not want to allow locking A. Therefore we have to refuse lock if any subtree is already locked and clear up the lock for all nodes that have been set up to the failure point. On the other hand we have to make sure that the rest of the world will recognize that a group is under OOM even though it doesn't have a lock. Therefore we have to introduce under_oom variable which is incremented and decremented for the whole subtree when we enter resp. leave mem_cgroup_handle_oom. under_oom, unlike oom_lock, doesn't need be updated under memcg_oom_mutex because its users only check a single group and they use atomic operations for that. This can be checked easily by the following test case: # cgcreate -g memory:A # cgset -r memory.use_hierarchy=1 A # cgset -r memory.oom_control=1 A # cgset -r memory.limit_in_bytes= 100M # cgset -r memory.memsw.limit_in_bytes= 100M # cgcreate -g memory:A/B # cgset -r memory.oom_control=1 A/B # cgset -r memory.limit_in_bytes=20M # cgset -r memory.memsw.limit_in_bytes=20M # cgexec -g memory:A/B malloc 30 & #->this will be blocked by OOM of group B # cgexec -g memory:A malloc 80 & #->this will be blocked by OOM of group A While B gets oom_lock A will not get it. Both of them go into sleep and wait for an external action. We can make the limit higher for A to enforce waking it up # cgset -r memory.memsw.limit_in_bytes=300M A # cgset -r memory.limit_in_bytes=300M A malloc in A has to wake up even though it doesn't have oom_lock. Finally, the unlock path is very easy because we always unlock only the subtree we have locked previously while we always decrement under_oom. Signed-off-by: Michal Hocko <mhocko@suse.cz> Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Balbir Singh <bsingharora@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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