- 11 Nov, 2009 6 commits
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Manfred Spraul authored
semaphores. Atomic operations that affect multiple semaphores are supported. The patch optimizes single semaphore operation calls that affect only one semaphore: It's not necessary to scan all pending operations, it is sufficient to scan the per-semaphore list. The idea is from Nick Piggin version of an ipc sem improvement, the implementation is different: The code tries to keep as much common code as possible. As the result, the patch is simpler, but optimizes fewer cases. Signed-off-by:
Manfred Spraul <manfred@colorfullife.com> Cc: Nick Piggin <npiggin@suse.de> Cc: Pierre Peiffer <peifferp@gmail.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org>
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Manfred Spraul authored
sysv sem has the concept of semaphore arrays that consist out of multiple semaphores. Atomic operations that affect multiple semaphores are supported. The patch is the first step for optimizing simple, single semaphore operations: In addition to the global list of all pending operations, a 2nd, per-semaphore list with the simple operations is added. Note: this patch does not make sense by itself, the new list is used nowhere. Signed-off-by:
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Manfred Spraul authored
If try_atomic_semop failed, then no changes were applied. Thus no need to restart. Additionally, this patch correct an incorrect comment: It's possible to wait for arbitrary semaphore values (do a dec by <x>, wait-for-zero, inc by <x> in one atomic operation) Both changes are from Nick Piggin, the patch is the result of a different split of the individual changes. Signed-off-by:
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Nick Piggin authored
involved, which could deadlock if preemption is enabled during the "lock". It is an implementation detail (due to a spinlock being held) that this is actually the case. However if "spinlocks" are made preemptible, or if the sem lock is changed to a sleeping lock for example, then the wakeup would become buggy. So this might be a bugfix for -rt kernels. Imagine waker being preempted by wakee and never clearing IN_WAKEUP -- if wakee has higher RT priority then there is a priority inversion deadlock. Even if there is not a priority inversion to cause a deadlock, then there is still time wasted spinning. Signed-off-by:
Nick Piggin <npiggin@suse.de> Signed-off-by:
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Nick Piggin authored
list_for_each_entry macros. list_for_each_entry_safe() must be used, because list entries can disappear immediately uppon the wakeup event. Signed-off-by:
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Nick Piggin authored
sysv sem algorithm: Most (at least: some important) users only use simple semaphore operations, therefore it's worthwile to optimize this use case. This patch: Move last looked up sem_undo struct to the head of the task's undo list. Attempt to move common entries to the front of the list so search time is reduced. This reduces lookup_undo on oprofile of problematic SAP workload by 30% (see patch 4 for a description of SAP workload). Signed-off-by:
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- 13 Oct, 2009 1 commit
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Serge E. Hallyn authored
7ca7e564 "ipc: store ipcs into IDRs" in 2007. The idr of which 3 exist for each ipc namespace is never freed. This patch simply frees them when the ipcns is freed. I don't believe any idr_remove() are done from rcu (and could therefore be delayed until after this idr_destroy()), so the patch should be safe. Some quick testing showed no harm, and the memory leak fixed. Caught by kmemleak. Signed-off-by:
Serge E. Hallyn <serue@us.ibm.com> Signed-off-by:
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- 11 Nov, 2009 1 commit
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Oleg Nesterov authored
Currently we add sub-threads to ->real_parent->children list. This buys nothing but slows down do_wait(). With this patch ->children contains only main threads (group leaders). The only complication is that forget_original_parent() should iterate over sub-threads by hand, and de_thread() needs another list_replace() when it changes ->group_leader. Henceforth do_wait_thread() can never see task_detached() && !EXIT_DEAD tasks, we can remove this check (and we can unify do_wait_thread() and ptrace_do_wait()). This change can confuse the optimistic search in mm_update_next_owner(), but this is fixable and minor. Perhaps badness() and oom_kill_process() should be updated, but they should be fixed in any case. Signed-off-by:
Oleg Nesterov <oleg@redhat.com> Cc: Roland McGrath <roland@redhat.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Ratan Nalumasu <rnalumasu@gmail.com> Cc: Vitaly Mayatskikh <vmayatsk@redhat.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by:
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- 30 Oct, 2009 1 commit
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Oleg Nesterov authored
->group_stop_count condition visible to tracers before do_signal_stop() will participate in this group-stop. Currently the patch has no effect, tracehook_get_signal() always returns 0. Signed-off-by:
Roland McGrath <roland@redhat.com> Signed-off-by:
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- 16 Oct, 2009 3 commits
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Oleg Nesterov authored
Signed-off-by:
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Oleg Nesterov authored
This is a bit confusing, we don't know the source of this signal. But we don't care, and "info->si_code = 0" is imho worse. Signed-off-by:
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Oleg Nesterov authored
triggers the "from_ancestor_ns" check. This fixes reparent_thread()->group_send_sig_info(pdeath_signal) behaviour, before this patch send_signal() does not detect the cross-namespace case when the child of the dying parent belongs to the sub-namespace. This patch can affect the behaviour of send_sig(), kill_pgrp() and kill_pid() when the caller sends the signal to the sub-namespace with "priv == 0" but surprisingly all callers seem to use them correctly, including disassociate_ctty(on_exit). Except: drivers/staging/comedi/drivers/addi-data/*.c incorrectly use send_sig(priv => 0). But his is minor and should be fixed anyway. Reported-by:
Daniel Lezcano <dlezcano@fr.ibm.com> Signed-off-by:
Sukadev Bhattiprolu <sukadev@us.ibm.com> Signed-off-by:
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- 11 Nov, 2009 1 commit
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Oleg Nesterov authored
and changes check_kill_permission() to use this helper. The real effect of this patch is that from now we "officially" consider SEND_SIG_NOINFO signal as "from user-space" signals. This is already true if we look at the code which uses SEND_SIG_NOINFO, except __send_signal() has another opinion - see the next patch. The naming of these special SEND_SIG_XXX siginfo's is really bad imho. From __send_signal()'s pov they mean SEND_SIG_NOINFO from user SEND_SIG_PRIV from kernel SEND_SIG_FORCED no info Signed-off-by:
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- 12 Nov, 2009 5 commits
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Oleg Nesterov authored
Unlike powepc, x86 always calls tracehook_report_syscall_exit(step) with step = 0, and sends the trap by hand. This results in unnecessary SIGTRAP when PTRACE_SINGLESTEP follows the syscall-exit stop. Change syscall_trace_leave() to pass the correct "step" argument to tracehook and remove the send_sigtrap() logic. Signed-off-by:
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Oleg Nesterov authored
Implement user_single_step_siginfo() for x86. Extract this code from send_sigtrap(). Since x86 calls tracehook_report_syscall_exit(step => 0) the new helper is not used yet. Signed-off-by:
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Oleg Nesterov authored
Change tracehook_report_syscall_exit() to look at step flag and send the trap signal if needed. This change affects ia64, microblaze, parisc, powerpc, sh. They pass nonzero "step" argument to tracehook but since it was ignored the tracee reports via ptrace_notify(), this is not right and not consistent. - PTRACE_SETSIGINFO doesn't work - if the tracer resumes the tracee with signr != 0 the new signal is generated rather than delivering it - If PT_TRACESYSGOOD is set the tracee reports the wrong exit_code I don't have a powerpc machine, but I think this test-case should see the difference: #include <unistd.h> #include <sys/ptrace.h> #include <sys/wait.h> #include <assert.h> #include <stdio.h> int main(void) { int pid, status; if (!(pid = fork())) { assert(ptrace(PTRACE_TRACEME) == 0); kill(getpid(), SIGSTOP); getppid(); return 0; } assert(pid == wait(&status)); assert(ptrace(PTRACE_SETOPTIONS, pid, 0, PTRACE_O_TRACESYSGOOD) == 0); assert(ptrace(PTRACE_SYSCALL, pid, 0,0) == 0); assert(pid == wait(&status)); assert(ptrace(PTRACE_SINGLESTEP, pid, 0,0) == 0); assert(pid == wait(&status)); if (status == 0x57F) return 0; printf("kernel bug: status=%X shouldn't have 0x80\n", status); return 1; } Signed-off-by: -
Oleg Nesterov authored
Implement user_single_step_siginfo() for powerpc. Signed-off-by:
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Oleg Nesterov authored
Currently there is no way to synthesize a single-stepping trap in the arch-independent manner. This patch adds the default helper which fills siginfo_t, arch/ can can override it. Architetures which implement user_enable_single_step() should add user_single_step_siginfo() also. Signed-off-by:
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- 11 Nov, 2009 1 commit
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Oleg Nesterov authored
starts with TIF_SINGLESTEP/X86_EFLAGS_TF bits copied from ptraced parent. This is not right, especially when the new child is not auto-attaced: in this case it is killed by SIGTRAP. Change copy_process() to call user_disable_single_step(). Tested on x86. Test-case: #include <stdio.h> #include <unistd.h> #include <signal.h> #include <sys/ptrace.h> #include <sys/wait.h> #include <assert.h> int main(void) { int pid, status; if (!(pid = fork())) { assert(ptrace(PTRACE_TRACEME) == 0); kill(getpid(), SIGSTOP); if (!fork()) { /* kernel bug: this child will be killed by SIGTRAP */ printf("Hello world\n"); return 43; } wait(&status); return WEXITSTATUS(status); } for (;;) { assert(pid == wait(&status)); if (WIFEXITED(status)) break; assert(ptrace(PTRACE_SINGLESTEP, pid, 0,0) == 0); } assert(WEXITSTATUS(status) == 43); return 0; } Signed-off-by:
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- 30 Oct, 2009 1 commit
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Oleg Nesterov authored
ptrace_init_task() looks confusing, as if we always auto-attach when "bool ptrace" argument is true, while in fact we attach only if current is traced. Make the code more explicit and kill now unused ptrace_link(). Signed-off-by:
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- 12 Nov, 2009 3 commits
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Daisuke Nishimura authored
caused by race between oom and cpuset_attach) instead of cgroup_mutex to fix a deadlock problem. The cgroup_mutex, which was removed by the commit, in mem_cgroup_out_of_memory() was originally introduced at commit c7ba5c9e (Memory controller: OOM handling). IIUC, the intention of this cgroup_mutex was to prevent task move during select_bad_process() so that situations like below can be avoided. Assume cgroup "foo" has exceeded its limit and is about to trigger oom. 1. Process A, which has been in cgroup "baa" and uses large memory, is just moved to cgroup "foo". Process A can be the candidates for being killed. 2. Process B, which has been in cgroup "foo" and uses large memory, is just moved from cgroup "foo". Process B can be excluded from the candidates for being killed. But these race window exists anyway even if we hold a lock, because __mem_cgroup_try_charge() decides wether it should trigger oom or not outside of the lock. So the original cgroup_mutex in mem_cgroup_out_of_memory and thus current memcg_tasklist has no use. And IMHO, those races are not so critical for users. This patch removes it and make codes simpler. Signed-off-by:
Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Acked-by:
KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by:
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Daisuke Nishimura authored
failure. IMHO, charge/uncharge(especially charge) is high cost operation, so we should avoid it as far as possible. This patch tries to delay try_charge in mem_cgroup_move_parent() by re-ordering checks it does. And this patch renames mem_cgroup_move_account() to __mem_cgroup_move_account(), changes the return value of __mem_cgroup_move_account() from int to void, and adds a new wrapper(mem_cgroup_move_account()), which checks whether a @pc is valid for moving account and calls __mem_cgroup_move_account(). This patch removes the last caller of trylock_page_cgroup(), so removes its definition too. Signed-off-by:
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Daisuke Nishimura authored
cancel the charge and the refcnt we have got by mem_cgroup_tyr_charge(). This patch introduces mem_cgroup_cancel_charge() and call it in those places. Signed-off-by:
Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by:
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- 11 Nov, 2009 1 commit
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KAMEZAWA Hiroyuki authored
grep difficult. Replace memcg's MAPPED_FILE with FILE_MAPPED And in global VM, mapped shared memory is accounted into FILE_MAPPED. But memcg doesn't. fix it. Note: page_is_file_cache() just checks SwapBacked or not. So, we need to check PageAnon. Cc: Balbir Singh <balbir@in.ibm.com> Reviewed-by:
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- 16 Oct, 2009 1 commit
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Daisuke Nishimura authored
actually lead to a BUG. Just do it once in initialization. Acked-by:
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- 10 Oct, 2009 2 commits
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Andrew Morton authored
Cc: Balbir Singh <balbir@in.ibm.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: -
KAMEZAWA Hiroyuki authored
caching. At charge, memcg charges 64pages and remember it in percpu cache. Because it's cache, drain/flush if necessary. This version uses public percpu area. 2 benefits for using public percpu area. 1. Sum of stocked charge in the system is limited to # of cpus not to the number of memcg. This shows better synchonization. 2. drain code for flush/cpuhotplug is very easy (and quick) The most important point of this patch is that we never touch res_counter in fast path. The res_counter is system-wide shared counter which is modified very frequently. We shouldn't touch it as far as we can for avoiding false sharing. On x86-64 8cpu server, I tested overheads of memcg at page fault by running a program which does map/fault/unmap in a loop. Running a task per a cpu by taskset and see sum of the number of page faults in 60secs. [without memcg config] 40156968 page-faults # 0.085 M/sec ( +- 0.046% ) 27.67 cache-miss/faults [root cgroup] 36659599 page-faults # 0.077 M/sec ( +- 0.247% ) 31.58 cache miss/faults [in a child cgroup] 18444157 page-faults # 0.039 M/sec ( +- 0.133% ) 69.96 cache miss/faults [ + coalescing uncharge patch] 27133719 page-faults # 0.057 M/sec ( +- 0.155% ) 47.16 cache miss/faults [ + coalescing uncharge patch + this patch ] 34224709 page-faults # 0.072 M/sec ( +- 0.173% ) 34.69 cache miss/faults Changelog (since Oct/2): - updated comments - replaced get_cpu_var() with __get_cpu_var() if possible. - removed mutex for system-wide drain. adds a counter instead of it. - removed CONFIG_HOTPLUG_CPU Changelog (old): - rebased onto the latest mmotm - moved charge size check before __GFP_WAIT check for avoiding unnecesary - added asynchronous flush routine. - fixed bugs pointed out by Nishimura-san. Signed-off-by:
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- 11 Nov, 2009 1 commit
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KAMEZAWA Hiroyuki authored
bottleneck. One strong techinque to reduce lock contention is reducing calls by coalescing some amount of calls into one. Considering charge/uncharge chatacteristic, - charge is done one by one via demand-paging. - uncharge is done by - in chunk at munmap, truncate, exit, execve... - one by one via vmscan/paging. It seems we have a chance to coalesce uncharges for improving scalability at unmap/truncation. This patch is a for coalescing uncharge. For avoiding scattering memcg's structure to functions under /mm, this patch adds memcg batch uncharge information to the task. A reason for per-task batching is for making use of caller's context information. We do batched uncharge (deleyed uncharge) when truncation/unmap occurs but do direct uncharge when uncharge is called by memory reclaim (vmscan.c). The degree of coalescing depends on callers - at invalidate/trucate... pagevec size - at unmap ....ZAP_BLOCK_SIZE (memory itself will be freed in this degree.) Then, we'll not coalescing too much. On x86-64 8cpu server, I tested overheads of memcg at page fault by running a program which does map/fault/unmap in a loop. Running a task per a cpu by taskset and see sum of the number of page faults in 60secs. [without memcg config] 40156968 page-faults # 0.085 M/sec ( +- 0.046% ) 27.67 cache-miss/faults [root cgroup] 36659599 page-faults # 0.077 M/sec ( +- 0.247% ) 31.58 miss/faults [in a child cgroup] 18444157 page-faults # 0.039 M/sec ( +- 0.133% ) 69.96 miss/faults [child with this patch] 27133719 page-faults # 0.057 M/sec ( +- 0.155% ) 47.16 miss/faults We can see some amounts of improvement. (root cgroup doesn't affected by this patch) Another patch for "charge" will follow this and above will be improved more. Changelog(since 2009/10/02): - renamed filed of memcg_batch (as pages to bytes, memsw to memsw_bytes) - some clean up and commentary/description updates. - added initialize code to copy_process(). (possible bug fix) Changelog(old): - fixed !CONFIG_MEM_CGROUP case. - rebased onto the latest mmotm + softlimit fix patches. - unified patch for callers - added commetns. - make ->do_batch as bool. - removed css_get() at el. We don't need it. Signed-off-by:
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- 10 Nov, 2009 1 commit
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Randy Dunlap authored
should also be updated. Remove reference to the OSDL PLM build farm. Signed-off-by:
Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by:
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- 03 Nov, 2009 1 commit
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Randy Dunlap authored
Fix some whitespace/formatting. Correct some filenames/paths. Signed-off-by:
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- 25 Sep, 2009 1 commit
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Zhaolei authored
broken-down time. time_to_tm() is more generic to do that. Signed-off-by:
Zhao Lei <zhaolei@cn.fujitsu.com> Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@elte.hu> Cc: Pavel Machek <pavel@ucw.cz> Cc: Andi Kleen <andi@firstfloor.org> Signed-off-by:
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- 13 Nov, 2009 1 commit
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Akinobu Mita authored
Signed-off-by:
Akinobu Mita <akinobu.mita@gmail.com> Cc: Mikulas Patocka <mikulas@artax.karlin.mff.cuni.cz> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by:
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- 11 Nov, 2009 1 commit
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Jan Kara authored
write_begin either because of some filesystem error (like ENOSPC) or because page with data to write has been removed from memory. We truncate these blocks so that we don't have dangling blocks beyond i_size. Cc: Jeff Mahoney <jeffm@suse.com> Signed-off-by:
Jan Kara <jack@suse.cz> Signed-off-by:
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- 14 Oct, 2009 1 commit
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Alexey Dobriyan authored
* fix #ifdeffery in procfs.c via Kconfig Signed-off-by:
Alexey Dobriyan <adobriyan@gmail.com> Cc: Jeff Mahoney <jeffm@suse.com> Signed-off-by:
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- 11 Nov, 2009 1 commit
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Alexey Dobriyan authored
It's empty however, so simply remove it instead of doing dummy conversion. It's hard to see what information userspace can extract from empty file. Signed-off-by:
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- 10 Nov, 2009 2 commits
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Alexey Dobriyan authored
Acked-by:
Evgeniy Dushistov <dushistov@mail.ru> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by:
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Alexey Dobriyan authored
Cc: Evgeniy Dushistov <dushistov@mail.ru> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by:
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- 25 Sep, 2009 1 commit
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Warren Turkal authored
"force" mount option) if it detects that the HFS+ volume has a journal. The code was unconditionally assuming that the volume had a jounal if the journal attribute was set in the volume header. However, the volume also has to have a non-zero journal info block to actually have a journal. In this patch, I refactored the journal detection into a function since the logic is used twice. The journal detection also uses the better logic to determine if there is a journal. Signed-off-by:
Warren Turkal <wt@penguintechs.org> Cc: Roman Zippel <zippel@linux-m68k.org> Signed-off-by:
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- 21 Nov, 2008 1 commit
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Warren Turkal authored
whether a volume has a journal or not. The code currently mounts an HFS+ volume read-only by default when a journal is detected. One can force a read/write mount by giving the "force" mount option. The current code has this behavior since there is no support for the HFS+ journal. My problem is that the detection of the journal could be better. The current code tests the attribute bit in the volume header that indicates there is a journal. If that bit is set, the code assumes that there is a journal. Unfortunately, this is not enough to really determine if there is a journal or not. When that bit is set, one must also examine the journal info block field of the volume header. If this field is 0, there is no journal, and the volume can be mounted read/write. This patch: The HFS+ support in the kernel currently will mount an HFS+ volume read-only if the volume header has the attribute bit set that indicates there is a journal. The kernel does this because there is no support for a journalled HFS+ volume. The problem is that this is only half of what needs to be checked to see if there really is a journal. There is also an entry in the volume header that tells you where to find the journal info block. In the kernel version of the kernel, this 4 byte block is labeled reserved. This patch identifies the journal info block in the header. Signed-off-by:
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- 03 Nov, 2009 1 commit
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Andrew Morton authored
#18: FILE: fs/ext2/super.c:1092: +static void ext2_clear_super_error(struct super_block * sb) total: 1 errors, 0 warnings, 37 lines checked ./patches/ext2-avoid-warn-messages-when-failing-to-write-to-the-superblock.patch has style problems, please review. If any of these errors are false positives report them to the maintainer, see CHECKPATCH in MAINTAINERS. Please run checkpatch prior to sending patches Cc: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by:
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