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* Merge branch 'semaphore' of ↵Linus Torvalds2008-04-182-1/+265
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/willy/misc * 'semaphore' of git://git.kernel.org/pub/scm/linux/kernel/git/willy/misc: Remove DEBUG_SEMAPHORE from Kconfig Improve semaphore documentation Simplify semaphore implementation Add down_timeout and change ACPI to use it Introduce down_killable() Generic semaphore implementation Add semaphore.h to kernel_lock.c Fix quota.h includes
| * Improve semaphore documentationMatthew Wilcox2008-04-171-11/+68
| | | | | | | | | | | | | | | | Move documentation from semaphore.h to semaphore.c as requested by Andrew Morton. Also reformat to kernel-doc style and add some more notes about the implementation. Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
| * Simplify semaphore implementationMatthew Wilcox2008-04-171-54/+24
| | | | | | | | | | | | | | | | | | By removing the negative values of 'count' and relying on the wait_list to indicate whether we have any waiters, we can simplify the implementation by removing the protection against an unlikely race condition. Thanks to David Howells for his suggestions. Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
| * Add down_timeout and change ACPI to use itMatthew Wilcox2008-04-171-7/+35
| | | | | | | | | | | | | | | | | | ACPI currently emulates a timeout for semaphores with calls to down_trylock and sleep. This produces horrible behaviour in terms of fairness and excessive wakeups. Now that we have a unified semaphore implementation, adding a real down_trylock is almost trivial. Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
| * Introduce down_killable()Matthew Wilcox2008-04-171-0/+22
| | | | | | | | | | | | down_killable() is the functional counterpart of mutex_lock_killable. Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
| * Generic semaphore implementationMatthew Wilcox2008-04-172-1/+188
| | | | | | | | | | | | | | | | | | | | | | Semaphores are no longer performance-critical, so a generic C implementation is better for maintainability, debuggability and extensibility. Thanks to Peter Zijlstra for fixing the lockdep warning. Thanks to Harvey Harrison for pointing out that the unlikely() was unnecessary. Signed-off-by: Matthew Wilcox <willy@linux.intel.com> Acked-by: Ingo Molnar <mingo@elte.hu>
* | Merge branch 'for-linus' of git://git390.osdl.marist.edu/pub/scm/linux-2.6Linus Torvalds2008-04-183-3/+5
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * 'for-linus' of git://git390.osdl.marist.edu/pub/scm/linux-2.6: (36 commits) [S390] Remove code duplication from monreader / dcssblk. [S390] kernel: show last breaking-event-address on oops [S390] lowcore: Change type of lowcores softirq_pending to __u32. [S390] zcrypt: Comments and kernel-doc cleanup [S390] uaccess: Always access the correct address space. [S390] Fix a lot of sparse warnings. [S390] Convert s390 to GENERIC_CLOCKEVENTS. [S390] genirq/clockevents: move irq affinity prototypes/inlines to interrupt.h [S390] Convert monitor calls to function calls. [S390] qdio (new feature): enhancing info-retrieval from QDIO-adapters [S390] replace remaining __FUNCTION__ occurrences [S390] remove redundant display of free swap space in show_mem() [S390] qdio: remove outdated developerworks link. [S390] Add debug_register_mode() function to debug feature API [S390] crypto: use more descriptive function names for init/exit routines. [S390] switch sched_clock to store-clock-extended. [S390] zcrypt: add support for large random numbers [S390] hw_random: allow rng_dev_read() to return hardware errors. [S390] Vertical cpu management. [S390] cpu topology support for s390. ...
| * | [S390] genirq/clockevents: move irq affinity prototypes/inlines to interrupt.hRussell King2008-04-173-3/+5
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | > Generic code is not supposed to include irq.h. Replace this include > by linux/hardirq.h instead and add/replace an include of linux/irq.h > in asm header files where necessary. > This change should only matter for architectures that make use of > GENERIC_CLOCKEVENTS. > Architectures in question are mips, x86, arm, sh, powerpc, uml and sparc64. > > I did some cross compile tests for mips, x86_64, arm, powerpc and sparc64. > This patch fixes also build breakages caused by the include replacement in > tick-common.h. I generally dislike adding optional linux/* includes in asm/* includes - I'm nervous about this causing include loops. However, there's a separate point to be discussed here. That is, what interfaces are expected of every architecture in the kernel. If generic code wants to be able to set the affinity of interrupts, then that needs to become part of the interfaces listed in linux/interrupt.h rather than linux/irq.h. So what I suggest is this approach instead (against Linus' tree of a couple of days ago) - we move irq_set_affinity() and irq_can_set_affinity() to linux/interrupt.h, change the linux/irq.h includes to linux/interrupt.h and include asm/irq_regs.h where needed (asm/irq_regs.h is supposed to be rarely used include since not much touches the stacked parent context registers.) Build tested on ARM PXA family kernels and ARM's Realview platform kernels which both use genirq. [ tglx@linutronix.de: add GENERIC_HARDIRQ dependencies ] Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
* | ptrace_signal subroutineRoland McGrath2008-04-181-29/+42
| | | | | | | | | | | | | | | | | | | | | | | | | | This breaks out the ptrace handling from get_signal_to_deliver into a new subroutine. The actual code there doesn't change, and it gets inlined into nearly identical compiled code. This makes the function substantially shorter and thus easier to read, and it nicely isolates the ptrace magic. Signed-off-by: Roland McGrath <roland@redhat.com> Acked-by: Kyle McMartin <kyle@mcmartin.ca> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | cgroup: fix a race condition in manipulating tsk->cg_listLi Zefan2008-04-181-1/+6
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When I ran a test program to fork mass processes and at the same time 'cat /cgroup/tasks', I got the following oops: ------------[ cut here ]------------ kernel BUG at lib/list_debug.c:72! invalid opcode: 0000 [#1] SMP Pid: 4178, comm: a.out Not tainted (2.6.25-rc9 #72) ... Call Trace: [<c044a5f9>] ? cgroup_exit+0x55/0x94 [<c0427acf>] ? do_exit+0x217/0x5ba [<c0427ed7>] ? do_group_exit+0.65/0x7c [<c0427efd>] ? sys_exit_group+0xf/0x11 [<c0404842>] ? syscall_call+0x7/0xb [<c05e0000>] ? init_cyrix+0x2fa/0x479 ... EIP: [<c04df671>] list_del+0x35/0x53 SS:ESP 0068:ebc7df4 ---[ end trace caffb7332252612b ]--- Fixing recursive fault but reboot is needed! After digging into the code and debugging, I finlly found out a race situation: do_exit() ->cgroup_exit() ->if (!list_empty(&tsk->cg_list)) list_del(&tsk->cg_list); cgroup_iter_start() ->cgroup_enable_task_cg_list() ->list_add(&tsk->cg_list, ..); In this case the list won't be deleted though the process has exited. We got two bug reports in the past, which seem to be the same bug as this one: http://lkml.org/lkml/2008/3/5/332 http://lkml.org/lkml/2007/10/17/224 Actually sometimes I got oops on list_del, sometimes oops on list_add. And I can change my test program a bit to trigger other oops. The patch has been tested both on x86_32 and x86_64. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Paul Menage <menage@google.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Fix locking bug in "acquire_console_semaphore_for_printk()"Linus Torvalds2008-04-151-2/+15
| | | | | | | | | | | | | | | | | | | When I cleaned up printk() and split up the printk locking logic in commit 266c2e0abeca649fa6667a1a427ad1da507c6375 ("Make printk() console semaphore accesses sensible") I had incorrectly moved the call to have_callable_console() outside of the console semaphore. That was buggy. The console semaphore protects the console_drivers list that is used by have_callable_console(). Thanks go to Bongani Hlope who saw this as a hang on shutdown and reboot and bisected the bug to the right commit, and tested this patch. See http://lkml.org/lkml/2008/4/11/315 Bisected-and-tested-by: Bongani Hlope <bonganilinux@mweb.co.za> Cc: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* revert "sched: fix fair sleepers"Ingo Molnar2008-04-141-4/+2
| | | | | | | | | | | | | revert "sched: fix fair sleepers" (e22ecef1d2658ba54ed7d3fdb5d60829fb434c23), because it is causing audio skipping, see: http://bugzilla.kernel.org/show_bug.cgi?id=10428 the patch is correct and the real cause of the skipping is not understood (tracing makes it go away), but time has run out so we'll revert it and re-try in 2.6.26. Signed-off-by: Ingo Molnar <mingo@elte.hu>
* cgroups: include hierarchy ids in /proc/<pid>/cgroupPaul Menage2008-04-111-0/+1
| | | | | | | | | | | | | | | | | | Extend the /proc/<pid>/cgroup file to include the appropriate hierarchy ID on each line. Currently this ID isn't really needed since a hierarchy can be completely identified by the set of subsystems bound to it, but this is likely to change in the near future in order to support stateless subsystems and merging/rebinding of subsystems. Getting this change into 2.6.25 reduces the need for an API change later. Signed-off-by: Paul Menage <menage@google.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Pavel Emelyanov <xemul@openvz.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>
* asmlinkage_protect replaces prevent_tail_callRoland McGrath2008-04-102-13/+13
| | | | | | | | | | | | | | | | | | | | | | The prevent_tail_call() macro works around the problem of the compiler clobbering argument words on the stack, which for asmlinkage functions is the caller's (user's) struct pt_regs. The tail/sibling-call optimization is not the only way that the compiler can decide to use stack argument words as scratch space, which we have to prevent. Other optimizations can do it too. Until we have new compiler support to make "asmlinkage" binding on the compiler's own use of the stack argument frame, we have work around all the manifestations of this issue that crop up. More cases seem to be prevented by also keeping the incoming argument variables live at the end of the function. This makes their original stack slots attractive places to leave those variables, so the compiler tends not clobber them for something else. It's still no guarantee, but it handles some observed cases that prevent_tail_call() did not. Signed-off-by: Roland McGrath <roland@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* cgroups: add cgroup support for enabling controllers at boot timePaul Menage2008-04-041-5/+37
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The effects of cgroup_disable=foo are: - foo isn't auto-mounted if you mount all cgroups in a single hierarchy - foo isn't visible as an individually mountable subsystem As a result there will only ever be one call to foo->create(), at init time; all processes will stay in this group, and the group will never be mounted on a visible hierarchy. Any additional effects (e.g. not allocating metadata) are up to the foo subsystem. This doesn't handle early_init subsystems (their "disabled" bit isn't set be, but it could easily be extended to do so if any of the early_init systems wanted it - I think it would just involve some nastier parameter processing since it would occur before the command-line argument parser had been run. Hugh said: Ballpark figures, I'm trying to get this question out rather than processing the exact numbers: CONFIG_CGROUP_MEM_RES_CTLR adds 15% overhead to the affected paths, booting with cgroup_disable=memory cuts that back to 1% overhead (due to slightly bigger struct page). I'm no expert on distros, they may have no interest whatever in CONFIG_CGROUP_MEM_RES_CTLR=y; and the rest of us can easily build with or without it, or apply the cgroup_disable=memory patches. Unix bench's execl test result on x86_64 was == just after boot without mounting any cgroup fs.== mem_cgorup=off : Execl Throughput 43.0 3150.1 732.6 mem_cgroup=on : Execl Throughput 43.0 2932.6 682.0 == [lizf@cn.fujitsu.com: fix boot option parsing] Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Paul Menage <menage@google.com> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hugh@veritas.com> Cc: Sudhir Kumar <skumar@linux.vnet.ibm.com> Cc: YAMAMOTO Takashi <yamamoto@valinux.co.jp> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* markers: use synchronize_sched()Mathieu Desnoyers2008-04-021-0/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Markers do not mix well with CONFIG_PREEMPT_RCU because it uses preempt_disable/enable() and not rcu_read_lock/unlock for minimal intrusiveness. We would need call_sched and sched_barrier primitives. Currently, the modification (connection and disconnection) of probes from markers requires changes to the data structure done in RCU-style : a new data structure is created, the pointer is changed atomically, a quiescent state is reached and then the old data structure is freed. The quiescent state is reached once all the currently running preempt_disable regions are done running. We use the call_rcu mechanism to execute kfree() after such quiescent state has been reached. However, the new CONFIG_PREEMPT_RCU version of call_rcu and rcu_barrier does not guarantee that all preempt_disable code regions have finished, hence the race. The "proper" way to do this is to use rcu_read_lock/unlock, but we don't want to use it to minimize intrusiveness on the traced system. (we do not want the marker code to call into much of the OS code, because it would quickly restrict what can and cannot be instrumented, such as the scheduler). The temporary fix, until we get call_rcu_sched and rcu_barrier_sched in mainline, is to use synchronize_sched before each call_rcu calls, so we wait for the quiescent state in the system call code path. It will slow down batch marker enable/disable, but will make sure the race is gone. Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* futex_compat __user annotationAl Viro2008-03-301-1/+1
| | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* NULL noise: fs/*, mm/*, kernel/*Al Viro2008-03-302-3/+3
| | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* audit: silence two kerneldoc warnings in kernel/audit.cDave Jones2008-03-281-3/+3
| | | | | | | | | | | | | | | Silence two kerneldoc warnings. Warning(kernel/audit.c:1276): No description found for parameter 'string' Warning(kernel/audit.c:1276): No description found for parameter 'len' [also fix a typo for bonus points] Signed-off-by: Dave Jones <davej@codemonkey.org.uk> Acked-by: Randy Dunlap <randy.dunlap@oracle.com> 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>
* memcgroup: fix spurious EBUSY on memory cgroup removalYAMAMOTO Takashi2008-03-281-1/+1
| | | | | | | | | | | | Call mm_free_cgroup earlier. Otherwise a reference due to lazy mm switching can prevent cgroup removal. Signed-off-by: YAMAMOTO Takashi <yamamoto@valinux.co.jp> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Paul Menage <menage@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Give futex init a proper nameBenjamin Herrenschmidt2008-03-271-2/+2
| | | | | | | | | | The futex init function is called init(). This is a pain in the neck when debugging when you code dies in ... init :-) This renames it to futex_init(). Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'master' of ↵Linus Torvalds2008-03-263-2/+53
|\ | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tglx/linux-2.6-hrt * 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/tglx/linux-2.6-hrt: NOHZ: reevaluate idle sleep length after add_timer_on() clocksource: revert: use init_timer_deferrable for clocksource_watchdog
| * NOHZ: reevaluate idle sleep length after add_timer_on()Thomas Gleixner2008-03-262-1/+52
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | add_timer_on() can add a timer on a CPU which is currently in a long idle sleep, but the timer wheel is not reevaluated by the nohz code on that CPU. So a timer can be delayed for quite a long time. This triggered a false positive in the clocksource watchdog code. To avoid this we need to wake up the idle CPU and enforce the reevaluation of the timer wheel for the next timer event. Add a function, which checks a given CPU for idle state, marks the idle task with NEED_RESCHED and sends a reschedule IPI to notify the other CPU of the change in the timer wheel. Call this function from add_timer_on(). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: stable@kernel.org -- include/linux/sched.h | 6 ++++++ kernel/sched.c | 43 +++++++++++++++++++++++++++++++++++++++++++ kernel/timer.c | 10 +++++++++- 3 files changed, 58 insertions(+), 1 deletion(-)
| * clocksource: revert: use init_timer_deferrable for clocksource_watchdogThomas Gleixner2008-03-251-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Revert commit 1077f5a917b7c630231037826b344b2f7f5b903f Author: Parag Warudkar <parag.warudkar@gmail.com> Date: Wed Jan 30 13:30:01 2008 +0100 clocksource.c: use init_timer_deferrable for clocksource_watchdog clocksource_watchdog can use a deferrable timer - reduces wakeups from idle per second. The watchdog timer needs to run with the specified interval. Otherwise it will miss the possible wrap of the watchdog clocksource. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@kernel.org
* | relay: set an spd_release() hook for spliceJens Axboe2008-03-261-0/+5
| | | | | | | | | | | | | | relay doesn't reference the pages it adds, however we need a non-NULL hook or splice_to_pipe() can oops. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* | set relay file can not be read by pread(2)Lai Jiangshan2008-03-261-1/+1
|/ | | | | | | | I found that relay files can be read by pread(2). I fix it, for relay files are not capable of seeking. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* Make printk() console semaphore accesses sensibleLinus Torvalds2008-03-241-35/+48
| | | | | | | | The printk() logic on when/how to get the console semaphore was unreadable, this splits the code up into a few helper functions and makes it easier to follow what is going on. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* bsd_acct: using task_struct->tgid is not right in pid-namespacesPavel Emelyanov2008-03-241-6/+15
| | | | | | | | | | | | | | | | In case we're accounting from a sub-namespace, the tgids reported will not refer to the right namespace. Save the pid_namespace we're accounting in on the acct_glbs and use it in do_acct_process. Two less :) places using the task_struct.tgid member. Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Cc: Oleg Nesterov <oleg@tv-sign.ru> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* bsd_acct: plain current->real_parent access is not always safePavel Emelyanov2008-03-241-1/+3
| | | | | | | | | | | | | | | This is minor, but dereferencing even current real_parent is not safe on debug kernels, since the memory, this points to, can be unmapped - RCU protection is required. Besides, the tgid field is deprecated and is to be replaced with task_tgid_xxx call (the 2nd patch), so RCU will be required anyway. Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Cc: Oleg Nesterov <oleg@tv-sign.ru> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* markers: remove ACCESS_ONCEMathieu Desnoyers2008-03-241-6/+6
| | | | | | | | | | | | | | | | As Paul pointed out, the ACCESS_ONCE are not needed because we already have the explicit surrounding memory barriers. Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Cc: Christoph Hellwig <hch@infradead.org> Cc: Mike Mason <mmlnx@us.ibm.com> Cc: Dipankar Sarma <dipankar@in.ibm.com> Cc: David Smith <dsmith@redhat.com> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Adrian Bunk <adrian.bunk@movial.fi> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* markers: update preempt_disable. call_rcu, rcu_barrier commentsMathieu Desnoyers2008-03-241-11/+8
| | | | | | | | | | | | | | | | | | Add comments requested by Andrew. Updated comments about synchronize_sched(). Since we use call_rcu and rcu_barrier now, these comments were out of sync with the code. Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Cc: Christoph Hellwig <hch@infradead.org> Cc: Mike Mason <mmlnx@us.ibm.com> Cc: Dipankar Sarma <dipankar@in.ibm.com> Cc: David Smith <dsmith@redhat.com> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Adrian Bunk <adrian.bunk@movial.fi> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Don't 'printk()' while holding xtime lock for writingLinus Torvalds2008-03-241-0/+4
| | | | | | | | | | | The printk() can deadlock because it can wake up klogd(), and task enqueueing will try to read the time in order to set a hrtimer. Reported-by: Marcin Slusarz <marcin.slusarz@gmail.com> Debugged-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* sched: add arch_update_cpu_topology hook.Heiko Carstens2008-03-211-0/+5
| | | | | | | | | Will be called each time the scheduling domains are rebuild. Needed for architectures that don't have a static cpu topology. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* sched: add exported arch_reinit_sched_domains() to header file.Heiko Carstens2008-03-211-1/+1
| | | | | | | | Needed so it can be called from outside of sched.c. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* sched: remove double unlikely from schedule()Roel Kluin2008-03-211-1/+1
| | | | | | | Combine two unlikely's Signed-off-by: Roel Kluin <12o3l@tiscali.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* sched: cleanup old and rarely used 'debug' features.Peter Zijlstra2008-03-212-20/+2
| | | | | | | | | TREE_AVG and APPROX_AVG are initial task placement policies that have been disabled for a long while.. time to remove them. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> CC: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6Linus Torvalds2008-03-211-3/+8
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (46 commits) [NET] ifb: set separate lockdep classes for queue locks [IPV6] KCONFIG: Fix description about IPV6_TUNNEL. [TCP]: Fix shrinking windows with window scaling netpoll: zap_completion_queue: adjust skb->users counter bridge: use time_before() in br_fdb_cleanup() [TG3]: Fix build warning on sparc32. MAINTAINERS: bluez-devel is subscribers-only audit: netlink socket can be auto-bound to pid other than current->pid (v2) [NET]: Fix permissions of /proc/net [SCTP]: Fix a race between module load and protosw access [NETFILTER]: ipt_recent: sanity check hit count [NETFILTER]: nf_conntrack_h323: logical-bitwise & confusion in process_setup() [RT2X00] drivers/net/wireless/rt2x00/rt2x00dev.c: remove dead code, fix warning [IPV4]: esp_output() misannotations [8021Q]: vlan_dev misannotations xfrm: ->eth_proto is __be16 [IPV4]: ipv4_is_lbcast() misannotations [SUNRPC]: net/* NULL noise [SCTP]: fix misannotated __sctp_rcv_asconf_lookup() [PKT_SCHED]: annotate cls_u32 ...
| * audit: netlink socket can be auto-bound to pid other than current->pid (v2)Pavel Emelyanov2008-03-201-3/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | From: Pavel Emelyanov <xemul@openvz.org> This patch is based on the one from Thomas. The kauditd_thread() calls the netlink_unicast() and passes the audit_pid to it. The audit_pid, in turn, is received from the user space and the tool (I've checked the audit v1.6.9) uses getpid() to pass one in the kernel. Besides, this tool doesn't bind the netlink socket to this id, but simply creates it allowing the kernel to auto-bind one. That's the preamble. The problem is that netlink_autobind() _does_not_ guarantees that the socket will be auto-bound to the current pid. Instead it uses the current pid as a hint to start looking for a free id. So, in case of conflict, the audit messages can be sent to a wrong socket. This can happen (it's unlikely, but can be) in case some task opens more than one netlink sockets and then the audit one starts - in this case the audit's pid can be busy and its socket will be bound to another id. The proposal is to introduce an audit_nlk_pid in audit subsys, that will point to the netlink socket to send packets to. It will most often be equal to audit_pid. The socket id can be got from the skb's netlink CB right in the audit_receive_msg. The audit_nlk_pid reset to 0 is not required, since all the decisions are taken based on audit_pid value only. Later, if the audit tools will bind the socket themselves, the kernel will have to provide a way to setup the audit_nlk_pid as well. A good side effect of this patch is that audit_pid can later be converted to struct pid, as it is not longer safe to use pid_t-s in the presence of pid namespaces. But audit code still uses the tgid from task_struct in the audit_signal_info and in the audit_filter_syscall. Signed-off-by: Thomas Graf <tgraf@suug.ch> Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Acked-by: Eric Paris <eparis@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | revert "clocksource: make clocksource watchdog cycle through online CPUs"Andrew Morton2008-03-191-10/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Revert commit 1ada5cba6a0318f90e45b38557e7b5206a9cba38 ("clocksource: make clocksource watchdog cycle through online CPUs") due to the regression reported by Gabriel C at http://lkml.org/lkml/2008/2/24/281 (short vesion: it makes TSC be marked as always unstable on his machine). Cc: Andi Kleen <ak@suse.de> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Robert Hancock <hancockr@shaw.ca> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Gabriel C <nix.or.die@googlemail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | sched: retune wake granularityIngo Molnar2008-03-191-2/+2
| | | | | | | | | | | | reduce wake-up granularity for better interactivity. Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | sched: wakeup-buddy tasks are cache-hotIngo Molnar2008-03-191-0/+6
| | | | | | | | | | | | | | | | Wakeup-buddy tasks are cache-hot - this makes it a bit harder for the load-balancer to tear them apart. (but it's still possible, if the load is sufficiently assymetric) Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | sched: improve affine wakeupsIngo Molnar2008-03-193-17/+47
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | improve affine wakeups. Maintain the 'overlap' metric based on CFS's sum_exec_runtime - which means the amount of time a task executes after it wakes up some other task. Use the 'overlap' for the wakeup decisions: if the 'overlap' is short, it means there's strong workload coupling between this task and the woken up task. If the 'overlap' is large then the workload is decoupled and the scheduler will move them to separate CPUs more easily. ( Also slightly move the preempt_check within try_to_wake_up() - this has no effect on functionality but allows 'early wakeups' (for still-on-rq tasks) to be correctly accounted as well.) Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | sched: clean up wakeup balancing, code flowIngo Molnar2008-03-191-15/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Clean up the code flow. No code changed: kernel/sched.o: text data bss dec hex filename 42521 2858 232 45611 b22b sched.o.before 42521 2858 232 45611 b22b sched.o.after md5: 09b31c44e9aff8666f72773dc433e2df sched.o.before.asm 09b31c44e9aff8666f72773dc433e2df sched.o.after.asm Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | sched: clean up wakeup balancing, rename variablesIngo Molnar2008-03-191-12/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | rename 'cpu' to 'prev_cpu'. No code changed: kernel/sched.o: text data bss dec hex filename 42521 2858 232 45611 b22b sched.o.before 42521 2858 232 45611 b22b sched.o.after md5: 09b31c44e9aff8666f72773dc433e2df sched.o.before.asm 09b31c44e9aff8666f72773dc433e2df sched.o.after.asm Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | sched: clean up wakeup balancing, move wake_affine()Ingo Molnar2008-03-191-59/+75
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | split out the affine-wakeup bits. No code changed: kernel/sched.o: text data bss dec hex filename 42521 2858 232 45611 b22b sched.o.before 42521 2858 232 45611 b22b sched.o.after md5: 9d76738f1272aa82f0b7affd2f51df6b sched.o.before.asm 09b31c44e9aff8666f72773dc433e2df sched.o.after.asm (the md5's changed because stack slots changed and some registers get scheduled by gcc in a different order - but otherwise the before and after assembly is instruction for instruction equivalent.) Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | relay: fix subbuf_splice_actor() adding too many pagesJens Axboe2008-03-171-2/+3
|/ | | | | | | | If subbuf_pages was larger than the max number of pages the pipe buffer will hold, subbuf_splice_actor() would happily go beyond the array size. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* sched: simplify sched_slice()Ingo Molnar2008-03-151-6/+2
| | | | | | | | | | | | | | | Use the existing calc_delta_mine() calculation for sched_slice(). This saves a divide and simplifies the code because we share it with the other /cfs_rq->load users. It also improves code size: text data bss dec hex filename 42659 2740 144 45543 b1e7 sched.o.before 42093 2740 144 44977 afb1 sched.o.after Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
* sched: fix fair sleepersIngo Molnar2008-03-151-2/+4
| | | | | | | | Fair sleepers need to scale their latency target down by runqueue weight. Otherwise busy systems will gain ever larger sleep bonus. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
* sched: fix overload performance: buddy wakeupsPeter Zijlstra2008-03-152-1/+27
| | | | | | | | | | | | | | | | | | Currently we schedule to the leftmost task in the runqueue. When the runtimes are very short because of some server/client ping-pong, especially in over-saturated workloads, this will cycle through all tasks trashing the cache. Reduce cache trashing by keeping dependent tasks together by running newly woken tasks first. However, by not running the leftmost task first we could starve tasks because the wakee can gain unlimited runtime. Therefore we only run the wakee if its within a small (wakeup_granularity) window of the leftmost task. This preserves fairness, but does alternate server/client task groups. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* sched: fix calc_delta_mine()Ingo Molnar2008-03-151-1/+1
| | | | | | | lw->weight can be 0 for a short time during bootup. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
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