user/sven/linux.git/kernel/timer.c, branch v3.0-rc2

Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

2011-03-16T01:53:35Z

* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (62 commits) posix-clocks: Check write permissions in posix syscalls hrtimer: Remove empty hrtimer_init_hres_timer() hrtimer: Update hrtimer->state documentation hrtimer: Update base[CLOCK_BOOTTIME].offset correctly timers: Export CLOCK_BOOTTIME via the posix timers interface timers: Add CLOCK_BOOTTIME hrtimer base time: Extend get_xtime_and_monotonic_offset() to also return sleep time: Introduce get_monotonic_boottime and ktime_get_boottime hrtimers: extend hrtimer base code to handle more then 2 clockids ntp: Remove redundant and incorrect parameter check mn10300: Switch do_timer() to xtimer_update() posix clocks: Introduce dynamic clocks posix-timers: Cleanup namespace posix-timers: Add support for fd based clocks x86: Add clock_adjtime for x86 posix-timers: Introduce a syscall for clock tuning. time: Splitout compat timex accessors ntp: Add ADJ_SETOFFSET mode bit time: Introduce timekeeping_inject_offset posix-timer: Update comment ... Fix up new system-call-related conflicts in arch/x86/ia32/ia32entry.S arch/x86/include/asm/unistd_32.h arch/x86/include/asm/unistd_64.h arch/x86/kernel/syscall_table_32.S (name_to_handle_at()/open_by_handle_at() vs clock_adjtime()), and some due to movement of get_jiffies_64() in: kernel/time.c

Merge branch 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

2011-03-16T01:28:30Z

* 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: rtmutex: tester: Remove the remaining BKL leftovers lockdep/timers: Explain in detail the locking problems del_timer_sync() may cause rtmutex: Simplify PI algorithm and make highest prio task get lock rwsem: Remove redundant asmregparm annotation rwsem: Move duplicate function prototypes to linux/rwsem.h rwsem: Unify the duplicate rwsem_is_locked() inlines rwsem: Move duplicate init macros and functions to linux/rwsem.h rwsem: Move duplicate struct rwsem declaration to linux/rwsem.h x86: Cleanup rwsem_count_t typedef rwsem: Cleanup includes locking: Remove deprecated lock initializers cred: Replace deprecated spinlock initialization kthread: Replace deprecated spinlock initialization xtensa: Replace deprecated spinlock initialization um: Replace deprecated spinlock initialization sparc: Replace deprecated spinlock initialization mips: Replace deprecated spinlock initialization cris: Replace deprecated spinlock initialization alpha: Replace deprecated spinlock initialization rtmutex-tester: Remove BKL tests

debugobjects: Add hint for better object identification

2011-03-08T15:10:38Z

In complex subsystems like mac80211 structures can contain several timers and work structs, so identifying a specific instance from the call trace and object type output of debugobjects can be hard. Allow the subsystems which support debugobjects to provide a hint function. This function returns a pointer to a kernel address (preferrably the objects callback function) which is printed along with the debugobjects type. Add hint methods for timer_list, work_struct and hrtimer. [ tglx: Massaged changelog, made it compile ] Signed-off-by: Stanislaw Gruszka LKML-Reference: <20110307085809.GA9334@redhat.com> Signed-off-by: Thomas Gleixner

lockdep/timers: Explain in detail the locking problems del_timer_sync() may cause

2011-02-16T12:35:08Z

Twice I had to explain the output about why lockdep gives an error with locks in IRQ context and with del_timer_sync(). Might as well write it up and place it in the comments above the code in del_timer_sync(). Perhaps the next time this lockdep dump triggers people will understand the issues. It is a ticky issue and very subtle, explaining it in detail in the code may help others understand the issue when they stumble upon the bug again. Signed-off-by: Steven Rostedt Signed-off-by: Peter Zijlstra LKML-Reference: <1297186794.23343.19.camel@gandalf.stny.rr.com> Signed-off-by: Ingo Molnar

Revert "lockdep, timer: Fix del_timer_sync() annotation"

2011-02-08T15:18:39Z

Both attempts at trying to allow softirq usage for del_timer_sync() failed (produced bogus warnings), so revert the commit for this release: f266a5110d45: lockdep, timer: Fix del_timer_sync() annotation and try again later. Reported-by: Borislav Petkov Signed-off-by: Peter Zijlstra Cc: Linus Torvalds Cc: Yong Zhang Cc: Thomas Gleixner LKML-Reference: <1297174680.13327.107.camel@laptop> Signed-off-by: Ingo Molnar

lockdep, timer: Fix del_timer_sync() annotation

2011-02-04T09:31:22Z

Calling local_bh_enable() will want to actually start processing softirqs, which isn't a good idea since this can get called with IRQs disabled. Cure this by using _local_bh_enable() which doesn't start processing softirqs, and use raw_local_irq_save() to avoid any softirqs from happening without letting lockdep think IRQs are in fact disabled. Reported-by: Nick Bowler Signed-off-by: Peter Zijlstra Reviewed-by: Yong Zhang LKML-Reference: <20110203141548.039540914@chello.nl> Signed-off-by: Thomas Gleixner

time: Move do_timer() to kernel/time/timekeeping.c

2011-01-31T13:55:41Z

do_timer() is primary timekeeping related. calc_global_load() is called from do_timer() as well, but that's more for historical reasons. [ tglx: Fixed up the calc_global_load() reject andmassaged changelog ] Signed-off-by: Torben Hohn Cc: Peter Zijlstra Cc: johnstul@us.ibm.com Cc: yong.zhang0@gmail.com Cc: hch@infradead.org LKML-Reference: <20110127145855.23248.56933.stgit@localhost> Signed-off-by: Thomas Gleixner

Merge branch 'timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

2011-01-06T18:42:43Z

* 'timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: MAINTAINERS: Update timer related entries timers: Use this_cpu_read timerqueue: Make timerqueue_getnext() static inline hrtimer: fix timerqueue conversion flub hrtimers: Convert hrtimers to use timerlist infrastructure timers: Fixup allmodconfig build issue timers: Rename timerlist infrastructure to timerqueue timers: Introduce timerlist infrastructure. hrtimer: Remove stale comment on curr_timer timer: Warn when del_timer_sync() is called in hardirq context timer: Del_timer_sync() can be used in softirq context timer: Make try_to_del_timer_sync() the same on SMP and UP posix-timers: Annotate lock_timer() timer: Permit statically-declared work with deferrable timers time: Use ARRAY_SIZE macro in timecompare.c timer: Initialize the field slack of timer_list timer_list: Remove alignment padding on 64 bit when CONFIG_TIMER_STATS time: Compensate for rounding on odd-frequency clocksources Fix up trivial conflict in MAINTAINERS

timers: Use this_cpu_read

2010-12-12T17:38:09Z

Eric asked for this. [tglx: Because it generates faster code according to Erics ] Signed-off-by: Christoph Lameter Cc: Pekka Enberg Cc: Eric Dumazet Cc: Mathieu Desnoyers Cc: Tejun Heo Cc: linux-mm@kvack.org LKML-Reference: Signed-off-by: Thomas Gleixner

nohz: Fix get_next_timer_interrupt() vs cpu hotplug

2010-12-08T19:15:07Z

This fixes a bug as seen on 2.6.32 based kernels where timers got enqueued on offline cpus. If a cpu goes offline it might still have pending timers. These will be migrated during CPU_DEAD handling after the cpu is offline. However while the cpu is going offline it will schedule the idle task which will then call tick_nohz_stop_sched_tick(). That function in turn will call get_next_timer_intterupt() to figure out if the tick of the cpu can be stopped or not. If it turns out that the next tick is just one jiffy off (delta_jiffies == 1) tick_nohz_stop_sched_tick() incorrectly assumes that the tick should not stop and takes an early exit and thus it won't update the load balancer cpu. Just afterwards the cpu will be killed and the load balancer cpu could be the offline cpu. On 2.6.32 based kernel get_nohz_load_balancer() gets called to decide on which cpu a timer should be enqueued (see __mod_timer()). Which leads to the possibility that timers get enqueued on an offline cpu. These will never expire and can cause a system hang. This has been observed 2.6.32 kernels. On current kernels __mod_timer() uses get_nohz_timer_target() which doesn't have that problem. However there might be other problems because of the too early exit tick_nohz_stop_sched_tick() in case a cpu goes offline. The easiest and probably safest fix seems to be to let get_next_timer_interrupt() just lie and let it say there isn't any pending timer if the current cpu is offline. I also thought of moving migrate_[hr]timers() from CPU_DEAD to CPU_DYING, but seeing that there already have been fixes at least in the hrtimer code in this area I'm afraid that this could add new subtle bugs. Signed-off-by: Heiko Carstens Signed-off-by: Peter Zijlstra LKML-Reference: <20101201091109.GA8984@osiris.boeblingen.de.ibm.com> Cc: stable@kernel.org Signed-off-by: Ingo Molnar