user/sven/linux.git/kernel/time, branch v3.2.45

clockevents: Set dummy handler on CPU_DEAD shutdown

2013-05-13T14:02:26Z

commit 6f7a05d7018de222e40ca003721037a530979974 upstream. Vitaliy reported that a per cpu HPET timer interrupt crashes the system during hibernation. What happens is that the per cpu HPET timer gets shut down when the nonboot cpus are stopped. When the nonboot cpus are onlined again the HPET code sets up the MSI interrupt which fires before the clock event device is registered. The event handler is still set to hrtimer_interrupt, which then crashes the machine due to highres mode not being active. See http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=700333 There is no real good way to avoid that in the HPET code. The HPET code alrady has a mechanism to detect spurious interrupts when event handler == NULL for a similar reason. We can handle that in the clockevent/tick layer and replace the previous functional handler with a dummy handler like we do in tick_setup_new_device(). The original clockevents code did this in clockevents_exchange_device(), but that got removed by commit 7c1e76897 (clockevents: prevent clockevent event_handler ending up handler_noop) which forgot to fix it up in tick_shutdown(). Same issue with the broadcast device. Reported-by: Vitaliy Fillipov Cc: Ben Hutchings Cc: 700333@bugs.debian.org Signed-off-by: Thomas Gleixner Signed-off-by: Ben Hutchings

clockevents: Don't allow dummy broadcast timers

2013-04-10T02:19:54Z

commit a7dc19b8652c862d5b7c4d2339bd3c428bd29c4a upstream. Currently tick_check_broadcast_device doesn't reject clock_event_devices with CLOCK_EVT_FEAT_DUMMY, and may select them in preference to real hardware if they have a higher rating value. In this situation, the dummy timer is responsible for broadcasting to itself, and the core clockevents code may attempt to call non-existent callbacks for programming the dummy, eventually leading to a panic. This patch makes tick_check_broadcast_device always reject dummy timers, preventing this problem. Signed-off-by: Mark Rutland Cc: linux-arm-kernel@lists.infradead.org Cc: Jon Medhurst (Tixy) Signed-off-by: Thomas Gleixner Signed-off-by: Ben Hutchings

timekeeping: Cast raw_interval to u64 to avoid shift overflow

2012-10-30T23:26:40Z

commit 5b3900cd409466c0070b234d941650685ad0c791 upstream. We fixed a bunch of integer overflows in timekeeping code during the 3.6 cycle. I did an audit based on that and found this potential overflow. Signed-off-by: Dan Carpenter Acked-by: John Stultz Link: http://lkml.kernel.org/r/20121009071823.GA19159@elgon.mountain Signed-off-by: Thomas Gleixner [bwh: Backported to 3.2: adjust context; use timekeeper.raw_interval] Signed-off-by: Ben Hutchings

time: Move ktime_t overflow checking into timespec_valid_strict

2012-09-19T14:05:00Z

This is a -stable backport of cee58483cf56e0ba355fdd97ff5e8925329aa936 Andreas Bombe reported that the added ktime_t overflow checking added to timespec_valid in commit 4e8b14526ca7 ("time: Improve sanity checking of timekeeping inputs") was causing problems with X.org because it caused timeouts larger then KTIME_T to be invalid. Previously, these large timeouts would be clamped to KTIME_MAX and would never expire, which is valid. This patch splits the ktime_t overflow checking into a new timespec_valid_strict function, and converts the timekeeping codes internal checking to use this more strict function. Reported-and-tested-by: Andreas Bombe Cc: Zhouping Liu Cc: Ingo Molnar Cc: Prarit Bhargava Cc: Thomas Gleixner Signed-off-by: John Stultz Signed-off-by: Linus Torvalds Cc: Linux Kernel Signed-off-by: John Stultz

time: Avoid making adjustments if we haven't accumulated anything

2012-09-19T14:05:00Z

This is a -stable backport of bf2ac312195155511a0f79325515cbb61929898a If update_wall_time() is called and the current offset isn't large enough to accumulate, avoid re-calling timekeeping_adjust which may change the clock freq and can cause 1ns inconsistencies with CLOCK_REALTIME_COARSE/CLOCK_MONOTONIC_COARSE. Signed-off-by: John Stultz Cc: Prarit Bhargava Cc: Ingo Molnar Link: http://lkml.kernel.org/r/1345595449-34965-5-git-send-email-john.stultz@linaro.org Signed-off-by: Thomas Gleixner Cc: Linux Kernel Signed-off-by: John Stultz

time: Improve sanity checking of timekeeping inputs

2012-09-19T14:04:59Z

This is a -stable backport of 4e8b14526ca7fb046a81c94002c1c43b6fdf0e9b Unexpected behavior could occur if the time is set to a value large enough to overflow a 64bit ktime_t (which is something larger then the year 2262). Also unexpected behavior could occur if large negative offsets are injected via adjtimex. So this patch improves the sanity check timekeeping inputs by improving the timespec_valid() check, and then makes better use of timespec_valid() to make sure we don't set the time to an invalid negative value or one that overflows ktime_t. Note: This does not protect from setting the time close to overflowing ktime_t and then letting natural accumulation cause the overflow. Reported-by: CAI Qian Reported-by: Sasha Levin Signed-off-by: John Stultz Cc: Peter Zijlstra Cc: Prarit Bhargava Cc: Zhouping Liu Cc: Ingo Molnar Link: http://lkml.kernel.org/r/1344454580-17031-1-git-send-email-john.stultz@linaro.org Signed-off-by: Thomas Gleixner Cc: Linux Kernel Signed-off-by: John Stultz

sched/nohz: Fix rq->cpu_load calculations some more

2012-08-02T13:37:38Z

commit 5aaa0b7a2ed5b12692c9ffb5222182bd558d3146 upstream. Follow up on commit 556061b00 ("sched/nohz: Fix rq->cpu_load[] calculations") since while that fixed the busy case it regressed the mostly idle case. Add a callback from the nohz exit to also age the rq->cpu_load[] array. This closes the hole where either there was no nohz load balance pass during the nohz, or there was a 'significant' amount of idle time between the last nohz balance and the nohz exit. So we'll update unconditionally from the tick to not insert any accidental 0 load periods while busy, and we try and catch up from nohz idle balance and nohz exit. Both these are still prone to missing a jiffy, but that has always been the case. Signed-off-by: Peter Zijlstra Cc: pjt@google.com Cc: Venkatesh Pallipadi Link: http://lkml.kernel.org/n/tip-kt0trz0apodbf84ucjfdbr1a@git.kernel.org Signed-off-by: Ingo Molnar [bwh: Backported to 3.2: adjust filenames and context] Signed-off-by: Ben Hutchings

timekeeping: Add missing update call in timekeeping_resume()

2012-07-25T03:11:37Z

This is a backport of 3e997130bd2e8c6f5aaa49d6e3161d4d29b43ab0 The leap second rework unearthed another issue of inconsistent data. On timekeeping_resume() the timekeeper data is updated, but nothing calls timekeeping_update(), so now the update code in the timer interrupt sees stale values. This has been the case before those changes, but then the timer interrupt was using stale data as well so this went unnoticed for quite some time. Add the missing update call, so all the data is consistent everywhere. Reported-by: Andreas Schwab Reported-and-tested-by: "Rafael J. Wysocki" Reported-and-tested-by: Martin Steigerwald Cc: LKML Cc: Linux PM list Cc: John Stultz Cc: Ingo Molnar Cc: Peter Zijlstra , Cc: Prarit Bhargava Signed-off-by: Thomas Gleixner Signed-off-by: John Stultz Signed-off-by: Linus Torvalds [John Stultz: Backported to 3.2] Cc: Prarit Bhargava Cc: Thomas Gleixner Cc: Linux Kernel Signed-off-by: John Stultz Signed-off-by: Ben Hutchings

timekeeping: Provide hrtimer update function

2012-07-25T03:11:36Z

This is a backport of f6c06abfb3972ad4914cef57d8348fcb2932bc3b To finally fix the infamous leap second issue and other race windows caused by functions which change the offsets between the various time bases (CLOCK_MONOTONIC, CLOCK_REALTIME and CLOCK_BOOTTIME) we need a function which atomically gets the current monotonic time and updates the offsets of CLOCK_REALTIME and CLOCK_BOOTTIME with minimalistic overhead. The previous patch which provides ktime_t offsets allows us to make this function almost as cheap as ktime_get() which is going to be replaced in hrtimer_interrupt(). Signed-off-by: Thomas Gleixner Reviewed-by: Ingo Molnar Acked-by: Peter Zijlstra Acked-by: Prarit Bhargava Signed-off-by: John Stultz Link: http://lkml.kernel.org/r/1341960205-56738-7-git-send-email-johnstul@us.ibm.com Signed-off-by: Thomas Gleixner [John Stultz: Backported to 3.2] Cc: Prarit Bhargava Cc: Thomas Gleixner Cc: Linux Kernel Signed-off-by: John Stultz Signed-off-by: Ben Hutchings

timekeeping: Maintain ktime_t based offsets for hrtimers

2012-07-25T03:11:35Z

This is a backport of 5b9fe759a678e05be4937ddf03d50e950207c1c0 We need to update the hrtimer clock offsets from the hrtimer interrupt context. To avoid conversions from timespec to ktime_t maintain a ktime_t based representation of those offsets in the timekeeper. This puts the conversion overhead into the code which updates the underlying offsets and provides fast accessible values in the hrtimer interrupt. Signed-off-by: Thomas Gleixner Signed-off-by: John Stultz Reviewed-by: Ingo Molnar Acked-by: Peter Zijlstra Acked-by: Prarit Bhargava Link: http://lkml.kernel.org/r/1341960205-56738-4-git-send-email-johnstul@us.ibm.com Signed-off-by: Thomas Gleixner [John Stultz: Backported to 3.2] Cc: Prarit Bhargava Cc: Thomas Gleixner Cc: Linux Kernel Signed-off-by: John Stultz Signed-off-by: Ben Hutchings