user/sven/linux.git/kernel/time, branch v2.6.25.2

clocksource: revert: use init_timer_deferrable for clocksource_watchdog

2008-03-25T19:13:25Z

Revert commit 1077f5a917b7c630231037826b344b2f7f5b903f Author: Parag Warudkar 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 Cc: stable@kernel.org

Don't 'printk()' while holding xtime lock for writing

2008-03-24T18:07:15Z

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 Debugged-by: Peter Zijlstra Cc: Ingo Molnar Cc: Thomas Gleixner Signed-off-by: Linus Torvalds

revert "clocksource: make clocksource watchdog cycle through online CPUs"

2008-03-20T01:53:37Z

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 Acked-by: Ingo Molnar Cc: Thomas Gleixner Cc: Robert Hancock Acked-by: Linus Torvalds Cc: "Rafael J. Wysocki" Cc: Gabriel C Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

time: remove obsolete CLOCK_TICK_ADJUST

2008-03-09T07:42:57Z

The first version of the ntp_interval/tick_length inconsistent usage patch was recently merged as bbe4d18ac2e058c56adb0cd71f49d9ed3216a405 http://git.kernel.org/gitweb.cgi?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=bbe4d18ac2e058c56adb0cd71f49d9ed3216a405 While the fix did greatly improve the situation, it was correctly pointed out by Roman that it does have a small bug: If the users change clocksources after the system has been running and NTP has made corrections, the correctoins made against the old clocksource will be applied against the new clocksource, causing error. The second attempt, which corrects the issue in the NTP_INTERVAL_LENGTH definition has also made it up-stream as commit e13a2e61dd5152f5499d2003470acf9c838eab84 http://git.kernel.org/gitweb.cgi?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=e13a2e61dd5152f5499d2003470acf9c838eab84 Roman has correctly pointed out that CLOCK_TICK_ADJUST is calculated based on the PIT's frequency, and isn't really relevant to non-PIT driven clocksources (that is, clocksources other then jiffies and pit). This patch reverts both of those changes, and simply removes CLOCK_TICK_ADJUST. This does remove the granularity error correction for users of PIT and Jiffies clocksource users, but the granularity error but for the majority of users, it should be within the 500ppm range NTP can accommodate for. For systems that have granularity errors greater then 500ppm, the "ntp_tick_adj=" boot option can be used to compensate. [johnstul@us.ibm.com: provided changelog] [mattilinnanvuori@yahoo.com: maek ntp_tick_adj static] Signed-off-by: Roman Zippel Acked-by: john stultz Signed-off-by: Matti Linnanvuori Signed-off-by: Andrew Morton Cc: mingo@elte.hu Signed-off-by: Thomas Gleixner

time: don't touch an offlined CPU's ts->tick_stopped in tick_cancel_sched_timer()

2008-03-09T07:42:57Z

Silences WARN_ONs in rcu_enter_nohz() and rcu_exit_nohz(), which appeared before caused by (repeated) calls to: $ echo 0 > /sys/devices/system/cpu/cpu1/online $ echo 1 > /sys/devices/system/cpu/cpu1/online Signed-off-by: Karsten Wiese Cc: johnstul@us.ibm.com Cc: Rafael Wysocki Cc: Steven Rostedt Cc: Ingo Molnar Acked-by: Paul E. McKenney Signed-off-by: Andrew Morton Signed-off-by: Thomas Gleixner

ntp: use unsigned input for do_div()

2008-03-09T07:42:57Z

The kernel NTP code shouldn't hand 64-bit *signed* values to do_div(). Make it instead hand 64-bit unsigned values. This gets rid of a couple of warnings. Signed-off-by: David Howells Cc: Roman Zippel Cc: Ingo Molnar Cc: john stultz Signed-off-by: Andrew Morton Signed-off-by: Thomas Gleixner

rcu: add support for dynamic ticks and preempt rcu

2008-02-29T17:46:50Z

The PREEMPT-RCU can get stuck if a CPU goes idle and NO_HZ is set. The idle CPU will not progress the RCU through its grace period and a synchronize_rcu my get stuck. Without this patch I have a box that will not boot when PREEMPT_RCU and NO_HZ are set. That same box boots fine with this patch. This patch comes from the -rt kernel where it has been tested for several months. Signed-off-by: Steven Rostedt Signed-off-by: Paul E. McKenney Signed-off-by: Ingo Molnar

timer_list: print relative expiry time signed

2008-02-17T16:29:38Z

Relative expiry time can get negative, so it should be signed. Signed-off-by: Pavel Machek Signed-off-by: Thomas Gleixner

ntp: correct inconsistent interval/tick_length usage

2008-02-10T09:48:03Z

clocksource initialization and error accumulation. This corrects a 280ppm drift seen on some systems using acpi_pm, and affects other clocksources as well (likely to a lesser degree). Signed-off-by: John Stultz Cc: Roman Zippel Cc: Steven Rostedt Signed-off-by: Andrew Morton Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner

time: fix typo in comments

2008-02-08T17:22:29Z

Fix typo in comments. BTW: I have to fix coding style in arch/ia64/kernel/time.c also, otherwise checkpatch.pl will be complaining. Signed-off-by: Li Zefan Cc: Thomas Gleixner Cc: Ingo Molnar Cc: john stultz Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds