linux/kernel/time/alarmtimer.c, branch v3.2-rc2

alarmtimers: Fix error handling

2011-09-14T08:54:29Z

commit 8bc0daf (alarmtimers: Rework RTC device selection using class interface) did not implement required error checks. Add them. Signed-off-by: Thomas Gleixner

alarmtimers: Rework RTC device selection using class interface

2011-08-10T21:55:30Z

This allows cleaner detection of the RTC device being registered, rather then probing any time someone calls alarmtimer_get_rtcdev. CC: Thomas Gleixner Signed-off-by: John Stultz

alarmtimers: Add try_to_cancel functionality

2011-08-10T21:55:29Z

There's a number of edge cases when cancelling a alarm, so to be sure we accurately do so, introduce try_to_cancel, which returns proper failure errors if it cannot. Also modify cancel to spin until the alarm is properly disabled. CC: Thomas Gleixner Signed-off-by: John Stultz

alarmtimers: Add more refined alarm state tracking

2011-08-10T21:55:27Z

In order to allow for functionality like try_to_cancel, add more refined state tracking (similar to hrtimers). CC: Thomas Gleixner Signed-off-by: John Stultz

alarmtimers: Remove period from alarm structure

2011-08-10T21:55:26Z

Now that periodic alarmtimers are managed by the handler function, remove the period value from the alarm structure and let the handlers manage the interval on their own. CC: Thomas Gleixner Signed-off-by: John Stultz

alarmtimers: Remove interval cap limit hack

2011-08-10T21:55:24Z

Now that the alarmtimers code has been refactored, the interval cap limit can be removed. CC: Thomas Gleixner Signed-off-by: John Stultz

alarmtimers: Add alarm_forward functionality

2011-08-10T21:55:23Z

In order to avoid wasting time expiring and re-adding very high freq periodic alarmtimers, introduce alarm_forward() which is similar to hrtimer_forward and moves the timer to the next future expiration time and returns the number of overruns. CC: Thomas Gleixner Signed-off-by: John Stultz

alarmtimers: Push rearming peroidic timers down into alamrtimer handler

2011-08-10T21:55:22Z

This patch pushes the periodic alarmtimer re-arming down into the alarmtimer handler, mimicking how hrtimers handle this. CC: Thomas Gleixner Signed-off-by: John Stultz

alarmtimers: Change alarmtimer functions to return alarmtimer_restart values

2011-08-10T21:55:20Z

In order to properly fix the denial of service issue with high freq periodic alarm timers, we need to push the re-arming logic into the alarm timer handler, much as the hrtimer code does. This patch introduces alarmtimer_restart enum and changes the alarmtimer handler declarations to use it as a return value. Further, to ease following changes, it extends the alarmtimer handler functions to also take the time at expiration. No logic is yet modified. CC: Thomas Gleixner Signed-off-by: John Stultz

alarmtimers: Avoid possible denial of service with high freq periodic timers

2011-08-10T17:26:09Z

Its possible to jam up the alarm timers by setting very small interval timers, which will cause the alarmtimer subsystem to spend all of its time firing and restarting timers. This can effectivly lock up a box. A deeper fix is needed, closely mimicking the hrtimer code, but for now just cap the interval to 100us to avoid userland hanging the system. CC: Thomas Gleixner CC: stable@kernel.org Signed-off-by: John Stultz