linux.git/kernel/hrtimer.c, branch v2.6.26-rc2

hrtimer: remove duplicate helper function

2008-05-03T16:11:48+00:00

The helper function hrtimer_callback_running() is used in
kernel/hrtimer.c as well as in the updated net/can/bcm.c which now
supports hrtimers. Moving the helper function to hrtimer.h removes the
duplicate definition in the C-files.

Signed-off-by: Oliver Hartkopp 
Cc: David Miller 
Signed-off-by: Thomas Gleixner

add hrtimer specific debugobjects code

2008-04-30T15:29:53+00:00

hrtimers have now dynamic users in the network code.  Put them under
debugobjects surveillance as well.

Add calls to the generic object debugging infrastructure and provide fixup
functions which allow to keep the system alive when recoverable problems have
been detected by the object debugging core code.

Signed-off-by: Thomas Gleixner 
Cc: Greg KH 
Cc: Randy Dunlap 
Cc: Kay Sievers 
Cc: Ingo Molnar 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

hrtimer: raise softirq unlocked to avoid circular lock dependency

2008-04-28T20:22:21+00:00

The scheduler hrtimer bits in 2.6.25 introduced a circular lock
dependency in a rare code path:

=======================================================
[ INFO: possible circular locking dependency detected ]
2.6.25-sched-devel.git-x86-latest.git #19
-------------------------------------------------------
X/2980 is trying to acquire lock:
 (&rq->rq_lock_key#2){++..}, at: [] task_rq_lock+0x56/0xa0

but task is already holding lock:
 (&cpu_base->lock){++..}, at: [] lock_hrtimer_base+0x31/0x60

which lock already depends on the new lock.

The scenario which leads to this is:

posix-timer signal is delivered
 -> posix-timer is rearmed
    timer is already expired in hrtimer_enqueue()
     -> softirq is raised

To prevent this we need to move the raise of the softirq out of the
base->lock protected code path.

Signed-off-by: Thomas Gleixner 
Cc: stable@kernel.org
Acked-by: Peter Zijlstra

hrtimer: timeout too long when using HRTIMER_CB_SOFTIRQ

2008-04-27T16:26:43+00:00

When using hrtimer with timer->cb_mode == HRTIMER_CB_SOFTIRQ
in some cases the clockevent is not programmed.
This happens, if:
 - a timer is rearmed while it's state is HRTIMER_STATE_CALLBACK
 - hrtimer_reprogram() returns -ETIME, when it is called after
   CALLBACK is finished. This occurs if the new timer->expires
   is in the past when CALLBACK is done.
In this case, the timer needs to be removed from the tree and put
onto the pending list again.

The patch is against 2.6.22.5, but AFAICS, it is relevant
for 2.6.25 also (in run_hrtimer_pending()).

Signed-off-by: Bodo Stroesser 
Cc: stable@kernel.org
Signed-off-by: Thomas Gleixner

hrtimer: optimize the softirq time optimization

2008-04-21T05:59:51+00:00

The previous optimization did not take the case into account where a
clock provides its own softirq_get_time() function.

Check for the availablitiy of the clock get time function first and
then check if we need to retrieve the time for both clocks via
hrtimer_softirq_gettime() to avoid a double evaluation of time in that
case as well.

Signed-off-by: Thomas Gleixner

hrtimer: reduce calls to hrtimer_get_softirq_time()

2008-04-21T05:59:51+00:00

It seems that hrtimer_run_queues() is calling hrtimer_get_softirq_time() more
often than it needs to.  This can cause frequent contention on systems with
large numbers of processors/cores.

With this patch, hrtimer_run_queues only calls hrtimer_get_softirq_time() if
there is a pending timer in one of the hrtimer bases, and only once.

This also combines hrtimer_run_queues() and the inline run_hrtimer_queue()
into one function.

[ tglx@linutronix.de: coding style ]

Signed-off-by: Dimitri Sivanich 
Cc: Peter Zijlstra 
Cc: Ingo Molnar 
Signed-off-by: Andrew Morton 
Signed-off-by: Thomas Gleixner

hrtimers: simplify lockdep handling

2008-04-17T10:22:31+00:00

In order to avoid the false positive from lockdep, each per-cpu base->lock has
the separate lock class and migrate_hrtimers() uses double_spin_lock().

This is overcomplicated: except for migrate_hrtimers() we never take 2 locks
at once, and migrate_hrtimers() can use spin_lock_nested().

Signed-off-by: Oleg Nesterov 
Cc: Arjan van de Ven 
Cc: Heiko Carstens 
Cc: Ingo Molnar 
Cc: Peter Zijlstra 
Signed-off-by: Andrew Morton 
Signed-off-by: Thomas Gleixner

hrtimer: use nanosleep specific restart_block fields

2008-04-17T10:22:30+00:00

Convert all the nanosleep related users of restart_block to the
new nanosleep specific restart_block fields.

Signed-off-by: Thomas Gleixner

hrtimer: catch expired CLOCK_REALTIME timers early

2008-02-14T21:08:30+00:00

A CLOCK_REALTIME timer, which has an absolute expiry time less than
the clock realtime offset calls with a negative delta into the clock
events code and triggers the WARN_ON() there.

This is a false positive and needs to be prevented. Check the result
of timer->expires - timer->base->offset right away and return -ETIME
right away.

Thanks to Frans Pop, who reported the problem and tested the fixes.

Signed-off-by: Thomas Gleixner 
Tested-by: Frans Pop

hrtimer: check relative timeouts for overflow

2008-02-14T21:08:30+00:00

Various user space callers ask for relative timeouts. While we fixed
that overflow issue in hrtimer_start(), the sites which convert
relative user space values to absolute timeouts themself were uncovered.

Instead of putting overflow checks into each place add a function
which does the sanity checking and convert all affected callers to use
it.

Thanks to Frans Pop, who reported the problem and tested the fixes.

Signed-off-by: Thomas Gleixner 
Acked-by: Ingo Molnar 
Tested-by: Frans Pop