linux-toradex.git/include/linux/hrtimer.h, branch v2.6.25-rc2

hrtimer: fix *rmtp handling in hrtimer_nanosleep()

2008-02-10T09:48:03+00:00

Spotted by Pavel Emelyanov and Alexey Dobriyan.

hrtimer_nanosleep() sets restart_block->arg1 = rmtp, but this rmtp points to
the local variable which lives in the caller's stack frame. This means that
if sys_restart_syscall() actually happens and it is interrupted as well, we
don't update the user-space variable, but write into the already dead stack
frame.

Introduced by commit 04c227140fed77587432667a574b14736a06dd7f
hrtimer: Rework hrtimer_nanosleep to make sys_compat_nanosleep easier

Change the callers to pass "__user *rmtp" to hrtimer_nanosleep(), and change
hrtimer_nanosleep() to use copy_to_user() to actually update *rmtp.

Small problem remains. man 2 nanosleep states that *rtmp should be written if
nanosleep() was interrupted (it says nothing whether it is OK to update *rmtp
if nanosleep returns 0), but (with or without this patch) we can dirty *rem
even if nanosleep() returns 0.

NOTE: this patch doesn't change compat_sys_nanosleep(), because it has other
bugs. Fixed by the next patch.

Signed-off-by: Oleg Nesterov 
Cc: Alexey Dobriyan 
Cc: Michael Kerrisk 
Cc: Pavel Emelyanov 
Cc: Peter Zijlstra 
Cc: Toyo Abe 
Cc: Andrew Morton 
Signed-off-by: Thomas Gleixner 

 include/linux/hrtimer.h |    2 -
 kernel/hrtimer.c        |   51 +++++++++++++++++++++++++-----------------------
 kernel/posix-timers.c   |   14 +------------
 3 files changed, 30 insertions(+), 37 deletions(-)

time: fix typo in comments

2008-02-08T17:22:29+00:00

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

Fix compilation of powerpc asm-offsets.c with old gcc

2008-02-07T22:54:45+00:00

Commit ad7f71674ad7c3c4467e48f6ab9e85516dae2720 ("[POWERPC] Use a
sensible default for clock_getres() in the VDSO") corrected the clock
resolution reported by the VDSO clock_getres() but introduced another
problem in that older versions of gcc (gcc-4.0 and earlier) fail to
compile the new code in arch/powerpc/kernel/asm-offsets.c.

This fixes it by introducing a new MONOTONIC_RES_NSEC define in the
generic code which is equivalent to KTIME_MONOTONIC_RES but is just an
integer constant, not a ktime union.

Signed-off-by: Tony Breeds 
Signed-off-by: Paul Mackerras 
Signed-off-by: Linus Torvalds

timerfd: new timerfd API

2008-02-05T17:44:07+00:00

This is the new timerfd API as it is implemented by the following patch:

int timerfd_create(int clockid, int flags);
int timerfd_settime(int ufd, int flags,
		    const struct itimerspec *utmr,
		    struct itimerspec *otmr);
int timerfd_gettime(int ufd, struct itimerspec *otmr);

The timerfd_create() API creates an un-programmed timerfd fd.  The "clockid"
parameter can be either CLOCK_MONOTONIC or CLOCK_REALTIME.

The timerfd_settime() API give new settings by the timerfd fd, by optionally
retrieving the previous expiration time (in case the "otmr" parameter is not
NULL).

The time value specified in "utmr" is absolute, if the TFD_TIMER_ABSTIME bit
is set in the "flags" parameter.  Otherwise it's a relative time.

The timerfd_gettime() API returns the next expiration time of the timer, or
{0, 0} if the timerfd has not been set yet.

Like the previous timerfd API implementation, read(2) and poll(2) are
supported (with the same interface).  Here's a simple test program I used to
exercise the new timerfd APIs:

http://www.xmailserver.org/timerfd-test2.c

[akpm@linux-foundation.org: coding-style cleanups]
[akpm@linux-foundation.org: fix ia64 build]
[akpm@linux-foundation.org: fix m68k build]
[akpm@linux-foundation.org: fix mips build]
[akpm@linux-foundation.org: fix alpha, arm, blackfin, cris, m68k, s390, sparc and sparc64 builds]
[heiko.carstens@de.ibm.com: fix s390]
[akpm@linux-foundation.org: fix powerpc build]
[akpm@linux-foundation.org: fix sparc64 more]
Signed-off-by: Davide Libenzi 
Cc: Michael Kerrisk 
Cc: Thomas Gleixner 
Cc: Davide Libenzi 
Cc: Michael Kerrisk 
Cc: Martin Schwidefsky 
Signed-off-by: Heiko Carstens 
Cc: Michael Kerrisk 
Cc: Davide Libenzi 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

timerfd: introduce a new hrtimer_forward_now() function

2008-02-05T17:44:07+00:00

I think that advancing the timer against the timer's current "now" can be a
pretty common usage, so, w/out exposing hrtimer's internals, we add a new
hrtimer_forward_now() function.

Signed-off-by: Davide Libenzi 
Cc: Michael Kerrisk 
Cc: Thomas Gleixner 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

time: delete comments that refer to noexistent symbols

2008-02-03T14:20:13+00:00

Function do_timer_interrupt_hook() don't take argument regs,
and structure hrtimer_sleeper don't have member cb_pending.
So delete comments refering to these symbols.

Signed-off-by: Li Zefan 
Signed-off-by: Adrian Bunk

hrtimer: fixup the HRTIMER_CB_IRQSAFE_NO_SOFTIRQ fallback

2008-01-25T20:08:31+00:00

Currently all highres=off timers are run from softirq context, but
HRTIMER_CB_IRQSAFE_NO_SOFTIRQ timers expect to run from irq context.

Fix this up by splitting it similar to the highres=on case.

Signed-off-by: Peter Zijlstra 
Signed-off-by: Ingo Molnar

sched: high-res preemption tick

2008-01-25T20:08:29+00:00

Use HR-timers (when available) to deliver an accurate preemption tick.

The regular scheduler tick that runs at 1/HZ can be too coarse when nice
level are used. The fairness system will still keep the cpu utilisation 'fair'
by then delaying the task that got an excessive amount of CPU time but try to
minimize this by delivering preemption points spot-on.

The average frequency of this extra interrupt is sched_latency / nr_latency.
Which need not be higher than 1/HZ, its just that the distribution within the
sched_latency period is important.

Signed-off-by: Peter Zijlstra 
Signed-off-by: Ingo Molnar

hrtimer: Rework hrtimer_nanosleep to make sys_compat_nanosleep easier

2007-10-18T20:54:18+00:00

Pull the copy_to_user out of hrtimer_nanosleep and into the callers
(common_nsleep, sys_nanosleep) in preparation for converting
compat_sys_nanosleep to use hrtimers.

Signed-off-by: Anton Blanchard 
Acked-by: Arnd Bergmann 
Signed-off-by: Thomas Gleixner

Add a flag to indicate deferrable timers in /proc/timer_stats

2007-07-16T16:05:45+00:00

Add a flag in /proc/timer_stats to indicate deferrable timers.  This will
let developers/users to differentiate between types of tiemrs in
/proc/timer_stats.

Deferrable timer and normal timer will appear in /proc/timer_stats as below.
  10D,     1 swapper          queue_delayed_work_on (delayed_work_timer_fn)
   10,     1 swapper          queue_delayed_work_on (delayed_work_timer_fn)

Also version of timer_stats changes from v0.1 to v0.2

Signed-off-by: Venkatesh Pallipadi 
Acked-by: Ingo Molnar 
Cc: Thomas Gleixner 
Cc: john stultz 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds