linux-toradex.git/kernel/time, branch v2.6.22-rc7

timer stats: speedups

2007-06-01T15:18:30+00:00

Make timer-stats have almost zero overhead when enabled in the config but
not used.  (this way distros can enable it more easily)

Also update the documentation about overhead of timer_stats - it was
written for the first version which had a global lock and a linear list
walk based lookup ;-)

Signed-off-by: Ingo Molnar 
Cc: Thomas Gleixner 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

timer statistics: fix race

2007-06-01T15:18:30+00:00

Fix two races in the timer stats lookup code.  One by ensuring that the
initialization of a new entry is finished upon insertion of that entry.
The other by cleaning up the hash table when the entries array is cleared,
so that we don't have any "pre-inserted" entries.

Thanks to Eric Dumazet for reminding me of the memory barriers.

Signed-off-by: Bjorn Steinbrink 
Signed-off-by: Ian Kumlien 
Acked-by: Ingo Molnar 
Cc: Eric Dumazet 
Cc: Thomas Gleixner 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

NOHZ: prevent multiplication overflow - stop timer for huge timeouts

2007-05-30T01:11:10+00:00

get_next_timer_interrupt() returns a delta of (LONG_MAX > 1) in case
there is no timer pending. On 64 bit machines this results in a
multiplication overflow in tick_nohz_stop_sched_tick().

Reported by: Dave Miller 

Make the return value a constant and limit the return value to a 32 bit
value.

When the max timeout value is returned, we can safely stop the tick
timer device. The max jiffies delta results in a 12 days timeout for
HZ=1000.

In the long term the get_next_timer_interrupt() code needs to be
reworked to return ktime instead of jiffies, but we have to wait until
the last users of the original NO_IDLE_HZ code are converted.

Signed-off-by: Thomas Gleixner 
Acked-off-by: David S. Miller 
Signed-off-by: Linus Torvalds

NOHZ: Rate limit the local softirq pending warning output

2007-05-24T03:14:11+00:00

The warning in the NOHZ code, which triggers when a CPU goes idle with
softirqs pending can fill up the logs quite quickly.  Rate limit the output
until we found the root cause of that problem.

Signed-off-by: Thomas Gleixner 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Ignore bogus ACPI info for offline CPUs

2007-05-24T03:14:11+00:00

Booting a SMP kernel with maxcpus=1 on a SMP system leads to a hard hang,
because ACPI ignores the maxcpus setting and sends timer broadcast info for
the offline CPUs.  This results in a stuck for ever call to
smp_call_function_single() on an offline CPU.

Ignore the bogus information and print a kernel error to remind ACPI
folks to fix it.

Signed-off-by: Thomas Gleixner 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Detach sched.h from mm.h

2007-05-21T16:18:19+00:00

First thing mm.h does is including sched.h solely for can_do_mlock() inline
function which has "current" dereference inside. By dealing with can_do_mlock()
mm.h can be detached from sched.h which is good. See below, why.

This patch
a) removes unconditional inclusion of sched.h from mm.h
b) makes can_do_mlock() normal function in mm/mlock.c
c) exports can_do_mlock() to not break compilation
d) adds sched.h inclusions back to files that were getting it indirectly.
e) adds less bloated headers to some files (asm/signal.h, jiffies.h) that were
   getting them indirectly

Net result is:
a) mm.h users would get less code to open, read, preprocess, parse, ... if
   they don't need sched.h
b) sched.h stops being dependency for significant number of files:
   on x86_64 allmodconfig touching sched.h results in recompile of 4083 files,
   after patch it's only 3744 (-8.3%).

Cross-compile tested on

	all arm defconfigs, all mips defconfigs, all powerpc defconfigs,
	alpha alpha-up
	arm
	i386 i386-up i386-defconfig i386-allnoconfig
	ia64 ia64-up
	m68k
	mips
	parisc parisc-up
	powerpc powerpc-up
	s390 s390-up
	sparc sparc-up
	sparc64 sparc64-up
	um-x86_64
	x86_64 x86_64-up x86_64-defconfig x86_64-allnoconfig

as well as my two usual configs.

Signed-off-by: Alexey Dobriyan 
Signed-off-by: Linus Torvalds

clocksource: fix lock order in the resume path

2007-05-15T15:54:00+00:00

lockdep complains about the lock nesting of clocksource and watchdog lock
in the resume path.

Change the resume marker to a bit operation and remove the lock from this
path.

Signed-off-by: Thomas Gleixner 
Cc: john stultz 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

timekeeping fix patch got mis-applied

2007-05-14T19:13:11+00:00

The time keeping code move to kernel/time/timekeeping.c broke the
clocksource resume logic patch, which got applied to the old file by a
fuzzy application.  Fix it up and move the clocksource_resume() call to
the appropriate place.

Signed-off-by: Thomas Gleixner 
[ tssk, tssk, everybody should use --fuzz=0 ]
Signed-off-by: Linus Torvalds

clocksource: fix resume logic

2007-05-09T19:30:56+00:00

We need to make sure that the clocksources are resumed, when timekeeping is
resumed.  The current resume logic does not guarantee this.

Add a resume function pointer to the clocksource struct, so clocksource
drivers which need to reinitialize the clocksource can provide a resume
function.

Add a resume function, which calls the maybe available clocksource resume
functions and resets the watchdog function, so a stable TSC can be used
accross suspend/resume.

Signed-off-by: Thomas Gleixner 
Cc: john stultz 
Cc: Andi Kleen 
Cc: Ingo Molnar 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Fix printk format warnings in timer_list.c

2007-05-09T19:30:50+00:00

u64 and s64 are not necessarily 'long long' on some 64-bit
platforms, so explicit the type to kill the compiler warnings.

Also consistently use '%Lu' which is unsigned.

Signed-off-by: David S. Miller 
Cc: Thomas Gleixner 
Cc: Ingo Molnar 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds