linux-toradex.git/kernel/timer.c, branch v2.6.20.21

[PATCH] schedule_timeout(): improve warning message

2006-12-22T16:55:49+00:00

Kyle is hitting this warning, and we don't have a clue what it's caused by.
Add the obligatory dump_stack().

Cc: kyle 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] Optimize calc_load()

2006-12-13T17:05:55+00:00

calc_load() is called by timer interrupt to update avenrun[].  It currently
calls nr_active() at each timer tick (HZ per second), while the update of
avenrun[] is done only once every 5 seconds.  (LOAD_FREQ=5 Hz)

nr_active() is quite expensive on SMP machines, since it has to sum up
nr_running and nr_uninterruptible of all online CPUS, bringing foreign
dirty cache lines.

This patch is an optimization of calc_load() so that nr_active() is called
only if we need it.

The use of unlikely() is welcome since the condition is true only once every
5*HZ time.

Signed-off-by: Eric Dumazet 
Cc: Ingo Molnar 
Acked-by: "Siddha, Suresh B" 
Cc: Nick Piggin 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] clocksource: small cleanup

2006-12-10T17:57:22+00:00

Mostly changing alignment.  Just some general cleanup.

[akpm@osdl.org: build fix]
Signed-off-by: Daniel Walker 
Acked-by: John Stultz 
Cc: Thomas Gleixner 
Cc: Ingo Molnar 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] round_jiffies infrastructure

2006-12-10T17:57:22+00:00

Introduce a round_jiffies() function as well as a round_jiffies_relative()
function.  These functions round a jiffies value to the next whole second.
The primary purpose of this rounding is to cause all "we don't care exactly
when" timers to happen at the same jiffy.

This avoids multiple timers firing within the second for no real reason;
with dynamic ticks these extra timers cause wakeups from deep sleep CPU
sleep states and thus waste power.

The exact wakeup moment is skewed by the cpu number, to avoid all cpus from
waking up at the exact same time (and hitting the same lock/cachelines
there)

[akpm@osdl.org: fix variable type]
Signed-off-by: Arjan van de Ven 
Cc: Thomas Gleixner 
Cc: Ingo Molnar 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] kill wall_jiffies

2006-10-01T07:39:27+00:00

With 2.6.18-rc4-mm2, now wall_jiffies will always be the same as jiffies.
So we can kill wall_jiffies completely.

This is just a cleanup and logically should not change any real behavior
except for one thing: RTC updating code in (old) ppc and xtensa use a
condition "jiffies - wall_jiffies == 1".  This condition is never met so I
suppose it is just a bug.  I just remove that condition only instead of
kill the whole "if" block.

[heiko.carstens@de.ibm.com: s390 build fix and cleanup]
Signed-off-by: Atsushi Nemoto 
Cc: Andi Kleen 
Cc: Paul Mackerras 
Cc: Benjamin Herrenschmidt 
Cc: Richard Henderson 
Cc: Ivan Kokshaysky 
Cc: Russell King 
Cc: Ian Molton 
Cc: Mikael Starvik 
Cc: David Howells 
Cc: Yoshinori Sato 
Cc: Hirokazu Takata 
Cc: Ralf Baechle 
Cc: Kyle McMartin 
Cc: Heiko Carstens 
Cc: Martin Schwidefsky 
Cc: Paul Mundt 
Cc: Kazumoto Kojima 
Cc: Richard Curnow 
Cc: William Lee Irwin III 
Cc: "David S. Miller" 
Cc: Jeff Dike 
Cc: Paolo 'Blaisorblade' Giarrusso 
Cc: Miles Bader 
Cc: Chris Zankel 
Cc: "Luck, Tony" 
Cc: Geert Uytterhoeven 
Cc: Roman Zippel 
Signed-off-by: Heiko Carstens 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] ntp: add time_adjust to tick length

2006-10-01T07:39:26+00:00

This folds update_ntp_one_tick() into second_overflow() and adds time_adjust
to the tick length, this makes time_next_adjust unnecessary.  This slightly
changes the adjtime() behaviour, instead of applying it to the next tick, it's
applied to the next second.

Signed-off-by: Roman Zippel 
Cc: john stultz 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] ntp: add ntp_update_frequency

2006-10-01T07:39:26+00:00

This introduces ntp_update_frequency() and deinlines ntp_clear() (as it's not
performance critical).  ntp_update_frequency() calculates the base tick length
using tick_usec and adds a base adjustment, in case the frequency doesn't
divide evenly by HZ.

Signed-off-by: Roman Zippel 
Cc: john stultz 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] NTP: Move all the NTP related code to ntp.c

2006-10-01T07:39:26+00:00

Move all the NTP related code to ntp.c

[akpm@osdl.org: cleanups, build fix]
Signed-off-by: John Stultz 
Cc: Ingo Molnar 
Cc: Roman Zippel 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] simplify update_times (avoid jiffies/jiffies_64 aliasing problem)

2006-09-29T16:18:15+00:00

Pass ticks to do_timer() and update_times(), and adjust x86_64 and s390
timer interrupt handler with this change.

Currently update_times() calculates ticks by "jiffies - wall_jiffies", but
callers of do_timer() should know how many ticks to update.  Passing ticks
get rid of this redundant calculation.  Also there are another redundancy
pointed out by Martin Schwidefsky.

This cleanup make a barrier added by
5aee405c662ca644980c184774277fc6d0769a84 needless.  So this patch removes
it.

As a bonus, this cleanup make wall_jiffies can be removed easily, since now
wall_jiffies is always synced with jiffies.  (This patch does not really
remove wall_jiffies.  It would be another cleanup patch)

Signed-off-by: Atsushi Nemoto 
Cc: Martin Schwidefsky 
Cc: "Eric W. Biederman" 
Cc: Thomas Gleixner 
Cc: Ingo Molnar 
Cc: john stultz 
Cc: Andi Kleen 
Cc: Paul Mackerras 
Cc: Benjamin Herrenschmidt 
Cc: Richard Henderson 
Cc: Ivan Kokshaysky 
Acked-by: Russell King 
Cc: Ian Molton 
Cc: Mikael Starvik 
Acked-by: David Howells 
Cc: Yoshinori Sato 
Cc: Hirokazu Takata 
Acked-by: Ralf Baechle 
Cc: Kyle McMartin 
Cc: Heiko Carstens 
Cc: Martin Schwidefsky 
Cc: Paul Mundt 
Cc: Kazumoto Kojima 
Cc: Richard Curnow 
Cc: William Lee Irwin III 
Cc: "David S. Miller" 
Cc: Jeff Dike 
Cc: Paolo 'Blaisorblade' Giarrusso 
Cc: Miles Bader 
Cc: Chris Zankel 
Acked-by: "Luck, Tony" 
Cc: Geert Uytterhoeven 
Cc: Roman Zippel 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] check return value of cpu_callback

2006-09-29T16:18:14+00:00

Spawing ksoftirqd, migration, or watchdog, and calling init_timers_cpu()
may fail with small memory.  If it happens in initcalls, kernel NULL
pointer dereference happens later.  This patch makes crash happen
immediately in such cases.  It seems a bit better than getting kernel NULL
pointer dereference later.

Cc: Ingo Molnar 
Signed-off-by: Akinobu Mita 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds