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  1. 29 3月, 2007 1 次提交
  3. 28 3月, 2007 2 次提交
    • R
      [PATCH] Revert "swsusp: disable nonboot CPUs before entering platform suspend" · 436ce716
      由 Rafael J. Wysocki 提交于 
      This reverts commit 94985134 and
insteads removes the WARN_ON() that caused that commit in the first
place.

The problem is that we call disable_nonboot_cpus() in swsusp before
powering down the system in order to avoid triggering the WARN_ON()
in arch/x86_64/kernel/acpi/sleep.c:init_low_mapping() and this doesn't
work well on Thomas' system.

So instead, remove the WARN_ON() in arch/x86_64/kernel/acpi/sleep.c:
init_low_mapping(), which triggers every time during the suspend to disk
in the platform mode, as the potential problem it is related to doesn't
seem to occur in practice.

[ I think we might want to disallow the case of multiple users of that
  mm, or something.  Normally, playing with the current process page
  tables on the current CPU should be fine as long as we don't have
  other threads using those tables at the same time..

  Anyway, not pretty, but better than the warning or the lockup - Linus ]
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      436ce716
    • J
      [PATCH] ntp: avoid time_offset overflows · d62ac21a
      由 john stultz 提交于 
      I've been seeing some odd NTP behavior recently on a few boxes and
finally narrowed it down to time_offset overflowing when converted to
SHIFT_UPDATE units (which was a side effect from my HZfreeNTP patch).

This patch converts time_offset from a long to a s64 which resolves the
issue.

[tglx@linutronix.de: signedness fixes]
Signed-off-by: NJohn Stultz <johnstul@us.ibm.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      d62ac21a
  5. 27 3月, 2007 1 次提交
  7. 26 3月, 2007 2 次提交
  9. 24 3月, 2007 1 次提交
  11. 23 3月, 2007 3 次提交
  13. 17 3月, 2007 8 次提交
  15. 15 3月, 2007 1 次提交
  17. 10 3月, 2007 1 次提交
  19. 07 3月, 2007 5 次提交
  21. 05 3月, 2007 4 次提交
    • H
      [PATCH] timer/hrtimer: take per cpu locks in sane order · e81ce1f7
      由 Heiko Carstens 提交于 
      Doing something like this on a two cpu system

  # echo 0 > /sys/devices/system/cpu/cpu0/online
  # echo 1 > /sys/devices/system/cpu/cpu0/online
  # echo 0 > /sys/devices/system/cpu/cpu1/online

will give me this:

  =======================================================
  [ INFO: possible circular locking dependency detected ]
  2.6.21-rc2-g562aa1d4-dirty #7
  -------------------------------------------------------
  bash/1282 is trying to acquire lock:
   (&cpu_base->lock_key){.+..}, at: [<000000000005f17e>] hrtimer_cpu_notify+0xc6/0x240

  but task is already holding lock:
   (&cpu_base->lock_key#2){.+..}, at: [<000000000005f174>] hrtimer_cpu_notify+0xbc/0x240

  which lock already depends on the new lock.

This happens because we have the following code in kernel/hrtimer.c:

  migrate_hrtimers(int cpu)
  [...]
  old_base = &per_cpu(hrtimer_bases, cpu);
  new_base = &get_cpu_var(hrtimer_bases);
  [...]
  spin_lock(&new_base->lock);
  spin_lock(&old_base->lock);

Which means the spinlocks are taken in an order which depends on which cpu
gets shut down from which other cpu. Therefore lockdep complains that there
might be an ABBA deadlock. Since migrate_hrtimers() gets only called on
cpu hotplug it's safe to assume that it isn't executed concurrently on a

The same problem exists in kernel/timer.c: migrate_timers().

As pointed out by Christian Borntraeger one possible solution to avoid
the locking order complaints would be to make sure that the locks are
always taken in the same order. E.g. by taking the lock of the cpu with
the lower number first.

To achieve this we introduce two new spinlock functions double_spin_lock
and double_spin_unlock which lock or unlock two locks in a given order.

Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Roman Zippel <zippel@linux-m68k.org>
Cc: John Stultz <johnstul@us.ibm.com>
Cc: Christian Borntraeger <cborntra@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      e81ce1f7
    • J
      [PATCH] clocksource init adjustments (fix bug #7426) · 6bb74df4
      由 john stultz 提交于 
      This patch resolves the issue found here:
http://bugme.osdl.org/show_bug.cgi?id=7426

The basic summary is:
Currently we register most of i386/x86_64 clocksources at module_init
time. Then we enable clocksource selection at late_initcall time. This
causes some problems for drivers that use gettimeofday for init
calibration routines (specifically the es1968 driver in this case),
where durring module_init, the only clocksource available is the low-res
jiffies clocksource. This may cause slight calibration errors, due to
the small sampling time used.

It should be noted that drivers that require fine grained time may not
function on architectures that do not have better then jiffies
resolution timekeeping (there are a few). However, this does not
discount the reasonable need for such fine-grained timekeeping at init
time.

Thus the solution here is to register clocksources earlier (ideally when
the hardware is being initialized), and then we enable clocksource
selection at fs_initcall (before device_initcall).

This patch should probably get some testing time in -mm, since
clocksource selection is one of the most important issues for correct
timekeeping, and I've only been able to test this on a few of my own
boxes.
Signed-off-by: NJohn Stultz <johnstul@us.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      6bb74df4
    • C
      [PATCH] sched: remove SMT nice · 69f7c0a1
      由 Con Kolivas 提交于 
      Remove the SMT-nice feature which idles sibling cpus on SMT cpus to
facilitiate nice working properly where cpu power is shared.  The idling of
cpus in the presence of runnable tasks is considered too fragile, easy to
break with outside code, and the complexity of managing this system if an
architecture comes along with many logical cores sharing cpu power will be
unworkable.

Remove the associated per_cpu_gain variable in sched_domains used only by
this code.

Also:

  The reason is that with dynticks enabled, this code breaks without yet
  further tweaks so dynticks brought on the rapid demise of this code.  So
  either we tweak this code or kill it off entirely.  It was Ingo's preference
  to kill it off.  Either way this needs to happen for 2.6.21 since dynticks
  has gone in.
Signed-off-by: NCon Kolivas <kernel@kolivas.org>
Acked-by: NIngo Molnar <mingo@elte.hu>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      69f7c0a1
    • P
      sysctl: Support vdso_enabled sysctl on SH. · 5c36e657
      由 Paul Mundt 提交于 
      All of the logic for this was already in place, we just hadn't wired it
up in the sysctl table.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>
      5c36e657
  23. 02 3月, 2007 6 次提交
  25. 27 2月, 2007 3 次提交
  27. 24 2月, 2007 2 次提交