1. 25 5月, 2008 1 次提交
  2. 27 4月, 2008 1 次提交
    • P
      fix idle (arch, acpi and apm) and lockdep · 7f424a8b
      Peter Zijlstra 提交于
      OK, so 25-mm1 gave a lockdep error which made me look into this.
      
      The first thing that I noticed was the horrible mess; the second thing I
      saw was hacks like: 71e93d15
      
      The problem is that arch idle routines are somewhat inconsitent with
      their IRQ state handling and instead of fixing _that_, we go paper over
      the problem.
      
      So the thing I've tried to do is set a standard for idle routines and
      fix them all up to adhere to that. So the rules are:
      
        idle routines are entered with IRQs disabled
        idle routines will exit with IRQs enabled
      
      Nearly all already did this in one form or another.
      
      Merge the 32 and 64 bit bits so they no longer have different bugs.
      
      As for the actual lockdep warning; __sti_mwait() did a plainly un-annotated
      irq-enable.
      Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
      Tested-by: NBob Copeland <me@bobcopeland.com>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      7f424a8b
  3. 17 4月, 2008 1 次提交
  4. 15 4月, 2008 2 次提交
  5. 30 1月, 2008 5 次提交
  6. 12 1月, 2008 1 次提交
  7. 20 10月, 2007 1 次提交
  8. 11 10月, 2007 2 次提交
  9. 10 10月, 2007 1 次提交
    • J
      drivers/firmware: const-ify DMI API and internals · 1855256c
      Jeff Garzik 提交于
      Three main sets of changes:
      
      1) dmi_get_system_info() return value should have been marked const,
         since callers should not be changing that data.
      
      2) const-ify DMI internals, since DMI firmware tables should,
         whenever possible, be marked const to ensure we never ever write to
         that data area.
      
      3) const-ify DMI API, to enable marking tables const where possible
         in low-level drivers.
      
      And if we're really lucky, this might enable some additional
      optimizations on the part of the compiler.
      
      The bulk of the changes are #2 and #3, which are interrelated.  #1 could
      have been a separate patch, but it was so small compared to the others,
      it was easier to roll it into this changeset.
      Signed-off-by: NJeff Garzik <jgarzik@redhat.com>
      1855256c
  10. 01 8月, 2007 1 次提交
  11. 18 7月, 2007 1 次提交
    • R
      Freezer: make kernel threads nonfreezable by default · 83144186
      Rafael J. Wysocki 提交于
      Currently, the freezer treats all tasks as freezable, except for the kernel
      threads that explicitly set the PF_NOFREEZE flag for themselves.  This
      approach is problematic, since it requires every kernel thread to either
      set PF_NOFREEZE explicitly, or call try_to_freeze(), even if it doesn't
      care for the freezing of tasks at all.
      
      It seems better to only require the kernel threads that want to or need to
      be frozen to use some freezer-related code and to remove any
      freezer-related code from the other (nonfreezable) kernel threads, which is
      done in this patch.
      
      The patch causes all kernel threads to be nonfreezable by default (ie.  to
      have PF_NOFREEZE set by default) and introduces the set_freezable()
      function that should be called by the freezable kernel threads in order to
      unset PF_NOFREEZE.  It also makes all of the currently freezable kernel
      threads call set_freezable(), so it shouldn't cause any (intentional)
      change of behaviour to appear.  Additionally, it updates documentation to
      describe the freezing of tasks more accurately.
      
      [akpm@linux-foundation.org: build fixes]
      Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
      Acked-by: NNigel Cunningham <nigel@nigel.suspend2.net>
      Cc: Pavel Machek <pavel@ucw.cz>
      Cc: Oleg Nesterov <oleg@tv-sign.ru>
      Cc: Gautham R Shenoy <ego@in.ibm.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      83144186
  12. 09 5月, 2007 2 次提交
  13. 03 5月, 2007 2 次提交
  14. 17 2月, 2007 1 次提交
  15. 13 2月, 2007 2 次提交
  16. 23 12月, 2006 1 次提交
    • I
      [PATCH] sched: fix bad missed wakeups in the i386, x86_64, ia64, ACPI and APM idle code · 0888f06a
      Ingo Molnar 提交于
      Fernando Lopez-Lezcano reported frequent scheduling latencies and audio
      xruns starting at the 2.6.18-rt kernel, and those problems persisted all
      until current -rt kernels. The latencies were serious and unjustified by
      system load, often in the milliseconds range.
      
      After a patient and heroic multi-month effort of Fernando, where he
      tested dozens of kernels, tried various configs, boot options,
      test-patches of mine and provided latency traces of those incidents, the
      following 'smoking gun' trace was captured by him:
      
                       _------=> CPU#
                      / _-----=> irqs-off
                     | / _----=> need-resched
                     || / _---=> hardirq/softirq
                     ||| / _--=> preempt-depth
                     |||| /
                     |||||     delay
         cmd     pid ||||| time  |   caller
            \   /    |||||   \   |   /
        IRQ_19-1479  1D..1    0us : __trace_start_sched_wakeup (try_to_wake_up)
        IRQ_19-1479  1D..1    0us : __trace_start_sched_wakeup <<...>-5856> (37 0)
        IRQ_19-1479  1D..1    0us : __trace_start_sched_wakeup (c01262ba 0 0)
        IRQ_19-1479  1D..1    0us : resched_task (try_to_wake_up)
        IRQ_19-1479  1D..1    0us : __spin_unlock_irqrestore (try_to_wake_up)
        ...
        <idle>-0     1...1   11us!: default_idle (cpu_idle)
        ...
        <idle>-0     0Dn.1  602us : smp_apic_timer_interrupt (c0103baf 1 0)
        ...
         <...>-5856  0D..2  618us : __switch_to (__schedule)
         <...>-5856  0D..2  618us : __schedule <<idle>-0> (20 162)
         <...>-5856  0D..2  619us : __spin_unlock_irq (__schedule)
         <...>-5856  0...1  619us : trace_stop_sched_switched (__schedule)
         <...>-5856  0D..1  619us : trace_stop_sched_switched <<...>-5856> (37 0)
      
      what is visible in this trace is that CPU#1 ran try_to_wake_up() for
      PID:5856, it placed PID:5856 on CPU#0's runqueue and ran resched_task()
      for CPU#0. But it decided to not send an IPI that no CPU - due to
      TS_POLLING. But CPU#0 never woke up after its NEED_RESCHED bit was set,
      and only rescheduled to PID:5856 upon the next lapic timer IRQ. The
      result was a 600+ usecs latency and a missed wakeup!
      
      the bug turned out to be an idle-wakeup bug introduced into the mainline
      kernel this summer via an optimization in the x86_64 tree:
      
          commit 495ab9c0
          Author: Andi Kleen <ak@suse.de>
          Date:   Mon Jun 26 13:59:11 2006 +0200
      
          [PATCH] i386/x86-64/ia64: Move polling flag into thread_info_status
      
          During some profiling I noticed that default_idle causes a lot of
          memory traffic. I think that is caused by the atomic operations
          to clear/set the polling flag in thread_info. There is actually
          no reason to make this atomic - only the idle thread does it
          to itself, other CPUs only read it. So I moved it into ti->status.
      
      the problem is this type of change:
      
              if (!hlt_counter && boot_cpu_data.hlt_works_ok) {
      -               clear_thread_flag(TIF_POLLING_NRFLAG);
      +               current_thread_info()->status &= ~TS_POLLING;
                      smp_mb__after_clear_bit();
                      while (!need_resched()) {
                              local_irq_disable();
      
      this changes clear_thread_flag() to an explicit clearing of TS_POLLING.
      clear_thread_flag() is defined as:
      
              clear_bit(flag, &ti->flags);
      
      and clear_bit() is a LOCK-ed atomic instruction on all x86 platforms:
      
        static inline void clear_bit(int nr, volatile unsigned long * addr)
        {
                __asm__ __volatile__( LOCK_PREFIX
                        "btrl %1,%0"
      
      hence smp_mb__after_clear_bit() is defined as a simple compile barrier:
      
        #define smp_mb__after_clear_bit()       barrier()
      
      but the explicit TS_POLLING clearing introduced by the patch:
      
      +               current_thread_info()->status &= ~TS_POLLING;
      
      is not an atomic op! So the clearing of the TS_POLLING bit is freely
      reorderable with the reading of the NEED_RESCHED bit - and both now
      reside in different memory addresses.
      
      CPU idle wakeup very much depends on ordered memory ops, the clearing of
      the TS_POLLING flag must always be done before we test need_resched()
      and hit the idle instruction(s). [Symmetrically, the wakeup code needs
      to set NEED_RESCHED before it tests the TS_POLLING flag, so memory
      ordering is paramount.]
      
      Fernando's dual-core Athlon64 system has a sufficiently advanced memory
      ordering model so that it triggered this scenario very often.
      
      ( And it also turned out that the reason why these latencies never
        triggered on my testsystems is that i routinely use idle=poll, which
        was the only idle variant not affected by this bug. )
      
      The fix is to change the smp_mb__after_clear_bit() to an smp_mb(), to
      act as an absolute barrier between the TS_POLLING write and the
      NEED_RESCHED read. This affects almost all idling methods (default,
      ACPI, APM), on all 3 x86 architectures: i386, x86_64, ia64.
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      Tested-by: NFernando Lopez-Lezcano <nando@ccrma.Stanford.EDU>
      Signed-off-by: NAndrew Morton <akpm@osdl.org>
      Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      0888f06a
  17. 14 12月, 2006 1 次提交
    • R
      [PATCH] getting rid of all casts of k[cmz]alloc() calls · 5cbded58
      Robert P. J. Day 提交于
      Run this:
      
      	#!/bin/sh
      	for f in $(grep -Erl "\([^\)]*\) *k[cmz]alloc" *) ; do
      	  echo "De-casting $f..."
      	  perl -pi -e "s/ ?= ?\([^\)]*\) *(k[cmz]alloc) *\(/ = \1\(/" $f
      	done
      
      And then go through and reinstate those cases where code is casting pointers
      to non-pointers.
      
      And then drop a few hunks which conflicted with outstanding work.
      
      Cc: Russell King <rmk@arm.linux.org.uk>, Ian Molton <spyro@f2s.com>
      Cc: Mikael Starvik <starvik@axis.com>
      Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
      Cc: Roman Zippel <zippel@linux-m68k.org>
      Cc: Geert Uytterhoeven <geert@linux-m68k.org>
      Cc: Ralf Baechle <ralf@linux-mips.org>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Kyle McMartin <kyle@mcmartin.ca>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: "David S. Miller" <davem@davemloft.net>
      Cc: Jeff Dike <jdike@addtoit.com>
      Cc: Greg KH <greg@kroah.com>
      Cc: Jens Axboe <jens.axboe@oracle.com>
      Cc: Paul Fulghum <paulkf@microgate.com>
      Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
      Cc: Karsten Keil <kkeil@suse.de>
      Cc: Mauro Carvalho Chehab <mchehab@infradead.org>
      Cc: Jeff Garzik <jeff@garzik.org>
      Cc: James Bottomley <James.Bottomley@steeleye.com>
      Cc: Ian Kent <raven@themaw.net>
      Cc: Steven French <sfrench@us.ibm.com>
      Cc: David Woodhouse <dwmw2@infradead.org>
      Cc: Neil Brown <neilb@cse.unsw.edu.au>
      Cc: Jaroslav Kysela <perex@suse.cz>
      Cc: Takashi Iwai <tiwai@suse.de>
      Signed-off-by: NAndrew Morton <akpm@osdl.org>
      Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      5cbded58
  18. 07 12月, 2006 1 次提交
  19. 31 10月, 2006 1 次提交
  20. 17 10月, 2006 1 次提交
    • P
      [PATCH] lockdep: annotate i386 apm · 3864c489
      Peter Zijlstra 提交于
      Lockdep doesn't like to enable interrupts when they are enabled already.
      
      BUG: warning at kernel/lockdep.c:1814/trace_hardirqs_on() (Not tainted)
       [<c04051ed>] show_trace_log_lvl+0x58/0x16a
       [<c04057fa>] show_trace+0xd/0x10
       [<c0405913>] dump_stack+0x19/0x1b
       [<c043abfb>] trace_hardirqs_on+0xa2/0x11e
       [<c041463c>] apm_bios_call_simple+0xcd/0xfd
       [<c0415242>] apm+0x92/0x5b1
       [<c0402005>] kernel_thread_helper+0x5/0xb
      DWARF2 unwinder stuck at kernel_thread_helper+0x5/0xb
      Leftover inexact backtrace:
       [<c04057fa>] show_trace+0xd/0x10
       [<c0405913>] dump_stack+0x19/0x1b
       [<c043abfb>] trace_hardirqs_on+0xa2/0x11e
       [<c041463c>] apm_bios_call_simple+0xcd/0xfd
       [<c0415242>] apm+0x92/0x5b1
       [<c0402005>] kernel_thread_helper+0x5/0xb
      Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: Stephen Rothwell <sfr@canb.auug.org.au>
      Cc: Ingo Molnar <mingo@elte.hu>
      Signed-off-by: NAndrew Morton <akpm@osdl.org>
      Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      3864c489
  21. 30 9月, 2006 1 次提交
  22. 26 9月, 2006 2 次提交
  23. 01 7月, 2006 1 次提交
  24. 27 6月, 2006 1 次提交
    • A
      [PATCH] i386/x86-64/ia64: Move polling flag into thread_info_status · 495ab9c0
      Andi Kleen 提交于
      During some profiling I noticed that default_idle causes a lot of
      memory traffic. I think that is caused by the atomic operations
      to clear/set the polling flag in thread_info. There is actually
      no reason to make this atomic - only the idle thread does it
      to itself, other CPUs only read it. So I moved it into ti->status.
      
      Converted i386/x86-64/ia64 for now because that was the easiest
      way to fix ACPI which also manipulates these flags in its idle
      function.
      
      Cc: Nick Piggin <npiggin@novell.com>
      Cc: Tony Luck <tony.luck@intel.com>
      Cc: Len Brown <len.brown@intel.com>
      Signed-off-by: NAndi Kleen <ak@suse.de>
      Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      495ab9c0
  25. 23 6月, 2006 1 次提交
  26. 20 4月, 2006 1 次提交
  27. 24 3月, 2006 1 次提交
  28. 12 1月, 2006 1 次提交
  29. 09 1月, 2006 1 次提交
  30. 07 1月, 2006 1 次提交
    • J
      [PATCH] APM Screen Blanking fix · 3841b0a1
      Jordan Crouse 提交于
      - Fix screen blanking on BIOSes that return APM_NOT_ENGAGED when APM enabled
        screen blanking is not turned on.
      
        The original code only tried to set the state on device 0x100, and then
        0x1FF, and I added 0x101 to the mix too.
      
      - Clean up logic in apm_console_blank().
      
      - Prevent the error message from printing out twice.
      
      Cc: Jordan Crouse <jordan.crouse@amd.com>
      Cc: Stephen Rothwell <sfr@canb.auug.org.au>
      Signed-off-by: NAndrew Morton <akpm@osdl.org>
      Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      3841b0a1