1. 30 Jun, 2006 1 commit
  2. 05 Jun, 2006 1 commit
    • Ivan Kokshaysky's avatar
      [PATCH] alpha: SMP IRQ routing fix · c7d2d28b
      Ivan Kokshaysky authored
      
      
      From: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
      
      After removal of fixup_cpu_present_map() function Alpha ended up with an empty
      cpu_present_map, so secondary CPUs on SMP systems are not being started.
      
      Worse, on some platforms we route interrupts to secondary CPUs using
      cpu_possible_map which is still populated properly.  As a result, these
      interrupts go nowhere so the machines like DP264 aren't able to boot even with
      a primary CPU.
      
      Fixed basically by s/cpu_present_mask/cpu_present_map/.
      
      Thanks to Ernst Herzberg for reporting the bug and testing the fix.
      
      Cc: Ernst Herzberg <list-lkml@net4u.de>
      Cc: Richard Henderson <rth@twiddle.net>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      c7d2d28b
  3. 12 Jan, 2006 3 commits
  4. 08 Jan, 2006 1 commit
    • Eric W. Biederman's avatar
      [PATCH] Don't attempt to power off if power off is not implemented · 5e38291d
      Eric W. Biederman authored
      
      
      The problem.  It is expected that /sbin/halt -p works exactly like
      /sbin/halt, when the kernel does not implement power off functionality.
      
      The kernel can do a lot of work in the reboot notifiers and in
      device_shutdown before we even get to machine_power_off.  Some of that
      shutdown is not safe if you are leaving the power on, and it definitely
      gets in the way of using sysrq or pressing ctrl-alt-del.  Since the
      shutdown happens in generic code there is no way to fix this in
      architecture specific code :(
      
      Some machines are kernel oopsing today because of this.
      
      The simple solution is to turn LINUX_REBOOT_CMD_POWER_OFF into
      LINUX_REBOOT_CMD_HALT if power_off functionality is not implemented.
      
      This has the unfortunate side effect of disabling the power off
      functionality on architectures that leave pm_power_off to null and still
      implement something in machine_power_off.  And it will break the build on
      some architectures that don't have a pm_power_off variable at all.
      
      On both counts I say tough.
      
      For architectures like alpha that don't implement the pm_power_off variable
      pm_power_off is declared in linux/pm.h and it is a generic part of our
      power management code, and all architectures should implement it.
      
      For architectures like parisc that have a default power off method in
      machine_power_off if pm_power_off is not implemented or fails.  It is easy
      enough to set the pm_power_off variable.  And nothing bad happens there,
      the machines just stop powering off.
      
      The current semantics are impossible without a flag at the top level so we
      can avoid the problem code if a power off is not implemented.  pm_power_off
      is as good a flag as any with the bonus that it works without modification
      on at least x86, x86_64, powerpc, and ppc today.
      
      Andrew can you pick this up and put this in the mm tree.  Kernels that
      don't compile or don't power off seem saner than kernels that oops or
      panic.  Until we get the arch specific patches for the problem
      architectures this probably isn't smart to push into the stable kernel.
      Unfortunately I don't have the time at the moment to walk through every
      architecture and make them work.  And even if I did I couldn't test it :(
      
      From: Hirokazu Takata <takata@linux-m32r.org>
      
          Add pm_power_off() for build fix of arch/m32r/kernel/process.c.
      
      From: Miklos Szeredi <miklos@szeredi.hu>
      
          UML build fix
      
      Signed-off-by: default avatarEric W. Biederman <ebiederm@xmission.com>
      Signed-off-by: default avatarHayato Fujiwara <fujiwara@linux-m32r.org>
      Signed-off-by: default avatarHirokazu Takata <takata@linux-m32r.org>
      Signed-off-by: default avatarMiklos Szeredi <miklos@szeredi.hu>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      5e38291d
  5. 09 Nov, 2005 1 commit
    • Nick Piggin's avatar
      [PATCH] sched: resched and cpu_idle rework · 64c7c8f8
      Nick Piggin authored
      
      
      Make some changes to the NEED_RESCHED and POLLING_NRFLAG to reduce
      confusion, and make their semantics rigid.  Improves efficiency of
      resched_task and some cpu_idle routines.
      
      * In resched_task:
      - TIF_NEED_RESCHED is only cleared with the task's runqueue lock held,
        and as we hold it during resched_task, then there is no need for an
        atomic test and set there. The only other time this should be set is
        when the task's quantum expires, in the timer interrupt - this is
        protected against because the rq lock is irq-safe.
      
      - If TIF_NEED_RESCHED is set, then we don't need to do anything. It
        won't get unset until the task get's schedule()d off.
      
      - If we are running on the same CPU as the task we resched, then set
        TIF_NEED_RESCHED and no further action is required.
      
      - If we are running on another CPU, and TIF_POLLING_NRFLAG is *not* set
        after TIF_NEED_RESCHED has been set, then we need to send an IPI.
      
      Using these rules, we are able to remove the test and set operation in
      resched_task, and make clear the previously vague semantics of
      POLLING_NRFLAG.
      
      * In idle routines:
      - Enter cpu_idle with preempt disabled. When the need_resched() condition
        becomes true, explicitly call schedule(). This makes things a bit clearer
        (IMO), but haven't updated all architectures yet.
      
      - Many do a test and clear of TIF_NEED_RESCHED for some reason. According
        to the resched_task rules, this isn't needed (and actually breaks the
        assumption that TIF_NEED_RESCHED is only cleared with the runqueue lock
        held). So remove that. Generally one less locked memory op when switching
        to the idle thread.
      
      - Many idle routines clear TIF_POLLING_NRFLAG, and only set it in the inner
        most polling idle loops. The above resched_task semantics allow it to be
        set until before the last time need_resched() is checked before going into
        a halt requiring interrupt wakeup.
      
        Many idle routines simply never enter such a halt, and so POLLING_NRFLAG
        can be always left set, completely eliminating resched IPIs when rescheduling
        the idle task.
      
        POLLING_NRFLAG width can be increased, to reduce the chance of resched IPIs.
      
      Signed-off-by: default avatarNick Piggin <npiggin@suse.de>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Con Kolivas <kernel@kolivas.org>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      64c7c8f8
  6. 22 Sep, 2005 1 commit
  7. 26 Jul, 2005 1 commit
  8. 16 Apr, 2005 1 commit
    • Linus Torvalds's avatar
      Linux-2.6.12-rc2 · 1da177e4
      Linus Torvalds authored
      Initial git repository build. I'm not bothering with the full history,
      even though we have it. We can create a separate "historical" git
      archive of that later if we want to, and in the meantime it's about
      3.2GB when imported into git - space that would just make the early
      git days unnecessarily complicated, when we don't have a lot of good
      infrastructure for it.
      
      Let it rip!
      1da177e4