1. 07 5月, 2010 2 次提交
    • T
      stop_machine: reimplement using cpu_stop · 3fc1f1e2
      Tejun Heo 提交于
      Reimplement stop_machine using cpu_stop.  As cpu stoppers are
      guaranteed to be available for all online cpus,
      stop_machine_create/destroy() are no longer necessary and removed.
      
      With resource management and synchronization handled by cpu_stop, the
      new implementation is much simpler.  Asking the cpu_stop to execute
      the stop_cpu() state machine on all online cpus with cpu hotplug
      disabled is enough.
      
      stop_machine itself doesn't need to manage any global resources
      anymore, so all per-instance information is rolled into struct
      stop_machine_data and the mutex and all static data variables are
      removed.
      
      The previous implementation created and destroyed RT workqueues as
      necessary which made stop_machine() calls highly expensive on very
      large machines.  According to Dimitri Sivanich, preventing the dynamic
      creation/destruction makes booting faster more than twice on very
      large machines.  cpu_stop resources are preallocated for all online
      cpus and should have the same effect.
      Signed-off-by: NTejun Heo <tj@kernel.org>
      Acked-by: NRusty Russell <rusty@rustcorp.com.au>
      Acked-by: NPeter Zijlstra <peterz@infradead.org>
      Cc: Oleg Nesterov <oleg@redhat.com>
      Cc: Dimitri Sivanich <sivanich@sgi.com>
      3fc1f1e2
    • T
      cpu_stop: implement stop_cpu[s]() · 1142d810
      Tejun Heo 提交于
      Implement a simplistic per-cpu maximum priority cpu monopolization
      mechanism.  A non-sleeping callback can be scheduled to run on one or
      multiple cpus with maximum priority monopolozing those cpus.  This is
      primarily to replace and unify RT workqueue usage in stop_machine and
      scheduler migration_thread which currently is serving multiple
      purposes.
      
      Four functions are provided - stop_one_cpu(), stop_one_cpu_nowait(),
      stop_cpus() and try_stop_cpus().
      
      This is to allow clean sharing of resources among stop_cpu and all the
      migration thread users.  One stopper thread per cpu is created which
      is currently named "stopper/CPU".  This will eventually replace the
      migration thread and take on its name.
      
      * This facility was originally named cpuhog and lived in separate
        files but Peter Zijlstra nacked the name and thus got renamed to
        cpu_stop and moved into stop_machine.c.
      
      * Better reporting of preemption leak as per Peter's suggestion.
      Signed-off-by: NTejun Heo <tj@kernel.org>
      Acked-by: NPeter Zijlstra <peterz@infradead.org>
      Cc: Oleg Nesterov <oleg@redhat.com>
      Cc: Dimitri Sivanich <sivanich@sgi.com>
      1142d810
  2. 05 1月, 2009 1 次提交
    • H
      stop_machine: introduce stop_machine_create/destroy. · 9ea09af3
      Heiko Carstens 提交于
      Introduce stop_machine_create/destroy. With this interface subsystems
      that need a non-failing stop_machine environment can create the
      stop_machine machine threads before actually calling stop_machine.
      When the threads aren't needed anymore they can be killed with
      stop_machine_destroy again.
      
      When stop_machine gets called and the threads aren't present they
      will be created and destroyed automatically. This restores the old
      behaviour of stop_machine.
      
      This patch also converts cpu hotplug to the new interface since it
      is special: cpu_down calls __stop_machine instead of stop_machine.
      However the kstop threads will only be created when stop_machine
      gets called.
      
      Changing the code so that the threads would be created automatically
      on __stop_machine is currently not possible: when __stop_machine gets
      called we hold cpu_add_remove_lock, which is the same lock that
      create_rt_workqueue would take. So the workqueue needs to be created
      before the cpu hotplug code locks cpu_add_remove_lock.
      Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
      Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
      9ea09af3
  3. 01 1月, 2009 1 次提交
  4. 25 8月, 2008 1 次提交
  5. 28 7月, 2008 3 次提交
  6. 26 4月, 2006 1 次提交
  7. 17 4月, 2005 1 次提交
    • L
      Linux-2.6.12-rc2 · 1da177e4
      Linus Torvalds 提交于
      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