sched: Fix rq->clock synchronization when migrating tasks
authorPeter Zijlstra <peterz@infradead.org>
Thu, 19 Aug 2010 11:31:43 +0000 (13:31 +0200)
committerIngo Molnar <mingo@elte.hu>
Fri, 20 Aug 2010 12:59:01 +0000 (14:59 +0200)
commit861d034ee814917a83bd5de4b26e3b8336ddeeb8
tree6514cb3ebbb58fb0a638e267dfd6da510a5c8a00
parent763008c4357b73c8d18396dfd8d79dc58fa3f99d
sched: Fix rq->clock synchronization when migrating tasks

sched_fork() -- we do task placement in ->task_fork_fair() ensure we
  update_rq_clock() so we work with current time. We leave the vruntime
  in relative state, so the time delay until wake_up_new_task() doesn't
  matter.

wake_up_new_task() -- Since task_fork_fair() left p->vruntime in
  relative state we can safely migrate, the activate_task() on the
  remote rq will call update_rq_clock() and causes the clock to be
  synced (enough).

Tested-by: Jack Daniel <wanders.thirst@gmail.com>
Tested-by: Philby John <pjohn@mvista.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1281002322.1923.1708.camel@laptop>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
kernel/sched_fair.c