Messages in this thread | | | Date | Mon, 3 Oct 2011 15:24:24 -0400 | From | Konrad Rzeszutek Wilk <> | Subject | Re: [Xen-devel] [PATCH RFC V2 2/5] stop_machine: make stop_machine safe and efficient to call early |
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On Sat, Oct 01, 2011 at 02:55:34PM -0700, Jeremy Fitzhardinge wrote: > From: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> > > Make stop_machine() safe to call early in boot, before SMP has been > set up, by simply calling the callback function directly if there's > only one CPU online. > > [ Fixes from AKPM: > - add comment > - local_irq_flags, not save_flags > - also call hard_irq_disable() for systems which need it > > Tejun suggested using an explicit flag rather than just looking at > the online cpu count. ] > > Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> > Cc: Tejun Heo <tj@kernel.org> > Cc: Rusty Russell <rusty@rustcorp.com.au> > Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> > Cc: Andrew Morton <akpm@linux-foundation.org> > Cc: H. Peter Anvin <hpa@linux.intel.com> > Cc: Ingo Molnar <mingo@elte.hu> > Cc: Steven Rostedt <rostedt@goodmis.org> > --- > kernel/stop_machine.c | 21 +++++++++++++++++++++ > 1 files changed, 21 insertions(+), 0 deletions(-) > > diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c > index ba5070c..9c59d9e 100644 > --- a/kernel/stop_machine.c > +++ b/kernel/stop_machine.c > @@ -41,6 +41,7 @@ struct cpu_stopper { > }; > > static DEFINE_PER_CPU(struct cpu_stopper, cpu_stopper); > +static bool stop_machine_initialized = false;
__read_mostly?
Thought it probably does not really matter that much in what section it is put in.
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