Messages in this thread | | | Subject | Re: [PATCH 04/32] x86: New cpuset nohz irq vector | From | Steven Rostedt <> | Date | Tue, 30 Oct 2012 13:39:47 -0400 |
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On Mon, 2012-10-29 at 16:27 -0400, Steven Rostedt wrote: > plain text document attachment > (0004-x86-New-cpuset-nohz-irq-vector.patch) > From: Frederic Weisbecker <fweisbec@gmail.com> > > We need a way to send an IPI (remote or local) in order to > asynchronously restart the tick for CPUs in nohz adaptive mode. > > This must be asynchronous such that we can trigger it with irqs > disabled. This must be usable as a self-IPI as well for example > in cases where we want to avoid random dealock scenario while > restarting the tick inline otherwise. > > This only settles the x86 backend. The core tick restart function > will be defined in a later patch. > > [CHECKME: Perhaps we instead need to use irq work for self IPIs. > But we also need a way to send async remote IPIs.]
Probably just use irq_work for self ipis, and normal ipis for other CPUs.
Also, what reason do we have to force a task out of nohz? IOW, do we really need this?
Also, perhaps we could just tag onto the schedule_ipi() function instead of having to create a new IPI for all archs?
-- Steve
> > Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> > Cc: Alessio Igor Bogani <abogani@kernel.org> > Cc: Andrew Morton <akpm@linux-foundation.org> > Cc: Avi Kivity <avi@redhat.com> > Cc: Chris Metcalf <cmetcalf@tilera.com> > Cc: Christoph Lameter <cl@linux.com> > Cc: Daniel Lezcano <daniel.lezcano@linaro.org> > Cc: Geoff Levand <geoff@infradead.org> > Cc: Gilad Ben Yossef <gilad@benyossef.com> > Cc: Hakan Akkan <hakanakkan@gmail.com> > Cc: Ingo Molnar <mingo@kernel.org> > Cc: Kevin Hilman <khilman@ti.com> > Cc: Max Krasnyansky <maxk@qualcomm.com> > Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> > Cc: Peter Zijlstra <peterz@infradead.org> > Cc: Stephen Hemminger <shemminger@vyatta.com> > Cc: Steven Rostedt <rostedt@goodmis.org> > Cc: Sven-Thorsten Dietrich <thebigcorporation@gmail.com> > Cc: Thomas Gleixner <tglx@linutronix.de>
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