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 <[email protected]> > > 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 <[email protected]> > Cc: Alessio Igor Bogani <[email protected]> > Cc: Andrew Morton <[email protected]> > Cc: Avi Kivity <[email protected]> > Cc: Chris Metcalf <[email protected]> > Cc: Christoph Lameter <[email protected]> > Cc: Daniel Lezcano <[email protected]> > Cc: Geoff Levand <[email protected]> > Cc: Gilad Ben Yossef <[email protected]> > Cc: Hakan Akkan <[email protected]> > Cc: Ingo Molnar <[email protected]> > Cc: Kevin Hilman <[email protected]> > Cc: Max Krasnyansky <[email protected]> > Cc: Paul E. McKenney <[email protected]> > Cc: Peter Zijlstra <[email protected]> > Cc: Stephen Hemminger <[email protected]> > Cc: Steven Rostedt <[email protected]> > Cc: Sven-Thorsten Dietrich <[email protected]> > Cc: Thomas Gleixner <[email protected]> -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
