On Sat, Feb 15, 2014 at 7:24 AM, Kevin Hilman <[email protected]> wrote: > From 902a2b58d61a51415457ea6768d687cdb7532eff Mon Sep 17 00:00:00 2001 > From: Kevin Hilman <[email protected]> > Date: Fri, 14 Feb 2014 15:10:58 -0800 > Subject: [PATCH] workqueue: for NO_HZ_FULL, set default cpumask to > !tick_nohz_full_mask > > To help in keeping NO_HZ_FULL CPUs isolated, keep unbound workqueues > from running on full dynticks CPUs. To do this, set the default > workqueue cpumask to be the set of "housekeeping" CPUs instead of all > possible CPUs. > > This is just just the starting/default cpumask, and can be overridden > with all the normal ways (NUMA settings, apply_workqueue_attrs and via > sysfs for workqueus with the WQ_SYSFS attribute.) > > Cc: Tejun Heo <[email protected]> > Cc: Paul McKenney <[email protected]> > Cc: Frederic Weisbecker <[email protected]> > Signed-off-by: Kevin Hilman <[email protected]> > --- > kernel/workqueue.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/kernel/workqueue.c b/kernel/workqueue.c > index 987293d03ebc..9a9d9b0eaf6d 100644 > --- a/kernel/workqueue.c > +++ b/kernel/workqueue.c > @@ -48,6 +48,7 @@ > #include <linux/nodemask.h> > #include <linux/moduleparam.h> > #include <linux/uaccess.h> > +#include <linux/tick.h> > > #include "workqueue_internal.h" > > @@ -3436,7 +3437,11 @@ struct workqueue_attrs *alloc_workqueue_attrs(gfp_t > gfp_mask) > if (!alloc_cpumask_var(&attrs->cpumask, gfp_mask)) > goto fail; > > +#ifdef CONFIG_NO_HZ_FULL > + cpumask_complement(attrs->cpumask, tick_nohz_full_mask); > +#else > cpumask_copy(attrs->cpumask, cpu_possible_mask); > +#endif > return attrs; > fail: > free_workqueue_attrs(attrs);
Can we play with this mask at runtime? I thought a better idea would be to keep this mask as mask of all CPUs initially and once any CPU enters NO_HZ_FULL mode we can remove that from mask? And ones it leaves that mode we can get that added again.. I am looking to use similar concept in case of un-pinned timers with my activity around cpuset.quiesce option.. -- 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/
