On Thu, May 08, 2014 at 09:22:51PM +0800, Lai Jiangshan wrote: > On Thu, May 8, 2014 at 12:37 AM, Frederic Weisbecker <[email protected]> > wrote: > > Allow to modify the low-level unbound workqueues cpumask through > > sysfs. This is performed by traversing the entire workqueue list > > and calling apply_workqueue_attrs() on the unbound workqueues. > > > > Cc: Christoph Lameter <[email protected]> > > Cc: Kevin Hilman <[email protected]> > > Cc: Lai Jiangshan <[email protected]> > > Cc: Mike Galbraith <[email protected]> > > Cc: Paul E. McKenney <[email protected]> > > Cc: Tejun Heo <[email protected]> > > Cc: Viresh Kumar <[email protected]> > > Signed-off-by: Frederic Weisbecker <[email protected]> > > --- > > kernel/workqueue.c | 65 > > ++++++++++++++++++++++++++++++++++++++++++++++++++++-- > > 1 file changed, 63 insertions(+), 2 deletions(-) > > > > diff --git a/kernel/workqueue.c b/kernel/workqueue.c > > index 2aa296d..5978cee 100644 > > --- a/kernel/workqueue.c > > +++ b/kernel/workqueue.c > > @@ -293,7 +293,7 @@ static DEFINE_SPINLOCK(wq_mayday_lock); /* protects > > wq->maydays list */ > > static LIST_HEAD(workqueues); /* PL: list of all workqueues */ > > static bool workqueue_freezing; /* PL: have wqs started > > freezing? */ > > > > -static cpumask_var_t wq_unbound_cpumask; > > +static cpumask_var_t wq_unbound_cpumask; /* PL: low level cpumask for all > > unbound wqs */ > > > > /* the per-cpu worker pools */ > > static DEFINE_PER_CPU_SHARED_ALIGNED(struct worker_pool > > [NR_STD_WORKER_POOLS], > > @@ -4084,19 +4084,80 @@ static struct bus_type wq_subsys = { > > .dev_groups = wq_sysfs_groups, > > }; > > > > +static int unbounds_cpumask_apply(cpumask_var_t cpumask) > > +{ > > + struct workqueue_struct *wq; > > + int ret; > > + > > + lockdep_assert_held(&wq_pool_mutex); > > + > > + list_for_each_entry(wq, &workqueues, list) { > > + struct workqueue_attrs *attrs; > > + > > + if (!(wq->flags & WQ_UNBOUND)) > > + continue; > > + > > + attrs = wq_sysfs_prep_attrs(wq); > > + if (!attrs) > > + return -ENOMEM; > > + > > + ret = apply_workqueue_attrs_locked(wq, attrs, cpumask); > > + free_workqueue_attrs(attrs); > > + if (ret) > > + break; > > + } > > + > > + return 0; > > +} > > + > > +static ssize_t unbounds_cpumask_store(struct device *dev, > > + struct device_attribute *attr, > > + const char *buf, size_t count) > > +{ > > + cpumask_var_t cpumask; > > + int ret = -EINVAL; > > + > > + if (!zalloc_cpumask_var(&cpumask, GFP_KERNEL)) > > + return -ENOMEM; > > + > > + ret = cpumask_parse(buf, cpumask); > > + if (ret) > > + goto out; > > > cpumask_and(cpumask, cpumask, cpu_possible_mask);
Is it really useful? I mean in the end we only apply online bits. -- 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/
