ping..
On 6/11/20 6:07 PM, Bob Liu wrote: > Current code always set 'Unbound && max_active == 1' workqueues to ordered > implicitly, while this may be not an expected behaviour for some use cases. > > E.g some scsi and iscsi workqueues(unbound && max_active = 1) want to be bind > to different cpu so as to get better isolation, but their cpumask can't be > changed because WQ_ORDERED is set implicitly. > > This patch adds a flag __WQ_ORDERED_DISABLE and also > create_singlethread_workqueue_noorder() to offer an new option. > > Signed-off-by: Bob Liu <[email protected]> > --- > include/linux/workqueue.h | 4 ++++ > kernel/workqueue.c | 4 +++- > 2 files changed, 7 insertions(+), 1 deletion(-) > > diff --git a/include/linux/workqueue.h b/include/linux/workqueue.h > index e48554e..4c86913 100644 > --- a/include/linux/workqueue.h > +++ b/include/linux/workqueue.h > @@ -344,6 +344,7 @@ enum { > __WQ_ORDERED = 1 << 17, /* internal: workqueue is ordered */ > __WQ_LEGACY = 1 << 18, /* internal: create*_workqueue() */ > __WQ_ORDERED_EXPLICIT = 1 << 19, /* internal: > alloc_ordered_workqueue() */ > + __WQ_ORDERED_DISABLE = 1 << 20, /* internal: don't set __WQ_ORDERED > implicitly */ > > WQ_MAX_ACTIVE = 512, /* I like 512, better ideas? */ > WQ_MAX_UNBOUND_PER_CPU = 4, /* 4 * #cpus for unbound wq */ > @@ -433,6 +434,9 @@ struct workqueue_struct *alloc_workqueue(const char *fmt, > #define create_singlethread_workqueue(name) \ > alloc_ordered_workqueue("%s", __WQ_LEGACY | WQ_MEM_RECLAIM, name) > > +#define create_singlethread_workqueue_noorder(name) \ > + alloc_workqueue("%s", WQ_SYSFS | __WQ_LEGACY | WQ_MEM_RECLAIM | \ > + WQ_UNBOUND | __WQ_ORDERED_DISABLE, 1, (name)) > extern void destroy_workqueue(struct workqueue_struct *wq); > > struct workqueue_attrs *alloc_workqueue_attrs(void); > diff --git a/kernel/workqueue.c b/kernel/workqueue.c > index 4e01c44..2167013 100644 > --- a/kernel/workqueue.c > +++ b/kernel/workqueue.c > @@ -4237,7 +4237,9 @@ struct workqueue_struct *alloc_workqueue(const char > *fmt, > * on NUMA. > */ > if ((flags & WQ_UNBOUND) && max_active == 1) > - flags |= __WQ_ORDERED; > + /* the caller may don't want __WQ_ORDERED to be set implicitly. > */ > + if (!(flags & __WQ_ORDERED_DISABLE)) > + flags |= __WQ_ORDERED; > > /* see the comment above the definition of WQ_POWER_EFFICIENT */ > if ((flags & WQ_POWER_EFFICIENT) && wq_power_efficient) >
