Messages in this thread | | | Subject | Re: [PATCH 3/3] mm,vmacache: optimize overflow system-wide flushing | From | Davidlohr Bueso <> | Date | Mon, 14 Apr 2014 17:02:13 -0700 |
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Stupid script... Cc'ing Oleg.
On Mon, 2014-04-14 at 16:57 -0700, Davidlohr Bueso wrote: > For single threaded workloads, we can avoid flushing > and iterating through the entire list of tasks, making > the whole function a lot faster, requiring only a single > atomic read for the mm_users. > > Suggested-by: Oleg Nesterov <oleg@redhat.com> > Signed-off-by: Davidlohr Bueso <davidlohr@hp.com> > --- > mm/vmacache.c | 10 ++++++++++ > 1 file changed, 10 insertions(+) > > diff --git a/mm/vmacache.c b/mm/vmacache.c > index e167da2..61c38ae 100644 > --- a/mm/vmacache.c > +++ b/mm/vmacache.c > @@ -17,6 +17,16 @@ void vmacache_flush_all(struct mm_struct *mm) > { > struct task_struct *g, *p; > > + /* > + * Single threaded tasks need not iterate the entire > + * list of process. We can avoid the flushing as well > + * since the mm's seqnum was increased and don't have > + * to worry about other threads' seqnum. Current's > + * flush will occur upon the next lookup. > + */ > + if (atomic_read(&mm->mm_users) == 1) > + return; > + > rcu_read_lock(); > for_each_process_thread(g, p) { > /*
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