Messages in this thread Patch in this message | ![/](/images/icornerl.gif) | | Date | Fri, 12 Nov 2010 11:12:20 -0500 | From | David Teigland <> | Subject | Re: dlm: Use cmwq for send and receive workqueues |
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On Fri, Nov 12, 2010 at 12:12:29PM +0000, Steven Whitehouse wrote: > > So far as I can tell, there is no reason to use a single-threaded > send workqueue for dlm, since it may need to send to several sockets > concurrently. Both workqueues are set to WQ_MEM_RECLAIM to avoid > any possible deadlocks, WQ_HIGHPRI since locking traffic is highly > latency sensitive (and to avoid a priority inversion wrt GFS2's > glock_workqueue) and WQ_FREEZABLE just in case someone needs to do > that (even though with current cluster infrastructure, it doesn't > make sense as the node will most likely land up ejected from the > cluster) in the future.
Thanks, I'll want to do some testing with this, but my test machines do not seem to create more than one dlm_recv workqueue thread (prior to this patch). Have you tested in any cases where many threads end up being created? I've noticed while debugging some many-cpu machines a huge number of dlm_recv threads, which is just excessive. Does this patch address that?
> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com> > Cc: Tejun Heo <tj@kernel.org> > > diff --git a/fs/dlm/lowcomms.c b/fs/dlm/lowcomms.c > index 37a34c2..0893b30 100644 > --- a/fs/dlm/lowcomms.c > +++ b/fs/dlm/lowcomms.c > @@ -1431,14 +1431,16 @@ static void work_stop(void) > static int work_start(void) > { > int error; > - recv_workqueue = create_workqueue("dlm_recv"); > + recv_workqueue = alloc_workqueue("dlm_recv", WQ_MEM_RECLAIM | > + WQ_HIGHPRI | WQ_FREEZEABLE, 0); > error = IS_ERR(recv_workqueue); > if (error) { > log_print("can't start dlm_recv %d", error); > return error; > } > > - send_workqueue = create_singlethread_workqueue("dlm_send"); > + send_workqueue = alloc_workqueue("dlm_send", WQ_MEM_RECLAIM | > + WQ_HIGHPRI | WQ_FREEZEABLE, 0); > error = IS_ERR(send_workqueue); > if (error) { > log_print("can't start dlm_send %d", error); > >
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