If you are talking about 5 second timedwait(), then it is only used to
exit the thread. It won't ensure progress (shouldn't based on my code
review).
Regards, Malahal.
Matt W. Benjamin [m...@cohortfs.com] wrote:
> From memory.
>
> The code isn't trying to eliminate that race, no. If/when it arises, and all
> threads are idle, then the timeout will ensure progress.
>
> In particular, if there is no work for -any- threads, it is desirable for at
> least
> most to go idle. As work ramps up, threads will be woken.
>
> The next optimization, I would intuit, might be to have a leader that is
> resistant
> to idle.
>
> Matt
>
> ----- "Malahal Naineni" <mala...@us.ibm.com> wrote:
>
> > The nfs_rpc_enqueue_req is called by the producer and
> > nfs_rpc_dequeue_req is called by the consumer. Here is the high level
> > view of those functions.
> >
> > In particular, if a consumer finds no request in the queue, and then
> > attempts to go to sleep, but before he adds himself to the wait list
> > (before step 2b), if producer adds another request at that instant,
> > the
> > producer would find the wait list empty and couldn't wake up any
> > consumer.
> >
> > Later the consumer would add himself to the wait list and goes to
> > sleep
> > (in a loop actually due to timedwait call. This will continue if
> > there
> > was no other request coming in. Am I missing something?
> >
> > nfs_rpc_dequeue_req()
> > {
> > 1. request = nfs_rpc_consume_req()
> > 2. if (request == NULL) { /* no work to do */
> > a) set Wqe_LFlag_WaitSync flag
> > b) add itself to the wait list
> > c) while not Wqe_LFlag_SyncDone {
> > pthread_cond_timedwait(5 seconds)
> > }
> > goto step 1; /* woke up with SyncDone */
> > }
> > }
> >
> > nfs_rpc_enqueue_req()
> > {
> > 1. add request to the list
> > 2. if (wait list is not empty) {
> > a) pick up first waiting thread.
> > b) set Wqe_LFlag_SyncDone
> > c) if Wqe_LFlag_WaitSync() pthread_cond_signal().
> > }
> > }
> >
> >
> > ------------------------------------------------------------------------------
> > Monitor Your Dynamic Infrastructure at Any Scale With Datadog!
> > Get real-time metrics from all of your servers, apps and tools
> > in one place.
> > SourceForge users - Click here to start your Free Trial of Datadog
> > now!
> > http://pubads.g.doubleclick.net/gampad/clk?id=241902991&iu=/4140
> > _______________________________________________
> > Nfs-ganesha-devel mailing list
> > Nfs-ganesha-devel@lists.sourceforge.net
> > https://lists.sourceforge.net/lists/listinfo/nfs-ganesha-devel
>
> --
> Matt Benjamin
> CohortFS, LLC.
> 315 West Huron Street, Suite 140A
> Ann Arbor, Michigan 48103
>
> http://cohortfs.com
>
> tel. 734-761-4689
> fax. 734-769-8938
> cel. 734-216-5309
>
------------------------------------------------------------------------------
Monitor Your Dynamic Infrastructure at Any Scale With Datadog!
Get real-time metrics from all of your servers, apps and tools
in one place.
SourceForge users - Click here to start your Free Trial of Datadog now!
http://pubads.g.doubleclick.net/gampad/clk?id=241902991&iu=/4140
_______________________________________________
Nfs-ganesha-devel mailing list
Nfs-ganesha-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/nfs-ganesha-devel
