On Fri, Nov 6, 2015 at 9:44 AM, Hans Petter Selasky <h...@selasky.org> wrote: > On 11/06/15 01:08, Rasool Al-Saadi wrote: >> >> >> On Thursday, 5 November 2015 8:53 PM, Hans Petter Selasky wrote: >>> >>> >>> On 11/05/15 00:44, Rasool Al-Saadi wrote: ... >> Removing C_HARDCLOCK reduces the problem but doesn't solve it completely. >> However, removing C_DIRECT_EXEC instead solves the problem (but >> occasionally very small spike(s) appears in high hz values). >> I mentioned in my first email that removing these flags makes the issue to >> disappear. But what the effects of removing these flags? If it cause timing >> issue to Dummynet, why we should use them? >> > > Hi, > > The C_DIRECT_EXEC flag reduces task switching overhead, that you don't have > to wakeup a thread to wakeup the dummynet worker thread. It affects timing.
Hans, thanks for the explanation. Can you clarify the behaviour of C_DIRECT_EXEC ? Does this mean that the task is run within some common thread instead of a dedicated one ? If so, for this type of task (dummynet may run at high rate and use a significant amount of cpu time) it may be a good idea to remove C_DIRECT_EXEC altogether. cheers luigi _______________________________________________ freebsd-net@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/freebsd-net To unsubscribe, send any mail to "freebsd-net-unsubscr...@freebsd.org"
