Date: Mon, 13 Aug 2012 14:40:14 -0700 From: Jack Vogel <jfvogel@gmail.com> To: Vijay Singh <vijju.singh@gmail.com> Cc: net@freebsd.org Subject: Re: ixgbe rx & tx locks Message-ID: <CAFOYbc=i=59hXDUUyac4JORw-189=LHqXzNF8XKZh3Zwdm7tdA@mail.gmail.com> In-Reply-To: <CALCNsJSSQSWV7vNVR-Sn8CPDKbUBBLpSH0b-HYMJo3SXvkOY=w@mail.gmail.com> References: <CALCNsJSSQSWV7vNVR-Sn8CPDKbUBBLpSH0b-HYMJo3SXvkOY=w@mail.gmail.com>
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Hmmm, this is odd, because the interrupt vector is not being re-enabled unless you are not scheduling the task, and when you are the interrupt isn't enabled til the end.... Something funny going on. You could get contention due to mq_start however, you sure about where its coming from? Jack On Mon, Aug 13, 2012 at 2:15 PM, Vijay Singh <vijju.singh@gmail.com> wrote: > Folks, I've been looking into lock contention on the ixgbe rx & tx locks. > > I have collected this data: > > debug.lock.prof.stats: > max wait_max total wait_total count avg wait_avg > cnt_hold cnt_lock name > 263 304 1329357 858873 322010 4 2 > 0 45210 sys/dev/ixgbe/ixgbe.c:1349 (sleep mutex:e2a:tx(0)) > 415 189 14314889 62933 739895 19 0 > 0 13694 sys/dev/ixgbe/ixgbe.c:1445 (sleep mutex:e2a:tx(0)) > > So the lock contention is coming from lock acquisitions in > ixgbe_handle_que() and ixgbe_msix_que(). > > I am unable to understand why, since I would not expect the deferred > task to execute in parallel with the msix interrupt handler. > > rx is similar: > > debug.lock.prof.stats: > max wait_max total wait_total count avg wait_avg > cnt_hold cnt_lock name > 88 893 672058 269855 821847 0 0 > 0 753 sys/dev/ixgbe/ixgbe.c:4211 (sleep mutex:e6b:rx(0)) > 893 25 3994289 1937 1093238 3 0 > 0 561 sys/dev/ixgbe/ixgbe.c:4276 (sleep mutex:e6b:rx(0)) > > Any thoughts? > > -vijay > _______________________________________________ > freebsd-net@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-net > To unsubscribe, send any mail to "freebsd-net-unsubscribe@freebsd.org" >
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