Date: Sat, 27 Sep 2014 20:55:52 -0500 From: Bryan Venteicher <bryanv@daemoninthecloset.org> To: Steven Hartland <killing@multiplay.co.uk> Cc: "freebsd-hackers@freebsd.org" <freebsd-hackers@freebsd.org> Subject: Re: Change uma_mtx to rwlock Message-ID: <CAMo0n6QMogoNS-X0exL-LHc_pymRGDA1kn408KF59XgJ1qRQtw@mail.gmail.com> In-Reply-To: <CF61374E89D8461093CEDB42D4FCBABE@multiplay.co.uk> References: <CAMo0n6Q=P5H3%2BCqr8KjFRVLvWHZfJYnROVe4xF3DmKw95D%2B5zQ@mail.gmail.com> <CF61374E89D8461093CEDB42D4FCBABE@multiplay.co.uk>
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On Sat, Sep 27, 2014 at 8:42 PM, Steven Hartland <killing@multiplay.co.uk> wrote: > Out of interest does that include ZFS and its UMA zones, as we're current= ly > investigating issues around this. > > =E2=80=8BYes, I believe this would include ZFS's zones too.=E2=80=8B > Regards > Steve > > ----- Original Message ----- From: "Bryan Venteicher" < > bryanv@daemoninthecloset.org> > To: <freebsd-hackers@freebsd.org> > Sent: Sunday, September 28, 2014 1:59 AM > Subject: Change uma_mtx to rwlock > > > > Hi, >> >> I'd appreciate some comments attached patch that changes the uma_mtx to = a >> rwlock. >> >> At $JOB, we have machines with ~400GB RAM, with much of that being >> allocated through UMA zones. We've observed that timeouts were sometimes >> unexpectedly delayed by a half second or more. We tracked one of the >> reasons for this down to when the page daemon was running, calling >> uma_reclaim() -> zone_foreach(). zone_foreach() holds the uma_mtx while >> zone_drain()'ing each zone. If uma_timeout() fires, it will block on the >> uma_mtx when it tries to zone_timeout() each zone. >> >> > > ------------------------------------------------------------ > -------------------- > > > _______________________________________________ >> freebsd-hackers@freebsd.org mailing list >> http://lists.freebsd.org/mailman/listinfo/freebsd-hackers >> To unsubscribe, send any mail to "freebsd-hackers-unsubscribe@freebsd.or= g >> " >> >
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