Date: Sat, 24 Aug 2013 12:27:41 -0700 From: Adrian Chadd <adrian@freebsd.org> To: Scott Long <scottl@netflix.com> Cc: FreeBSD Net <freebsd-net@freebsd.org>, Alfred Perlstein <bright@mu.org>, "Robert N. M. Watson" <rwatson@freebsd.org>, "Alexander V. Chernikov" <melifaro@ipfw.ru>, freebsd-current <freebsd-current@freebsd.org> Subject: Re: [rfc] migrate lagg to an rmlock Message-ID: <CAJ-VmomsOkxiQRnYna-=se%2BezBy2GajAKBBKCw4p8JiRrmBq3A@mail.gmail.com> In-Reply-To: <E263D234-751F-4948-83CE-48F883F85A59@yahoo.com> References: <CAJ-Vmo=VKVDEmmPrTbob6Ft%2B7FWypodNoL36Og=7p_CXBSfktg@mail.gmail.com> <5218AA36.1080807@ipfw.ru> <alpine.BSF.2.00.1308241511400.92711@fledge.watson.org> <5218E108.6090901@mu.org> <A4BA90F3-AB8A-41A6-B931-20AF81F903E0@FreeBSD.org> <5218F803.7000405@mu.org> <E263D234-751F-4948-83CE-48F883F85A59@yahoo.com>
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Hihi, There's two parts to my patch: * one is migrating the rwlock to rmlock - not because of counters, but because the lock is protecting consistency when changing the lagg config * one is adding a new lock specifically to ensure that the callout is atomically created/called/destroyed The latter has nothing to do with the actual counters - they're already using the atomic counter API, so the lock doesn't need to be held just to read them for _counter_ consistency. It's just held to make sure the callout is never called parallel to the destruction of the lagg interface. -adrian
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