Date: Sun, 4 Jan 2015 10:58:54 -0800 From: Adrian Chadd <adrian@freebsd.org> To: Hans Petter Selasky <hps@selasky.org> Cc: Ivan Klymenko <fidaj@ukr.net>, FreeBSD Current <freebsd-current@freebsd.org>, "freebsd-arch@freebsd.org" <freebsd-arch@freebsd.org> Subject: Re: [RFC] kern/kern_timeout.c rewrite in progress Message-ID: <CAJ-Vmo=tc-hqykhyc5bQW8qd_34PZU6yfGY8wziByA0xnR3ANQ@mail.gmail.com> In-Reply-To: <54A92ED1.2070906@selasky.org> References: <54A1B38C.1000709@selasky.org> <20150101005613.4f788b0c@nonamehost.local> <54A49CA5.2060801@selasky.org> <54A4A002.8010802@selasky.org> <54A53F4F.2000003@selasky.org> <54A92ED1.2070906@selasky.org>
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Hi! Can you throw this into reviews.freebsd.org please? This is something that should be very closely reviewed and tested. (I'm going to go over this quite closely as it related to a lot of the random crap I do ..) -adrian On 4 January 2015 at 04:15, Hans Petter Selasky <hps@selasky.org> wrote: > Hi, > > Please find attached an updated timeout patch which also updates clients in > the kernel area to use the callout API properly, like cv_timedwait(). > Previously there was some custom sleepqueue code in the callout subsystem. > All of that has now been removed and we allow callouts to be protected by > spinlocks. This allows us to tear down the callback like done with regular > mutexes, and a "td_slpmutex" has been added to "struct thread" to atomically > teardown the "td_slpcallout". Further the "TDF_TIMOFAIL" and > "SWT_SLEEPQTIMO" states can now be completely removed. > > Summary of changes: > > 1) Make consistent callout API which also supports spinlocks for the > callback function. This has been done to allow atomic callout stop of > "td_slpcallout" without the need of many kernel threading quirks. > > 2) It is not allowed to migrate CPU if the timeout is restarted while the > timeout callback is executing. Callouts must be stopped before CPU migration > is allowed. Optionally drained. > > 3) Shared lock support has been removed, because it prevents atomic stop of > the callback function. > > 4) A new API to drain callouts asynchronously has been added, called > "callout_drain_async()". > > Please test and report any errors! > > Patch applies to FreeBSD-11-current as of today. > > Thank you! > > --HPS > > > _______________________________________________ > freebsd-arch@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-arch > To unsubscribe, send any mail to "freebsd-arch-unsubscribe@freebsd.org"
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