Date: Mon, 31 Jul 2006 17:38:07 +0800 From: "Intron" <mag@intron.ac> To: mykola.stryebkov@gmail.com Cc: freebsd-hackers@freebsd.org Subject: Re: VM question related to faults Message-ID: <courier.44CDCF7F.00018427@intron.ac> In-Reply-To: <20060731085906.GA869@taran.infoua.com.ua> References: <20060730105731.GA64955@stud.fit.vutbr.cz> <20060730200354.GA82547@stud.fit.vutbr.cz> <courier.44CD9F44.00017212@intron.ac> <20060731085906.GA869@taran.infoua.com.ua>
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mykola.stryebkov@gmail.com wrote: > On 31.07.2006 14:12:20, Intron wrote: > >> Mutex(9) is sometimes too heavy, and has many limitations, while sx(9) >> is somewhat enough. > > First paragraph from sx(9) manual says: > > Shared/exclusive locks are used to protect data that are read > far more often than they are written. Mutexes are inherently > more efficient than shared/exclusive locks, so shared/exclusive > locks should be used prudently. > > > -- > Nick Strebkov > Public key: http://humgat.org/~nick/pubkey.txt > fpr: 552C 88D6 895B 6E64 F277 D367 8A70 8132 47F5 C1B6 > _______________________________________________ > freebsd-hackers@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-hackers > To unsubscribe, send any mail to "freebsd-hackers-unsubscribe@freebsd.org" But sx(9) also says in section "CONTEXT", A thread may hold a shared or exclusive lock on an sx lock while sleep- ing. You may try copyout() when holding a mutex(9) on 7.0-CURRENT. Look out for kernel crash. ------------------------------------------------------------------------ From Beijing, China
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