Date: Mon, 26 Jun 2000 22:14:59 -0400 (EDT) From: Luoqi Chen <luoqi@watermarkgroup.com> To: eischen@vigrid.com Cc: smp@FreeBSD.ORG Subject: Re: SMP meeting summary Message-ID: <200006270214.e5R2Exu13573@lor.watermarkgroup.com>
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> In regards to turnstiles, each kernel thread is born with its own > turnstile. When it blocks on a mutex that doesn't have any waiters > (no turnstile allocated to it), it uses the threads turnstile. If > the mutex already has a turnstile (there are other waiters), then > the threads turnstile is added to the system (per-CPU?) pool of > turnstiles. When the thread wakes up and acquires the mutex, it > takes a turnstile back from the turnstile pool. Turnstiles are > also used for read/write locks. > > -- > Dan Eischen > Does anyone know why a turnstile structure is used, instead of a sleep queue embedded in the mutex structure? With cache line size of 16/32 bytes, the latter seems to be more advantageous. -lq To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-smp" in the body of the message
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