From: erik quanstrom <quanstro@quanstro.net>
To: 9fans@9fans.net
Subject: Re: [9fans] userspace semlocks
Date: Mon, 23 Sep 2013 09:56:51 -0400 [thread overview]
Message-ID: <3ddf9699caf0ffcff5ebb9f50b49f996@brasstown.quanstro.net> (raw)
In-Reply-To: <CAJQxxw=KpdBcoC1suKHDsLbCX0mnm-pR+QNS-b11VEM2w-bOcQ@mail.gmail.com>
> you are missing the reason. read the paper.
the paper in question one assumes is "Semaphores in Plan 9",
Sape Mullender and Russ Cox, IWP9, 2008.
the idea in the paper is the scheduler might hurt, but i don't think
there's any real development of that idea. so it's also possible that
the scheduler might not hurt due to some interactions not discussed.
it's also possible that the implementation of semaphores, which
requires two locks in the kernel contended case, and always requires two
calls to seg and validaddr is slower than the old method of sleep(0).
and finally, it's difficult to explain why my results do not square with
Table 2.
- erik
next prev parent reply other threads:[~2013-09-23 13:56 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-09-22 2:55 erik quanstrom
2013-09-22 5:48 ` Bruce Ellis
2013-09-23 13:56 ` erik quanstrom [this message]
2013-09-23 21:11 ` Charles Forsyth
2013-09-23 21:19 ` erik quanstrom
2013-09-23 22:27 ` erik quanstrom
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