From: Manfred Spraul <manfred@colorfullife.com>
To: Matthew Kirkwood <matthew@hairy.beasts.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>, linux-kernel@vger.kernel.org
Subject: Re: [PATCH][RFC] Lightweight user-level semaphores
Date: Sun, 13 Jan 2002 13:55:33 +0100 [thread overview]
Message-ID: <3C4183C5.8CF17487@colorfullife.com> (raw)
In-Reply-To: <Pine.LNX.4.33.0201131216230.24442-100000@sphinx.mythic-beasts.com>
Matthew Kirkwood wrote:
>
>
> Yep, that'd be fine. However, you then lose the neatness
> of "lock==file descriptor", and need something other than
> read/write for down/up.
>
pread(), use the file pointer.
>
> I guess the alternative is to store them in a hash table
> or tree but I don't know what that would do to the
> contended case.
>
I'd start with file descriptor+pread(), and then check how much faster
your could get without any protection at all (i.e. just trust user
space). If the difference is small, then use the file descriptor.
--
Manfred
next prev parent reply other threads:[~2002-01-13 12:56 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2002-01-11 15:50 [PATCH][RFC] Lightweight user-level semaphores Manfred Spraul
2002-01-11 16:15 ` Matthew Kirkwood
2002-01-11 17:03 ` Alan Cox
2002-01-13 12:38 ` Matthew Kirkwood
2002-01-13 12:55 ` Manfred Spraul [this message]
2002-01-13 15:13 ` Alan Cox
2002-01-14 1:35 ` Rusty Russell
[not found] <Pine.LNX.4.33.0201081443540.8169-100000@penguin.transmeta.com>
2002-01-09 23:23 ` Matthew Kirkwood
2002-01-11 5:55 ` Rusty Russell
2002-01-11 11:40 ` Matthew Kirkwood
-- strict thread matches above, loose matches on Subject: below --
2002-01-07 20:05 Matthew Kirkwood
2002-01-07 20:28 ` Linus Torvalds
2002-01-07 22:03 ` Matthew Kirkwood
2002-01-07 22:38 ` Linus Torvalds
2002-01-08 13:56 ` Alan Cox
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