public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: David Howells <dhowells@redhat.com>
To: Roman Zippel <zippel@linux-m68k.org>
Cc: Christoph Hellwig <hch@infradead.org>,
	"Adam J. Richter" <adam@yggdrasil.com>,
	dhowells@redhat.com, linux-kernel@vger.kernel.org
Subject: Re: Patch: linux-2.5.29 __downgrade_write() for CONFIG_RWSEM_GENERIC_SPINLOCK
Date: Mon, 29 Jul 2002 08:42:16 +0100	[thread overview]
Message-ID: <9911.1027928536@warthog.cambridge.redhat.com> (raw)
In-Reply-To: Message from Roman Zippel <zippel@linux-m68k.org>  of "Mon, 29 Jul 2002 00:55:26 +0200." <Pine.LNX.4.44.0207290048070.8911-100000@serv>


Roman Zippel <zippel@linux-m68k.org> wrote:
> You don't really need that extra argument, testing sem->activity should do
> the same job.
> If you exchange the wakewrite (or sem->activity) test and the
> waiter->flags you can fold it into the next test (this means all the extra
> work would only be done, if we have a writer waiting at the top).

The reason for doing it this way is that it allows the compiler to discard
parts of the function when inlining it since the value is set at compile time
rather than being worked out at runtime. The value itself should be
disappeared entirely by the compiler.

David


  reply	other threads:[~2002-07-29  7:39 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2002-07-28 17:50 Patch: linux-2.5.29 __downgrade_write() for CONFIG_RWSEM_GENERIC_SPINLOCK Adam J. Richter
2002-07-28 18:07 ` Roman Zippel
2002-07-28 18:08 ` Christoph Hellwig
2002-07-28 22:55   ` Roman Zippel
2002-07-29  7:42     ` David Howells [this message]
2002-07-29  8:01       ` Roman Zippel
2002-07-29  8:31         ` David Howells
2002-07-29  9:13           ` David Howells
2002-07-29 11:42             ` Roman Zippel
2002-07-29 12:08               ` David Howells
2002-07-29 12:46                 ` Roman Zippel

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=9911.1027928536@warthog.cambridge.redhat.com \
    --to=dhowells@redhat.com \
    --cc=adam@yggdrasil.com \
    --cc=hch@infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=zippel@linux-m68k.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox