From: Jeremy Fitzhardinge <jeremy@goop.org>
To: Eric Dumazet <dada1@cosmosbay.com>
Cc: Ingo Molnar <mingo@elte.hu>, Tejun Heo <htejun@gmail.com>,
linux kernel <linux-kernel@vger.kernel.org>,
Linux Netdev List <netdev@vger.kernel.org>,
Joe Perches <joe@perches.com>,
Rusty Russell <rusty@rustcorp.com.au>
Subject: Re: [PATCH] x86: percpu_to_op() misses memory and flags clobbers
Date: Wed, 01 Apr 2009 11:07:29 -0700 [thread overview]
Message-ID: <49D3AD61.5090206@goop.org> (raw)
In-Reply-To: <49D3A0C2.9000403@cosmosbay.com>
Eric Dumazet wrote:
> +#define percpu_inc(var) percpu_to_op0("inc", per_cpu__##var)
> +#define percpu_dec(var) percpu_to_op0("dec", per_cpu__##var)
>
There's probably not a lot of value in this. The Intel and AMD
optimisation guides tend to deprecate inc/dec in favour of using
add/sub, because the former can cause pipeline stalls due to its partial
flags update.
J
next prev parent reply other threads:[~2009-04-01 18:08 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-04-01 8:13 [PATCH] x86: percpu_to_op() misses memory and flags clobbers Eric Dumazet
2009-04-01 9:02 ` Jeremy Fitzhardinge
2009-04-01 10:14 ` Eric Dumazet
2009-04-01 16:12 ` Ingo Molnar
2009-04-01 16:41 ` Jeremy Fitzhardinge
2009-04-01 16:44 ` Ingo Molnar
2009-04-01 17:13 ` Eric Dumazet
2009-04-01 18:07 ` Jeremy Fitzhardinge [this message]
2009-04-01 18:47 ` Eric Dumazet
2009-04-02 9:52 ` Herbert Xu
2009-04-02 14:12 ` Jeremy Fitzhardinge
2009-04-01 18:44 ` [RFC] percpu: convert SNMP mibs to new infra Eric Dumazet
2009-04-02 0:13 ` Tejun Heo
2009-04-02 4:05 ` Ingo Molnar
2009-04-02 8:07 ` [PATCH] " Eric Dumazet
2009-04-03 0:39 ` Tejun Heo
2009-04-03 17:10 ` Ingo Molnar
2009-04-02 5:04 ` [RFC] " Rusty Russell
2009-04-02 5:19 ` Eric Dumazet
2009-04-02 11:46 ` Rusty Russell
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=49D3AD61.5090206@goop.org \
--to=jeremy@goop.org \
--cc=dada1@cosmosbay.com \
--cc=htejun@gmail.com \
--cc=joe@perches.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@elte.hu \
--cc=netdev@vger.kernel.org \
--cc=rusty@rustcorp.com.au \
/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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.