From: Andrew Morton <akpm@linux-foundation.org>
To: Paul Mackerras <paulus@samba.org>
Cc: mm-commits@vger.kernel.org, clalance@redhat.com,
dada1@cosmosbay.com, dhecht@vmware.com, jeremy@goop.org,
jmorris@namei.org, johnstul@us.ibm.com, mingo@elte.hu,
prarit@redhat.com, ricklind@us.ibm.com, schwidefsky@de.ibm.com,
tglx@linutronix.de, zach@vmware.com
Subject: Re: + ignore-stolen-time-in-the-softlockup-watchdog-fix.patch added to -mm tree
Date: Tue, 24 Apr 2007 19:14:25 -0700 [thread overview]
Message-ID: <20070424191425.28a55eb6.akpm@linux-foundation.org> (raw)
In-Reply-To: <17966.45949.796715.978244@cargo.ozlabs.ibm.com>
On Wed, 25 Apr 2007 11:48:45 +1000 Paul Mackerras <paulus@samba.org> wrote:
> akpm@linux-foundation.org writes:
>
> > Avoid reevaluating smp_processor_id()
>
> > int this_cpu = smp_processor_id();
> > - unsigned long touch_timestamp = __get_cpu_var(touch_timestamp);
> > + unsigned long touch_timestamp = per_cpu(touch_timestamp, this_cpu);
>
> This is actually worse on those cpus that have a fast way to get to
> the current cpu's per-cpu data.
>
The patch adds 4 bytes (strange number) to powerpc text and removes 32 from
i386's. A net win, I guess.
i386 now has a considerably better smp_processor_id(), but no special-case
handling of per-cpu data. Maybe Jeremy has plans to move i386's per-cpu
data into the pda also?
next prev parent reply other threads:[~2007-04-25 2:15 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-04-24 20:45 + ignore-stolen-time-in-the-softlockup-watchdog-fix.patch added to -mm tree akpm
[not found] ` <17966.45949.796715.978244@cargo.ozlabs.ibm.com>
2007-04-25 2:14 ` Andrew Morton [this message]
[not found] ` <462EB849.4080402@goop.org>
2007-04-25 2:16 ` Andrew Morton
[not found] ` <462EDB1B.5010909@goop.org>
2007-04-25 4:48 ` Andrew Morton
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=20070424191425.28a55eb6.akpm@linux-foundation.org \
--to=akpm@linux-foundation.org \
--cc=clalance@redhat.com \
--cc=dada1@cosmosbay.com \
--cc=dhecht@vmware.com \
--cc=jeremy@goop.org \
--cc=jmorris@namei.org \
--cc=johnstul@us.ibm.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@elte.hu \
--cc=mm-commits@vger.kernel.org \
--cc=paulus@samba.org \
--cc=prarit@redhat.com \
--cc=ricklind@us.ibm.com \
--cc=schwidefsky@de.ibm.com \
--cc=tglx@linutronix.de \
--cc=zach@vmware.com \
/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.