From: Andi Kleen <ak@suse.de>
To: Anton Blanchard <anton@samba.org>
Cc: Brian Gerst <bgerst@didntduck.org>,
lkml <linux-kernel@vger.kernel.org>,
Andrew Morton <akpm@osdl.org>
Subject: Re: [PATCH] Fix hotplug cpu on x86_64
Date: Sat, 8 Oct 2005 12:33:12 +0200 [thread overview]
Message-ID: <200510081233.12551.ak@suse.de> (raw)
In-Reply-To: <20051008005016.GG5210@krispykreme>
On Saturday 08 October 2005 02:50, Anton Blanchard wrote:
> Hi,
>
> > I also have a followon patch to avoid the extreme memory wastage
> > currently caused by hotplug CPUs (e.g. with NR_CPUS==128 you currently
> > lose 4MB of memory just for preallocated per CPU data). But that is
> > something for post 2.6.14.
>
> Im interested in doing that on ppc64 too. Are you currently only
> creating per cpu data areas for possible cpus?
Yes. In fact that caused some of the problems that lead to the investigation
of this.
> The generic code does
> NR_CPUS worth, we should change that in 2.6.15.
You need to audit all architecture code then that fills up possible map.
(at least for the architectures that support CPU hotplug)
With that change x86-64 could move back to the generic code BTW -
the numa allocation in the architecture specific code doesn't work anymore
because we usually find out about the cpu<->node mapping now only
afterwards :/
-Andi
next prev parent reply other threads:[~2005-10-08 10:31 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-10-05 7:16 Bogus load average and cpu times on x86_64 SMP kernels Brian Gerst
2005-10-05 18:00 ` Brian Gerst
2005-10-07 4:15 ` [PATCH] Fix hotplug cpu on x86_64 Brian Gerst
2005-10-07 9:50 ` Andi Kleen
2005-10-08 0:50 ` Anton Blanchard
2005-10-08 10:33 ` Andi Kleen [this message]
-- strict thread matches above, loose matches on Subject: below --
2005-10-07 15:07 Protasevich, Natalie
2005-10-07 15:27 ` Brian Gerst
2005-10-07 16:24 ` Andi Kleen
2005-10-07 16:00 Protasevich, Natalie
2005-10-07 16:42 Protasevich, Natalie
2005-10-07 17:25 ` Andi Kleen
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=200510081233.12551.ak@suse.de \
--to=ak@suse.de \
--cc=akpm@osdl.org \
--cc=anton@samba.org \
--cc=bgerst@didntduck.org \
--cc=linux-kernel@vger.kernel.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