From: Jeremy Fitzhardinge <jeremy@goop.org>
To: Brian Gerst <brgerst@gmail.com>
Cc: Tejun Heo <htejun@gmail.com>, Ingo Molnar <mingo@elte.hu>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: unified percpu stuff
Date: Tue, 27 Jan 2009 09:50:58 -0800 [thread overview]
Message-ID: <497F4982.8060103@goop.org> (raw)
In-Reply-To: <73c1f2160901270435t5623b0d8tbf832b1f8a575b2e@mail.gmail.com>
Brian Gerst wrote:
>> BTW, does the initial cpu0 percpu area get reallocated and moved during
>> boot, or does cpu0 keep using the same memory forever?
>>
>
> It is reallocated in setup_per_cpu_areas().
>
Hm, OK. What's the reason we need to move cpu 0's percpu area? Its
always seemed a bit awkward.
Once it has been moved, how can I find the address of a variable in the
original boot-time cpu 0 percpu area? There's a couple of pages which
Xen will have marked RO which need to be made RW if they're being freed
back into the kernel pool. Currently I use per_cpu_var(gdt_page), but
guess that's a small offset rather than a directly usable address.
Thanks,
J
next prev parent reply other threads:[~2009-01-27 17:51 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-01-27 1:12 unified percpu stuff Jeremy Fitzhardinge
2009-01-27 4:17 ` Tejun Heo
2009-01-29 10:43 ` Jeremy Fitzhardinge
2009-01-29 11:01 ` Tejun Heo
2009-01-29 13:43 ` [PATCH] x86: pass in cpu number to switch_to_new_gdt() Brian Gerst
2009-01-29 21:36 ` Jeremy Fitzhardinge
2009-01-29 21:36 ` [PATCH 1/2] x86: split loading percpu segments from loading gdt Jeremy Fitzhardinge
2009-01-29 21:36 ` [PATCH 2/2] xen: setup percpu data pointers Jeremy Fitzhardinge
2009-01-30 8:50 ` Tejun Heo
2009-01-30 8:50 ` [PATCH] x86: pass in cpu number to switch_to_new_gdt() Tejun Heo
2009-01-27 5:57 ` unified percpu stuff Brian Gerst
2009-01-27 7:24 ` Jeremy Fitzhardinge
2009-01-27 12:35 ` Brian Gerst
2009-01-27 17:50 ` Jeremy Fitzhardinge [this message]
2009-01-27 19:07 ` Brian Gerst
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=497F4982.8060103@goop.org \
--to=jeremy@goop.org \
--cc=brgerst@gmail.com \
--cc=htejun@gmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@elte.hu \
/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