From: Jeremy Fitzhardinge <jeremy@goop.org>
To: Rusty Russell <rusty@rustcorp.com.au>
Cc: lkml - Kernel Mailing List <linux-kernel@vger.kernel.org>,
Zachary Amsden <zach@vmware.com>,
Jeremy Fitzhardinge <jeremy@xensource.com>,
Ingo Molnar <mingo@elte.hu>,
Andrew Morton <akpm@linux-foundation.org>,
Andi Kleen <ak@suse.de>
Subject: Re: [PATCH 0/8] x86 boot, pda and gdt cleanups
Date: Wed, 14 Mar 2007 18:57:01 -0700 [thread overview]
Message-ID: <45F8A7ED.7090009@goop.org> (raw)
In-Reply-To: <1173916541.19022.47.camel@localhost.localdomain>
Rusty Russell wrote:
> Hmm, this invalidated my assumption that write_gdt_entry is always a
> write to this cpu's active gdt. Better fix is not to call it twice
> anyway...
>
No, I don't think that's true. I implemented the write_*_entry
functions with the assumption they could be called either on setup or on
an in-use entry. I think its good policy to use it all the time anyway,
since the pv_ops backend might want to fiddle with the values on the way
through.
I tried to avoid calling init_gdt twice, but it seemed cleaner to just
let it happen.
> Getting rid of the call in smp_prepare_boot_cpu currently works, but
> it's fragile: __get_cpu_var(x) && per_cpu(x, smp_processor_id()) will
> differ, and changes made to __get_cpu_var(x) will vanish...
>
Yes. I think its definitely a good idea to call init_gdt asap after
doing the percpu setup.
> Fortunately, UP doesn't have to call init_gdt at all, so I think it's
> better to place it in smp_prepare_boot_cpu only and then clean up the UP
> code. I'll try now...
>
It doesn't? The per-cpu gdt is the same as the boot gdt?
J
prev parent reply other threads:[~2007-03-15 1:57 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-03-06 12:39 [PATCH 0/8] x86 boot, pda and gdt cleanups Rusty Russell
2007-03-06 12:53 ` [PATCH 1/8] Remove cpu_gdt_table: use boot_gdt_table until migration to per-cpu Rusty Russell
2007-03-06 12:54 ` [PATCH 2/8] Remove NR_CPUS from asm-generic/percpu.h Rusty Russell
2007-03-06 12:55 ` [PATCH 3/8] Use per-cpu variables for GDT, PDA Rusty Russell
2007-03-06 12:57 ` [PATCH 4/8] Cleanup setup_pda Rusty Russell
2007-03-06 12:58 ` [PATCH 5/8] Cleanup GDT access Rusty Russell
2007-03-06 13:00 ` [PATCH 6/8] Allow per-cpu variables to be page-aligned Rusty Russell
2007-03-06 13:01 ` [PATCH 7/8] Page-align the GDT Rusty Russell
2007-03-06 13:03 ` [PATCH 8/8] Convert PDA into the percpu section Rusty Russell
2007-03-06 13:10 ` Ingo Molnar
2007-03-07 0:12 ` Rusty Russell
2007-03-07 0:35 ` Jeremy Fitzhardinge
2007-03-06 18:28 ` Jeremy Fitzhardinge
2007-03-06 19:34 ` Andi Kleen
2007-03-06 18:37 ` Jeremy Fitzhardinge
2007-03-07 0:33 ` Rusty Russell
2007-03-07 11:55 ` Rusty Russell
2007-03-13 17:15 ` Jeremy Fitzhardinge
2007-03-14 2:27 ` Rusty Russell
2007-03-06 13:15 ` [PATCH 6/8] Allow per-cpu variables to be page-aligned Ingo Molnar
2007-03-07 0:16 ` Rusty Russell
2007-03-07 0:44 ` H. Peter Anvin
2007-03-06 18:17 ` Jeremy Fitzhardinge
2007-03-07 0:29 ` Rusty Russell
2007-03-06 18:16 ` [PATCH 5/8] Cleanup GDT access Jeremy Fitzhardinge
2007-03-06 18:14 ` [PATCH 3/8] Use per-cpu variables for GDT, PDA Jeremy Fitzhardinge
2007-03-06 13:21 ` [PATCH 2/8] Remove NR_CPUS from asm-generic/percpu.h Ingo Molnar
2007-03-06 13:20 ` [PATCH 1/8] Remove cpu_gdt_table: use boot_gdt_table until migration to per-cpu Ingo Molnar
2007-03-06 13:26 ` Ingo Molnar
2007-03-07 0:22 ` Rusty Russell
2007-03-13 20:48 ` [PATCH 0/8] x86 boot, pda and gdt cleanups Jeremy Fitzhardinge
2007-03-14 2:25 ` Rusty Russell
2007-03-14 4:39 ` Jeremy Fitzhardinge
2007-03-14 6:54 ` Rusty Russell
2007-03-14 23:55 ` Rusty Russell
2007-03-15 1:57 ` Jeremy Fitzhardinge [this message]
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=45F8A7ED.7090009@goop.org \
--to=jeremy@goop.org \
--cc=ak@suse.de \
--cc=akpm@linux-foundation.org \
--cc=jeremy@xensource.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@elte.hu \
--cc=rusty@rustcorp.com.au \
--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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).