From: Jeremy Fitzhardinge <jeremy@goop.org>
To: benh@kernel.crashing.org
Cc: Zachary Amsden <zach@vmware.com>,
Rusty Russell <rusty@rustcorp.com.au>,
xen-devel <xen-devel@lists.xensource.com>,
Peter Zijlstra <a.p.zijlstra@chello.nl>,
kvm-devel <kvm-devel@lists.sourceforge.net>,
x86@kernel.org, LKML <linux-kernel@vger.kernel.org>,
Virtualization Mailing List <virtualization@lists.osdl.org>,
Hugh Dickins <hugh@veritas.com>, Ingo Molnar <mingo@elte.hu>,
Linus Torvalds <torvalds@linux-foundation.org>,
Thomas Gleixner <tglx@linutronix.de>
Subject: Re: [PATCH 1 of 4] mm: add a ptep_modify_prot transaction abstraction
Date: Wed, 18 Jun 2008 16:59:05 -0700 [thread overview]
Message-ID: <4859A149.9090004@goop.org> (raw)
In-Reply-To: <1213831403.8011.24.camel@pasglop>
Benjamin Herrenschmidt wrote:
> On Mon, 2008-06-16 at 04:30 -0700, Jeremy Fitzhardinge wrote:
>
>> The only current user of this interface is mprotect
>>
>
> Do you plan to use it with fork ultimately ?
>
Good point, I'd overlooked that. I guess that means using it in
ptep_set_wrprotect().
At present the x86 ptep_set_wrprotect() just uses clear_bit on the pte,
which is a locked cycle. Is that significantly cheaper than an xchg +
set? (Same number of locked operations...)
J
WARNING: multiple messages have this Message-ID (diff)
From: Jeremy Fitzhardinge <jeremy@goop.org>
To: benh@kernel.crashing.org
Cc: Ingo Molnar <mingo@elte.hu>, LKML <linux-kernel@vger.kernel.org>,
x86@kernel.org, xen-devel <xen-devel@lists.xensource.com>,
Thomas Gleixner <tglx@linutronix.de>,
Hugh Dickins <hugh@veritas.com>, Zachary Amsden <zach@vmware.com>,
kvm-devel <kvm-devel@lists.sourceforge.net>,
Virtualization Mailing List <virtualization@lists.osdl.org>,
Rusty Russell <rusty@rustcorp.com.au>,
Peter Zijlstra <a.p.zijlstra@chello.nl>,
Linus Torvalds <torvalds@linux-foundation.org>
Subject: Re: [PATCH 1 of 4] mm: add a ptep_modify_prot transaction abstraction
Date: Wed, 18 Jun 2008 16:59:05 -0700 [thread overview]
Message-ID: <4859A149.9090004@goop.org> (raw)
In-Reply-To: <1213831403.8011.24.camel@pasglop>
Benjamin Herrenschmidt wrote:
> On Mon, 2008-06-16 at 04:30 -0700, Jeremy Fitzhardinge wrote:
>
>> The only current user of this interface is mprotect
>>
>
> Do you plan to use it with fork ultimately ?
>
Good point, I'd overlooked that. I guess that means using it in
ptep_set_wrprotect().
At present the x86 ptep_set_wrprotect() just uses clear_bit on the pte,
which is a locked cycle. Is that significantly cheaper than an xchg +
set? (Same number of locked operations...)
J
next prev parent reply other threads:[~2008-06-18 23:59 UTC|newest]
Thread overview: 59+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-06-16 11:29 [PATCH 0 of 4] mm+paravirt+xen: add pte read-modify-write abstraction (take 2) Jeremy Fitzhardinge
2008-06-16 11:29 ` Jeremy Fitzhardinge
2008-06-16 11:30 ` [PATCH 1 of 4] mm: add a ptep_modify_prot transaction abstraction Jeremy Fitzhardinge
2008-06-16 11:30 ` Jeremy Fitzhardinge
2008-06-16 17:29 ` Linus Torvalds
2008-06-16 17:29 ` Linus Torvalds
2008-06-16 18:13 ` Hugh Dickins
2008-06-16 18:49 ` Ingo Molnar
2008-06-16 18:49 ` Ingo Molnar
2008-06-18 23:23 ` Benjamin Herrenschmidt
2008-06-18 23:59 ` Jeremy Fitzhardinge [this message]
2008-06-18 23:59 ` Jeremy Fitzhardinge
2008-06-19 0:15 ` Jeremy Fitzhardinge
2008-06-19 0:24 ` Linus Torvalds
2008-06-19 0:24 ` Linus Torvalds
2008-06-19 0:37 ` Jeremy Fitzhardinge
2008-06-19 0:37 ` Jeremy Fitzhardinge
2008-06-19 0:49 ` Linus Torvalds
2008-06-19 4:03 ` Linus Torvalds
2008-06-19 4:03 ` Linus Torvalds
2008-06-19 11:58 ` Ingo Molnar
2008-06-19 11:58 ` Ingo Molnar
2008-06-19 12:03 ` Ingo Molnar
2008-06-19 12:20 ` Akinobu Mita
2008-06-19 16:30 ` Linus Torvalds
2008-06-19 16:30 ` Linus Torvalds
2008-06-19 16:47 ` Ingo Molnar
2008-06-19 16:47 ` Ingo Molnar
2008-06-20 10:10 ` Ingo Molnar
2008-06-20 10:10 ` Ingo Molnar
2008-06-20 19:06 ` Jeremy Fitzhardinge
2008-06-20 19:06 ` Jeremy Fitzhardinge
2008-06-20 19:15 ` Linus Torvalds
2008-06-20 19:15 ` Linus Torvalds
2008-06-20 19:56 ` Ingo Molnar
2008-06-20 19:56 ` Ingo Molnar
2008-06-20 20:03 ` Linus Torvalds
2008-06-20 20:16 ` Jeremy Fitzhardinge
2008-06-20 20:16 ` Jeremy Fitzhardinge
2008-06-20 20:22 ` Jeremy Fitzhardinge
2008-06-21 6:06 ` Ingo Molnar
2008-06-21 6:06 ` Ingo Molnar
2008-06-20 20:05 ` Jeremy Fitzhardinge
2008-06-20 20:05 ` Jeremy Fitzhardinge
2008-06-19 0:39 ` Benjamin Herrenschmidt
2008-06-19 5:03 ` Jeremy Fitzhardinge
2008-06-19 7:20 ` Benjamin Herrenschmidt
2008-06-19 17:57 ` Jeremy Fitzhardinge
2008-06-19 17:57 ` Jeremy Fitzhardinge
2008-06-16 11:30 ` [PATCH 2 of 4] paravirt: add hooks for ptep_modify_prot_start/commit Jeremy Fitzhardinge
2008-06-16 11:30 ` [PATCH 3 of 4] xen: implement ptep_modify_prot_start/commit Jeremy Fitzhardinge
2008-06-16 11:30 ` Jeremy Fitzhardinge
2008-06-16 11:30 ` [PATCH 4 of 4] xen: add mechanism to extend existing multicalls Jeremy Fitzhardinge
2008-06-16 11:30 ` Jeremy Fitzhardinge
-- strict thread matches above, loose matches on Subject: below --
2008-05-31 0:04 [PATCH 0 of 4] mm+paravirt+xen: add pte read-modify-write abstraction (take 2) Jeremy Fitzhardinge
2008-05-31 0:04 ` [PATCH 1 of 4] mm: add a ptep_modify_prot transaction abstraction Jeremy Fitzhardinge
2008-06-02 11:13 ` Ingo Molnar
2008-06-02 11:13 ` Ingo Molnar
2008-06-02 11:57 ` Jeremy Fitzhardinge
2008-06-02 11:57 ` Jeremy Fitzhardinge
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=4859A149.9090004@goop.org \
--to=jeremy@goop.org \
--cc=a.p.zijlstra@chello.nl \
--cc=benh@kernel.crashing.org \
--cc=hugh@veritas.com \
--cc=kvm-devel@lists.sourceforge.net \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@elte.hu \
--cc=rusty@rustcorp.com.au \
--cc=tglx@linutronix.de \
--cc=torvalds@linux-foundation.org \
--cc=virtualization@lists.osdl.org \
--cc=x86@kernel.org \
--cc=xen-devel@lists.xensource.com \
--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.