From: Jan Kiszka <jan.kiszka@siemens.com>
To: Avi Kivity <avi@redhat.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>, kvm <kvm@vger.kernel.org>,
Zachary Amsden <zamsden@redhat.com>
Subject: Re: [PATCH 1/2] KVM: Convert kvm_lock to raw_spinlock
Date: Wed, 09 Feb 2011 13:31:01 +0100 [thread overview]
Message-ID: <4D528905.8030802@siemens.com> (raw)
In-Reply-To: <4D525D7D.8080306@redhat.com>
On 2011-02-09 10:25, Avi Kivity wrote:
> On 02/09/2011 11:24 AM, Avi Kivity wrote:
>> On 02/08/2011 01:55 PM, Jan Kiszka wrote:
>>> Code under this lock requires non-preemptibility. Ensure this also over
>>> -rt by converting it to raw spinlock.
>>>
>>
>> Please add a code comment documenting what data under this lock
>> requires it to be a raw spinlock.
>>
>
> Or better, put it in Documentation/kvm/locking.txt, which we'll try to
> grow to cover all locks.
>
Something like
[Documentation/kvm/locking.txt]
KVM Lock Overview
-----------------
1. Spin locks
1.1 tsc_write_lock
Type: raw
Arch: x86
Protects: kvm_arch::{last_tsc_write,last_tsc_nsec,last_tsc_offset}
tsc offset in vmcb
Comment: 'raw' because updating the tsc offsets must not be preempted
...
?
Jan
--
Siemens AG, Corporate Technology, CT T DE IT 1
Corporate Competence Center Embedded Linux
next prev parent reply other threads:[~2011-02-09 12:31 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-02-08 11:55 [PATCH 1/2] KVM: Convert kvm_lock to raw_spinlock Jan Kiszka
2011-02-09 9:24 ` Avi Kivity
2011-02-09 9:25 ` Avi Kivity
2011-02-09 12:31 ` Jan Kiszka [this message]
2011-02-09 13:20 ` Avi Kivity
2011-02-09 13:38 ` Avi Kivity
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=4D528905.8030802@siemens.com \
--to=jan.kiszka@siemens.com \
--cc=avi@redhat.com \
--cc=kvm@vger.kernel.org \
--cc=mtosatti@redhat.com \
--cc=zamsden@redhat.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).