From: Jeremy Fitzhardinge <jeremy@goop.org>
To: Gerd Hoffmann <kraxel@redhat.com>
Cc: kvm-devel@lists.sourceforge.net, Marcelo Tosatti <mtosatti@redhat.com>
Subject: Re: [ RfC / patch ] kvmclock fixes
Date: Mon, 21 Apr 2008 23:38:19 +1000 [thread overview]
Message-ID: <480C98CB.4000209@goop.org> (raw)
In-Reply-To: <480C9011.7080507@redhat.com>
Gerd Hoffmann wrote:
> +cycle_t pvclock_clocksource_read(struct kvm_vcpu_time_info *src)
> +{
> + struct pvclock_shadow_time *shadow;
> + cycle_t ret;
> + unsigned version;
> +
> + shadow = &get_cpu_var(shadow_time);
> + do {
> + version = pvclock_get_time_values(shadow, src);
> + barrier();
> + ret = shadow->system_timestamp + pvclock_get_nsec_offset(shadow);
> + barrier();
>
Is barrier() strong enough? Does kvm guarantee that the per-cpu time
parameters are only ever updated by that cpu? I'm pretty sure Xen does,
so that's OK.
J
-------------------------------------------------------------------------
This SF.net email is sponsored by the 2008 JavaOne(SM) Conference
Don't miss this year's exciting event. There's still time to save $100.
Use priority code J8TL2D2.
http://ad.doubleclick.net/clk;198757673;13503038;p?http://java.sun.com/javaone
next prev parent reply other threads:[~2008-04-21 13:38 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-04-07 11:53 paravirt clock stil causing hangs in kvm-65 Nikola Ciprich
2008-04-07 21:34 ` Marcelo Tosatti
2008-04-08 1:18 ` Marcelo Tosatti
2008-04-08 5:59 ` Nikola Ciprich
2008-04-19 15:29 ` Marcelo Tosatti
2008-04-19 16:22 ` Glauber Costa
2008-04-19 16:49 ` Marcelo Tosatti
2008-04-21 7:15 ` Gerd Hoffmann
2008-04-21 8:33 ` [ RfC / patch ] kvmclock fixes Gerd Hoffmann
2008-04-21 9:57 ` Jeremy Fitzhardinge
2008-04-21 13:01 ` Gerd Hoffmann
2008-04-21 13:38 ` Jeremy Fitzhardinge [this message]
2008-04-24 13:20 ` paravirt clock stil causing hangs in kvm-65 Glauber Costa
2008-04-26 14:24 ` extmaillist
2008-04-19 16:29 ` Marcelo Tosatti
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=480C98CB.4000209@goop.org \
--to=jeremy@goop.org \
--cc=kraxel@redhat.com \
--cc=kvm-devel@lists.sourceforge.net \
--cc=mtosatti@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 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.