From: Andrew Cooper <andrew.cooper3@citrix.com>
To: Jan Beulich <JBeulich@suse.com>
Cc: Jinsong Liu <jinsong.liu@intel.com>,
xen-devel <xen-devel@lists.xenproject.org>,
Keir Fraser <keir@xen.org>
Subject: Re: [PATCH] x86/cpuidle: publish new states only after fully initializing them
Date: Tue, 10 Dec 2013 15:40:21 +0000 [thread overview]
Message-ID: <52A735E5.9000503@citrix.com> (raw)
In-Reply-To: <52A740B5020000780010BEC8@nat28.tlf.novell.com>
[-- Attachment #1.1: Type: text/plain, Size: 1448 bytes --]
On 10/12/13 15:26, Jan Beulich wrote:
> Since state information coming from Dom0 can arrive at any time, on
> any CPU, we ought to make sure that a new state is fully initialized
> before the target CPU might be using it.
>
> Once touching that code, also do minor cleanup: A missing (but benign)
> "break" and some white space adjustments.
>
> Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
>
> --- a/xen/arch/x86/acpi/cpu_idle.c
> +++ b/xen/arch/x86/acpi/cpu_idle.c
> @@ -912,7 +912,7 @@ static void set_cx(
> acpi_power->cpu, xen_cx->type);
> return;
> }
> - cx = &acpi_power->states[acpi_power->count++];
> + cx = &acpi_power->states[acpi_power->count];
> cx->type = xen_cx->type;
> break;
> }
> @@ -937,11 +937,14 @@ static void set_cx(
> break;
> default:
> cx->entry_method = ACPI_CSTATE_EM_NONE;
> + break;
> }
>
> - cx->latency = xen_cx->latency;
> -
> + cx->latency = xen_cx->latency;
> cx->target_residency = cx->latency * latency_factor;
> +
> + smp_wmb();
> + acpi_power->count++;
> if ( cx->type == ACPI_STATE_C1 || cx->type == ACPI_STATE_C2 )
> acpi_power->safe_state = cx;
> }
>
>
>
>
>
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xen.org
> http://lists.xen.org/xen-devel
[-- Attachment #1.2: Type: text/html, Size: 2364 bytes --]
[-- Attachment #2: Type: text/plain, Size: 126 bytes --]
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xen.org
http://lists.xen.org/xen-devel
next prev parent reply other threads:[~2013-12-10 15:40 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-12-10 15:26 [PATCH] x86/cpuidle: publish new states only after fully initializing them Jan Beulich
2013-12-10 15:40 ` Andrew Cooper [this message]
2013-12-11 6:39 ` Liu, Jinsong
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=52A735E5.9000503@citrix.com \
--to=andrew.cooper3@citrix.com \
--cc=JBeulich@suse.com \
--cc=jinsong.liu@intel.com \
--cc=keir@xen.org \
--cc=xen-devel@lists.xenproject.org \
/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).