Jan Beulich
2013-Dec-10 15:26 UTC
[PATCH] x86/cpuidle: publish new states only after fully initializing them
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>
--- 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
Andrew Cooper
2013-Dec-10 15:40 UTC
Re: [PATCH] x86/cpuidle: publish new states only after fully initializing them
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_______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel
Liu, Jinsong
2013-Dec-11 06:39 UTC
Re: [PATCH] x86/cpuidle: publish new states only after fully initializing them
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: Liu Jinsong <jinsong.liu@intel.com>