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authorTony Breeds <tony@bakeyournoodle.com>2008-03-17 05:23:29 (GMT)
committerPaul Mackerras <paulus@samba.org>2008-03-25 21:44:05 (GMT)
commit96366a8d3f17ee964802378d4a1f51fda86f070e (patch)
tree80ee328c588a1fbef0134c3ffcd8bb07267a22d8 /arch/powerpc/platforms
parent71e91a0abb839f8d2372236d8fe0513c295ec717 (diff)
downloadlinux-96366a8d3f17ee964802378d4a1f51fda86f070e.tar.xz
[POWERPC] Update wait_state_cycles in the VPA
The hypervisor can look at the value in the wait_state_cycles field of the VPA for an estimate of how busy dedicated processors are. Currently, as the kernel never touches this field, we appear to be 100% busy. This records the duration the kernel is in powersave and passes that to the HV to provide a reasonable indication of utilisation. Signed-off-by: Tony Breeds <tony@bakeyournoodle.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
Diffstat (limited to 'arch/powerpc/platforms')
-rw-r--r--arch/powerpc/platforms/pseries/setup.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/pseries/setup.c b/arch/powerpc/platforms/pseries/setup.c
index fdb9b1c..90555a3 100644
--- a/arch/powerpc/platforms/pseries/setup.c
+++ b/arch/powerpc/platforms/pseries/setup.c
@@ -393,6 +393,7 @@ static void pseries_dedicated_idle_sleep(void)
{
unsigned int cpu = smp_processor_id();
unsigned long start_snooze;
+ unsigned long in_purr, out_purr;
/*
* Indicate to the HV that we are idle. Now would be
@@ -400,6 +401,7 @@ static void pseries_dedicated_idle_sleep(void)
*/
get_lppaca()->idle = 1;
get_lppaca()->donate_dedicated_cpu = 1;
+ in_purr = mfspr(SPRN_PURR);
/*
* We come in with interrupts disabled, and need_resched()
@@ -432,6 +434,8 @@ static void pseries_dedicated_idle_sleep(void)
out:
HMT_medium();
+ out_purr = mfspr(SPRN_PURR);
+ get_lppaca()->wait_state_cycles += out_purr - in_purr;
get_lppaca()->donate_dedicated_cpu = 0;
get_lppaca()->idle = 0;
}