The hypervisor can look at the value in wait_state_cycles for an estimate of
how busy dedicated processors are. Currently as the kernel never touches this
field so we appear to be 100% busy. Record the duration the kernel is in
powersave and pass that to the HV to provide a reasonable indication of
utilisation.
Signed-off-by: Tony Breeds <[EMAIL PROTECTED]>
---
arch/powerpc/platforms/pseries/setup.c | 4 ++++
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;
}
--
1.5.4.3
Yours Tony
linux.conf.au http://www.marchsouth.org/
Jan 19 - 24 2009 The Australian Linux Technical Conference!
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