From: Tony Breeds Date: Mon, 17 Mar 2008 05:23:29 +0000 (+1100) Subject: [POWERPC] Update wait_state_cycles in the VPA X-Git-Tag: v2.6.26-rc1~1125^2~137 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=96366a8d3f17ee964802378d4a1f51fda86f070e;p=linux-2.6 [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 Signed-off-by: Paul Mackerras --- diff --git a/arch/powerpc/platforms/pseries/setup.c b/arch/powerpc/platforms/pseries/setup.c index fdb9b1c8f9..90555a39fe 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; }