Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 96366a8d authored by Tony Breeds's avatar Tony Breeds Committed by Paul Mackerras
Browse files

[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: default avatarTony Breeds <tony@bakeyournoodle.com>
Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
parent 71e91a0a

arch/powerpc/platforms/pseries/setup.c

+4 −0
Original line number Diff line number Diff line
@@ -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;

}