Add two timestamps to measure PSCI cache flush overhead

Testing showed that the time spent in a cluster power down
operation is dominated by cache flushes.  Add two more timestamps
in runtime instrumentation to keep track of the time spent
flushing the L1/L2 caches.

Change-Id: I4c5a04e7663543225a85d3c6b271d7b706deffc4
Signed-off-by: dp-arm <dimitris.papastamos@arm.com>
This commit is contained in:
dp-arm 2016-11-15 13:25:30 +00:00
parent 1b5fa6ef10
commit 7941816a34
3 changed files with 37 additions and 1 deletions

View File

@ -31,11 +31,13 @@
#ifndef __RUNTIME_INSTR_H__
#define __RUNTIME_INSTR_H__
#define RT_INSTR_TOTAL_IDS 4
#define RT_INSTR_ENTER_PSCI 0
#define RT_INSTR_EXIT_PSCI 1
#define RT_INSTR_ENTER_HW_LOW_PWR 2
#define RT_INSTR_EXIT_HW_LOW_PWR 3
#define RT_INSTR_ENTER_CFLUSH 4
#define RT_INSTR_EXIT_CFLUSH 5
#define RT_INSTR_TOTAL_IDS 6
#ifndef __ASSEMBLY__
PMF_DECLARE_CAPTURE_TIMESTAMP(rt_instr_svc)

View File

@ -107,12 +107,29 @@ int psci_do_cpu_off(unsigned int end_pwrlvl)
psci_stats_update_pwr_down(end_pwrlvl, &state_info);
#endif
#if ENABLE_RUNTIME_INSTRUMENTATION
/*
* Flush cache line so that even if CPU power down happens
* the timestamp update is reflected in memory.
*/
PMF_CAPTURE_TIMESTAMP(rt_instr_svc,
RT_INSTR_ENTER_CFLUSH,
PMF_CACHE_MAINT);
#endif
/*
* Arch. management. Perform the necessary steps to flush all
* cpu caches.
*/
psci_do_pwrdown_cache_maintenance(psci_find_max_off_lvl(&state_info));
#if ENABLE_RUNTIME_INSTRUMENTATION
PMF_CAPTURE_TIMESTAMP(rt_instr_svc,
RT_INSTR_EXIT_CFLUSH,
PMF_NO_CACHE_MAINT);
#endif
/*
* Plat. management: Perform platform specific actions to turn this
* cpu off e.g. exit cpu coherency, program the power controller etc.

View File

@ -109,6 +109,17 @@ static void psci_suspend_to_pwrdown_start(unsigned int end_pwrlvl,
*/
cm_init_my_context(ep);
#if ENABLE_RUNTIME_INSTRUMENTATION
/*
* Flush cache line so that even if CPU power down happens
* the timestamp update is reflected in memory.
*/
PMF_CAPTURE_TIMESTAMP(rt_instr_svc,
RT_INSTR_ENTER_CFLUSH,
PMF_CACHE_MAINT);
#endif
/*
* Arch. management. Perform the necessary steps to flush all
* cpu caches. Currently we assume that the power level correspond
@ -117,6 +128,12 @@ static void psci_suspend_to_pwrdown_start(unsigned int end_pwrlvl,
* and the cpu-ops power down to perform from the platform.
*/
psci_do_pwrdown_cache_maintenance(max_off_lvl);
#if ENABLE_RUNTIME_INSTRUMENTATION
PMF_CAPTURE_TIMESTAMP(rt_instr_svc,
RT_INSTR_EXIT_CFLUSH,
PMF_NO_CACHE_MAINT);
#endif
}
/*******************************************************************************