Amit Kucheria <amit.kucheria@xxxxxxxxxx> writes: > On 10 Aug 28, vishwanath.sripathy@xxxxxxxxxx wrote: >> From: Vishwanath BS <vishwanath.sripathy@xxxxxxxxxx> >> >> This patch has instrumentation code for measuring latencies for >> various CPUIdle C states for OMAP. Idea here is to capture the >> timestamp at various phases of CPU Idle and then compute the sw >> latency for various c states. For OMAP, 32k clock is chosen as >> reference clock this as is an always on clock. wkup domain memory >> (scratchpad memory) is used for storing timestamps. One can see the >> worstcase latencies in below sysfs entries (after enabling CONFIG_CPU_IDLE_PROF >> in .config). This information can be used to correctly configure cpu idle >> latencies for various C states after adding HW latencies for each of >> these sw latencies. >> /sys/devices/system/cpu/cpu0/cpuidle/state<n>/actual_latency >> /sys/devices/system/cpu/cpu0/cpuidle/state<n>/sleep_latency >> /sys/devices/system/cpu/cpu0/cpuidle/state<n>/wkup_latency >> >> THis patch is tested on OMAP ZOOM3 using kevin's pm branch. >> >> Signed-off-by: Vishwanath BS <vishwanath.sripathy@xxxxxxxxxx> >> Cc: linaro-dev@xxxxxxxxxxxxxxxx >> --- >> arch/arm/mach-omap2/cpuidle34xx.c | 58 ++++++++++++++++-- >> arch/arm/mach-omap2/pm.h | 5 ++ >> arch/arm/mach-omap2/sleep34xx.S | 121 +++++++++++++++++++++++++++++++++++++ >> drivers/cpuidle/Kconfig | 5 ++ >> drivers/cpuidle/sysfs.c | 16 +++++- >> include/linux/cpuidle.h | 3 + >> 6 files changed, 202 insertions(+), 6 deletions(-) > > You should perhaps cc Len Brown and LKML for V2 to get acceptance for the new > counters in cpuidle Before a v2, we need to have some discussions about the general direction of how to best do PM instrumentation. As I said in my review of this patch[1], I am not a fan of the current approach. Kevin [1] http://marc.info/?l=linux-omap&m=128293652216542&w=2 NOTE: This post may not have made it to linaro-dev since it's moderated, an I wasn't subscribed when I posted this, but am now. -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
