> -----Original Message-----
> From: linux-omap-ow...@vger.kernel.org [mailto:linux-omap-
> ow...@vger.kernel.org] On Behalf Of C V, Silesh
> Sent: Friday, August 27, 2010 3:28 PM
> To: vishwanath.sripa...@linaro.org
> Cc: linux-o...@vger.kernel.org; linaro-dev@lists.linaro.org
> Subject: Re: [PATCH] OMAP CPUIDLE: CPU Idle latency measurement
>
> g 28, 2010 at 3:38 AM, <vishwanath.sripa...@linaro.org> wrote:
> > From: Vishwanath BS <vishwanath.sripa...@linaro.org>
> >
> > 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.sripa...@linaro.org>
> > Cc: linaro-dev@lists.linaro.org
> > ---
> > 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(-)
> >
> > diff --git a/arch/arm/mach-omap2/cpuidle34xx.c b/arch/arm/mach-
> omap2/cpuidle34xx.c
> > index 3d3d035..398bef8
> > --- a/arch/arm/mach-omap2/cpuidle34xx.c
> > +++ b/arch/arm/mach-omap2/cpuidle34xx.c
> > @@ -25,6 +25,7 @@
> > #include <linux/sched.h>
> > #include <linux/cpuidle.h>
> >
> > +#include <linux/clk.h>
> > #include <plat/prcm.h>
> > #include <plat/irqs.h>
> > #include <plat/powerdomain.h>
> > @@ -86,6 +87,11 @@ static struct cpuidle_params cpuidle_params_table[] = {
> > {1, 10000, 30000, 300000},
> > };
> >
> > +#ifdef CONFIG_CPU_IDLE_PROF
> > +static struct clk *clk_32k;
> > +#define CONVERT_32K_USEC(lat) (lat * (USEC_PER_SEC/clk_get_rate(clk_32k)))
> > +#endif
> > +
> > static int omap3_idle_bm_check(void)
> > {
> > if (!omap3_can_sleep())
> > @@ -115,21 +121,28 @@ static int _cpuidle_deny_idle(struct powerdomain
> *pwrdm,
> > * Called from the CPUidle framework to program the device to the
> > * specified target state selected by the governor.
> > */
> > +
> > static int omap3_enter_idle(struct cpuidle_device *dev,
> > struct cpuidle_state *state)
> > {
> > struct omap3_processor_cx *cx = cpuidle_get_statedata(state);
> > struct timespec ts_preidle, ts_postidle, ts_idle;
> > u32 mpu_state = cx->mpu_state, core_state = cx->core_state;
> > +#ifdef CONFIG_CPU_IDLE_PROF
> > + int idle_time, latency;
> > + long sleep_time, wkup_time, total_sleep_time;
> > + long preidle_time, postidle_time;
> > +#endif
> >
> > current_cx_state = *cx;
> >
> > - /* Used to keep track of the total time in idle */
> > - getnstimeofday(&ts_preidle);
> > -
> > local_irq_disable();
> > local_fiq_disable();
> > -
> > + /* Used to keep track of the total time in idle */
> > + getnstimeofday(&ts_preidle);
> > +#ifdef CONFIG_CPU_IDLE_PROF
> > + preidle_time = omap3_sram_get_32k_tick();
> > +#endif
> > pwrdm_set_next_pwrst(mpu_pd, mpu_state);
> > pwrdm_set_next_pwrst(core_pd, core_state);
> >
> > @@ -153,9 +166,39 @@ return_sleep_time:
> > getnstimeofday(&ts_postidle);
> > ts_idle = timespec_sub(ts_postidle, ts_preidle);
> >
> > +#ifdef CONFIG_CPU_IDLE_PROF
> > + postidle_time = omap3_sram_get_32k_tick();
> > +#endif
> > local_irq_enable();
> > local_fiq_enable();
> >
> > +#ifdef CONFIG_CPU_IDLE_PROF
> > + sleep_time = omap3_sram_get_sleep_time();
> > + wkup_time = omap3_sram_get_wkup_time();
> > +
> > + /* take care of overflow */
> > + if (postidle_time < preidle_time)
> > + postidle_time += (u32) 0xffffffff;
> > + if (wkup_time < sleep_time)
> > + wkup_time += (u32) 0xffffffff;
> > +
> > + idle_time = postidle_time - preidle_time;
> > + total_sleep_time = wkup_time - sleep_time;
> > + latency = idle_time - total_sleep_time;
> > + sleep_time = omap3_sram_get_sleep_time();
> > + wkup_time = omap3_sram_get_wkup_time();
> > +
> > + /* calculate average latency after ignoring sprious ones */
> > + if ((total_sleep_time > 0) && (latency > state->actual_latency)
> > + && (latency >= 0)) {
> > + state->actual_latency = CONVERT_32K_USEC(latency);
> > + latency = (sleep_time - preidle_time);
> > + state->sleep_latency = CONVERT_32K_USEC(latency);
> > + latency = postidle_time - wkup_time;
> > + state->wkup_latency = CONVERT_32K_USEC(latency);
> > + }
> > +#endif
> > +
> > return ts_idle.tv_nsec / NSEC_PER_USEC + ts_idle.tv_sec *
> > USEC_PER_SEC;
> > }
> >
> > @@ -423,7 +466,9 @@ int __init omap3_idle_init(void)
> > struct omap3_processor_cx *cx;
> > struct cpuidle_state *state;
> > struct cpuidle_device *dev;
> > -
> > +#ifdef CONFIG_CPU_IDLE_PROF
> > + static struct device dummy_device;
> > +#endif
> > mpu_pd = pwrdm_lookup("mpu_pwrdm");
> > core_pd = pwrdm_lookup("core_pwrdm");
> >
> > @@ -456,6 +501,9 @@ int __init omap3_idle_init(void)
> >
> > omap3_cpuidle_update_states();
> >
> > +#ifdef CONFIG_CPU_IDLE_PROF
> > + clk_32k = clk_get(&dummy_device, "wkup_32k_fck");
> > +#endif
> > if (cpuidle_register_device(dev)) {
> > printk(KERN_ERR "%s: CPUidle register device failed\n",
> > __func__);
> > diff --git a/arch/arm/mach-omap2/pm.h b/arch/arm/mach-omap2/pm.h
> > index 3de6ece..e62e87d 100644
> > --- a/arch/arm/mach-omap2/pm.h
> > +++ b/arch/arm/mach-omap2/pm.h
> > @@ -82,4 +82,9 @@ extern unsigned int save_secure_ram_context_sz;
> > extern unsigned int omap24xx_cpu_suspend_sz;
> > extern unsigned int omap34xx_cpu_suspend_sz;
> >
> > +#ifdef CONFIG_CPU_IDLE_PROF
> > +extern u32 omap3_sram_get_wkup_time();
> > +extern u32 omap3_sram_get_sleep_time();
> > +extern u32 omap3_sram_get_32k_tick();
> > +#endif
> > #endif
> > diff --git a/arch/arm/mach-omap2/sleep34xx.S b/arch/arm/mach-
> omap2/sleep34xx.S
> > index d522cd7..8dec5ef 100644
> > --- a/arch/arm/mach-omap2/sleep34xx.S
> > +++ b/arch/arm/mach-omap2/sleep34xx.S
> > @@ -59,6 +59,20 @@
> > #define SDRC_DLLA_STATUS_V
> OMAP34XX_SDRC_REGADDR(SDRC_DLLA_STATUS)
> > #define SDRC_DLLA_CTRL_V OMAP34XX_SDRC_REGADDR(SDRC_DLLA_CTRL)
> >
> > +#define TIMER_32K_SYNC_P 0x48320010
> > +#define TIMER_32K_SYNC OMAP2_L4_IO_ADDRESS(TIMER_32K_SYNC_P)
> > +
> > +#define SCRATCHPAD_SLEEP_TIME_OFFSET 0x9f8
> > +#define SCRATCHPAD_WKUP_TIME_OFFSET 0x9fc
> > +#define SCRATCHPAD_SLEEP_TIME
> OMAP343X_CTRL_REGADDR(SCRATCHPAD_SLEEP_TIME_OFFSET)
> > +#define SCRATCHPAD_WKUP_TIME
> OMAP343X_CTRL_REGADDR(SCRATCHPAD_WKUP_TIME_OFFSET)
> > +#define SCRATCHPAD_WKUP_TIME_P OMAP343X_CTRL_BASE +
> SCRATCHPAD_WKUP_TIME_OFFSET
> > +
> > +#define CM_ICLKEN_WKUP OMAP34XX_CM_REGADDR(WKUP_MOD, CM_ICLKEN)
> > +#define CM_ICLKEN_WKUP_P OMAP3430_CM_BASE + WKUP_MOD +
> CM_ICLKEN
> > +#define CM_IDLEST_WKUP OMAP34XX_CM_REGADDR(WKUP_MOD, CM_IDLEST)
> > +#define CM_IDLEST_WKUP_P OMAP3430_CM_BASE + WKUP_MOD +
> CM_IDLEST
> > +
> > .text
> > /* Function to aquire the semaphore in scratchpad */
> > ENTRY(lock_scratchpad_sem)
> > @@ -183,7 +197,31 @@ api_params:
> > .word 0x4, 0x0, 0x0, 0x1, 0x1
> > ENTRY(save_secure_ram_context_sz)
> > .word . - save_secure_ram_context
> > +#ifdef CONFIG_CPU_IDLE_PROF
> > +ENTRY(omap3_sram_get_wkup_time)
> > + stmfd sp!, {lr} @ save registers on stack
> > + ldr r0, wkup_time
> > + ldr r0, [r0]
> > + ldmfd sp!, {pc} @ restore regs and return
> > +ENTRY(omap3_sram_get_wkup_time_sz)
> > + .word . - omap3_sram_get_wkup_time
> > +
> > +ENTRY(omap3_sram_get_sleep_time)
> > + stmfd sp!, {lr} @ save registers on stack
> > + ldr r0, sleep_time
> > + ldr r0, [r0]
> > + ldmfd sp!, {pc} @ restore regs and return
> > +ENTRY(omap3_sram_get_sleep_time_sz)
> > + .word . - omap3_sram_get_sleep_time
> >
> > +ENTRY(omap3_sram_get_32k_tick)
> > + stmfd sp!, {lr} @ save registers on stack
> > + ldr r0, sync_32k_timer
> > + ldr r0, [r0]
> > + ldmfd sp!, {pc} @ restore regs and return
> > +ENTRY(omap3_sram_get_32k_tick_sz)
> > + .word . - omap3_sram_get_32k_tick
> > +#endif
> > /*
> > * Forces OMAP into idle state
> > *
> > @@ -207,6 +245,13 @@ loop:
> > cmp r1, #0x0
> > /* If context save is required, do that and execute wfi */
> > bne save_context_wfi
> > +
> > +#ifdef CONFIG_CPU_IDLE_PROF
> > + ldr r4, sync_32k_timer
> > + ldr r5, [r4]
> > + ldr r6, sleep_time
> > + str r5, [r6]
> > +#endif
> > /* Data memory barrier and Data sync barrier */
> > mov r1, #0
> > mcr p15, 0, r1, c7, c10, 4
> > @@ -224,8 +269,25 @@ loop:
> > nop
> > nop
> > nop
> > +#ifdef CONFIG_CPU_IDLE_PROF
> > + ldr r4, iclken_wkup
> > + ldr r5, [r4]
> > + orr r5, r5, #0x4
> > + str r5, [r4]
> > + ldr r4, idlest_wkup
> > +wait_idlest:
> > + ldr r5, [r4]
> > + and r5, r5, #0x4
> > + cmp r5, #0x0
> > + bne wait_idlest
> > + ldr r4, sync_32k_timer
> > + ldr r5, [r4]
> > + ldr r6, wkup_time
> > + str r5, [r6]
> > +#endif
> > bl wait_sdrc_ok
> >
> > +
> > ldmfd sp!, {r0-r12, pc} @ restore regs and return
> > restore_es3:
> > /*b restore_es3*/ @ Enable to debug restore code
> > @@ -247,6 +309,23 @@ copy_to_sram:
> > blx r1
> > restore:
> > /* b restore*/ @ Enable to debug restore code
> > +#ifdef CONFIG_CPU_IDLE_PROF
> > + ldr r4, iclken_wkup_p
> > + ldr r5, [r4]
> > + orr r5, r5, #0x4
> > + str r5, [r4]
> > + ldr r4, idlest_wkup_p
> > +wait_idlest1:
> > + ldr r5, [r4]
> > + and r5, r5, #0x4
> > + cmp r5, #0x0
> > + bne wait_idlest1
> > + ldr r4, sync_32k_timer_p
> > + ldr r5, [r4]
> > + ldr r6, wkup_time_p
> > + str r5, [r6]
> > +#endif
> > +
> > /* Check what was the reason for mpu reset and store the reason in
> > r9*/
> > /* 1 - Only L1 and logic lost */
> > /* 2 - Only L2 lost - In this case, we wont be here */
> > @@ -587,6 +666,12 @@ finished:
> > mcr p15, 2, r10, c0, c0, 0
> > isb
> > skip_l2_inval:
> > +#ifdef CONFIG_CPU_IDLE_PROF
> > + ldr r4, sync_32k_timer
> > + ldr r5, [r4]
> > + ldr r6, sleep_time
> > + str r5, [r6]
> > +#endif
> > /* Data memory barrier and Data sync barrier */
> > mov r1, #0
> > mcr p15, 0, r1, c7, c10, 4
> > @@ -603,6 +688,22 @@ skip_l2_inval:
> > nop
> > nop
> > nop
> > +#ifdef CONFIG_CPU_IDLE_PROF
> > + ldr r4, iclken_wkup
> > + ldr r5, [r4]
> > + orr r5, r5, #0x4
> > + str r5, [r4]
> > + ldr r4, idlest_wkup
> > +wait_idlest2:
> > + ldr r5, [r4]
> > + and r5, r5, #0x4
> > + cmp r5, #0x0
> > + bne wait_idlest2
> > + ldr r4, sync_32k_timer
> > + ldr r5, [r4]
> > + ldr r6, wkup_time
> > + str r5, [r6]
> > +#endif
> > bl wait_sdrc_ok
> > /* restore regs and return */
> > ldmfd sp!, {r0-r12, pc}
> > @@ -668,5 +769,25 @@ cache_pred_disable_mask:
> > .word 0xFFFFE7FB
> > control_stat:
> > .word CONTROL_STAT
> > +#ifdef CONFIG_CPU_IDLE_PROF
> > +sync_32k_timer:
> > + .word TIMER_32K_SYNC
> > +sync_32k_timer_p:
> > + .word TIMER_32K_SYNC_P
> > +sleep_time:
> > + .word SCRATCHPAD_SLEEP_TIME
> > +wkup_time:
> > + .word SCRATCHPAD_WKUP_TIME
> > +wkup_time_p:
> > + .word SCRATCHPAD_WKUP_TIME_P
> > +iclken_wkup:
> > + .word CM_ICLKEN_WKUP
> > +iclken_wkup_p:
> > + .word CM_ICLKEN_WKUP_P
> > +idlest_wkup:
> > + .word CM_IDLEST_WKUP
> > +idlest_wkup_p:
> > + .word CM_IDLEST_WKUP_P
> > +#endif
> > ENTRY(omap34xx_cpu_suspend_sz)
> > .word . - omap34xx_cpu_suspend
> > diff --git a/drivers/cpuidle/Kconfig b/drivers/cpuidle/Kconfig
> > index 7dbc4a8..147456d 100644
> > --- a/drivers/cpuidle/Kconfig
> > +++ b/drivers/cpuidle/Kconfig
> > @@ -18,3 +18,8 @@ config CPU_IDLE_GOV_MENU
> > bool
> > depends on CPU_IDLE && NO_HZ
> > default y
> > +
> > +config CPU_IDLE_PROF
> > + bool
>
> Should not this be something like bool "CPU idle profiling " so that
> this entry shows up in
> 'make menuconfig' ? and this should have dependency on ARCH_OMAP3 also ?
Thanks. Will fix it in V2.
Vishwa
>
> > + depends on CPU_IDLE
> > + default n
> > diff --git a/drivers/cpuidle/sysfs.c b/drivers/cpuidle/sysfs.c
> > index 0310ffa..a3e9db1 100644
> > --- a/drivers/cpuidle/sysfs.c
> > +++ b/drivers/cpuidle/sysfs.c
> > @@ -249,6 +249,11 @@ define_show_state_ull_function(usage)
> > define_show_state_ull_function(time)
> > define_show_state_str_function(name)
> > define_show_state_str_function(desc)
> > +#ifdef CONFIG_CPU_IDLE_PROF
> > +define_show_state_function(actual_latency)
> > +define_show_state_function(sleep_latency)
> > +define_show_state_function(wkup_latency)
> > +#endif
> >
> > define_one_state_ro(name, show_state_name);
> > define_one_state_ro(desc, show_state_desc);
> > @@ -256,7 +261,11 @@ define_one_state_ro(latency, show_state_exit_latency);
> > define_one_state_ro(power, show_state_power_usage);
> > define_one_state_ro(usage, show_state_usage);
> > define_one_state_ro(time, show_state_time);
> > -
> > +#ifdef CONFIG_CPU_IDLE_PROF
> > +define_one_state_ro(actual_latency, show_state_actual_latency);
> > +define_one_state_ro(sleep_latency, show_state_sleep_latency);
> > +define_one_state_ro(wkup_latency, show_state_wkup_latency);
> > +#endif
> > static struct attribute *cpuidle_state_default_attrs[] = {
> > &attr_name.attr,
> > &attr_desc.attr,
> > @@ -264,6 +273,11 @@ static struct attribute *cpuidle_state_default_attrs[]
> > = {
> > &attr_power.attr,
> > &attr_usage.attr,
> > &attr_time.attr,
> > +#ifdef CONFIG_CPU_IDLE_PROF
> > + &attr_actual_latency.attr,
> > + &attr_sleep_latency.attr,
> > + &attr_wkup_latency.attr,
> > +#endif
> > NULL
> > };
> >
> > diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h
> > index 55215cc..6474f6a 100644
> > --- a/include/linux/cpuidle.h
> > +++ b/include/linux/cpuidle.h
> > @@ -43,6 +43,9 @@ struct cpuidle_state {
> >
> > int (*enter) (struct cpuidle_device *dev,
> > struct cpuidle_state *state);
> > +#ifdef CONFIG_CPU_IDLE_PROF
> > + u32 actual_latency, sleep_latency, wkup_latency;
> > +#endif
> > };
> >
> > /* Idle State Flags */
> > --
> > 1.7.0.4
> >
> > --
> > To unsubscribe from this list: send the line "unsubscribe linux-omap" in
> > the body of a message to majord...@vger.kernel.org
> > More majordomo info at http://vger.kernel.org/majordomo-info.html
> >
>
>
>
> --
> Silesh
> --
> To unsubscribe from this list: send the line "unsubscribe linux-omap" in
> the body of a message to majord...@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
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