From: Daniel Lezcano <daniel.lezcano@linaro.org>
To: Santosh Shilimkar <santosh.shilimkar@ti.com>
Cc: linux-omap@vger.kernel.org,
Lists Linaro-dev <linaro-dev@lists.linaro.org>
Subject: Re: Question regarding broadcast timer/cpuidle and /proc/interrupts
Date: Mon, 21 Jan 2013 15:39:42 +0100 [thread overview]
Message-ID: <50FD532E.2000306@linaro.org> (raw)
In-Reply-To: <50FD52D3.8010601@ti.com>
On 01/21/2013 03:38 PM, Santosh Shilimkar wrote:
> On Monday 21 January 2013 07:47 PM, Daniel Lezcano wrote:
>>
>> Hi All,
>>
>> I have a question regarding the behavior of cpuidle on pandaboard.
>>
>> 1. cpuidle is enabled
>>
>> 2. The deep idle states seem to be reach
>>
>> for i in $(find /sys/devices/system/cpu -name "usage"); do echo "$i :
>> $(cat $i)"; done
>> /sys/devices/system/cpu/cpu0/cpuidle/state0/usage : 7049
>> /sys/devices/system/cpu/cpu0/cpuidle/state1/usage : 17
>> /sys/devices/system/cpu/cpu0/cpuidle/state2/usage : 1341
>> /sys/devices/system/cpu/cpu1/cpuidle/state0/usage : 6318
>> /sys/devices/system/cpu/cpu1/cpuidle/state1/usage : 17
>> /sys/devices/system/cpu/cpu1/cpuidle/state2/usage : 1341
>>
>> 3. Regarding the cpuidle driver code : the "state1" and "state2" are
>> coupled states where the broadcast timer is used instead of the local
>> timer. I assume this is because they go down when we reach these idle
>> states.
>>
> Thats correct. Local timer are not wakeup capable and hence we switch
> to a wakeup capable broadcast timer.
>
>> 4. The content of /proc/interrupts shows no broadcast timer used at all.
>>
>> ...
>> IPI1: 0 0 Timer broadcast interrupts
>> ...
>>
>> Shouldn't be the broadcast timer used sometimes ? or did I miss
>> something ?
>>
> There might be an issue with status updating. Just look for gptimer1
> interrupts. if they are incrementing then, broadcast is being used
> but just the status update isn't happening some how.
Is it the interrupt 69 ?
29: 293 395 GIC twd
41: 0 0 GIC l3-dbg-irq
42: 0 0 GIC l3-app-irq
44: 0 0 GIC DMA
69: 61 0 GIC gp_timer
88: 0 0 GIC i2c.9
89: 0 0 GIC i2c.10
93: 0 0 GIC i2c.11
94: 0 0 GIC i2c.12
106: 93 0 GIC OMAP UART2
169: 0 0 PRCM hwmod_io
IPI0: 0 0 Timer broadcast interrupts
IPI1: 1424 1260 Rescheduling interrupts
IPI2: 0 0 Function call interrupts
IPI3: 81 90 Single function call interrupts
IPI4: 0 0 CPU stop interrupts
Err: 0
>
> regards
> santosh
>
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prev parent reply other threads:[~2013-01-21 14:39 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-01-21 14:17 Question regarding broadcast timer/cpuidle and /proc/interrupts Daniel Lezcano
2013-01-21 14:38 ` Santosh Shilimkar
2013-01-21 14:39 ` Daniel Lezcano [this message]
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