From: Santosh Shilimkar <santosh.shilimkar@ti.com>
To: balbi@ti.com
Cc: linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
Kevin Hilman <khilman@deeprootsystems.com>
Subject: Re: [PATCH] ARM: OMAP4: PM: Avoid expensive cpu_suspend() path for all CPU power states except off
Date: Fri, 8 Feb 2013 21:04:09 +0530 [thread overview]
Message-ID: <51151AF1.20202@ti.com> (raw)
In-Reply-To: <20130208152607.GJ23979@arwen.pp.htv.fi>
On Friday 08 February 2013 08:56 PM, Felipe Balbi wrote:
> On Fri, Feb 08, 2013 at 08:41:46PM +0530, Santosh Shilimkar wrote:
>> Current CPU PM code code make use of common cpu_suspend() path for all the
>> CPU power states which is not optimal. In fact cpu_suspend() path is needed
>> only when we put CPU power domain to off state where the CPU context is lost.
>>
>> Update the code accordingly so that the expensive cpu_suspend() path
>> can be avoided for the shallow CPU power states like CPU PD INA/CSWR.
>>
>> Cc: Kevin Hilman <khilman@deeprootsystems.com>
>>
>> Reported-by: Richard Woodruff <r-woodruff2@ti.com>
>> Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
>
> some numbers showing the benefit would be cool...
>
The numbers depends on CPU clock you are running generally. The main
issue is, for the shallow power states where we were not loosing
CPU context or Caches, we were doing all the book keeping. States
like INA are of 6-8 uS and above overhead is quite significant
their.
Regards
Santosh
WARNING: multiple messages have this Message-ID (diff)
From: santosh.shilimkar@ti.com (Santosh Shilimkar)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] ARM: OMAP4: PM: Avoid expensive cpu_suspend() path for all CPU power states except off
Date: Fri, 8 Feb 2013 21:04:09 +0530 [thread overview]
Message-ID: <51151AF1.20202@ti.com> (raw)
In-Reply-To: <20130208152607.GJ23979@arwen.pp.htv.fi>
On Friday 08 February 2013 08:56 PM, Felipe Balbi wrote:
> On Fri, Feb 08, 2013 at 08:41:46PM +0530, Santosh Shilimkar wrote:
>> Current CPU PM code code make use of common cpu_suspend() path for all the
>> CPU power states which is not optimal. In fact cpu_suspend() path is needed
>> only when we put CPU power domain to off state where the CPU context is lost.
>>
>> Update the code accordingly so that the expensive cpu_suspend() path
>> can be avoided for the shallow CPU power states like CPU PD INA/CSWR.
>>
>> Cc: Kevin Hilman <khilman@deeprootsystems.com>
>>
>> Reported-by: Richard Woodruff <r-woodruff2@ti.com>
>> Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
>
> some numbers showing the benefit would be cool...
>
The numbers depends on CPU clock you are running generally. The main
issue is, for the shallow power states where we were not loosing
CPU context or Caches, we were doing all the book keeping. States
like INA are of 6-8 uS and above overhead is quite significant
their.
Regards
Santosh
next prev parent reply other threads:[~2013-02-08 15:32 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-02-08 15:11 [PATCH] ARM: OMAP2+: PM: Fix the dt return condition in pm_late_init() Santosh Shilimkar
2013-02-08 15:11 ` Santosh Shilimkar
2013-02-08 15:11 ` [PATCH] ARM: OMAP2+: Remove duplicate omap4430_init_late() declaration Santosh Shilimkar
2013-02-08 15:11 ` Santosh Shilimkar
2013-02-08 15:21 ` Felipe Balbi
2013-02-08 15:21 ` Felipe Balbi
2013-02-15 9:35 ` Santosh Shilimkar
2013-02-15 9:35 ` Santosh Shilimkar
2013-03-04 18:19 ` Tony Lindgren
2013-03-04 18:19 ` Tony Lindgren
2013-02-08 15:11 ` [PATCH] ARM: OMAP4: PM: Avoid expensive cpu_suspend() path for all CPU power states except off Santosh Shilimkar
2013-02-08 15:11 ` Santosh Shilimkar
2013-02-08 15:26 ` Felipe Balbi
2013-02-08 15:26 ` Felipe Balbi
2013-02-08 15:34 ` Santosh Shilimkar [this message]
2013-02-08 15:34 ` Santosh Shilimkar
2013-02-08 21:19 ` Kevin Hilman
2013-02-08 21:19 ` Kevin Hilman
2013-02-12 4:55 ` Santosh Shilimkar
2013-02-12 4:55 ` Santosh Shilimkar
2013-02-12 15:18 ` Kevin Hilman
2013-02-12 15:18 ` Kevin Hilman
2013-02-13 5:05 ` Santosh Shilimkar
2013-02-13 5:05 ` Santosh Shilimkar
2013-02-08 15:20 ` [PATCH] ARM: OMAP2+: PM: Fix the dt return condition in pm_late_init() Felipe Balbi
2013-02-08 15:20 ` Felipe Balbi
2013-02-08 15:34 ` Paul Walmsley
2013-02-08 15:34 ` Paul Walmsley
2013-02-08 15:36 ` Santosh Shilimkar
2013-02-08 15:36 ` Santosh Shilimkar
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