From: MyungJoo Ham <myungjoo.ham@samsung.com>
To: Kyungmin Park <kyungmin.park@samsung.com>,
Chanwoo Choi <cw00.choi@samsung.com>,
Rob Herring <robh+dt@kernel.org>,
Mark Rutland <mark.rutland@arm.com>
Cc: Saravana Kannan <skannan@codeaurora.org>,
Rajendra Nayak <rjendra@codeaurora.org>,
Amit Kucheria <amit.kucheria@linaro.org>,
"linux-pm@vger.kernel.org" <linux-pm@vger.kernel.org>,
"devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: RE: [PATCH 2/2] PM / devfreq: Generic cpufreq governor
Date: Mon, 28 May 2018 15:00:14 +0900 [thread overview]
Message-ID: <20180528060014epcms1p87ec68a4d44f9447b06f979a87e545b7d@epcms1p8> (raw)
In-Reply-To: <1526631889-5084-3-git-send-email-skannan@codeaurora.org>
>Many CPU architectures have caches that can scale independent of the CPUs.
>Frequency scaling of the caches is necessary to make sure the cache is not
>a performance bottleneck that leads to poor performance and power. The same
>idea applies for RAM/DDR.
>
>To achieve this, this patch series adds a generic devfreq governor that can
>listen to the frequency transitions of each CPU frequency domain and then
>adjusts the frequency of the cache (or any devfreq device) based on the
>frequency of the CPUs.
I agree that we have some hardware pieces that want to configure
frequencies based on the CPUfreq.
Creating a devfreq governor that configures devfreq-freq
based on incoming events (CPUFreq-transition-event in this case)
is indeed a good idea.
However, I would like to ask the followings:
The overall code appears to be overly complex compared what you need.
- Do you really need to revive "CPUFREQ POLICY" events for this?
especially when you are going to look at "first CPU" only?
Cheers,
MyungJoo
next prev parent reply other threads:[~2018-05-28 6:00 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-05-18 8:24 [PATCH 0/2] Adding support for scaling cache/memory based on CPU frequency Saravana Kannan
2018-05-18 8:24 ` [PATCH 1/2] Revert "cpufreq: Remove policy create/remove notifiers" Saravana Kannan
2018-05-18 8:29 ` Rafael J. Wysocki
2018-05-18 8:31 ` skannan
2018-05-18 8:33 ` Rafael J. Wysocki
2018-05-18 8:47 ` skannan
2018-05-18 8:59 ` Rafael J. Wysocki
2018-05-18 8:24 ` [PATCH 2/2] PM / devfreq: Generic cpufreq governor Saravana Kannan
2018-05-23 16:58 ` Rob Herring
2018-05-31 21:53 ` Saravana Kannan
[not found] ` <CGME20180518082505epcas2p265038f51fc070a4aada4c692a71ebc3c@epcms1p8>
2018-05-28 6:00 ` MyungJoo Ham [this message]
2018-06-05 23:26 ` Saravana Kannan
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