From: Lukasz Luba <l.luba@partner.samsung.com>
To: linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org
Cc: b.zolnierkie@samsung.com, myungjoo.ham@samsung.com,
cw00.choi@samsung.com, kyungmin.park@samsung.com,
m.szyprowski@samsung.com, s.nawrocki@samsung.com,
tkjos@google.com, joel@joelfernandes.org, chris.diamand@arm.com,
mka@chromium.org, Lukasz Luba <l.luba@partner.samsung.com>
Subject: [PATCH v2 0/2] drivers: devfreq: fix and optimize workqueue mechanism
Date: Mon, 11 Feb 2019 16:30:03 +0100 [thread overview]
Message-ID: <1549899005-7760-1-git-send-email-l.luba@partner.samsung.com> (raw)
In-Reply-To: CGME20190211153030eucas1p19bd9a7eca565ca066ab00dc2243cfb46@eucas1p1.samsung.com
This patch set changes workqueue related features in devfreq framework.
First patch switches to delayed work instead of deferred.
The second switches to regular system work and deletes custom 'devfreq'.
Using deferred work in this context might harm the system performance.
When the CPU enters idle, deferred work is not fired. The devfreq device's
utilization does not have to be connected with a particular CPU.
The drivers for GPUs, Network on Chip, cache L3 rely on devfreq governor.
They all are missing opportunity to check the HW state and react when
the deferred work is not fired.
A corner test case, when Dynamic Memory Controller is utilized by CPUs running
on full speed, might show x5 worse performance if the crucial CPU is in idle.
Changes:
v2:
- single patch split into two
- added cover letter
link for the previous version and discussion:
https://marc.info/?l=linux-pm&m=154904631226997&w=2
Regards,
Lukasz Luba
Lukasz Luba (2):
drivers: devfreq: change devfreq workqueue mechanism
drivers: devfreq: change deferred work into delayed
drivers/devfreq/devfreq.c | 27 +++++++--------------------
1 file changed, 7 insertions(+), 20 deletions(-)
--
2.7.4
next parent reply other threads:[~2019-02-11 15:30 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CGME20190211153030eucas1p19bd9a7eca565ca066ab00dc2243cfb46@eucas1p1.samsung.com>
2019-02-11 15:30 ` Lukasz Luba [this message]
[not found] ` <CGME20190211153035eucas1p12ecdd3289a20ce9fb28588ba20869c60@eucas1p1.samsung.com>
2019-02-11 15:30 ` [PATCH v2 1/2] drivers: devfreq: change devfreq workqueue mechanism Lukasz Luba
2019-02-11 21:42 ` Matthias Kaehlcke
2019-02-12 11:20 ` Lukasz Luba
2019-02-12 20:12 ` Matthias Kaehlcke
2019-02-12 21:37 ` Lukasz Luba
2019-02-13 0:48 ` Matthias Kaehlcke
[not found] ` <CGME20190211153037eucas1p20b80e44795e3599dabd9c2fc0291c063@eucas1p2.samsung.com>
2019-02-11 15:30 ` [PATCH v2 2/2] drivers: devfreq: change deferred work into delayed Lukasz Luba
2019-02-11 21:36 ` Matthias Kaehlcke
2019-02-12 11:03 ` Lukasz Luba
2019-02-12 5:46 ` [PATCH v2 0/2] drivers: devfreq: fix and optimize workqueue mechanism Chanwoo Choi
2019-02-12 12:05 ` Lukasz Luba
2019-02-13 1:09 ` Chanwoo Choi
2019-02-13 10:47 ` Lukasz Luba
2019-02-14 4:00 ` Chanwoo Choi
2019-02-12 19:32 ` Matthias Kaehlcke
2019-02-12 21:20 ` Lukasz Luba
2019-02-13 0:30 ` Matthias Kaehlcke
2019-02-13 13:00 ` Lukasz Luba
2019-02-14 20:40 ` Matthias Kaehlcke
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