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Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.4.0 MIME-Version: 1.0 In-Reply-To: <1550010238-24002-1-git-send-email-l.luba@partner.samsung.com> Content-Language: en-US Content-Transfer-Encoding: 8bit X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFrrIJsWRmVeSWpSXmKPExsWy7bCmrq5/UnKMwbT9ehYbZ6xntZj26TKL xbIGVYuzTW/YLW41yFhc3jWHzeJz7xFGi7VH7rJbXDqwgMni84bHjBa3G1ewWezreMBkcfhN O6sDr8eaeWsYPWY3XGTxaNl3i91j4aevrB4H3+1h8ni/7yqbR9+WVYwenzfJBXBEZdtkpCam pBYppOYl56dk5qXbKnkHxzvHm5oZGOoaWlqYKynkJeam2iq5+AToumXmAF2spFCWmFMKFApI LC5W0rezKcovLUlVyMgvLrFVSi1IySmwLNArTswtLs1L10vOz7UyNDAwMgUqTMjOeHDuJFvB ZpmKyzcnMzYw9ot1MXJySAiYSJx6+4m9i5GLQ0hgB6PEoYlPGCGcT4wS7f19LBDON0aJ938n MsO07FpwDqplL6PEl9a9bBDOe0aJx3tfs4FUCQuESMz8tYkFxBYRSJN4236XCaSIWeAjo8TG A+1gCTYBLYn9L26ANfALKEpc/fGYEcTmFbCTONrXC9TAwcEioCrR2agCEhYViJA43PsOqkRQ 4uTMJ2BjOAW8Jc5MW8kKYjMLiEvcejKfCcKWl2jeOpsZZK+EwDZ2iT9NC9ghXnCR2LfqPNQ7 whKvjm+BiktJfH63lw3CrpZYefIIG0RzB6PElv0XWCESxhL7l04GO45ZQFNi/S59iGV8Eu++ 9rCChCUEeCU62oQgqpUlLj+4ywRhS0osbu+EGu8h8fPePaYJjIqzkLwzC8kLs5C8MAth2QJG llWMYqkFxbnpqcWGBSbI0b2JEZyctSx2MO4553OIUYCDUYmHd8XRpBgh1sSy4srcQ4wSHMxK IrwtickxQrwpiZVVqUX58UWlOanFhxhNgYE9kVlKNDkfmDnySuINTY2MjY0tTAzNTA0NlcR5 1zs4xwgJpCeWpGanphakFsH0MXFwSjUwigQa9LF/ePvzTSTTklSRCx658if4xMsN5MQ6BB0F 0i9H332++MhLcfdr3XanHpal8G7W+tB0n5dPdP0vxmBGhae7/Rf5LP++03u9vLr9pS1phYem ygVuEKibcuC5k8AjoyMHpMtdei98+aFuVuTAZiRt966jkEs//Ot2x9KF9Y/3TDoVl+alxFKc kWioxVxUnAgATJMPLOQDAAA= X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFtrFIsWRmVeSWpSXmKPExsWy7bCSvK5fUnKMwcQZ4hYbZ6xntZj26TKL xbIGVYuzTW/YLW41yFhc3jWHzeJz7xFGi7VH7rJbXDqwgMni84bHjBa3G1ewWezreMBkcfhN O6sDr8eaeWsYPWY3XGTxaNl3i91j4aevrB4H3+1h8ni/7yqbR9+WVYwenzfJBXBEcdmkpOZk lqUW6dslcGU8OHeSrWCzTMXlm5MZGxj7xboYOTkkBEwkdi04x97FyMUhJLCbUaL12RpmiISk xLSLR4FsDiBbWOLw4WKQsJDAW0aJjvWWILawQIjEzF+bWEBsEYE0iUMNt8HmMAt8ZJQ49OwA 1NB5jBItM54ygVSxCWhJ7H9xgw3E5hdQlLj64zEjiM0rYCdxtK+XCWQZi4CqRGejCkhYVCBC 4uPTfUwQJYISJ2c+AVvGKeAtcWbaSlYQm1lAXeLPvEvMELa4xK0n85kgbHmJ5q2zmScwCs9C 0j4LScssJC2zkLQsYGRZxSiZWlCcm55bbFhglJdarlecmFtcmpeul5yfu4kRHKNaWjsYT5yI P8QowMGoxMO74mhSjBBrYllxZe4hRgkOZiUR3pbE5Bgh3pTEyqrUovz4otKc1OJDjNIcLEri vPL5xyKFBNITS1KzU1MLUotgskwcnFINjEuZstZFOWdOqlkx4X/yg/6g1orJ3Rcm/59epdK0 UfzIibX7Cz/EeaxQqH595MtZfY67pufVl6kw5RzNPPyx4UAaq8nyVUcOOVS+jZXexjnnGaPm BbknYuLf3Xyid35fKPdR4uLlnVo/1ySvrPF3Y5I5UvP32511MTtcrj+RsO8U/Wu8oTksm02J pTgj0VCLuag4EQDRB6nkzQIAAA== X-CMS-MailID: 20190213001822epcas1p125811e96cdbc21b7f87f21a57fafb4ae X-Msg-Generator: CA Content-Type: text/plain; charset="utf-8" CMS-TYPE: 101P DLP-Filter: Pass X-CFilter-Loop: Reflected X-CMS-RootMailID: 20190212222422eucas1p1624203db4db3e495035820dea542e23a References: <1550010238-24002-1-git-send-email-l.luba@partner.samsung.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 19. 2. 13. 오전 7:23, Lukasz Luba wrote: > 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. > > There was a discussion regarding v2 that the power usage because of waking up We have not yet finished the any discussion. We only just had a few reply and you didn't wait for any reply from other. As I already commented on exynos5422-dmc series, please don't send the next patch without any final agreement. In this series, patch1/patch2 are same at version 2 patchset. Even if we need to discuss more them, you just send same patches without any agreement among reviewers. At least, you have to wait the reply instead of just sending the new patchset. It is basic review rule on mailing list. > an idle CPU would be too high. In my opinion it won't and fixing bug is more > important than < 1% more power used [1]. > I have addressed also this issue. In this patch set there is a mechanism > which prevents from to frequent checks when there is no need. > When the device enters its lowest state (OPP) the framework sets polling > interval to 'polling_idle_ms'. In default Kconfig it is 500ms, so 2 times per > second. > It is tunable from the sysfs interface per device, thus driver developer can > experiment and choose best intervals for the system. > > Changes: > v3: > - reordered first two patches > - added functionality to lower power consumption when the device is less busy; > there is a new polling interval enabled when device enters lowest frequency; > - added trace events to capture the behaviour of the system > v2: > - single patch split into two > - added cover letter > > link for the previous version and discussion: > https://marc.info/?l=linux-pm&m=154989907416072&w=2 > https://marc.info/?l=linux-pm&m=154904631226997&w=2 > > Regards, > Lukasz Luba > > [1] https://marc.info/?l=linux-kernel&m=155000641622443&w=2 > > Lukasz Luba (7): > drivers: devfreq: change deferred work into delayed > drivers: devfreq: change devfreq workqueue mechanism > Kconfig: drivers: devfreq: add default idle polling > include: devfreq: add polling_idle_ms to 'profile' > drivers: devfreq: add longer polling interval in idle > trace: events: add devfreq trace event file > drivers: devfreq: add tracing for scheduling work > > MAINTAINERS | 1 + > drivers/devfreq/Kconfig | 13 +++ > drivers/devfreq/devfreq.c | 184 ++++++++++++++++++++++++------ > drivers/devfreq/governor.h | 3 +- > drivers/devfreq/governor_simpleondemand.c | 6 +- > include/linux/devfreq.h | 6 + > include/trace/events/devfreq.h | 39 +++++++ > 7 files changed, 218 insertions(+), 34 deletions(-) > create mode 100644 include/trace/events/devfreq.h > -- Best Regards, Chanwoo Choi Samsung Electronics