From mboxrd@z Thu Jan 1 00:00:00 1970 From: joerg.krause@embedded.rocks (=?ISO-8859-1?Q?J=F6rg?= Krause) Date: Wed, 14 Dec 2016 10:03:24 +0100 Subject: mmc: core: complete/wait_for_completion performance In-Reply-To: <123257138.400786.e58aee3b-9fc2-4b39-a030-c2409c5b92fc.open-xchange@email.1und1.de> References: <1479644869.2653.3.camel@embedded.rocks> <585759233.283839.1cb53b4d-2805-48ea-aef1-dd282306d108.open-xchange@email.1und1.de> <1479652929.2841.1.camel@embedded.rocks> <187975187.249177.bccdc17e-e9c6-48c2-aeaf-3b81f1b61ec7.open-xchange@email.1und1.de> <1479669034.1975.1.camel@embedded.rocks> <1198138554.59982.63209ba1-8fb4-4a13-9ee0-f746a192f4c7.open-xchange@email.1und1.de> <1481095953.17027.0.camel@embedded.rocks> <123257138.400786.e58aee3b-9fc2-4b39-a030-c2409c5b92fc.open-xchange@email.1und1.de> Message-ID: <1481706204.3994.4.camel@embedded.rocks> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi Stefan, On Wed, 2016-12-07 at 20:23 +0100, Stefan Wahren wrote: > Hi J?rg, > > > J?rg Krause hat am 7. Dezember 2016 > > um 08:32 > > geschrieben: > > > > > > Hit Stefan, > > > > On Sat, 2016-11-26 at 20:10 +0100, Stefan Wahren wrote: > > > Hi J?rg, > > > > > > > J?rg Krause hat am 20. November > > > > 2016 > > > > um 20:10 > > > > geschrieben: > > > > > > > > > > > > On Sun, 2016-11-20 at 16:44 +0100, Stefan Wahren wrote: > > > > > > J?rg Krause hat am 20. > > > > > > November > > > > > > 2016 > > > > > > um 15:42 > > > > > > geschrieben: > > > > > > > > > > > > > > > > > > Hi Stefan, > > > > > > > > > > > > On Sun, 2016-11-20 at 14:28 +0100, Stefan Wahren wrote: > > > > > > > Hi J?rg, > > > > > > > > > > > > > > > J?rg Krause hat am 20. > > > > > > > > November > > > > > > > > 2016 > > > > > > > > um 13:27 > > > > > > > > geschrieben: > > > > > > > > > > > > > > > > > > > > > > > > Hi, > > > > > > > > > > > > > > > > I started the discussion on this mailing list in > > > > > > > > another > > > > > > > > thread > > > > > > > > [1], > > > > > > > > but I'd like to move it to a new thread, because it > > > > > > > > might > > > > > > > > be > > > > > > > > mmc > > > > > > > > specific. > > > > > > > > > > > > > > > > The issue is that I am noticed low wifi network > > > > > > > > throughput > > > > > > > > on > > > > > > > > an > > > > > > > > i.MX28 > > > > > > > > board with the mainline kernel (v4.7.10, about 6 Mbps) > > > > > > > > compared > > > > > > > > to > > > > > > > > the > > > > > > > > vendor kernel (Freescale v2.6.35.3, about 20 Mbps). The > > > > > > > > wifi > > > > > > > > chip > > > > > > > > is > > > > > > > > attached using the SDIO interface. > > > > > > > > > > > > > > > > I started investigation where the bottleneck in the > > > > > > > > mainline > > > > > > > > kernel?might come from. Therefore I checked that the > > > > > > > > configs > > > > > > > > and > > > > > > > > settings for the interfaces and drivers are the same. > > > > > > > > They > > > > > > > > are. > > > > > > > > > > > > > > so you're not using the mxs_defconfig settings anymore? > > > > > > > > > > > > No, I changed the settings. > > > > > > > > > > > > > > > > What happens to performance to if you change the following > > > > > settings > > > > > to the same > > > > > like in mxs_defconfig? > > > > > > > > > > CONFIG_PREEMPT_VOLUNTARY=y > > > > > CONFIG_DEFAULT_IOSCHED="noop" > > > > > > > > No much change at all. The time difference between complete() > > > > and > > > > wait_for_complete() decreases in best case to 110 us, but also > > > > varies > > > > to above 130 us. > > > > > > just a weird idea. Did you tried to add MMC_CAP_CMD23 into the > > > caps > > > [1]? > > > > > > [1] - http://lxr.free-electrons.com/source/drivers/mmc/host/mxs-m > > > mc.c > > > ?v=4.8#L642 > > > > I tried, but it did not improved the timing or throughput. However, > > many thanks for the input. > > > > J?rg > > did you try cyclictest [1]? Not yet. Not sure what to measure and which values to compare here. > > Beside the time for a request the amount of requests for the complete > iperf test > would we interesting. Maybe there are retries. > > I'm still interested in your PIO mode patches for mxs-mmc even > without clean up. Actually, the patch does not implement a PIO mode, but drops DMA and uses polling instead. I've attached the patch. > [1] - https://git.kernel.org/cgit/utils/rt-tests/rt-tests.git/ Best regards J?rg -------------- next part -------------- A non-text attachment was scrubbed... Name: 0001-mmc-mxs-mmc-drop-DMA-and-use-polling-mode.patch Type: text/x-patch Size: 7570 bytes Desc: not available URL: