Date: Fri, 14 Aug 2015 13:42:44 +0200 From: Svatopluk Kraus <onwahe@gmail.com> To: Hans Petter Selasky <hps@selasky.org> Cc: "freebsd-arm@freebsd.org" <freebsd-arm@freebsd.org> Subject: Re: DWC OTG TX path optimisation for 11-current Message-ID: <CAFHCsPV=E3rkZWks0fc4dnmcbGQeB1ZAh2JRhnSrAFtA8V%2BwBw@mail.gmail.com> In-Reply-To: <55CDB9BC.5000005@selasky.org> References: <55A7D8CE.4020809@selasky.org> <CAHNYxxNc9uB62hHEv1PM9PcsGgUs=zsvNgatqLD0p%2BiiDA3Aiw@mail.gmail.com> <55B73113.2020308@selasky.org> <CAFHCsPVaPZpqXLS7OApa=Xz5VLnLjVpV5dYV8Pn2uHh1Lcz7Tg@mail.gmail.com> <55B8AB76.7030603@selasky.org> <CAFHCsPUMaYEwJsaGUFuw9yZi_5bmraSBsOYpRWvSeuebpXBJUA@mail.gmail.com> <55B8B297.1010008@selasky.org> <CAFHCsPVGLs8j6LAV%2Bg4rP_ueTOd8pUOupYFGvmgC3XGcJC720Q@mail.gmail.com> <20150729154516.GH78154@funkthat.com> <55B8F5EC.2050908@selasky.org> <46ad096c958.1a82a175@mail.schwarzes.net> <55B9C3E2.5040501@selasky.org> <46ae815c7c3.447237c8@mail.schwarzes.net> <46aece00b53.3c1cdc1f@mail.schwarzes.net> <55BB2A5F.9000502@selasky.org> <55BB3CC6.4030002@selasky.org> <CAFHCsPXFJ_XhVsT1bRw=d20Mz=cbYdmwNNLvfs_cxJvEo8B6LA@mail.gmail.com> <55BB6A7F.3060402@selasky.org> <CAFHCsPVz4cYGrZRxVz9givvct_b1CagH1W%2BbTzS1v%2Bc3sws3LQ@mail.gmail.com> <55CB4BAF.3050702@selasky.org> <CAFHCsPUX0m-dW=4WzZW9E2Lw5oa_R=gdFAZ%2B5V=ujgco-hRoTw@mail.gmail.com> <55CDB9BC.5000005@selasky.org>
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On Fri, Aug 14, 2015 at 11:49 AM, Hans Petter Selasky <hps@selasky.org> wrote: > On 08/12/15 20:16, Svatopluk Kraus wrote: >> >> On Wed, Aug 12, 2015 at 3:35 PM, Hans Petter Selasky <hps@selasky.org> >> wrote: >>> >>> On 07/31/15 17:11, Svatopluk Kraus wrote: >>>> >>>> >>>> Note that I got about 24000 interrupts per a second during buildworld >>>> too. If I remember it correctly, it was about 4000 before r285935. >>>> When the trigger is pulled, the count is changing (in range of 4000 to >>>> 21000). It looks like something is taking more time (interrupt >>>> servicing probably). According to "systat -v", disk is going to be >>>> 100% (and more) busy very often for example. >>> >>> >>> >>> Hi, >>> >>> Finally my RPI-2 arrived :-) >> >> >> >> It's great! ;) I can do some debugging but it's hard to go deeper >> without usb controller specification. >> >> >>> >>> After r285935 we are polling for data more frequently, so the IRQ rate >>> will >>> go up. 3x 8000 IRQs/second would be normal to query the device every >>> 125us, >>> which the EHCI does. >>> >>> Can you give me some more information about your setup, so that I can >>> reproduce it? >> >> >> I use in-tree RPI2 configuration but with INVARIANTS and >> INVARIANT_SUPPORT options disabled. This is crucial as it's hard to >> trigger it with these options enabled. >> >> I use usb disk with three partitions: >> First one is mounted as a root. >> Second one is used for swapping. >> The third one is not mounted. >> >> The disk is connected thru usb hub. >> >> My fstab is empty. >> My kernel is loaded from SD card. >> I use UART as console. >> >> root@raspberry-pi:~ # usbconfig >> ugen0.1: <OTG Root HUB DWCOTG> at usbus0, cfg=0 md=HOST spd=HIGH >> (480Mbps) pwr=SAVE (0mA) >> ugen0.2: <product 0x9514 vendor 0x0424> at usbus0, cfg=0 md=HOST >> spd=HIGH (480Mbps) pwr=SAVE (2mA) >> ugen0.3: <product 0xec00 vendor 0x0424> at usbus0, cfg=0 md=HOST >> spd=HIGH (480Mbps) pwr=ON (2mA) >> ugen0.4: <USB2.0 Hub VIA Labs, Inc.> at usbus0, cfg=0 md=HOST spd=HIGH >> (480Mbps) pwr=SAVE (0mA) >> ugen0.5: <USB2.0 Hub VIA Labs, Inc.> at usbus0, cfg=0 md=HOST spd=HIGH >> (480Mbps) pwr=SAVE (0mA) >> ugen0.6: <HD710 ADATA> at usbus0, cfg=0 md=HOST spd=HIGH (480Mbps) pwr=ON >> (0mA) >> >> >> FreeBSD source tree is on /usr/src and I run native buildworld : "make >> -j6 buildworld" >> I run the buildworld on ssh to keep my console "clean and free" for >> debugging. The trigger is pulled in about 25 minutes, however it's >> more expessive with more time elapsed. >> >> So far it looks that it happens during "stage 2.1: cleaning up the >> object tree" when a lot of small and different disk request are done. >> >> I have tried to get big picture of the problem with KTR option >> enabled, but it's not possible as it's not triggered when all KTR >> classes are compiled in. What works is the following configuration: >> >> options KTR >> options KTR_ENTRIES=65536 >> options KTR_MASK=(KTR_SPARE3) >> options KTR_COMPILE=(KTR_SPARE3) >> >> However, even using of KTR_SPARE3 class for debugging is limited >> considering the trigger. >> >> I will send you more info about my investigation tomorow. >> >> Svata >> > > Hi, > > Here are some more clues. I've found a situation where if one USB class > driver gets too busy, the others gets starved. I have a patch in the works > to implement a round robin mechanism for this. > > In the meanwhile, maybe you can try to: > > cpuset -l 1-3 -p XXX > > Where XXX is pid for the usbus0 processes, typically 13 with my RPI-2. > > The DWC OTG interrupts on CPU #0 and if the usbus0 processes are running > there too, it is suboptimal. Well, I have tried it and it ran fine but it almost blocked buildworld in time when the trigger is pulled usually. According to systat, the disk is almost all time 100% and more busy. Svata
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