Date: Fri, 14 Aug 2015 11:49:48 +0200 From: Hans Petter Selasky <hps@selasky.org> To: Svatopluk Kraus <onwahe@gmail.com> Cc: "freebsd-arm@freebsd.org" <freebsd-arm@freebsd.org> Subject: Re: DWC OTG TX path optimisation for 11-current Message-ID: <55CDB9BC.5000005@selasky.org> In-Reply-To: <CAFHCsPUX0m-dW=4WzZW9E2Lw5oa_R=gdFAZ%2B5V=ujgco-hRoTw@mail.gmail.com> 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>
next in thread | previous in thread | raw e-mail | index | archive | help
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. --HPS
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?55CDB9BC.5000005>