From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lo.gmane.org ([80.91.229.12]) by linuxtogo.org with esmtp (Exim 4.72) (envelope-from ) id 1Qa8aq-0002ss-Nq for openembedded-devel@lists.openembedded.org; Fri, 24 Jun 2011 17:46:52 +0200 Received: from list by lo.gmane.org with local (Exim 4.69) (envelope-from ) id 1Qa8XL-000762-Ui for openembedded-devel@lists.openembedded.org; Fri, 24 Jun 2011 17:43:15 +0200 Received: from ip545070eb.adsl-surfen.hetnet.nl ([84.80.112.235]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Fri, 24 Jun 2011 17:43:15 +0200 Received: from koen by ip545070eb.adsl-surfen.hetnet.nl with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Fri, 24 Jun 2011 17:43:15 +0200 X-Injected-Via-Gmane: http://gmane.org/ To: openembedded-devel@lists.openembedded.org From: Koen Kooi Date: Fri, 24 Jun 2011 17:43:04 +0200 Message-ID: References: <201106202316.47662.schnitzeltony@gmx.de> <201106240052.59211.schnitzeltony@gmx.de> <201106241649.52323.schnitzeltony@gmx.de> Mime-Version: 1.0 X-Complaints-To: usenet@dough.gmane.org X-Gmane-NNTP-Posting-Host: ip545070eb.adsl-surfen.hetnet.nl User-Agent: Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.6; en-US; rv:1.9.1.16) Gecko/20101127 Shredder/3.0.11pre In-Reply-To: <201106241649.52323.schnitzeltony@gmx.de> X-Enigmail-Version: 1.0.1 Subject: Re: udev 171 caching working propely? X-BeenThere: openembedded-devel@lists.openembedded.org X-Mailman-Version: 2.1.11 Precedence: list Reply-To: openembedded-devel@lists.openembedded.org List-Id: Using the OpenEmbedded metadata to build Distributions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 24 Jun 2011 15:46:52 -0000 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 24-06-11 16:49, Andreas Mueller wrote: > On Friday, June 24, 2011 08:49:00 AM Koen Kooi wrote: >> On 24-06-11 00:52, Andreas Mueller wrote: >>> On Thursday, June 23, 2011 11:58:53 PM Koen Kooi wrote: >>>> On 23-06-11 22:58, Andreas Mueller wrote: >>>>> On Tuesday, June 21, 2011 11:31:45 PM Tom Rini wrote: >>>>>> On 06/20/2011 03:47 PM, Tom Rini wrote: >>>>>>> On 06/20/2011 02:16 PM, Andreas Mueller wrote: >>>>>>>> Dear OE-folks, >>>>>>>> >>>>>>>> Working with lastest classic oe master and angstrom it seems udev >>>>>>>> caching is not >>>>>>>> >>>>>>>> working as expected. On *every* boot I get: >>>>>>>>> Remounting root file system... >>>>>>>>> Caching udev devnodes >>>>>>>>> Populating dev cachemv: can't rename '/dev/shm/uname': No such file >>>>>>>>> or directory >>>>>>>> >>>>>>>> I don't know why this change came in but there was a change of >>>>>>>> storage location in Tom's commit few days ago [1]. To me it seems >>>>>>>> that >>>>>>>> >>>>>>>> 1. The files created by udev (init) get lost at remount so >>>>>>>> udev-cache (cache) is unable to find >>>>>>>> 2. Since this error occures not only at first boot the recipe's >>>>>>>> pkg_postinst_udev_append() seems never being executed. To check I >>>>>>>> added a simple echo 'foo text' >>>>>>>> in this function but 'foo text' is not found in log of first boot. >>>>>>>> >>>>>>>> Suggestions welcome >>>>>>> >>>>>>> Did udev change behaviors at some point then? I've been using an >>>>>>> older udev and didn't run into that problem. I changed from /tmp to >>>>>>> /dev/shm since we don't know that /tmp is writable at that point so >>>>>>> we were instead getting errors there. I wonder if we should just >>>>>>> switch to re-creating the contents for that step? >>>>>> >>>>>> I've gone with this change and some quick testing on a board. >>>>> >>>>> Hi Tom, >>>>> >>>>> thanks for taking care and sorry for late response - yesterday I had >>>>> one of these nightmares at the job... >>>>> >>>>> Now I tested the patch for two machines and sorry I am afraid to waste >>>>> your time again: >>>>> >>>>> First machine is overo with linux-omap-psp-2.6.32 and a hub connected >>>>> to the OTG connector. The kernel detects USB devices at a very early >>>>> boot state long before udev starts (see end of file 'overo' attached). >>>>> udev caching seems to work without errors. >>>>> >>>>> Second machine is tx28 with linux-2.6.38.5 (freescale imx28 based - I >>>>> will send patches when stable). This shows different behaviours on >>>>> first and all further boots (see udev-*boot attached). Problem is that >>>>> after second boot nothing connected to USB is detected / working. By >>>>> deleting /etc/udev/saved.* and rebooting all USB devices work fine and >>>>> log looks similar as first boot. >>>>> >>>>> Before I merged your patch I know the USB devices were working properly >>>>> on tx28. Don't misunderstand me: I think before your patch cache was >>>>> never read. Now you fixed this and it seems reading the cache does not >>>>> work (on my half cooked machine only?). >>>>> >>>>> I will have further investigations on this... >>>> >>>> With 171 you shouldn't need caching anymore, triggering has been sped up >>>> considerably, could you try disable caching and see how much it impacts >>>> your boot time? >>> >>> Uncached feels slower. Populating all devices takes 5-10s. Is there a >>> simple way to create time stamps for boot messages? >> >> Another test would be to unload the kernel modules and do: >> >> killall udevd ; time ( udevadm trigger ; udevadm settle ) >> >> That takes about 1s on my beagleboard and 3.5s on my hawkboard. >> >> Systemd keeps a track of it, have a look at the bright red portions of >> the graphs: >> >> http://dominion.thruhere.net/koen/angstrom/systemd/beagleboardC5-ubi-201106 >> 171148.svg http://dominion.thruhere.net/koen/angstrom/systemd/hawkboard.svg >> >> I my case the caching wasn't needed, but if it starts taking >4s on >> 'slow' systems and >2s on 'fast' systems it is worth considering. >> > News from udev-journey: > > I did modify the udev-init script so that I could see that > > | udevadm trigger ; udevadm settle > > lasted for ~10s! > > That made me think (usually that is not my domain..); Why is my board so slow > and why refuses udev to work proper for it? Checking all written I fell over > udev msg in one of my previous mails > > | insmod /lib/modules/2.6.38.5/kernel/drivers/usb/host/ehci-hcd.ko > > So I decided to change in kernel-config > -CONFIG_USB_HID=m > +CONFIG_USB_HID=y > > -CONFIG_USB_EHCI_HCD=m > +CONFIG_USB_EHCI_HCD=y > > This make the tx28 board now working very similar to my overo board: USB devices > are detected at a very early state of boot and udev is much faster now and USB > is working as expected. Also hotplugging seems to work. It does make the kernel boot ±1.5s slower, but that will still give you a big win in userspace. > I would say it's > partytime but still there is > > | udevd[588]: error: runtime directory '/run/udev' not writable, for now falling > back to '/dev/.udev' > | <30>udevd[589]: starting version 171 We don't support /run in oe.dev yet, the oe-core version of angstrom does since it's required for systemd support. regards, Koen -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.5 (Darwin) iD8DBQFOBLCIMkyGM64RGpERAlYQAJ0fbU+ruFljsfkXcB2x2Uki+T4yzgCgroEa tDe2l4nnMZAyp+Ag7tQKcEQ= =w2Xr -----END PGP SIGNATURE-----