Re: [systemd-devel] How to delete device units presented in systemd-analyze plot.
On Mon, 12.08.13 01:44, Tony Seo (tonys...@gmail.com) wrote: > I sincerely ask you a relationship between device unit and boot time if I > remove unnecessary device unit. > > And also, can I ask you detail process of making device unit by systemd? > (I alread read the manual page related with device unit) the kernel creates a directory in /sys for each device popping up. udev then maintains some additional metadata for all those devices. One part of that metadata is a "tag" that might be on select devices called "systemd". If a a device is tagged like that it will also show up as .device unit systemd. By default block devices, ttys and a few others are tagged like that. Some services need to wait for some block devices before they can be run (for example, fsck instances need to wait for their respective block devices to show up before they can be started), and this is implemented via dependencies to these device units. Device units hence are not really something active in themselves, they just reflect as units state of another component of the OS (which is udev/kernel). Lennart -- Lennart Poettering - Red Hat, Inc. ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] How to delete device units presented in systemd-analyze plot.
Hi Tony, to the green box and the comment about insmod: - Did you compile the kernel module or the whole kernel on your own? Maybe you missed stripping the kernel modules. Unstripped kernel modules can be pretty large and hence might need a long time to load depending on the storage connected. The same is true for the player binary and the shared libs ... To the device units: - the pink bars show that the devices are active. It has nothing to do with the time needed to activate them. These times are represented by the red bars. The pink ones are looking so long in your figures because you player needs so long to get up. To service-udev-trigger.service: - Udevadm trigger is expensive, I know from my own experiences. In you figure, it is looking even worse. This service is used to trigger udevd to set up cold plug devices. If you know your cold plug devices and how to set them up (modules loading, dev node creation, setting attributes, ...) you might consider setting them up manually during startup by respective service files and do a very selective udevadm trigger (using filters for subsystems for instance) only. Hope this helps ... Best regards Marko Hoyer Software Group II (ADITG/SW2) Tel. +49 5121 49 6948 > -Original Message- > From: systemd-devel-bounces+mhoyer=de.adit-jv@lists.freedesktop.org > [mailto:systemd-devel-bounces+mhoyer=de.adit-jv@lists.freedesktop.org] On > Behalf Of Tony Seo > Sent: Sunday, August 11, 2013 6:46 PM > To: systemd-devel@lists.freedesktop.org > Subject: Re: [systemd-devel] How to delete device units presented in systemd- > analyze plot. > > > Hi. > > Today, I would want to share dramatic results through your good aids. > > > > Could you visit my blog to check the results? > > blog: http://best-dream-boy.blogspot.kr/ > > (subject: 2013.08.11 - Test1, 2013.08.11 - Test2) > > > > If you visit to my blog, you can see test1 and test2 picture. > > Those things were results from my test board. > > Since the beginning of my test, I have erased many service units thought as > unnecessary for working my board. > > > Yeah, I want to optimize systemd to work my board. > > Finally, I got a result like "test 2" picture. > > As you see two pictures, Different things are avplayer.unit and some device > units. > > In those test, I didn't use /etc/fstab in my systemd, > > > The only dissimilarity was the existence of avplayer unit, and some device > units came up. > > I wonder why device unit was appeared in spite of erasing /etc/fstab. > > I sincerely ask you a relationship between device unit and boot time if I > remove unnecessary device unit. > > And also, can I ask you detail process of making device unit by systemd? > (I alread read the manual page related with device unit) > > Thanks. > > > Tony Seo. > > > > > ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] How to delete device units presented in systemd-analyze plot.
Hi. Today, I would want to share dramatic results through your good aids. Could you visit my blog to check the results? blog: http://best-dream-boy.blogspot.kr/ (subject: 2013.08.11 - Test1, 2013.08.11 - Test2) If you visit to my blog, you can see test1 and test2 picture. Those things were results from my test board. Since the beginning of my test, I have erased many service units thought as unnecessary for working my board. Yeah, I want to optimize systemd to work my board. Finally, I got a result like "test 2" picture. As you see two pictures, Different things are avplayer.unit and some device units. In those test, I didn't use /etc/fstab in my systemd, The only dissimilarity was the existence of avplayer unit, and some device units came up. I wonder why device unit was appeared in spite of erasing /etc/fstab. I sincerely ask you a relationship between device unit and boot time if I remove unnecessary device unit. And also, can I ask you detail process of making device unit by systemd? (I alread read the manual page related with device unit) Thanks. Tony Seo. ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] How to delete device units presented in systemd-analyze plot.
On Thu, Aug 8, 2013 at 4:10 AM, Tony Seo wrote: > > I understand what you mean, but I think that I will cut the time for > loading device unit if I keep those from appearing on my plot. No, just hiding them will not change anything. > What do think that loading time for device units doesn't affect to boot > speed at machine? It doesn't, because the units do not *exist*. That's the part you keep misunderstanding. Device units by themselves will not *make* systemd wait for a device. They exist only to *show* that systemd *knows about* that device. If you turn on the computer, and it takes several seconds for a device like /sys/devices/platform/soc-audio/sound/card0 to appear, then it *will* take several seconds for that device to appear, whether a systemd shows it as a .device unit or not. /sys/devices/platform/soc-audio/sound/card0 /sys/devices/platform/tcc-gmac/net/eth0 /sys/devices/platform/tcc-uart.0/tty/ttyTCC0 /sys/devices/platform/dwc_otg.0/gadget/tty/ttyGS0 ...what kind of a device is it, anyway? A raspberryπ? -- Mantas Mikulėnas ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] How to delete device units presented in systemd-analyze plot.
Hi Tony, best to my experiences, I doubt that suppressing the loading of device units will speed up systemd that much. There are other major parts that far more significantly delay the startup (cgroups in some cases, loading the unit set at startup, executing the generators, and finally loading the binary of systemd and the shared libraries ...). You'll probably gain more benefit when starting to optimize at these ends ... Best regards Marko Hoyer Software Group II (ADITG/SW2) Best regards Marko Hoyer Software Group II (ADITG/SW2) Tel. +49 5121 49 6948 > -Original Message- > From: systemd-devel-bounces+mhoyer=de.adit-jv@lists.freedesktop.org > [mailto:systemd-devel-bounces+mhoyer=de.adit-jv@lists.freedesktop.org] On > Behalf Of Tony Seo > Sent: Thursday, August 08, 2013 3:12 AM > To: Mantas Mikulėnas > Cc: systemd-devel@lists.freedesktop.org > Subject: Re: [systemd-devel] How to delete device units presented in systemd- > analyze plot. > > > I understand what you mean, but I think that I will cut the time for loading > device unit if I keep those from appearing on my plot. > > I want to do a try to temporarily disappear some kinds of device units and > then I'm supposed to measure boot speed depending a board of mine.(Actually, I > believe that loading time for device unit affects to boot speed) > > What do think that loading time for device units doesn't affect to boot speed > at machine? > > Thanks. > > > > 2013/8/8 Mantas Mikulėnas > > > On Wed, Aug 7, 2013 at 8:03 PM, Tony Seo wrote: > > > > Hello. > > > > Now, I have studied systemd for optimizing systemd on my board. > > > > After edited several units, I would like to delete some device > configuration > > units existing on my picture from systemd-analyze(best-dream- > boy.blogspot) > > > > I read the manual pages about systemd.device, I tried to delete > device units > > through editing /etc/fstab and systemctl mask. > > > > But I couldn't delete those device units, at least existing units on > the > > picture. > > > You cannot delete these units because they do not exist anywhere > except in memory – they're only a way to represent device status in > the format of systemd units. In other words, they do not cause the > problems you're having; they only make the problems visible in your > bootchart. > > -- > Mantas Mikulėnas > > ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] How to delete device units presented in systemd-analyze plot.
I understand what you mean, but I think that I will cut the time for loading device unit if I keep those from appearing on my plot. I want to do a try to temporarily disappear some kinds of device units and then I'm supposed to measure boot speed depending a board of mine.(Actually, I believe that loading time for device unit affects to boot speed) What do think that loading time for device units doesn't affect to boot speed at machine? Thanks. 2013/8/8 Mantas Mikulėnas > On Wed, Aug 7, 2013 at 8:03 PM, Tony Seo wrote: > > > > Hello. > > > > Now, I have studied systemd for optimizing systemd on my board. > > > > After edited several units, I would like to delete some device > configuration > > units existing on my picture from > systemd-analyze(best-dream-boy.blogspot) > > > > I read the manual pages about systemd.device, I tried to delete device > units > > through editing /etc/fstab and systemctl mask. > > > > But I couldn't delete those device units, at least existing units on the > > picture. > > You cannot delete these units because they do not exist anywhere > except in memory – they're only a way to represent device status in > the format of systemd units. In other words, they do not cause the > problems you're having; they only make the problems visible in your > bootchart. > > -- > Mantas Mikulėnas > ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] How to delete device units presented in systemd-analyze plot.
On Wed, Aug 7, 2013 at 8:03 PM, Tony Seo wrote: > > Hello. > > Now, I have studied systemd for optimizing systemd on my board. > > After edited several units, I would like to delete some device configuration > units existing on my picture from systemd-analyze(best-dream-boy.blogspot) > > I read the manual pages about systemd.device, I tried to delete device units > through editing /etc/fstab and systemctl mask. > > But I couldn't delete those device units, at least existing units on the > picture. You cannot delete these units because they do not exist anywhere except in memory – they're only a way to represent device status in the format of systemd units. In other words, they do not cause the problems you're having; they only make the problems visible in your bootchart. -- Mantas Mikulėnas ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
[systemd-devel] How to delete device units presented in systemd-analyze plot.
Hello. Now, I have studied systemd for optimizing systemd on my board. After edited several units, I would like to delete some device configuration units existing on my picture from systemd-analyze(best-dream-boy.blogspot) I read the manual pages about systemd.device, I tried to delete device units through editing /etc/fstab and systemctl mask. But I couldn't delete those device units, at least existing units on the picture. So I would ask you a question about it. Thanks. ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
