Re: [systemd-devel] make systemd service takes cpu exclusively
On Wed, 19.11.14 20:05, Andrei Borzenkov (arvidj...@gmail.com) wrote: В Tue, 18 Nov 2014 06:25:43 + Cao, XinX xinx@intel.com пишет: Hi, Umut David, My project needs the Graphical desktop to display on monitor as fast as possible, but I found lots of unrelated services( such as sound, network, ... ) are competing CPU even they are explicitly After graphical service. And this competion delays the startup of graphical desktop process. So, my opinion is to make graphical related programs runs first and the other unrelated services only starts after graphical program finished startup. Let me guess. Your Graphical desktop is defined of simple or forking, right? So from systemd point of view service is started as soon as process is forked and it proceeds with starting further service defined After this one. One minor correction: forking actually is supposed to provide propery synchronization too, as daemons that use double-forking to daemonize should return in the parent only after the daemon is fully initialized. THis is in fact what classic sysv init scripts rely on to properly serialize startup of services that need to talk to each other. Lennart -- Lennart Poettering, Red Hat ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] make systemd service takes cpu exclusively
Hi, Yes, you are right. My service is defined as simple. And I changed it to notify, seems that I can make the other services now successfully start after it finished startup. But I'm confused who will call sd_notify to send READY=1? I can't find the related code in system. Or the program itself? For example, if the [Service] part of my service file is like this: [Service] Type=notify NotifyAccess = all ExecStart = /usr/bin/abcdef ... ... In this service , if I want to use notify type, need I add something like sd_notify(0,READY=1) in the code of abcdef ? -Original Message- From: Andrei Borzenkov [mailto:arvidj...@gmail.com] Sent: Thursday, November 20, 2014 01:06 To: Cao, XinX Cc: Umut Tezduyar Lindskog; systemd-devel@lists.freedesktop.org Subject: Re: [systemd-devel] make systemd service takes cpu exclusively В Tue, 18 Nov 2014 06:25:43 + Cao, XinX xinx@intel.com пишет: Hi, Umut David, My project needs the Graphical desktop to display on monitor as fast as possible, but I found lots of unrelated services( such as sound, network, ... ) are competing CPU even they are explicitly After graphical service. And this competion delays the startup of graphical desktop process. So, my opinion is to make graphical related programs runs first and the other unrelated services only starts after graphical program finished startup. Let me guess. Your Graphical desktop is defined of simple or forking, right? So from systemd point of view service is started as soon as process is forked and it proceeds with starting further service defined After this one. The problem with After is that it is effective only if systemd can know when service startup is completed. And in general it is possible only with types dbus or notify (and cooperating server). In case of GUI you do not even have single process representing service, depending on definition of Graphical desktop. ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] make systemd service takes cpu exclusively
On Thu, Nov 27, 2014 at 12:56 PM, Cao, XinX xinx@intel.com wrote: Hi, Yes, you are right. My service is defined as simple. And I changed it to notify, seems that I can make the other services now successfully start after it finished startup. But I'm confused who will call sd_notify to send READY=1? I can't find the related code in system. Or the program itself? Yes, it has to be added to your program. That's the whole point of Type=notify, after all – systemd can't know when your program is ready unless the program tells it so. -- Mantas Mikulėnas graw...@gmail.com ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] make systemd service takes cpu exclusively
В Thu, 27 Nov 2014 12:44:50 + Cao, XinX xinx@intel.com пишет: But it’s very strange, for I can’t find “sd_notify” or “sd_notifyf” in my program, but seems that notify type can still work. So are there any other functions able to do this ? Sorry, I do not understand this. Could you try to rephrase? Thanks~~ From: Mantas Mikulėnas [mailto:graw...@gmail.com] Sent: Thursday, November 27, 2014 20:15 To: Cao, XinX Cc: systemd-devel@lists.freedesktop.org Subject: Re: [systemd-devel] make systemd service takes cpu exclusively On Thu, Nov 27, 2014 at 12:56 PM, Cao, XinX xinx@intel.commailto:xinx@intel.com wrote: Hi, Yes, you are right. My service is defined as simple. And I changed it to notify, seems that I can make the other services now successfully start after it finished startup. But I'm confused who will call sd_notify to send READY=1? I can't find the related code in system. Or the program itself? Yes, it has to be added to your program. That's the whole point of Type=notify, after all – systemd can't know when your program is ready unless the program tells it so. -- Mantas Mikulėnas graw...@gmail.commailto:graw...@gmail.com ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] make systemd service takes cpu exclusively
On Thu, Nov 27, 2014 at 12:44:50PM +, Cao, XinX wrote: But it’s very strange, for I can’t find “sd_notify” or “sd_notifyf” in my program, but seems that notify type can still work. So are there any other functions able to do this ? Thanks~~ Are you sure it's working? If you specify notify for non-notify program, it will start OK, but will get killed after 90s (by default). -- Tomasz Torcz Never underestimate the bandwidth of a station xmpp: zdzich...@chrome.plwagon filled with backup tapes. -- Jim Gray ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] make systemd service takes cpu exclusively
В Tue, 18 Nov 2014 06:25:43 + Cao, XinX xinx@intel.com пишет: Hi, Umut David, My project needs the Graphical desktop to display on monitor as fast as possible, but I found lots of unrelated services( such as sound, network, ... ) are competing CPU even they are explicitly After graphical service. And this competion delays the startup of graphical desktop process. So, my opinion is to make graphical related programs runs first and the other unrelated services only starts after graphical program finished startup. Let me guess. Your Graphical desktop is defined of simple or forking, right? So from systemd point of view service is started as soon as process is forked and it proceeds with starting further service defined After this one. The problem with After is that it is effective only if systemd can know when service startup is completed. And in general it is possible only with types dbus or notify (and cooperating server). In case of GUI you do not even have single process representing service, depending on definition of Graphical desktop. ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
[systemd-devel] make systemd service takes cpu exclusively
Hi, everybody, As we all know that currently systemd puts all the services into a run_queue, and lets them run together as possible as it can. However, this mechanism also brings in a problem, which means all the services will contend for CPU, and systemd is unable to make sure one service has priority ONE and only itself takes the CPU when this service is starting. For example, if we want to make sure a.service runs firstly , and all the other services runs after a.service is finished. So, does anybody know if systemd has this kind of mechanism? If not, can we create a way to do this and add this feature into systemd? Or is this idea possible? I think this is very usefull under some situations. Thanks~ ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] make systemd service takes cpu exclusively
Hi On Mon, Nov 17, 2014 at 9:40 AM, Cao, XinX xinx@intel.com wrote: Hi, everybody, As we all know that currently systemd puts all the services into a run_queue, and lets them run together as possible as it can. However, this mechanism also brings in a problem, which means all the services will contend for CPU, and systemd is unable to make sure one service has priority ONE and only itself takes the CPU when this service is starting. For example, if we want to make sure a.service runs firstly , and all the other services runs after a.service is finished. So, does anybody know if systemd has this kind of mechanism? If not, can we create a way to do this and add this feature into systemd? Or is this idea possible? I think this is very usefull under some situations. You could use explicit ordering (see Before= and After=) to make your unit run almost exclusively. But this will cause a significant bottle-neck during boot and is not recommended at all. The question really is _why_ you want that unit to be run before anything else. If you only want to prioritize one unit, have a look at man systemd.resource-control. It provides a huge set of options to configure your units. You have quite fine control over CPU shares etc. Specifically the StartupCPUShares= option might be of interest to you. Thanks David ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] make systemd service takes cpu exclusively
Hi XinX On Mon, Nov 17, 2014 at 9:40 AM, Cao, XinX xinx@intel.com wrote: Hi, everybody, As we all know that currently systemd puts all the services into a run_queue, and lets them run together as possible as it can. However, this mechanism also brings in a problem, which means all the services will contend for CPU, and systemd is unable to make sure one service has priority ONE and only itself takes the CPU when this service is starting. What exactly is the problem when they all want to get the CPU? For example, if we want to make sure a.service runs firstly , and all the other services runs after a.service is finished. So, does anybody know if systemd has this kind of mechanism? If not, can we create a way to do this and add this feature into systemd? Or is this idea possible? I think this is very usefull under some situations. It really depends on your use case and what you consider with a.service runs first. If you only want to start the service first, then you can always add After=a.service directive to other services that are starting at the same time. But this is pretty static information. You have to do this for every time you change your priority service. You could also prioritize a service by changing their StartupCPUShares= but this is not truly stopping other services from being scheduled in. Maybe they get the minimum CPU, but they still do. Lennart has recently considered to change the startup queue to prioritized startup queue where a prioritized service will be forked off before other services - http://lists.freedesktop.org/archives/systemd-devel/2014-October/024315.html. Umut Thanks~ ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] make systemd service takes cpu exclusively
Hi, Umut David, My project needs the Graphical desktop to display on monitor as fast as possible, but I found lots of unrelated services( such as sound, network, ... ) are competing CPU even they are explicitly After graphical service. And this competion delays the startup of graphical desktop process. So, my opinion is to make graphical related programs runs first and the other unrelated services only starts after graphical program finished startup. I will check StartupCPUShares= this item and I hope it's helpful for me. Thanks -Original Message- From: Umut Tezduyar Lindskog [mailto:u...@tezduyar.com] Sent: Monday, November 17, 2014 17:51 To: Cao, XinX Cc: systemd-devel@lists.freedesktop.org Subject: Re: [systemd-devel] make systemd service takes cpu exclusively Hi XinX On Mon, Nov 17, 2014 at 9:40 AM, Cao, XinX xinx@intel.com wrote: Hi, everybody, As we all know that currently systemd puts all the services into a run_queue, and lets them run together as possible as it can. However, this mechanism also brings in a problem, which means all the services will contend for CPU, and systemd is unable to make sure one service has priority ONE and only itself takes the CPU when this service is starting. What exactly is the problem when they all want to get the CPU? For example, if we want to make sure a.service runs firstly , and all the other services runs after a.service is finished. So, does anybody know if systemd has this kind of mechanism? If not, can we create a way to do this and add this feature into systemd? Or is this idea possible? I think this is very usefull under some situations. It really depends on your use case and what you consider with a.service runs first. If you only want to start the service first, then you can always add After=a.service directive to other services that are starting at the same time. But this is pretty static information. You have to do this for every time you change your priority service. You could also prioritize a service by changing their StartupCPUShares= but this is not truly stopping other services from being scheduled in. Maybe they get the minimum CPU, but they still do. Lennart has recently considered to change the startup queue to prioritized startup queue where a prioritized service will be forked off before other services - http://lists.freedesktop.org/archives/systemd-devel/2014-October/024315.html. Umut Thanks~ ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
