Re: [gentoo-user] real-time priority
On Thu, 11 Aug 2005, Joseph wrote: I'm not sure if that what they mean with "real-time priority". Realtime has nothing to do with 'nice'. With 'nice' you set the process' time-slice so that it gets more (or less) processor-time. With realtime ("soft" or "hard" realtime - there's a difference) the process is "guaranteed" to have processor-time within certain time-limits, something which "normal" schedulers don't do. See 'http://en.wikipedia.org/wiki/Real-time_computing'. HTH Best regards Peter K -- gentoo-user@gentoo.org mailing list
Re: [gentoo-user] real-time priority
Joseph wrote: >On Thu, 2005-08-11 at 17:19 -0700, Mark Knecht wrote: > > >>On 8/10/05, Joseph <[EMAIL PROTECTED]> wrote: >> >> >>>How to list real-time priority in Linux for an application (example >>>asterisk)? >>> >>> >>> >>man schedtoot >>man chrt >> >>Have fun, >>Mark >> >> > >Thanks Mark, > >But they must be part of some other package. >I can not find schedtoot or chrt on my system nor they are in portage. > > > Sorry, Joseph, I clearly have no idea what I am talking about. :) Ian begin:vcard fn:Ian K n:K;Ian email;internet:[EMAIL PROTECTED] note;quoted-printable:Pentium 3=0D=0A= 500mHz=0D=0A= 256MB RAM=0D=0A= 80.0GB HDD=0D=0A= ATI Radeon 7000 Evil Wizard 64MB=0D=0A= Computer name: "PentaQuad"=0D=0A= x-mozilla-html:TRUE version:2.1 end:vcard
Re: [gentoo-user] real-time priority
On 8/11/05, Joseph <[EMAIL PROTECTED]> wrote: > On Thu, 2005-08-11 at 17:19 -0700, Mark Knecht wrote: > > On 8/10/05, Joseph <[EMAIL PROTECTED]> wrote: > > > How to list real-time priority in Linux for an application (example > > > asterisk)? > > > > > > > man schedtoot > > man chrt > > > > Have fun, > > Mark > > Thanks Mark, > > But they must be part of some other package. > I can not find schedtoot or chrt on my system nor they are in portage. > > -- > #Joseph > My bad typing. schedtool, not schedtoot flash ~ # equery belongs schedtool [ Searching for file(s) schedtool in *... ] sys-process/schedtool-1.2.3 (/usr/share/doc/schedtool) sys-process/schedtool-1.2.3 (/usr/bin/schedtool) flash ~ # flash ~ # emerge -pv schedtool These are the packages that I would merge, in order: Calculating dependencies ...done! [ebuild R ] sys-process/schedtool-1.2.3 24 kB Total size of downloads: 24 kB flash ~ # flash ~ # equery belongs chrt [ Searching for file(s) chrt in *... ] sys-process/schedutils-1.3.5 (/usr/bin/chrt) flash ~ # emerge -pv schedutils These are the packages that I would merge, in order: Calculating dependencies ...done! [ebuild R ] sys-process/schedutils-1.3.5 0 kB Total size of downloads: 0 kB flash ~ # -- gentoo-user@gentoo.org mailing list
Re: [gentoo-user] real-time priority
On Thu, 2005-08-11 at 17:19 -0700, Mark Knecht wrote: > On 8/10/05, Joseph <[EMAIL PROTECTED]> wrote: > > How to list real-time priority in Linux for an application (example > > asterisk)? > > > > man schedtoot > man chrt > > Have fun, > Mark Thanks Mark, But they must be part of some other package. I can not find schedtoot or chrt on my system nor they are in portage. -- #Joseph -- gentoo-user@gentoo.org mailing list
Re: [gentoo-user] real-time priority
On 8/10/05, Joseph <[EMAIL PROTECTED]> wrote: > How to list real-time priority in Linux for an application (example > asterisk)? > man schedtoot man chrt Have fun, Mark -- gentoo-user@gentoo.org mailing list
Re: [gentoo-user] real-time priority
On Thu, 2005-08-11 at 15:06 +, Ian K wrote: > Joseph wrote: > > >How to list real-time priority in Linux for an application (example > >asterisk)? > > > > > > > Do you mean processor scheduling? "This program deserves more processor > time/power than others?" > > If so, find out the process ID of the app you want to 'promote' or 'demote' > and take it with you into a konsole/terminal and type this: > > renice > > The priority is on a scale. -21---0--+21 > The negative priorities are promotions. Giving it a -21 would bring down > many > other applications the second they tried to use the processor. I never > really go > above ten, either way. > > HTH, > Ian I'm not sure if that what they mean with "real-time priority". All I was able to find out that some of them are running Asterisk with switch -p; so they start asterisk with: asterisk -p This is an explanation what -p switch does (from asterisk man): If supported by the operating system (and executing as root), attempt to run with realtime priority for increased performance and responsiveness within the Asterisk process, at the expense of other programs running on the same machine. I now that I could start asterisk with higher priority level; so I modified the startup script to start asterisk with "nice -15". But some of the members in asterisk forum insisting that "nice" is not the same as "real-time priority". Here are two replies I received form Asterisk forum: -- reply 1 -- What do you mean with listing real-time priority? You can list process priorities with commands like top or "ps -eo pri,nice,%cpu,pid,args --sort pri" (for example). If you're interrested in asterisk's real-time responsiveness, the following might be of interrest. Real-time priority actually doesn't exist in Linux (you'll need to use a real RTOS for that). Still, Linux makes a destinction between processes that need sort of real-time response times and processes that don't. Controlling this in a direct way is a difficult, if possible at all. Prioritizing processes is done on the fly (in real time) by the scheduling process in the Linux core. However, there is a way to manipulate the prioritizing of processes with a command called 'nice'. Normally you use this command (with a positive adjustment value) to make a process to behave 'nice' to other processes. That is, it gives the process a lower priority that it would normally get, thus making it a relative low priority process. By using nice with a negative adjustment (you'll need to be root for that), you're able to give a certain process a higher priority than it would normally get, thus giving the process more of a 'real-time' priority. In my experience it proved to be more usefull to give all the processes, that stood in the way of asterisk performance, a positive nice adjustment, rather than giving asterisk a negative nice adjustment. I haven't tested this thoroughly, so I'm not sure about the reasons for this. It could have something to with asterisk getting in the way of Linux's core processes when incresing it's priority. Still, it's nothing more than a guess. - end replay 1 --- reply 2 - > Real-time priority actually doesn't exist in Linux Sure it does. > you'll need to use a real RTOS for that Thanks to Ingo Molnars' realtime patches, the gnu/linux audio community runs with latencies sub 1ms. > Controlling this in a direct way is a difficult, if possible at all chrt(1) --- end reply 2 - -- #Joseph -- gentoo-user@gentoo.org mailing list
Re: [gentoo-user] real-time priority
Joseph wrote: >How to list real-time priority in Linux for an application (example >asterisk)? > > > Do you mean processor scheduling? "This program deserves more processor time/power than others?" If so, find out the process ID of the app you want to 'promote' or 'demote' and take it with you into a konsole/terminal and type this: renice The priority is on a scale. -21---0--+21 The negative priorities are promotions. Giving it a -21 would bring down many other applications the second they tried to use the processor. I never really go above ten, either way. HTH, Ian begin:vcard fn:Ian K n:K;Ian email;internet:[EMAIL PROTECTED] note;quoted-printable:Pentium 3=0D=0A= 500mHz=0D=0A= 256MB RAM=0D=0A= 80.0GB HDD=0D=0A= ATI Radeon 7000 Evil Wizard 64MB=0D=0A= Computer name: "PentaQuad"=0D=0A= x-mozilla-html:TRUE version:2.1 end:vcard
[gentoo-user] real-time priority
How to list real-time priority in Linux for an application (example asterisk)? -- #Joseph -- gentoo-user@gentoo.org mailing list