Re: About nice(1), renice(8) and ULE scheduler
In fact nice is a very simple program. It only changes the priority value of a process in a POSIX-compliant way. There is no need to change or adapt it; it still works fine in the SMP world and with new schedulers. It's up to the scheduler to interpret and handle the priority values of processes. In other words: The nice(1) tool only attaches a number to a process, nothing more. Only the scheduler knows what that number means. So there's no need to change nice(1). Great. So, the key is the scheduler; it makes sense. By the way, the source code of nice(1) is almost trivial. Basically it just calls the setpriority(2) and execve(2) syscalls. 99% of the source file consists of the BSD license test, arguments parsing and C syntax overhead. Thanks for aclaration. ;) -- I must not fear. Fear is the mind-killer. Fear is the little-death that brings total obliteration. I will face my fear. I will permit it to pass over me and through me. And when it has gone past I will turn the inner eye to see its path. Where the fear has gone there will be nothing. Only I will remain. Bene Gesserit Litany Against Fear. ___ freebsd-stable@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to freebsd-stable-unsubscr...@freebsd.org
Re: About nice(1), renice(8) and ULE scheduler
Jordi Espasa Clofent jespa...@minibofh.org wrote: I've realized that the nice(1) code hasn't been modified for a long time (last code change seems from 4 years ago according the sources). ¿Is the nice(1) behaviour the expected? I mean, ¿Has been the ULE scheduler adapted to nice(1) command or not? nice(1) is a very old command based on old concepts and created in times when SMP didn't exist. So ¿it works correctly when a modern an re-designed scheduler as ULE is used? In fact nice is a very simple program. It only changes the priority value of a process in a POSIX-compliant way. There is no need to change or adapt it; it still works fine in the SMP world and with new schedulers. It's up to the scheduler to interpret and handle the priority values of processes. In other words: The nice(1) tool only attaches a number to a process, nothing more. Only the scheduler knows what that number means. So there's no need to change nice(1). By the way, the source code of nice(1) is almost trivial. Basically it just calls the setpriority(2) and execve(2) syscalls. 99% of the source file consists of the BSD license test, arguments parsing and C syntax overhead. Best regards Oliver -- Oliver Fromme, secnetix GmbH Co. KG, Marktplatz 29, 85567 Grafing b. M. Handelsregister: Registergericht Muenchen, HRA 74606, Geschäftsfuehrung: secnetix Verwaltungsgesellsch. mbH, Handelsregister: Registergericht Mün- chen, HRB 125758, Geschäftsführer: Maik Bachmann, Olaf Erb, Ralf Gebhart FreeBSD-Dienstleistungen, -Produkte und mehr: http://www.secnetix.de/bsd I have stopped reading Stephen King novels. Now I just read C code instead. -- Richard A. O'Keefe ___ freebsd-stable@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to freebsd-stable-unsubscr...@freebsd.org
About nice(1), renice(8) and ULE scheduler
HI all, I've realized that the nice(1) code hasn't been modified for a long time (last code change seems from 4 years ago according the sources). ¿Is the nice(1) behaviour the expected? I mean, ¿Has been the ULE scheduler adapted to nice(1) command or not? nice(1) is a very old command based on old concepts and created in times when SMP didn't exist. So ¿it works correctly when a modern an re-designed scheduler as ULE is used? Maybe I have to read again this paper: http://www.usenix.org/event/bsdcon03/tech/full_papers/roberson/roberson.pdf -- I must not fear. Fear is the mind-killer. Fear is the little-death that brings total obliteration. I will face my fear. I will permit it to pass over me and through me. And when it has gone past I will turn the inner eye to see its path. Where the fear has gone there will be nothing. Only I will remain. Bene Gesserit Litany Against Fear. ___ freebsd-stable@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to freebsd-stable-unsubscr...@freebsd.org
