Date: Sun, 24 Dec 2000 04:52:50 +1100 From: Kal Torak <kaltorak@quake.com.au> To: Matt Dillon <dillon@earth.backplane.com> Cc: Cy Schubert - ITSD Open Systems Group <Cy.Schubert@uumail.gov.bc.ca>, cjclark@alum.mit.edu, Mikhail Teterin <mi@aldan.algebra.com>, stable@FreeBSD.ORG Subject: Re: an unkillable process (again) Message-ID: <3A44E672.B6FCDC49@quake.com.au> References: <200012231434.eBNEYoc09416@cwsys.cwsent.com> <200012231718.eBNHIQ197462@earth.backplane.com>
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:Actually it is a "priority issue". Read Design and Implementation of :the 4.4BSD Operating System pp 83-85, and pp 89: To prevent a sleeping :process, e.g. one waiting for a device to respond, the kernel raises :the priority of that sleep to splhigh to prevent interrupts that might :cause process-state transitions. For example, see pp 84, Table 4-2 in :the book, if you have a process waiting for swap (PSWP, priority 0) and :you issue a kill which would run at the baseline kernel priority, PZERO :(priority 22), your kill will have no effect on a process in PSWP state :until that process transitions to a lower priority. On all this priority stuff, I am wondering, is it possible to raise the priority of a running process from the command line or start it with a specific priority some how? I have seen some programs with command line switches to change what priority they start at, is this something that needs to be programed into the application? Also if this can be done, would increasing the priority of a server program of some type make it more responsive? Would it be worth doing at all? Or dose this priority stuff have nothing to do with that sort of thing? For kernel use only or something? Thanks for any clarification :) Kal. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message
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