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Path: sserve!newshost.anu.edu.au!harbinger.cc.monash.edu.au!yeshua.marcam.com!news.kei.com!ddsw1!not-for-mail From: mikebo@MCS.COM (Michael Borowiec) Newsgroups: comp.unix.bsd Subject: Re: fork/vfork accounting in the kernel Date: 16 Oct 1994 10:52:51 -0500 Organization: MCSnet, Chicago Area Public Internet Access Lines: 45 Message-ID: <37ri8j$lgu@Mars.mcs.com> References: <374j2h$gev@mercury.mcs.com> <KSTAILEY.94Oct14132833@leidecker> NNTP-Posting-Host: mars.mcs.com In article <KSTAILEY.94Oct14132833@leidecker>, <kstailey@leidecker.std.com> wrote: >>In article <374j2h$gev@Mercury.mcs.com>, mikebo@MCS.COM (Michael Borowiec) writes: >> >> SunOS does fork/vfork accounting using a structure called "forkstat", >> containing ints cntfork, cntvfork, sizfork, sizvfork. I don't find >> any mechanism like this in FreeBSD. It's like six lines and could have >> been put just about anywhere in fork1() or vm_fork() where isvfork is >> tested. Do other BSDs have this structure? Am I missing something, or >> doesn't anyone (but me) care about this information? 8v) >> >4.3BSD has this, but later versions use Mach virtual memory. It's >probably not trivial to get forkstat to work, and it's less important >because of the introduction of copy on write paging. > I'm not a kernel hacker by any stretch. Nevertheless, I'm trying to port the "mon" program to FreeBSD (assuming it hasn't been done already). Anyway, all I want to do is find out how many times fork or vfork has been called during some period of time. It sure *seems* trivial to me having looked at the 4.3BSD kernel code which increments the int's in the forkstat struct. It's not like a system call or anything; just a kernel variable increment/read. Like I said, only four real lines of code. Why is the number of times fork has been called any less (or more) important? I guess I can accept that perhaps fork has less impact on the speed of the OS because of the Mach VM system... but I can't believe it's totally irrelevant. Besides, I thought it was an interesting stat, if for performance monitoring purposes if nothing else. - Mike -------------------------------------------------------------------------- Michael Borowiec All tied to their things, mikebo@MCS.COM they are netted by the strings... Free to flutter, in memory of their wasted wings... P.Gabriel --RAA06699.782173161/kitten.mcs.com-- -- -------------------------------------------------------------------------- Michael Borowiec All tied to their things, mikebo@MCS.COM they are netted by the strings... Free to flutter, in memory of their wasted wings... P.Gabriel