Date: Mon, 09 Jun 2003 21:04:40 +0900 (JST) From: Masachika ISHIZUKA <ishizuka@ish.org> To: das@freebsd.org Cc: stable@freebsd.org Subject: Re: system slowdown - vnode related Message-ID: <20030609.210440.112307207.ishizuka@ish.org> In-Reply-To: <20030609085454.GA5633@HAL9000.homeunix.com> References: <20030609041942.GA4029@HAL9000.homeunix.com> <20030609.163252.71109503.ishizuka@ish.org> <20030609085454.GA5633@HAL9000.homeunix.com>
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>>>> I have still vnodes problem in 4.8-stable with /sys/kern/vfs_subr.c >>>> 1.249.2.30. >>>> >>>> % sysctl kern.maxvnodes >>>> kern.maxvnodes: 17979 >>>> % sysctl vm.zone | grep VNODE >>>> VNODE: 192, 0, 18004, 122, 18004 >>> >>> This looks pretty normal to me for a quiescent system. >> >> I think the used(18004) exceeds maxvnodes(17979), isn't it ? > > Only by a little bit. maxvnodes isn't a hard limit, since making > it a hard limit would lead to deadlocks. Instead, the system > garbage collects vnodes to keep the number roughly in line with > maxvnodes. Judging by the numbers above, it's doing a pretty good > job, but that's probably because, from the looks of it, you > just booted the system. Hi, David-san. Thank you for mail. I understood. > The reason it might make sense to increase maxvnodes is that > having vnlru work overtime to keep your vnode count low may > result in vnodes being freed that are still needed, e.g. by the > buffer cache. This would cause the slowdown you were mentioning. I will try to increase kern.maxvnodes when the machine is slowdown. But I can not reproduce slowdown in experimental environment, yet. >>> Did you get a backtrace from the panics? >> >> It's too hard for me. Is there any way to do it ? > > The panics might be unrelated to the number of vnodes, so it's > important that we have additional information. See: > > http://www.freebsd.org/doc/en/books/developers-handbook/kerneldebug.html I'll try. Thank you very much. -- ishizuka@ish.org
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