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Subject: Re: zfs, a directory that used to hold lot of files and listing pause
To: "Eugene M. Zheganin" <emz@norma.perm.ru>, freebsd-stable@FreeBSD.org
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From: Andriy Gapon <avg@FreeBSD.org>
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Date: Fri, 21 Oct 2016 14:34:03 +0300
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Instead of the guesswork and black magic, you could try to use tools to analyze
the problem.  E.g., determine if the delay is because a CPU does a lot of work
or it is because of waiting.  Find the bottleneck, etc.
pmcstat, dtrace are your friends :-)

-- 
Andriy Gapon