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Date: Fri, 25 Oct 2013 09:37:38 +0300
From: Andriy Gapon <avg@FreeBSD.org>
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To: Vitalij Satanivskij <satan@ukr.net>
Subject: Re: FreeBSD 10.0-BETA1 #8 r256765M spend too  much time in locks
References: <20131024074826.GA50853@hell.ukr.net>
 <20131024075023.GA52443@hell.ukr.net> <20131024115519.GA72359@hell.ukr.net>
 <20131024165218.GA82686@hell.ukr.net>
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When that high load happens again could you please run some profiling tool that
is capable of capturing the whole stacks of hot code paths?

I can suggest two alternatives:

1. hwpmc
pmcstat -S instructions -O sample.out
pmcstat -R sample.out -G summary.out

2. The following DTrace script:

profile:::profile-1113
/!(curthread->td_flags & 0x20)/
{

        @stacks[stack()] = count();
}

END
{
        trunc(@stacks, 10);
        printa(@stacks);
}
-- 
Andriy Gapon