Skip site navigation (1)Skip section navigation (2)
Date:      Mon, 26 Aug 2002 19:48:12 +0100
From:      Ian Dowse <iedowse@maths.tcd.ie>
To:        cvs-committers@FreeBSD.org, cvs-all@FreeBSD.org
Subject:   Re: cvs commit: src/sys/sys ktr.h src/sys/kern kern_mutex.c 
Message-ID:   <200208261948.aa37056@salmon.maths.tcd.ie>
In-Reply-To: Your message of "Mon, 26 Aug 2002 11:39:38 PDT." <200208261839.g7QIdckr094663@freefall.freebsd.org> 

next in thread | previous in thread | raw e-mail | index | archive | help
In message <200208261839.g7QIdckr094663@freefall.freebsd.org>, Ian Dowse writes
:
>  Add a new KTR type KTR_CONTENTION, and use it in the mutex code to
>  log the start and end of periods during which mtx_lock() is waiting
>  to acquire a sleep mutex. The log message includes the file and
>  line of both the waiter and the holder.

A simple perl script for parsing the output of ktrdump into some
mutex contention statistics is at:

	http://people.freebsd.org/~iedowse/mtx_contention/

Without increasing the KTR buffer size or taking a lot of samples,
these statistics are going to be fairly crude, but they may help
to give some information about where the biggest bottlenecks lie.

Ian

To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe cvs-all" in the body of the message




Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi? <200208261948.aa37056>