Date: Sat, 24 Jan 2009 10:22:49 +0000 (UTC) From: Robert Watson <rwatson@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r187664 - head/sys/kern Message-ID: <200901241022.n0OAMntu069233@svn.freebsd.org>
next in thread | raw e-mail | index | archive | help
Author: rwatson Date: Sat Jan 24 10:22:49 2009 New Revision: 187664 URL: http://svn.freebsd.org/changeset/base/187664 Log: Add explicit static DTrace tracing to the callout mechanism, capturing pointers to the callout handler just before and just after the callout it invoked. I attempted to do this in a manner congruent to tracing in Solaris's callout mechanism, but couldn't quite use the same names due to convention and syntax differences. Example DTrace script to generate a distribution graph of callout execution times: callout_execute:::callout_start { self->cstart = timestamp; } callout_execute:::callout_end { @length = quantize(timestamp - self->cstart); } Reviewed by: jb MFC after: 3 days Modified: head/sys/kern/kern_timeout.c Modified: head/sys/kern/kern_timeout.c ============================================================================== --- head/sys/kern/kern_timeout.c Sat Jan 24 05:32:11 2009 (r187663) +++ head/sys/kern/kern_timeout.c Sat Jan 24 10:22:49 2009 (r187664) @@ -37,6 +37,8 @@ #include <sys/cdefs.h> __FBSDID("$FreeBSD$"); +#include "opt_kdtrace.h" + #include <sys/param.h> #include <sys/systm.h> #include <sys/bus.h> @@ -49,10 +51,19 @@ __FBSDID("$FreeBSD$"); #include <sys/malloc.h> #include <sys/mutex.h> #include <sys/proc.h> +#include <sys/sdt.h> #include <sys/sleepqueue.h> #include <sys/sysctl.h> #include <sys/smp.h> +SDT_PROVIDER_DEFINE(callout_execute); +SDT_PROBE_DEFINE(callout_execute, kernel, , callout_start); +SDT_PROBE_ARGTYPE(callout_execute, kernel, , callout_start, 0, + "struct callout *"); +SDT_PROBE_DEFINE(callout_execute, kernel, , callout_end); +SDT_PROBE_ARGTYPE(callout_execute, kernel, , callout_end, 0, + "struct callout *"); + static int avg_depth; SYSCTL_INT(_debug, OID_AUTO, to_avg_depth, CTLFLAG_RD, &avg_depth, 0, "Average number of items examined per softclock call. Units = 1/1000"); @@ -395,7 +406,11 @@ softclock(void *arg) binuptime(&bt1); #endif THREAD_NO_SLEEPING(); + SDT_PROBE(callout_execute, kernel, , + callout_start, c, 0, 0, 0, 0); c_func(c_arg); + SDT_PROBE(callout_execute, kernel, , + callout_end, c, 0, 0, 0, 0); THREAD_SLEEPING_OK(); #ifdef DIAGNOSTIC binuptime(&bt2);
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?200901241022.n0OAMntu069233>