svn commit: r198464 - head/sys/kern

[Joseph Koshy]

Author: jkoshy
Date: Sun Oct 25 04:34:47 2009
New Revision: 198464
URL: http://svn.freebsd.org/changeset/base/198464

Log:
  Inform hwpmc(4) of a thread's impending demise prior to invoking sched_throw().
  
  Debugging help:		fabient
  Review and testing by:	fabient

Modified:
  head/sys/kern/kern_thread.c

Modified: head/sys/kern/kern_thread.c
==============================================================================
--- head/sys/kern/kern_thread.c	Sun Oct 25 02:48:29 2009	(r198463)
+++ head/sys/kern/kern_thread.c	Sun Oct 25 04:34:47 2009	(r198464)
@@ -27,6 +27,7 @@
  */
 
 #include "opt_witness.h"
+#include "opt_hwpmc_hooks.h"
 
 #include <sys/cdefs.h>
 __FBSDID("$FreeBSD$");
@@ -47,6 +48,9 @@ __FBSDID("$FreeBSD$");
 #include <sys/ktr.h>
 #include <sys/umtx.h>
 #include <sys/cpuset.h>
+#ifdef	HWPMC_HOOKS
+#include <sys/pmckern.h>
+#endif
 
 #include <security/audit/audit.h>
 
@@ -417,6 +421,14 @@ thread_exit(void)
 			panic ("thread_exit: Last thread exiting on its own");
 		}
 	} 
+#ifdef	HWPMC_HOOKS
+	/*
+	 * If this thread is part of a process that is being tracked by hwpmc(4),
+	 * inform the module of the thread's impending exit.
+	 */
+	if (PMC_PROC_IS_USING_PMCS(td->td_proc))
+		PMC_SWITCH_CONTEXT(td, PMC_FN_CSW_OUT);
+#endif
 	PROC_UNLOCK(p);
 	thread_lock(td);
 	/* Save our tick information with both the thread and proc locked */