Module Name: src
Committed By: ad
Date: Wed Oct 4 20:46:33 UTC 2023
Modified Files:
src/sys/kern: kern_lwp.c
Log Message:
Do cv_broadcast(&p->p_lwpcv) after dropping p->p_lock in a few places, to
reduce contention.
To generate a diff of this commit:
cvs rdiff -u -r1.261 -r1.262 src/sys/kern/kern_lwp.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/kern/kern_lwp.c
diff -u src/sys/kern/kern_lwp.c:1.261 src/sys/kern/kern_lwp.c:1.262
--- src/sys/kern/kern_lwp.c:1.261 Wed Oct 4 20:45:13 2023
+++ src/sys/kern/kern_lwp.c Wed Oct 4 20:46:33 2023
@@ -1,4 +1,4 @@
-/* $NetBSD: kern_lwp.c,v 1.261 2023/10/04 20:45:13 ad Exp $ */
+/* $NetBSD: kern_lwp.c,v 1.262 2023/10/04 20:46:33 ad Exp $ */
/*-
* Copyright (c) 2001, 2006, 2007, 2008, 2009, 2019, 2020, 2023
@@ -217,7 +217,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: kern_lwp.c,v 1.261 2023/10/04 20:45:13 ad Exp $");
+__KERNEL_RCSID(0, "$NetBSD: kern_lwp.c,v 1.262 2023/10/04 20:46:33 ad Exp $");
#include "opt_ddb.h"
#include "opt_lockdebug.h"
@@ -1219,10 +1219,10 @@ lwp_exit(struct lwp *l)
}
lwp_unlock(l);
p->p_nrlwps--;
- cv_broadcast(&p->p_lwpcv);
if (l->l_lwpctl != NULL)
l->l_lwpctl->lc_curcpu = LWPCTL_CPU_EXITED;
mutex_exit(p->p_lock);
+ cv_broadcast(&p->p_lwpcv);
/*
* We can no longer block. At this point, lwp_free() may already
@@ -1311,13 +1311,13 @@ lwp_free(struct lwp *l, bool recycle, bo
p->p_nzlwps--;
if ((l->l_prflag & LPR_DETACHED) != 0)
p->p_ndlwps--;
+ mutex_exit(p->p_lock);
/*
* Have any LWPs sleeping in lwp_wait() recheck for
* deadlock.
*/
cv_broadcast(&p->p_lwpcv);
- mutex_exit(p->p_lock);
/* Free the LWP ID. */
mutex_enter(&proc_lock);
@@ -1759,11 +1759,11 @@ lwp_userret(struct lwp *l)
pcu_save_all(l);
mutex_enter(p->p_lock);
p->p_nrlwps--;
- cv_broadcast(&p->p_lwpcv);
lwp_lock(l);
l->l_stat = LSSUSPENDED;
lwp_unlock(l);
mutex_exit(p->p_lock);
+ cv_broadcast(&p->p_lwpcv);
lwp_lock(l);
spc_lock(l->l_cpu);
mi_switch(l);
