Module Name: src
Committed By: dyoung
Date: Fri Apr 30 21:17:22 UTC 2010
Modified Files:
src/sys/kern: subr_autoconf.c
Log Message:
IPL_VM is the highest interrupt priority where alldevs is read/written,
and acquiring alldevs_mtx already blocks those interrupts, so delete the
splhigh()/splx() in config_alldevs_lock()/_unlock().
Release alldevs_mtx while freeing memory with kmem_free(9); according to
new documentation, kmem_free(9) can sleep! :-) Thanks to rmind@ for the
tip.
Next step: use finer-grained locking, probably by adding a mutex to
cfdriver_t.
And after that: make sure that all threads of execution are out of the
device_t and/or softc before releasing their memory.
To generate a diff of this commit:
cvs rdiff -u -r1.205 -r1.206 src/sys/kern/subr_autoconf.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/subr_autoconf.c
diff -u src/sys/kern/subr_autoconf.c:1.205 src/sys/kern/subr_autoconf.c:1.206
--- src/sys/kern/subr_autoconf.c:1.205 Mon Apr 19 11:20:56 2010
+++ src/sys/kern/subr_autoconf.c Fri Apr 30 21:17:22 2010
@@ -1,4 +1,4 @@
-/* $NetBSD: subr_autoconf.c,v 1.205 2010/04/19 11:20:56 jruoho Exp $ */
+/* $NetBSD: subr_autoconf.c,v 1.206 2010/04/30 21:17:22 dyoung Exp $ */
/*
* Copyright (c) 1996, 2000 Christopher G. Demetriou
@@ -77,7 +77,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: subr_autoconf.c,v 1.205 2010/04/19 11:20:56 jruoho Exp $");
+__KERNEL_RCSID(0, "$NetBSD: subr_autoconf.c,v 1.206 2010/04/30 21:17:22 dyoung Exp $");
#ifdef _KERNEL_OPT
#include "opt_ddb.h"
@@ -1118,7 +1118,9 @@
* not hold alldevs_mtx, try again.
*/
if (cd->cd_devs != osp) {
+ mutex_exit(&alldevs_mtx);
kmem_free(nsp, sizeof(device_t[new]));
+ mutex_enter(&alldevs_mtx);
continue;
}
@@ -1128,8 +1130,11 @@
cd->cd_ndevs = new;
cd->cd_devs = nsp;
- if (old != 0)
+ if (old != 0) {
+ mutex_exit(&alldevs_mtx);
kmem_free(osp, sizeof(device_t[old]));
+ mutex_enter(&alldevs_mtx);
+ }
}
alldevs_nwrite--;
}
@@ -2005,11 +2010,8 @@
static int
config_alldevs_lock(void)
{
- int s;
-
- s = splhigh();
mutex_enter(&alldevs_mtx);
- return s;
+ return 0;
}
static void
@@ -2027,11 +2029,11 @@
config_dump_garbage(&af->af_garbage);
}
+/*ARGSUSED*/
static void
config_alldevs_unlock(int s)
{
mutex_exit(&alldevs_mtx);
- splx(s);
}
/*
