Module Name: src
Committed By: rmind
Date: Mon Aug 29 00:39:16 UTC 2011
Modified Files:
src/sys/kern: sys_select.c
Log Message:
Add kern.direct_select sysctl. Default to 0 for now.
To generate a diff of this commit:
cvs rdiff -u -r1.35 -r1.36 src/sys/kern/sys_select.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/sys_select.c
diff -u src/sys/kern/sys_select.c:1.35 src/sys/kern/sys_select.c:1.36
--- src/sys/kern/sys_select.c:1.35 Tue Aug 9 06:36:51 2011
+++ src/sys/kern/sys_select.c Mon Aug 29 00:39:16 2011
@@ -1,4 +1,4 @@
-/* $NetBSD: sys_select.c,v 1.35 2011/08/09 06:36:51 hannken Exp $ */
+/* $NetBSD: sys_select.c,v 1.36 2011/08/29 00:39:16 rmind Exp $ */
/*-
* Copyright (c) 2007, 2008, 2009, 2010 The NetBSD Foundation, Inc.
@@ -84,7 +84,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: sys_select.c,v 1.35 2011/08/09 06:36:51 hannken Exp $");
+__KERNEL_RCSID(0, "$NetBSD: sys_select.c,v 1.36 2011/08/29 00:39:16 rmind Exp $");
#include <sys/param.h>
#include <sys/systm.h>
@@ -103,6 +103,7 @@
#include <sys/atomic.h>
#include <sys/socketvar.h>
#include <sys/sleepq.h>
+#include <sys/sysctl.h>
/* Flags for lwp::l_selflag. */
#define SEL_RESET 0 /* awoken, interrupted, or not yet polling */
@@ -147,6 +148,7 @@
};
static selcluster_t *selcluster[SELCLUSTERS] __read_mostly;
+static int direct_select __read_mostly = 0;
/*
* Select system call.
@@ -378,9 +380,7 @@
fd_mask *ibitp, *obitp;
int msk, i, j, fd, n;
file_t *fp;
- kmutex_t *lock;
- lock = curlwp->l_selcluster->sc_lock;
ibitp = (fd_mask *)(bits + ni * 0);
obitp = (fd_mask *)(bits + ni * 3);
n = 0;
@@ -408,15 +408,15 @@
fd_putfile(fd);
}
if (obits != 0) {
-#ifndef NO_DIRECT_SELECT
- if (obits != *ibitp)
+ if (direct_select) {
+ kmutex_t *lock;
+ lock = curlwp->l_selcluster->sc_lock;
mutex_spin_enter(lock);
- *obitp |= obits;
- if (obits != *ibitp)
+ *obitp |= obits;
mutex_spin_exit(lock);
-#else
- *obitp |= obits;
-#endif
+ } else {
+ *obitp |= obits;
+ }
}
ibitp++;
obitp++;
@@ -715,15 +715,15 @@
*/
l = sip->sel_lwp;
oflag = l->l_selflag;
-#ifndef NO_DIRECT_SELECT
- if (!sel_setevents(l, sip, events)) {
+
+ if (!direct_select) {
+ l->l_selflag = SEL_RESET;
+ } else if (!sel_setevents(l, sip, events)) {
/* No events to return. */
mutex_spin_exit(lock);
return;
}
-#else
- l->l_selflag = SEL_RESET;
-#endif
+
/*
* If thread is sleeping, wake it up. If it's not
* yet asleep, it will notice the change in state
@@ -932,3 +932,23 @@
error = 0;
return (error);
}
+
+/*
+ * System control nodes.
+ */
+SYSCTL_SETUP(sysctl_select_setup, "sysctl select setup")
+{
+ const struct sysctlnode *node = NULL;
+
+ sysctl_createv(clog, 0, NULL, &node,
+ CTLFLAG_PERMANENT,
+ CTLTYPE_NODE, "kern", NULL,
+ NULL, 0, NULL, 0,
+ CTL_KERN, CTL_EOL);
+ sysctl_createv(clog, 0, &node, NULL,
+ CTLFLAG_PERMANENT | CTLFLAG_READWRITE,
+ CTLTYPE_INT, "direct_select",
+ SYSCTL_DESCR("Enable/disable direct select (for testing)"),
+ NULL, 0, &direct_select, 0,
+ CTL_CREATE, CTL_EOL);
+}
