Author: attilio
Date: Sun Apr 11 16:06:09 2010
New Revision: 206482
URL: http://svn.freebsd.org/changeset/base/206482
Log:
- Introduce a blessed list for sxlocks that prevents the deadlkres to
panic on those ones. [0]
- Fix ticks counter wrap-up
Sponsored by: Sandvine Incorporated
[0] Reported by: jilles
[0] Tested by: jilles
MFC: 1 week
Modified:
head/sys/kern/kern_clock.c
Modified: head/sys/kern/kern_clock.c
==============================================================================
--- head/sys/kern/kern_clock.c Sun Apr 11 16:04:08 2010 (r206481)
+++ head/sys/kern/kern_clock.c Sun Apr 11 16:06:09 2010 (r206482)
@@ -162,6 +162,11 @@ SYSCTL_PROC(_kern, OID_AUTO, cp_times, C
0,0, sysctl_kern_cp_times, "LU", "per-CPU time statistics");
#ifdef DEADLKRES
+static const char *blessed[] = {
+ "so_snd_sx",
+ "so_rcv_sx",
+ NULL
+};
static int slptime_threshold = 1800;
static int blktime_threshold = 900;
static int sleepfreq = 3;
@@ -172,7 +177,7 @@ deadlkres(void)
struct proc *p;
struct thread *td;
void *wchan;
- int blkticks, slpticks, slptype, tryl, tticks;
+ int blkticks, i, slpticks, slptype, tryl, tticks;
tryl = 0;
for (;;) {
@@ -205,6 +210,10 @@ deadlkres(void)
* turnstile channel is in good state.
*/
MPASS(td->td_blocked != NULL);
+
+ /* Handle ticks wrap-up. */
+ if (ticks < td->td_blktick)
+ continue;
tticks = ticks - td->td_blktick;
thread_unlock(td);
if (tticks > blkticks) {
@@ -222,6 +231,10 @@ deadlkres(void)
}
} else if (TD_IS_SLEEPING(td)) {
+ /* Handle ticks wrap-up. */
+ if (ticks < td->td_blktick)
+ continue;
+
/*
* Check if the thread is sleeping on a
* lock, otherwise skip the check.
@@ -242,7 +255,24 @@ deadlkres(void)
* thresholds, this thread is
* stuck for too long on a
* sleepqueue.
+ * However, being on a
+ * sleepqueue, we might still
+ * check for the blessed
+ * list.
*/
+ tryl = 0;
+ for (i = 0; blessed[i] != NULL;
+ i++) {
+ if (!strcmp(blessed[i],
+ td->td_wmesg)) {
+ tryl = 1;
+ break;
+ }
+ }
+ if (tryl != 0) {
+ tryl = 0;
+ continue;
+ }
PROC_UNLOCK(p);
sx_sunlock(&allproc_lock);
panic("%s: possible deadlock detected for %p, blocked for %d ticks\n",
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