Module Name: src
Committed By: riastradh
Date: Wed Feb 17 19:44:40 UTC 2016
Modified Files:
src/sys/kern: kern_rndq.c
Log Message:
Don't schedule a softint if we have nothing to do.
Some systems seem to have gotten stuck in a softint processing loop
doing nothing and then trying to do it again. Might fix gson's
frozen qemu/anita sparc autobuilds -- tested on macallan's real sparc
hardware and confirmed to fix at least some freeze at boot.
To generate a diff of this commit:
cvs rdiff -u -r1.80 -r1.81 src/sys/kern/kern_rndq.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_rndq.c
diff -u src/sys/kern/kern_rndq.c:1.80 src/sys/kern/kern_rndq.c:1.81
--- src/sys/kern/kern_rndq.c:1.80 Wed Feb 17 01:23:32 2016
+++ src/sys/kern/kern_rndq.c Wed Feb 17 19:44:40 2016
@@ -1,4 +1,4 @@
-/* $NetBSD: kern_rndq.c,v 1.80 2016/02/17 01:23:32 riastradh Exp $ */
+/* $NetBSD: kern_rndq.c,v 1.81 2016/02/17 19:44:40 riastradh Exp $ */
/*-
* Copyright (c) 1997-2013 The NetBSD Foundation, Inc.
@@ -32,7 +32,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: kern_rndq.c,v 1.80 2016/02/17 01:23:32 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: kern_rndq.c,v 1.81 2016/02/17 19:44:40 riastradh Exp $");
#include <sys/param.h>
#include <sys/atomic.h>
@@ -297,15 +297,15 @@ rnd_getmore(size_t byteswanted)
mutex_spin_exit(&rnd_global.lock);
/*
- * Assume some callback is likely to have entered entropy
- * synchronously. In that case, we may need to distribute
- * entropy to waiters. Do that, if we can do it
- * asynchronously. (Otherwise we may end up trying to
- * distribute to the very rndsink that is trying to get more
- * entropy in the first place, leading to lock recursion in
- * that rndsink's callback.)
+ * Check whether we got entropy samples to process. In that
+ * case, we may need to distribute entropy to waiters. Do
+ * that, if we can do it asynchronously.
+ *
+ * - Conditionally because we don't want a softint loop.
+ * - Asynchronously because if we did it synchronously, we may
+ * end up with lock recursion on rndsinks_lock.
*/
- if (__predict_true(rnd_process))
+ if (!SIMPLEQ_EMPTY(&rnd_samples.q) && rnd_process != NULL)
rnd_schedule_process();
}
