9-STABLE -> NFS -> NetAPP:

[John Baldwin]

On Friday, February 15, 2013 11:31:11 pm Marc Fournier wrote:
> 
> Trying the patch now … but what do you mean by using 'SIGSTOP'?  I generally
> do a 'kill -HUP' then when that doesn't work 'kill -9' … should Iuse -STOP
> instead of 9?

No.  This patch only helps if you are using kill -STOP to pause processes and
later resume them.  If you aren't doing that, then the suspension could be due
to a different cause.  Please try this patch instead and let me know if you
see any of the 'Deferring' messages on the console:

Index: kern_thread.c
===================================================================
--- kern_thread.c	(revision 246122)
+++ kern_thread.c	(working copy)
@@ -794,7 +794,30 @@ thread_suspend_check(int return_instead)
 		    (p->p_flag & P_SINGLE_BOUNDARY) && return_instead)
 			return (ERESTART);
 
+#if 0
 		/*
+		 * Ignore suspend requests for stop signals if they
+		 * are deferred.
+		 */
+		if (P_SHOULDSTOP(p) == P_STOPPED_SIG &&
+		    td->td_flags & TDF_SBDRY) {
+			KASSERT(return_instead,
+			    ("TDF_SBDRY set for unsafe thread_suspend_check"));
+			return (0);
+		}
+#else
+		/* Ignore syspend requests if stops are deferred. */
+		if (td->td_flags & TDF_SBDRY) {
+			if (!return_instead)
+				panic("TDF_SBDRY set, but return_instead not");
+			if (P_SHOULDSTOP(p) != P_STOPPED_SIG)
+				printf("Deferring non-STOP suspension: SHOULDSTOP: %x p_flag %x\n",
+				    P_SHOULDSTOP(p), p->p_flag);
+			return (0);
+		}
+#endif
+
+		/*
 		 * If the process is waiting for us to exit,
 		 * this thread should just suicide.
 		 * Assumes that P_SINGLE_EXIT implies P_STOPPED_SINGLE.



-- 
John Baldwin