# HG changeset patch
# User Keir Fraser <keir@xen.org>
# Date 1292414674 0
# Node ID a3a29e67aa7e75a094e1b4237b10a68cf829b542
# Parent  16673224c1cc2ca3bb9730f1d7c84fe4d96e5323
Reduce side effects of handling '*' debug key
References: bnc#659284

NMI watchdog should be suppressed when dumping IRQ handlers. Softirqs
should be handled periodically while processing non-IRQ handlers.

Signed-off-by: Jan Beulich <jbeulich@novell.com>

# HG changeset patch
# User Keir Fraser <keir@xen.org>
# Date 1293185578 0
# Node ID dca1b7cf2e2c27cd160bd1d1d284e3f810d4936c
# Parent  e8acb9753ff1a5cd3d6a45eda5f4c6f0059c281a
re-add calls accidentally deleted from run_all_nonirq_keyhandlers()

c/s 22538:a3a29e67aa7e, having got applied in a form different from
the one submitted, resulted in the calls to
console_{start,end}_log_everything() getting removed without
replacement. Add them back since, other than run_all_keyhandlers(),
this doesn't run with log-everything already in effect.

Signed-off-by: Jan Beulich <jbeulich@novell.com>

--- a/xen/common/keyhandler.c
+++ b/xen/common/keyhandler.c
@@ -407,14 +407,17 @@ static void run_all_nonirq_keyhandlers(u
     int k;
 
     console_start_log_everything();
+
     for ( k = 0; k < ARRAY_SIZE(key_table); k++ )
     {
+        process_pending_softirqs_nested();
         h = key_table[k];
         if ( (h == NULL) || !h->diagnostic || h->irq_callback )
             continue;
         printk("[%c: %s]\n", k, h->desc);
         (*h->u.fn)(k);
     }
+
     console_end_log_everything();
 }
 
@@ -426,10 +429,11 @@ static void run_all_keyhandlers(unsigned
     struct keyhandler *h;
     int k;
 
+    watchdog_disable();
+
     printk("'%c' pressed -> firing all diagnostic keyhandlers\n", key);
 
     /* Fire all the IRQ-context diangostic keyhandlers now */
-    console_start_log_everything();
     for ( k = 0; k < ARRAY_SIZE(key_table); k++ )
     {
         h = key_table[k];
@@ -438,7 +442,8 @@ static void run_all_keyhandlers(unsigned
         printk("[%c: %s]\n", k, h->desc);
         (*h->u.irq_fn)(k, regs);
     }
-    console_end_log_everything();
+
+    watchdog_enable();
 
     /* Trigger the others from a tasklet in non-IRQ context */
     tasklet_schedule(&run_all_keyhandlers_tasklet);
--- a/xen/common/softirq.c
+++ b/xen/common/softirq.c
@@ -54,6 +54,16 @@ void process_pending_softirqs(void)
     __do_softirq(1ul<<SCHEDULE_SOFTIRQ);
 }
 
+void process_pending_softirqs_nested(void)
+{
+    ASSERT(!in_irq() && local_irq_is_enabled());
+    /*
+     * Do not enter scheduler as it can preempt the calling context,
+     * and do not run tasklets as we're running one currently.
+     */
+    __do_softirq((1ul<<SCHEDULE_SOFTIRQ) | (1ul<<TASKLET_SOFTIRQ));
+}
+
 asmlinkage void do_softirq(void)
 {
     __do_softirq(0);
--- a/xen/include/xen/softirq.h
+++ b/xen/include/xen/softirq.h
@@ -39,6 +39,8 @@ void raise_softirq(unsigned int nr);
  * Use this instead of do_softirq() when you do not want to be preempted.
  */
 void process_pending_softirqs(void);
+/* ... and use this instead when running inside a tasklet. */
+void process_pending_softirqs_nested(void);
 
 /*
  * TASKLETS -- dynamically-allocatable tasks run in softirq context