[Xen-devel] [Resend PATCH 1/2] Xen/Keyhandler: Make keyhandler always run in tasklet

[Lan Tianyu <tianyu.lan@xxxxxxxxx>]

Keyhandler may run for a long time in a timer handler on the large machine
with a lot of physical cpus(E,G keyhandler for dumping timer info) when serial
port driver works in the poll mode. When timer interrupt arrives, timer 
subsystem
runs all timer handlers before programming next timer interrupt. So if timer 
handler
runs longer than time for watchdog timeout, the timer handler of watchdog will 
be
blocked to feed watchdog and xen hypervisor panics. This patch is to fix the 
issue
via always scheduling a tasklet to run keyhandler to avoid timer handler running
too long.

Signed-off-by: Lan Tianyu <tianyu.lan@xxxxxxxxx>
---
 xen/common/keyhandler.c |    8 +++++---
 1 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/xen/common/keyhandler.c b/xen/common/keyhandler.c
index 16de6e8..fce52d2 100644
--- a/xen/common/keyhandler.c
+++ b/xen/common/keyhandler.c
@@ -75,7 +75,9 @@ static struct keyhandler {
 
 static void keypress_action(unsigned long unused)
 {
-    handle_keypress(keypress_key, NULL);
+    console_start_log_everything();
+    key_table[keypress_key].fn(keypress_key);
+    console_end_log_everything();
 }
 
 static DECLARE_TASKLET(keypress_tasklet, keypress_action, 0);
@@ -87,10 +89,10 @@ void handle_keypress(unsigned char key, struct 
cpu_user_regs *regs)
     if ( key >= ARRAY_SIZE(key_table) || !(h = &key_table[key])->fn )
         return;
 
-    if ( !in_irq() || h->irq_callback )
+    if ( h->irq_callback )
     {
         console_start_log_everything();
-        h->irq_callback ? h->irq_fn(key, regs) : h->fn(key);
+        h->irq_fn(key, regs);
         console_end_log_everything();
     }
     else
-- 
1.7.1


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