If we have a large amount of livepatches and want to print them
on the console using 'xl debug-keys x' we eventually hit
the preemption check:
if ( i && !(i % 64) )
{
spin_unlock(&payload_lock);
process_pending_softirqs();
if ( spin_trylock(&payload_lock) )
return
<facepalm> The effect is that we have just effectively
taken the lock and returned without unlocking!
CC: Ross Lagerwall <ross.lagerw...@citrix.com>
CC: Boris Ostrovsky <boris.ostrov...@oracle.com>
CC: Jan Beulich <jbeul...@suse.com>
CC: Andrew Cooper <andrew.coop...@citrix.com>
CC: Julien Grall <julien.gr...@arm.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.w...@oracle.com>
---
xen/common/livepatch.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/xen/common/livepatch.c b/xen/common/livepatch.c
index f14bcbc..df67a1a 100644
--- a/xen/common/livepatch.c
+++ b/xen/common/livepatch.c
@@ -1642,7 +1642,7 @@ static void livepatch_printall(unsigned char key)
{
spin_unlock(&payload_lock);
process_pending_softirqs();
- if ( spin_trylock(&payload_lock) )
+ if ( !spin_trylock(&payload_lock) )
{
printk("Couldn't reacquire lock. Try again.\n");
return;
--
2.9.3
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