linuxppc-dev.lists.ozlabs.org archive mirror
 help / color / mirror / Atom feed
* [PATCH] powerpc/kdump: Fix timeout in crash_kexec_wait_realmode
@ 2011-07-05  6:12 Anton Blanchard
  2011-07-05  6:40 ` Michael Neuling
  0 siblings, 1 reply; 3+ messages in thread
From: Anton Blanchard @ 2011-07-05  6:12 UTC (permalink / raw)
  To: benh, mikey, linuxppc-dev


We check for timeout expiry in the outer loop, but we also need to
check it in the inner loop or we can lock up forever waiting for a
CPU to hit real mode.

Signed-off-by: Anton Blanchard <anton@samba.org>
Cc: <stable@kernel.org>
---

Index: linux-powerpc/arch/powerpc/kernel/crash.c
===================================================================
--- linux-powerpc.orig/arch/powerpc/kernel/crash.c	2011-07-05 15:04:18.512140484 +1000
+++ linux-powerpc/arch/powerpc/kernel/crash.c	2011-07-05 15:05:51.483747575 +1000
@@ -240,7 +240,8 @@ static void crash_kexec_wait_realmode(in
 		if (i == cpu)
 			continue;
 
-		while (paca[i].kexec_state < KEXEC_STATE_REAL_MODE) {
+		while ((paca[i].kexec_state < KEXEC_STATE_REAL_MODE) &&
+				(msecs > 0)) {
 			barrier();
 			if (!cpu_possible(i)) {
 				break;

^ permalink raw reply	[flat|nested] 3+ messages in thread

* [PATCH] powerpc/kdump: Fix timeout in crash_kexec_wait_realmode
  2011-07-05  6:12 [PATCH] powerpc/kdump: Fix timeout in crash_kexec_wait_realmode Anton Blanchard
@ 2011-07-05  6:40 ` Michael Neuling
  2011-07-06  7:55   ` Anton Blanchard
  0 siblings, 1 reply; 3+ messages in thread
From: Michael Neuling @ 2011-07-05  6:40 UTC (permalink / raw)
  To: Anton Blanchard; +Cc: linuxppc-dev

The existing code it pretty ugly.  How about we clean it up even more
like this?

From: Anton Blanchard <anton@samba.org>

We check for timeout expiry in the outer loop, but we also need to
check it in the inner loop or we can lock up forever waiting for a
CPU to hit real mode.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Neuling <mikey@neuling.org>
Cc: <stable@kernel.org>

diff --git a/arch/powerpc/kernel/crash.c b/arch/powerpc/kernel/crash.c
index 4e6ee94..cc6a9d5 100644
--- a/arch/powerpc/kernel/crash.c
+++ b/arch/powerpc/kernel/crash.c
@@ -242,12 +242,8 @@ static void crash_kexec_wait_realmode(int cpu)
 
 		while (paca[i].kexec_state < KEXEC_STATE_REAL_MODE) {
 			barrier();
-			if (!cpu_possible(i)) {
+			if (!cpu_possible(i) || !cpu_online(i) || (msecs <= 0))
 				break;
-			}
-			if (!cpu_online(i)) {
-				break;
-			}
 			msecs--;
 			mdelay(1);
 		}

^ permalink raw reply related	[flat|nested] 3+ messages in thread

* Re: [PATCH] powerpc/kdump: Fix timeout in crash_kexec_wait_realmode
  2011-07-05  6:40 ` Michael Neuling
@ 2011-07-06  7:55   ` Anton Blanchard
  0 siblings, 0 replies; 3+ messages in thread
From: Anton Blanchard @ 2011-07-06  7:55 UTC (permalink / raw)
  To: Michael Neuling; +Cc: linuxppc-dev

On Tue, 05 Jul 2011 16:40:10 +1000
Michael Neuling <mikey@neuling.org> wrote:

> The existing code it pretty ugly.  How about we clean it up even more
> like this?

Looks good and it passed my kdump test cases.

Anton
 
> From: Anton Blanchard <anton@samba.org>
> 
> We check for timeout expiry in the outer loop, but we also need to
> check it in the inner loop or we can lock up forever waiting for a
> CPU to hit real mode.
> 
> Signed-off-by: Anton Blanchard <anton@samba.org>
> Signed-off-by: Michael Neuling <mikey@neuling.org>
> Cc: <stable@kernel.org>
> 
> diff --git a/arch/powerpc/kernel/crash.c b/arch/powerpc/kernel/crash.c
> index 4e6ee94..cc6a9d5 100644
> --- a/arch/powerpc/kernel/crash.c
> +++ b/arch/powerpc/kernel/crash.c
> @@ -242,12 +242,8 @@ static void crash_kexec_wait_realmode(int cpu)
>  
>  		while (paca[i].kexec_state < KEXEC_STATE_REAL_MODE) {
>  			barrier();
> -			if (!cpu_possible(i)) {
> +			if (!cpu_possible(i) || !cpu_online(i) ||
> (msecs <= 0)) break;
> -			}
> -			if (!cpu_online(i)) {
> -				break;
> -			}
>  			msecs--;
>  			mdelay(1);
>  		}
> 

^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2011-07-06  7:55 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2011-07-05  6:12 [PATCH] powerpc/kdump: Fix timeout in crash_kexec_wait_realmode Anton Blanchard
2011-07-05  6:40 ` Michael Neuling
2011-07-06  7:55   ` Anton Blanchard

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).