Re: [patch] Cache error recovery

From: Russ Anderson <rja_at_sgi.com>
Date: 2006-12-21 04:32:27
Hidetoshi Seto wrote:
> Russ Anderson wrote:
> > @@ -688,11 +690,11 @@ recover_from_processor_error(int platfor
> >  	 * The cache check and bus check bits have four possible states
> >  	 *   cc bc
> >  	 *    0  0	Weird record, not recovered
> > -	 *    1  0	Cache error, not recovered
> > +	 *    1  0	Cache error, attempt recovered
> >  	 *    0  1	I/O error, attempt recovery
> >  	 *    1  1	Memory error, attempt recovery
> >  	 */
> 
> Which is right, attempt-"recovered" or "recovery"?
> 
> > -	if (psp->bc == 0 || pbci == NULL)
> > +	if (psp->cc == 0 && (psp->bc == 0 || pbci == NULL))
> >  		return fatal_mca("No bus check");
> 
> The message should be replaced by more appropriate one...
> "No recoverable check" or just "Weird record"?
> 
> And also there are some comments need to be fixed since this
> patch makes it incorrect, ex.
> 
>  >         /*
>  >          * Well, here is only one bus error.
>  >          */
> 
> Thanks,
> H.Seto

Here is an updated patch with comment clean up.

[patch] Cache error recovery

Similar to memory error recovery, when a cache error is consumed
by a user process terminate the user instead of crashing the system.

Signed-off-by: Russ Anderson (rja@sgi.com)

---
 arch/ia64/kernel/mca_drv.c |   32 +++++++++++---------------------
 1 file changed, 11 insertions(+), 21 deletions(-)

Index: test/arch/ia64/kernel/mca_drv.c
===================================================================
--- test.orig/arch/ia64/kernel/mca_drv.c	2006-12-19 10:28:36.000000000 -0600
+++ test/arch/ia64/kernel/mca_drv.c	2006-12-20 11:16:19.091608933 -0600
@@ -602,6 +602,8 @@ recover_from_platform_error(slidx_table_
 		default:
 			break;
 		}
+	} else if (psp->cc && !psp->bc) {	/* Cache error */
+		status = recover_from_read_error(slidx, peidx, pbci, sos);
 	}
 
 	return status;
@@ -645,13 +647,6 @@ recover_from_tlb_check(peidx_table_t *pe
  * Return value:
  *	1 on Success / 0 on Failure
  */
-/*
- *  Later we try to recover when below all conditions are satisfied.
- *   1. Only one processor error section is exist.
- *   2. BUS_CHECK is exist and the others are not exist.(Except TLB_CHECK)
- *   3. The entry of BUS_CHECK_INFO is 1.
- *   4. "External bus error" flag is set and the others are not set.
- */
 
 static int
 recover_from_processor_error(int platform, slidx_table_t *slidx,
@@ -687,36 +682,31 @@ recover_from_processor_error(int platfor
 	/*
 	 * The cache check and bus check bits have four possible states
 	 *   cc bc
-	 *    0  0	Weird record, not recovered
-	 *    1  0	Cache error, not recovered
-	 *    0  1	I/O error, attempt recovery
 	 *    1  1	Memory error, attempt recovery
+	 *    1  0	Cache error, attempt recovery
+	 *    0  1	I/O error, attempt recovery
+	 *    0  0	Other error type, not recovered
 	 */
-	if (psp->bc == 0 || pbci == NULL)
-		return fatal_mca("No bus check");
+	if (psp->cc == 0 && (psp->bc == 0 || pbci == NULL))
+		return fatal_mca("No cache or bus check");
 
 	/*
-	 * Sorry, we cannot handle so many.
+	 * Cannot handle more than one bus check.
 	 */
 	if (peidx_bus_check_num(peidx) > 1)
 		return fatal_mca("Too many bus checks");
-	/*
-	 * Well, here is only one bus error.
-	 */
+
 	if (pbci->ib)
 		return fatal_mca("Internal Bus error");
-	if (pbci->cc)
-		return fatal_mca("Cache-cache error");
 	if (pbci->eb && pbci->bsi > 0)
 		return fatal_mca("External bus check fatal status");
 
 	/*
-	 * This is a local MCA and estimated as recoverble external bus error.
-	 * (e.g. a load from poisoned memory)
-	 * This means "there are some platform errors".
+	 * This is a local MCA and estimated as a recoverble error.
 	 */
 	if (platform)
 		return recover_from_platform_error(slidx, peidx, pbci, sos);
+
 	/*
 	 * On account of strange SAL error record, we cannot recover.
 	 */

-- 
Russ Anderson, OS RAS/Partitioning Project Lead  
SGI - Silicon Graphics Inc          rja@sgi.com
-
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Received on Thu Dec 21 04:33:28 2006

This archive was generated by hypermail 2.1.8 : 2006-12-21 04:33:51 EST