[PATCH] UV: remove erroneous BAU initialization

[PATCH] UV: remove erroneous BAU initialization

[Cliff Wickman]

From: Cliff Wickman <cpw@sgi.com>

UV is the SGI "UltraViolet" machine, which is x86_64 based.
BAU is the "Broadcast Assist Unit", used for TLB shootdown in UV.

This patch removes the allocation and initialization of an unused table.

This table is left over from a development test mode.  It is unused in
the present code.
And it was incorrectly initialized: 8 entries allocated but 17 initialized,
causing slab corruption.

This patch should go into 2.6.27 and 2.6.28 as well as the current tree.

Diffed against 2.6.28 (linux-next, 12/30/08)

Signed-off-by: Cliff Wickman <cpw@sgi.com>
---
 arch/x86/kernel/tlb_uv.c |    9 ---------
 1 file changed, 9 deletions(-)

Index: linux/arch/x86/kernel/tlb_uv.c
===================================================================
--- linux.orig/arch/x86/kernel/tlb_uv.c
+++ linux/arch/x86/kernel/tlb_uv.c
@@ -582,7 +582,6 @@ static int __init uv_ptc_init(void)
 static struct bau_control * __init uv_table_bases_init(int blade, int node)
 {
 	int i;
-	int *ip;
 	struct bau_msg_status *msp;
 	struct bau_control *bau_tabp;
 
@@ -599,13 +598,6 @@ static struct bau_control * __init uv_ta
 		bau_cpubits_clear(&msp->seen_by, (int)
 				  uv_blade_nr_possible_cpus(blade));
 
-	bau_tabp->watching =
-	    kmalloc_node(sizeof(int) * DEST_NUM_RESOURCES, GFP_KERNEL, node);
-	BUG_ON(!bau_tabp->watching);
-
-	for (i = 0, ip = bau_tabp->watching; i < DEST_Q_SIZE; i++, ip++)
-		*ip = 0;
-
 	uv_bau_table_bases[blade] = bau_tabp;
 
 	return bau_tabp;
@@ -628,7 +620,6 @@ uv_table_bases_finish(int blade, int nod
 		bcp->bau_msg_head	= bau_tablesp->va_queue_first;
 		bcp->va_queue_first	= bau_tablesp->va_queue_first;
 		bcp->va_queue_last	= bau_tablesp->va_queue_last;
-		bcp->watching		= bau_tablesp->watching;
 		bcp->msg_statuses	= bau_tablesp->msg_statuses;
 		bcp->descriptor_base	= adp;
 	}

Re: [PATCH] UV: remove erroneous BAU initialization

[Ingo Molnar]

* Cliff Wickman <cpw@sgi.com> wrote:

> From: Cliff Wickman <cpw@sgi.com>
> 
> UV is the SGI "UltraViolet" machine, which is x86_64 based.
> BAU is the "Broadcast Assist Unit", used for TLB shootdown in UV.
> 
> This patch removes the allocation and initialization of an unused table.
> 
> This table is left over from a development test mode.  It is unused in
> the present code.
> And it was incorrectly initialized: 8 entries allocated but 17 initialized,
> causing slab corruption.
> 
> This patch should go into 2.6.27 and 2.6.28 as well as the current tree.
> 
> Diffed against 2.6.28 (linux-next, 12/30/08)
> 
> Signed-off-by: Cliff Wickman <cpw@sgi.com>
> ---
>  arch/x86/kernel/tlb_uv.c |    9 ---------
>  1 file changed, 9 deletions(-)

applied to tip/x86/urgent with a Cc: stable tag, thanks Cliff,

	Ingo