Re: [PULL] x86 cpumask work

[Rusty Russell <rusty@rustcorp.com.au>]

On Wednesday 18 March 2009 05:26:30 Cliff Wickman wrote:
> 
> From: Cliff Wickman <cpw@sgi.com>
> 
> A patch on Mar13 2009 introduced a bug. I hope the below 1-line fix can
> make the 'urgent' list, and get fixed before that patch moves on.
> 
> The Mar13 patch is saved at
> http://marc.info/?l=linux-kernel&m=123683186504948&w=2
> 
> The allocation of per-cpu uv_flush_tlb_mask's in arch/x86/kernel/tlb_uv.c
> changed a variable that should been reset to 0.

Hi Cliff,

   Thanks for tracking this.  May I suggest this slightly enhanced version?

Subject: cpumask: fix tlb_uv initialization

Impact: fix boot on UV systems

Commit 76ba0ecda0de9accea9a91cb6dbde46782110e1c "cpumask: use cpumask_var_t
in uv_flush_tlb_others" used cur_cpu as an iterator; it was supposed to be
zero for the code below it.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

diff --git a/arch/x86/kernel/tlb_uv.c b/arch/x86/kernel/tlb_uv.c
index 8afb691..deb5ebb 100644
--- a/arch/x86/kernel/tlb_uv.c
+++ b/arch/x86/kernel/tlb_uv.c
@@ -751,7 +751,7 @@ static int __init uv_bau_init(void)
 	int node;
 	int nblades;
 	int last_blade;
-	int cur_cpu = 0;
+	int cur_cpu;
 
 	if (!is_uv_system())
 		return 0;
@@ -765,6 +765,7 @@ static int __init uv_bau_init(void)
 	uv_mmask = (1UL << uv_hub_info->n_val) - 1;
 	nblades = 0;
 	last_blade = -1;
+	cur_cpu = 0;
 	for_each_online_node(node) {
 		blade = uv_node_to_blade_id(node);
 		if (blade == last_blade)