[PATCH] x86: Use online node real index in calulate_tbl_offset()

From: Yinghai Lu
Date: Sat Nov 13 2010 - 13:58:10 EST


--- resending, hope in can make into -rc2.

Found one numa system that doesn't have ram installed with first socket
hang during executing init scripts.

bisect to:

|commit 932967202182743c01a2eee4bdfa2c42697bc586
|Author: Shaohua Li <shaohua.li@xxxxxxxxx>
|Date: Wed Oct 20 11:07:03 2010 +0800
|
| x86: Spread tlb flush vector between nodes

It turns out when first socket is not online could have cpus on node1
tlb_offset set to bigger than NUM_INVALIDATE_TLB_VECTORS.

that could affect systems like 4 sockets, but socket 2 doesn't
have installed, sockets 3 will get too big tlb_offset.

Need to use real online node idx.

Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx>
Acked-by: Shaohua Li <shaohua.li@xxxxxxxxx>

---
arch/x86/mm/tlb.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

Index: linux-2.6/arch/x86/mm/tlb.c
===================================================================
--- linux-2.6.orig/arch/x86/mm/tlb.c
+++ linux-2.6/arch/x86/mm/tlb.c
@@ -223,7 +223,7 @@ void native_flush_tlb_others(const struc

static void __cpuinit calculate_tlb_offset(void)
{
- int cpu, node, nr_node_vecs;
+ int cpu, node, nr_node_vecs, idx = 0;
/*
* we are changing tlb_vector_offset for each CPU in runtime, but this
* will not cause inconsistency, as the write is atomic under X86. we
@@ -239,7 +239,7 @@ static void __cpuinit calculate_tlb_offs
nr_node_vecs = NUM_INVALIDATE_TLB_VECTORS/nr_online_nodes;

for_each_online_node(node) {
- int node_offset = (node % NUM_INVALIDATE_TLB_VECTORS) *
+ int node_offset = (idx % NUM_INVALIDATE_TLB_VECTORS) *
nr_node_vecs;
int cpu_offset = 0;
for_each_cpu(cpu, cpumask_of_node(node)) {
@@ -248,6 +248,7 @@ static void __cpuinit calculate_tlb_offs
cpu_offset++;
cpu_offset = cpu_offset % nr_node_vecs;
}
+ idx++;
}
}

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