From d6898a50a59884fa24b6f5f7303440d1a069a944 Mon Sep 17 00:00:00 2001 From: Keir Fraser Date: Wed, 7 Oct 2009 15:58:26 +0100 Subject: [PATCH] Fix hypervisor crash with unpopulated NUMA nodes On NUMA systems with memory-less nodes Xen crashes quite early in the hypervisor (while initializing the heaps). This is not an issue if this happens to be the last node, but "inner" nodes trigger this reliably. On multi-node processors it is much more likely to leave a node unequipped. The attached patch fixes this by enumerating the node via the node_online_map instead of counting from 0 to num_nodes. The resulting NUMA setup is still somewhat strange, but at least it does not crash. In lowlevel/xc/xc.c there is again this enumeration bug, but I suppose we cannot access the HV's node_online_map from this context, so the xm info output is not correct (but xm debug-keys H is). I plan to rework the handling of memory-less nodes later. Signed-off-by: Andre Przywara --- xen/common/page_alloc.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-) diff --git a/xen/common/page_alloc.c b/xen/common/page_alloc.c index 44813ebf1c..7d19bb24e7 100644 --- a/xen/common/page_alloc.c +++ b/xen/common/page_alloc.c @@ -294,7 +294,6 @@ static struct page_info *alloc_heap_pages( node = cpu_to_node(smp_processor_id()); ASSERT(node >= 0); - ASSERT(node < num_nodes); ASSERT(zone_lo <= zone_hi); ASSERT(zone_hi < NR_ZONES); @@ -323,8 +322,9 @@ static struct page_info *alloc_heap_pages( } while ( zone-- > zone_lo ); /* careful: unsigned zone may wrap */ /* Pick next node, wrapping around if needed. */ - if ( ++node == num_nodes ) - node = 0; + node = next_node(node, node_online_map); + if (node == MAX_NUMNODES) + node = first_node(node_online_map); } /* Try to free memory from tmem */ @@ -466,7 +466,6 @@ static void free_heap_pages( ASSERT(order <= MAX_ORDER); ASSERT(node >= 0); - ASSERT(node < num_online_nodes()); for ( i = 0; i < (1 << order); i++ ) { @@ -817,13 +816,13 @@ static void init_heap_pages( static unsigned long avail_heap_pages( unsigned int zone_lo, unsigned int zone_hi, unsigned int node) { - unsigned int i, zone, num_nodes = num_online_nodes(); + unsigned int i, zone; unsigned long free_pages = 0; if ( zone_hi >= NR_ZONES ) zone_hi = NR_ZONES - 1; - for ( i = 0; i < num_nodes; i++ ) + for_each_online_node(i) { if ( !avail[i] ) continue; -- 2.30.2