d->node_affinity defaults to NODE_MASK_ALL which has bits set outside of node_online_map. This in turn causes the loop in get_free_buddy() to waste effort iterating over offline nodes.
Always clamp d->node_affinity to node_online_map when in use. Signed-off-by: Andrew Cooper <[email protected]> Acked-by: Jan Beulich <[email protected]> --- CC: Jan Beulich <[email protected]> CC: Wei Liu <[email protected]> CC: Roger Pau Monné <[email protected]> CC: Stefano Stabellini <[email protected]> CC: Julien Grall <[email protected]> CC: George Dunlap <[email protected]> v3: * Rebase to before the nodemask API cleanup, to make it easier to backport. v2: * Rebase over the nodemask API change, and implement with a single nodes_and() --- xen/common/page_alloc.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/xen/common/page_alloc.c b/xen/common/page_alloc.c index 44a72d0b19..efa437c7df 100644 --- a/xen/common/page_alloc.c +++ b/xen/common/page_alloc.c @@ -811,11 +811,18 @@ static struct page_info *get_free_buddy(unsigned int zone_lo, const struct domain *d) { nodeid_t first, node = MEMF_get_node(memflags), req_node = node; - nodemask_t nodemask = d ? d->node_affinity : node_online_map; + nodemask_t nodemask = node_online_map; unsigned int j, zone, nodemask_retry = 0; struct page_info *pg; bool use_unscrubbed = (memflags & MEMF_no_scrub); + /* + * d->node_affinity is our preferred allocation set if provided, but it + * may have bit set outside of node_online_map. Clamp it. + */ + if ( d ) + nodes_and(nodemask, nodemask, d->node_affinity); + if ( node == NUMA_NO_NODE ) { if ( d != NULL ) -- 2.11.0 _______________________________________________ Xen-devel mailing list [email protected] https://lists.xenproject.org/mailman/listinfo/xen-devel
