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-rw-r--r--mm/mempolicy.c32
1 files changed, 30 insertions, 2 deletions
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index cfd26d7e61a1..58fb833fce0c 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -2060,8 +2060,36 @@ alloc_pages_vma(gfp_t gfp, int order, struct vm_area_struct *vma,
nmask = policy_nodemask(gfp, pol);
if (!nmask || node_isset(hpage_node, *nmask)) {
mpol_cond_put(pol);
- page = __alloc_pages_node(hpage_node,
- gfp | __GFP_THISNODE, order);
+ /*
+ * We cannot invoke reclaim if __GFP_THISNODE
+ * is set. Invoking reclaim with
+ * __GFP_THISNODE set, would cause THP
+ * allocations to trigger heavy swapping
+ * despite there may be tons of free memory
+ * (including potentially plenty of THP
+ * already available in the buddy) on all the
+ * other NUMA nodes.
+ *
+ * At most we could invoke compaction when
+ * __GFP_THISNODE is set (but we would need to
+ * refrain from invoking reclaim even if
+ * compaction returned COMPACT_SKIPPED because
+ * there wasn't not enough memory to succeed
+ * compaction). For now just avoid
+ * __GFP_THISNODE instead of limiting the
+ * allocation path to a strict and single
+ * compaction invocation.
+ *
+ * Supposedly if direct reclaim was enabled by
+ * the caller, the app prefers THP regardless
+ * of the node it comes from so this would be
+ * more desiderable behavior than only
+ * providing THP originated from the local
+ * node in such case.
+ */
+ if (!(gfp & __GFP_DIRECT_RECLAIM))
+ gfp |= __GFP_THISNODE;
+ page = __alloc_pages_node(hpage_node, gfp, order);
goto out;
}
}