Add a pageflag called "lookup_node"/ PG_lookup_node / Page*LookupNode().
Used by dynamic numa to indicate when a page has a new node assignment
waiting for it.
FIXME: This also exempts PG_lookup_node from PAGE_FLAGS_CHECK_AT_PREP
due to the asynchronous usage of PG_lookup_node, which needs to be
avoided.
Signed-off-by: Cody P Schafer <c...@linux.vnet.ibm.com>
---
include/linux/page-flags.h | 19 +++++++++++++++++++
mm/page_alloc.c | 3 +++
2 files changed, 22 insertions(+)
diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index 6d53675..09dd94e 100644
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -109,6 +109,9 @@ enum pageflags {
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
PG_compound_lock,
#endif
+#ifdef CONFIG_DYNAMIC_NUMA
+ PG_lookup_node, /* extra lookup required to find real node */
+#endif
__NR_PAGEFLAGS,
/* Filesystems */
@@ -275,6 +278,17 @@ PAGEFLAG_FALSE(HWPoison)
#define __PG_HWPOISON 0
#endif
+/* Setting is unconditional, simply leads to an extra lookup.
+ * Clearing must be conditional so we don't miss any memlayout changes.
+ */
+#ifdef CONFIG_DYNAMIC_NUMA
+PAGEFLAG(LookupNode, lookup_node)
+TESTCLEARFLAG(LookupNode, lookup_node)
+#else
+PAGEFLAG_FALSE(LookupNode)
+TESTCLEARFLAG_FALSE(LookupNode)
+#endif
+
u64 stable_page_flags(struct page *page);
static inline int PageUptodate(struct page *page)
@@ -509,7 +523,12 @@ static inline void ClearPageSlabPfmemalloc(struct page
*page)
* Pages being prepped should not have any flags set. It they are set,
* there has been a kernel bug or struct page corruption.
*/
+#ifndef CONFIG_DYNAMIC_NUMA
#define PAGE_FLAGS_CHECK_AT_PREP ((1 << NR_PAGEFLAGS) - 1)
+#else
+#define PAGE_FLAGS_CHECK_AT_PREP (((1 << NR_PAGEFLAGS) - 1) \
+ & ~(1 << PG_lookup_node))
+#endif
#define PAGE_FLAGS_PRIVATE \
(1 << PG_private | 1 << PG_private_2)
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 95e4a23..4628443 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -6170,6 +6170,9 @@ static const struct trace_print_flags pageflag_names[] = {
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
{1UL << PG_compound_lock, "compound_lock" },
#endif
+#ifdef CONFIG_DYNAMIC_NUMA
+ {1UL << PG_lookup_node, "lookup_node" },
+#endif
};
static void dump_page_flags(unsigned long flags)
--
1.8.2.1
--
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