The patch titled
Subject: mm, compaction: Use free lists to quickly locate a migration source -fix
has been added to the -mm tree. Its filename is
mm-compaction-use-free-lists-to-quickly-locate-a-migration-source-fix.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-compaction-use-free-lists-to-quickly-locate-a-migration-source-fix.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-compaction-use-free-lists-to-quickly-locate-a-migration-source-fix.patch
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------------------------------------------------------
From: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx>
Subject: mm, compaction: Use free lists to quickly locate a migration source -fix
Vlastimil correctly pointed out that when a fast search fails and cc->migrate_pfn
is reinitialised to the lowest PFN found that the caller does not use the updated
PFN.
He also pointed out that there is an inconsistency between
move_freelist_head and move_freelist_tail. This patch adds a new helper
and uses it in move_freelist_tail so that list manipulations are avoided
if the first list item traversed is a suitable migration source. The
end result will be that the helpers should be symmetrical and it's been
confirmed that the scan rates are slightly improved as a result of the
fix but not enough to rewrite the changelogs.
This is a fix for the mmotm patch
mm-compaction-use-free-lists-to-quickly-locate-a-migration-source.patch . It's
been provided as a combined patch as the first patch is not picked up at the
time of writing and a rolled up patch is less likely to fall through the cracks.
Link: http://lkml.kernel.org/r/20190204120111.GL9565@xxxxxxxxxxxxxxxxxxx
Signed-off-by: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx>
Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx>
Cc: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Cc: David Rientjes <rientjes@xxxxxxxxxx>
Cc: YueHaibing <yuehaibing@xxxxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
--- a/drivers/gpu/drm/i915/i915_utils.h~mm-compaction-use-free-lists-to-quickly-locate-a-migration-source-fix
+++ a/drivers/gpu/drm/i915/i915_utils.h
@@ -123,12 +123,6 @@ static inline u64 ptr_to_u64(const void
#include <linux/list.h>
-static inline int list_is_first(const struct list_head *list,
- const struct list_head *head)
-{
- return head->next == list;
-}
-
static inline void __list_del_many(struct list_head *head,
struct list_head *first)
{
--- a/include/linux/list.h~mm-compaction-use-free-lists-to-quickly-locate-a-migration-source-fix
+++ a/include/linux/list.h
@@ -207,6 +207,17 @@ static inline void list_bulk_move_tail(s
}
/**
+ * list_is_first -- tests whether @ list is the first entry in list @head
+ * @list: the entry to test
+ * @head: the head of the list
+ */
+static inline int list_is_first(const struct list_head *list,
+ const struct list_head *head)
+{
+ return list->prev == head;
+}
+
+/**
* list_is_last - tests whether @list is the last entry in list @head
* @list: the entry to test
* @head: the head of the list
--- a/mm/compaction.c~mm-compaction-use-free-lists-to-quickly-locate-a-migration-source-fix
+++ a/mm/compaction.c
@@ -1062,7 +1062,7 @@ move_freelist_tail(struct list_head *fre
{
LIST_HEAD(sublist);
- if (!list_is_last(freelist, &freepage->lru)) {
+ if (!list_is_first(freelist, &freepage->lru)) {
list_cut_position(&sublist, freelist, &freepage->lru);
if (!list_empty(&sublist))
list_splice_tail(&sublist, freelist);
@@ -1238,14 +1238,16 @@ update_fast_start_pfn(struct compact_con
cc->fast_start_pfn = min(cc->fast_start_pfn, pfn);
}
-static inline void
+static inline unsigned long
reinit_migrate_pfn(struct compact_control *cc)
{
if (!cc->fast_start_pfn || cc->fast_start_pfn == ULONG_MAX)
- return;
+ return cc->migrate_pfn;
cc->migrate_pfn = cc->fast_start_pfn;
cc->fast_start_pfn = ULONG_MAX;
+
+ return cc->migrate_pfn;
}
/*
@@ -1361,7 +1363,7 @@ static unsigned long fast_find_migratebl
* that had free pages as the basis for starting a linear scan.
*/
if (pfn == cc->migrate_pfn)
- reinit_migrate_pfn(cc);
+ pfn = reinit_migrate_pfn(cc);
return pfn;
}
_
Patches currently in -mm which might be from mgorman@xxxxxxxxxxxxxxxxxxx are
mm-compaction-shrink-compact_control.patch
mm-compaction-rearrange-compact_control.patch
mm-compaction-remove-last_migrated_pfn-from-compact_control.patch
mm-compaction-remove-unnecessary-zone-parameter-in-some-instances.patch
mm-compaction-rename-map_pages-to-split_map_pages.patch
mm-migrate-immediately-fail-migration-of-a-page-with-no-migration-handler.patch
mm-compaction-always-finish-scanning-of-a-full-pageblock.patch
mm-compaction-ignore-the-fragmentation-avoidance-boost-for-isolation-and-compaction.patch
mm-compaction-use-free-lists-to-quickly-locate-a-migration-source.patch
mm-compaction-use-free-lists-to-quickly-locate-a-migration-source-fix.patch
mm-compaction-keep-migration-source-private-to-a-single-compaction-instance.patch
mm-compaction-use-free-lists-to-quickly-locate-a-migration-target.patch
mm-compaction-avoid-rescanning-the-same-pageblock-multiple-times.patch
mm-compaction-finish-pageblock-scanning-on-contention.patch
mm-compaction-check-early-for-huge-pages-encountered-by-the-migration-scanner.patch
mm-compaction-keep-cached-migration-pfns-synced-for-unusable-pageblocks.patch
mm-compaction-rework-compact_should_abort-as-compact_check_resched.patch
mm-compaction-do-not-consider-a-need-to-reschedule-as-contention.patch
mm-compaction-reduce-premature-advancement-of-the-migration-target-scanner.patch
mm-compaction-round-robin-the-order-while-searching-the-free-lists-for-a-target.patch
mm-compaction-sample-pageblocks-for-free-pages.patch
mm-compaction-be-selective-about-what-pageblocks-to-clear-skip-hints.patch
mm-compaction-capture-a-page-under-direct-compaction.patch
mm-compaction-capture-a-page-under-direct-compaction-fix.patch
