The patch titled
Subject: mm, compaction: use the page allocator bulk-free helper for lists of pages
has been added to the -mm tree. Its filename is
mm-compaction-use-the-page-allocator-bulk-free-helper-for-lists-of-pages.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-compaction-use-the-page-allocator-bulk-free-helper-for-lists-of-pages.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-compaction-use-the-page-allocator-bulk-free-helper-for-lists-of-pages.patch
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------------------------------------------------------
From: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx>
Subject: mm, compaction: use the page allocator bulk-free helper for lists of pages
release_pages() is a simpler version of free_unref_page_list() but it
tracks the highest PFN for caching the restart point of the compaction
free scanner. This patch optionally tracks the highest PFN in the core
helper and converts compaction to use it. The performance impact is
limited but it should reduce lock contention slightly in some cases. The
main benefit is removing some partially duplicated code.
Link: http://lkml.kernel.org/r/20190104125011.16071-10-mgorman@xxxxxxxxxxxxxxxxxxx
Signed-off-by: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx>
Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx>
Cc: David Rientjes <rientjes@xxxxxxxxxx>
Cc: Huang Ying <ying.huang@xxxxxxxxx>
Cc: Kirill A. Shutemov <kirill@xxxxxxxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
--- a/include/linux/gfp.h~mm-compaction-use-the-page-allocator-bulk-free-helper-for-lists-of-pages
+++ a/include/linux/gfp.h
@@ -543,7 +543,12 @@ void * __meminit alloc_pages_exact_nid(i
extern void __free_pages(struct page *page, unsigned int order);
extern void free_pages(unsigned long addr, unsigned int order);
extern void free_unref_page(struct page *page);
-extern void free_unref_page_list(struct list_head *list);
+extern void __free_page_list(struct list_head *list, bool dropref, unsigned long *highest_pfn);
+
+static inline void free_unref_page_list(struct list_head *list)
+{
+ return __free_page_list(list, false, NULL);
+}
struct page_frag_cache;
extern void __page_frag_cache_drain(struct page *page, unsigned int count);
--- a/mm/compaction.c~mm-compaction-use-the-page-allocator-bulk-free-helper-for-lists-of-pages
+++ a/mm/compaction.c
@@ -52,16 +52,10 @@ static inline void count_compact_events(
static unsigned long release_freepages(struct list_head *freelist)
{
- struct page *page, *next;
- unsigned long high_pfn = 0;
+ unsigned long high_pfn;
- list_for_each_entry_safe(page, next, freelist, lru) {
- unsigned long pfn = page_to_pfn(page);
- list_del(&page->lru);
- __free_page(page);
- if (pfn > high_pfn)
- high_pfn = pfn;
- }
+ __free_page_list(freelist, true, &high_pfn);
+ INIT_LIST_HEAD(freelist);
return high_pfn;
}
--- a/mm/page_alloc.c~mm-compaction-use-the-page-allocator-bulk-free-helper-for-lists-of-pages
+++ a/mm/page_alloc.c
@@ -2876,18 +2876,26 @@ void free_unref_page(struct page *page)
/*
* Free a list of 0-order pages
*/
-void free_unref_page_list(struct list_head *list)
+void __free_page_list(struct list_head *list, bool dropref,
+ unsigned long *highest_pfn)
{
struct page *page, *next;
unsigned long flags, pfn;
int batch_count = 0;
+ if (highest_pfn)
+ *highest_pfn = 0;
+
/* Prepare pages for freeing */
list_for_each_entry_safe(page, next, list, lru) {
+ if (dropref)
+ WARN_ON_ONCE(!put_page_testzero(page));
pfn = page_to_pfn(page);
if (!free_unref_page_prepare(page, pfn))
list_del(&page->lru);
set_page_private(page, pfn);
+ if (highest_pfn && pfn > *highest_pfn)
+ *highest_pfn = pfn;
}
local_irq_save(flags);
_
Patches currently in -mm which might be from mgorman@xxxxxxxxxxxxxxxxxxx are
mm-page_alloc-do-not-wake-kswapd-with-zone-lock-held.patch
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-compaction-skip-pageblocks-with-reserved-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-use-the-page-allocator-bulk-free-helper-for-lists-of-pages.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-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-unnecessary-skipping-of-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-do-not-direct-compact-remote-memory.patch
