The patch titled
Subject: mm/compaction: split freepages without holding the zone lock
has been added to the -mm tree. Its filename is
mm-compaction-split-freepages-without-holding-the-zone-lock.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-compaction-split-freepages-without-holding-the-zone-lock.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-compaction-split-freepages-without-holding-the-zone-lock.patch
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/SubmitChecklist when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
Subject: mm/compaction: split freepages without holding the zone lock
We don't need to split freepages with holding the zone lock. It will
cause more contention on zone lock so not desirable.
Link: http://lkml.kernel.org/r/1464230275-25791-1-git-send-email-iamjoonsoo.kim@xxxxxxx
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx>
Cc: Minchan Kim <minchan@xxxxxxxxxx>
Cc: Alexander Potapenko <glider@xxxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/mm.h | 1 -
mm/compaction.c | 42 ++++++++++++++++++++++++++++++------------
mm/page_alloc.c | 27 ---------------------------
3 files changed, 30 insertions(+), 40 deletions(-)
diff -puN include/linux/mm.h~mm-compaction-split-freepages-without-holding-the-zone-lock include/linux/mm.h
--- a/include/linux/mm.h~mm-compaction-split-freepages-without-holding-the-zone-lock
+++ a/include/linux/mm.h
@@ -537,7 +537,6 @@ void __put_page(struct page *page);
void put_pages_list(struct list_head *pages);
void split_page(struct page *page, unsigned int order);
-int split_free_page(struct page *page);
/*
* Compound pages have a destructor function. Provide a
diff -puN mm/compaction.c~mm-compaction-split-freepages-without-holding-the-zone-lock mm/compaction.c
--- a/mm/compaction.c~mm-compaction-split-freepages-without-holding-the-zone-lock
+++ a/mm/compaction.c
@@ -64,13 +64,31 @@ static unsigned long release_freepages(s
static void map_pages(struct list_head *list)
{
- struct page *page;
+ unsigned int i, order, nr_pages;
+ struct page *page, *next;
+ LIST_HEAD(tmp_list);
+
+ list_for_each_entry_safe(page, next, list, lru) {
+ list_del(&page->lru);
+
+ order = page_private(page);
+ nr_pages = 1 << order;
+ set_page_private(page, 0);
+ set_page_refcounted(page);
+
+ arch_alloc_page(page, order);
+ kernel_map_pages(page, nr_pages, 1);
+ kasan_alloc_pages(page, order);
+ if (order)
+ split_page(page, order);
- list_for_each_entry(page, list, lru) {
- arch_alloc_page(page, 0);
- kernel_map_pages(page, 1, 1);
- kasan_alloc_pages(page, 0);
+ for (i = 0; i < nr_pages; i++) {
+ list_add(&page->lru, &tmp_list);
+ page++;
+ }
}
+
+ list_splice(&tmp_list, list);
}
static inline bool migrate_async_suitable(int migratetype)
@@ -405,12 +423,13 @@ static unsigned long isolate_freepages_b
unsigned long flags = 0;
bool locked = false;
unsigned long blockpfn = *start_pfn;
+ unsigned int order;
cursor = pfn_to_page(blockpfn);
/* Isolate free pages. */
for (; blockpfn < end_pfn; blockpfn++, cursor++) {
- int isolated, i;
+ int isolated;
struct page *page = cursor;
/*
@@ -476,13 +495,12 @@ static unsigned long isolate_freepages_b
goto isolate_fail;
}
- /* Found a free page, break it into order-0 pages */
- isolated = split_free_page(page);
+ /* Found a free page, will break it into order-0 pages */
+ order = page_order(page);
+ isolated = __isolate_free_page(page, page_order(page));
+ set_page_private(page, order);
total_isolated += isolated;
- for (i = 0; i < isolated; i++) {
- list_add(&page->lru, freelist);
- page++;
- }
+ list_add_tail(&page->lru, freelist);
/* If a page was split, advance to the end of it */
if (isolated) {
diff -puN mm/page_alloc.c~mm-compaction-split-freepages-without-holding-the-zone-lock mm/page_alloc.c
--- a/mm/page_alloc.c~mm-compaction-split-freepages-without-holding-the-zone-lock
+++ a/mm/page_alloc.c
@@ -2525,33 +2525,6 @@ int __isolate_free_page(struct page *pag
}
/*
- * Similar to split_page except the page is already free. As this is only
- * being used for migration, the migratetype of the block also changes.
- * As this is called with interrupts disabled, the caller is responsible
- * for calling arch_alloc_page() and kernel_map_page() after interrupts
- * are enabled.
- *
- * Note: this is probably too low level an operation for use in drivers.
- * Please consult with lkml before using this in your driver.
- */
-int split_free_page(struct page *page)
-{
- unsigned int order;
- int nr_pages;
-
- order = page_order(page);
-
- nr_pages = __isolate_free_page(page, order);
- if (!nr_pages)
- return 0;
-
- /* Split into individual pages */
- set_page_refcounted(page);
- split_page(page, order);
- return nr_pages;
-}
-
-/*
* Update NUMA hit/miss statistics
*
* Must be called with interrupts disabled.
_
Patches currently in -mm which might be from iamjoonsoo.kim@xxxxxxx are
mm-compaction-split-freepages-without-holding-the-zone-lock.patch
mm-page_owner-initialize-page-owner-without-holding-the-zone-lock.patch
mm-page_owner-copy-last_migrate_reason-in-copy_page_owner.patch
mm-page_owner-introduce-split_page_owner-and-replace-manual-handling.patch
tools-vm-page_owner-increase-temporary-buffer-size.patch
mm-page_owner-use-stackdepot-to-store-stacktrace.patch
mm-page_alloc-introduce-post-allocation-processing-on-page-allocator.patch
--
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
