The patch titled
page migration cleanup: drop nr_refs in remove_references()
has been removed from the -mm tree. Its filename is
page-migration-cleanup-drop-nr_refs-in-remove_references.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
Subject: page migration cleanup: drop nr_refs in remove_references()
From: Christoph Lameter <clameter@xxxxxxx>
Drop nr_refs parameter from migrate_page_remove_references()
The nr_refs parameter is not really useful since the number of remaining
references is always
1 for anonymous pages without a mapping
2 for pages with a mapping
3 for pages with a mapping and PagePrivate set.
Remove the early check for the number of references since we are checking
page_mapcount() earlier. Ultimately only the refcount matters after the
tree_lock has been obtained.
Signed-off-by: Christoph Lameter <clameter@xxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
mm/migrate.c | 21 +++++++++++----------
1 file changed, 11 insertions(+), 10 deletions(-)
diff -puN mm/migrate.c~page-migration-cleanup-drop-nr_refs-in-remove_references mm/migrate.c
--- a/mm/migrate.c~page-migration-cleanup-drop-nr_refs-in-remove_references
+++ a/mm/migrate.c
@@ -168,19 +168,19 @@ retry:
/*
* Remove references for a page and establish the new page with the correct
* basic settings to be able to stop accesses to the page.
+ *
+ * The number of remaining references must be:
+ * 1 for anonymous pages without a mapping
+ * 2 for pages with a mapping
+ * 3 for pages with a mapping and PagePrivate set.
*/
static int migrate_page_remove_references(struct page *newpage,
- struct page *page, int nr_refs)
+ struct page *page)
{
struct address_space *mapping = page_mapping(page);
struct page **radix_pointer;
- /*
- * Avoid doing any of the following work if the page count
- * indicates that the page is in use or truncate has removed
- * the page.
- */
- if (!mapping || page_mapcount(page) + nr_refs != page_count(page))
+ if (!mapping)
return -EAGAIN;
/*
@@ -218,7 +218,8 @@ static int migrate_page_remove_reference
&mapping->page_tree,
page_index(page));
- if (!page_mapping(page) || page_count(page) != nr_refs ||
+ if (!page_mapping(page) ||
+ page_count(page) != 2 + !!PagePrivate(page) ||
*radix_pointer != page) {
write_unlock_irq(&mapping->tree_lock);
return -EAGAIN;
@@ -309,7 +310,7 @@ int migrate_page(struct page *newpage, s
BUG_ON(PageWriteback(page)); /* Writeback must be complete */
- rc = migrate_page_remove_references(newpage, page, 2);
+ rc = migrate_page_remove_references(newpage, page);
if (rc)
return rc;
@@ -348,7 +349,7 @@ int buffer_migrate_page(struct page *new
head = page_buffers(page);
- rc = migrate_page_remove_references(newpage, page, 3);
+ rc = migrate_page_remove_references(newpage, page);
if (rc)
return rc;
_
Patches currently in -mm which might be from clameter@xxxxxxx are
origin.patch
mm-remove-vm_locked-before-remap_pfn_range-and-drop-vm_shm.patch
page-migration-support-a-vma-migration-function.patch
allow-migration-of-mlocked-pages.patch
zoned-vm-counters-create-vmstatc-h-from-page_allocc-h.patch
zoned-vm-counters-basic-zvc-zoned-vm-counter-implementation.patch
zoned-vm-counters-basic-zvc-zoned-vm-counter-implementation-tidy.patch
zoned-vm-counters-convert-nr_mapped-to-per-zone-counter.patch
zoned-vm-counters-conversion-of-nr_pagecache-to-per-zone-counter.patch
zoned-vm-counters-remove-nr_file_mapped-from-scan-control-structure.patch
zoned-vm-counters-remove-nr_file_mapped-from-scan-control-structure-fix.patch
zoned-vm-counters-split-nr_anon_pages-off-from-nr_file_mapped.patch
zoned-vm-counters-zone_reclaim-remove-proc-sys-vm-zone_reclaim_interval.patch
zoned-vm-counters-conversion-of-nr_slab-to-per-zone-counter.patch
zoned-vm-counters-conversion-of-nr_pagetables-to-per-zone-counter.patch
zoned-vm-counters-conversion-of-nr_dirty-to-per-zone-counter.patch
zoned-vm-counters-conversion-of-nr_writeback-to-per-zone-counter.patch
zoned-vm-counters-conversion-of-nr_unstable-to-per-zone-counter.patch
zoned-vm-counters-conversion-of-nr_bounce-to-per-zone-counter.patch
zoned-vm-counters-remove-useless-struct-wbs.patch
cpuset-remove-extra-cpuset_zone_allowed-check-in-__alloc_pages.patch
corrections-to-memory-barrier-doc.patch
-
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