The patch titled
Subject: mm/memory_hotplug: simplify page offlining
has been added to the -mm tree. Its filename is
mm-memory_hotplug-simplify-page-offlining.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/mm-memory_hotplug-simplify-page-offlining.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/mm-memory_hotplug-simplify-page-offlining.patch
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------------------------------------------------------
From: David Hildenbrand <david@xxxxxxxxxx>
Subject: mm/memory_hotplug: simplify page offlining
We make sure that we cannot have any memory holes right at the beginning
of offline_pages(). We no longer need walk_system_ram_range() and can
call test_pages_isolated() and __offline_isolated_pages() directly.
offlined_pages always corresponds to nr_pages, so we can simplify that.
Link: https://lkml.kernel.org/r/20200819175957.28465-4-david@xxxxxxxxxx
Signed-off-by: David Hildenbrand <david@xxxxxxxxxx>
Acked-by: Michal Hocko <mhocko@xxxxxxxx>
Cc: Wei Yang <richard.weiyang@xxxxxxxxxxxxxxxxx>
Cc: Baoquan He <bhe@xxxxxxxxxx>
Cc: Pankaj Gupta <pankaj.gupta.linux@xxxxxxxxx>
Cc: Oscar Salvador <osalvador@xxxxxxx>
Cc: Charan Teja Reddy <charante@xxxxxxxxxxxxxx>
Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
Cc: Fenghua Yu <fenghua.yu@xxxxxxxxx>
Cc: Logan Gunthorpe <logang@xxxxxxxxxxxx>
Cc: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx>
Cc: Michel Lespinasse <walken@xxxxxxxxxx>
Cc: Mike Rapoport <rppt@xxxxxxxxxx>
Cc: Tony Luck <tony.luck@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/memory_hotplug.c | 46 +++++++++---------------------------------
1 file changed, 10 insertions(+), 36 deletions(-)
--- a/mm/memory_hotplug.c~mm-memory_hotplug-simplify-page-offlining
+++ a/mm/memory_hotplug.c
@@ -1375,28 +1375,6 @@ do_migrate_range(unsigned long start_pfn
return ret;
}
-/* Mark all sections offline and remove all free pages from the buddy. */
-static int
-offline_isolated_pages_cb(unsigned long start, unsigned long nr_pages,
- void *data)
-{
- unsigned long *offlined_pages = (unsigned long *)data;
-
- *offlined_pages += __offline_isolated_pages(start, start + nr_pages);
- return 0;
-}
-
-/*
- * Check all pages in range, recorded as memory resource, are isolated.
- */
-static int
-check_pages_isolated_cb(unsigned long start_pfn, unsigned long nr_pages,
- void *data)
-{
- return test_pages_isolated(start_pfn, start_pfn + nr_pages,
- MEMORY_OFFLINE);
-}
-
static int __init cmdline_parse_movable_node(char *p)
{
movable_node_enabled = true;
@@ -1483,7 +1461,7 @@ static int count_system_ram_pages_cb(uns
int __ref offline_pages(unsigned long start_pfn, unsigned long nr_pages)
{
const unsigned long end_pfn = start_pfn + nr_pages;
- unsigned long pfn, system_ram_pages = 0, offlined_pages = 0;
+ unsigned long pfn, system_ram_pages = 0;
int ret, node, nr_isolate_pageblock;
unsigned long flags;
struct zone *zone;
@@ -1581,16 +1559,12 @@ int __ref offline_pages(unsigned long st
reason = "failure to dissolve huge pages";
goto failed_removal_isolated;
}
- /* check again */
- ret = walk_system_ram_range(start_pfn, end_pfn - start_pfn,
- NULL, check_pages_isolated_cb);
- } while (ret);
-
- /* Ok, all of our target is isolated.
- We cannot do rollback at this point. */
- walk_system_ram_range(start_pfn, end_pfn - start_pfn,
- &offlined_pages, offline_isolated_pages_cb);
- pr_info("Offlined Pages %ld\n", offlined_pages);
+ } while (test_pages_isolated(start_pfn, end_pfn, MEMORY_OFFLINE));
+
+ /* Mark all sections offline and remove free pages from the buddy. */
+ __offline_isolated_pages(start_pfn, end_pfn);
+ pr_info("Offlined Pages %ld\n", nr_pages);
+
/*
* Onlining will reset pagetype flags and makes migrate type
* MOVABLE, so just need to decrease the number of isolated
@@ -1601,11 +1575,11 @@ int __ref offline_pages(unsigned long st
spin_unlock_irqrestore(&zone->lock, flags);
/* removal success */
- adjust_managed_page_count(pfn_to_page(start_pfn), -offlined_pages);
- zone->present_pages -= offlined_pages;
+ adjust_managed_page_count(pfn_to_page(start_pfn), -nr_pages);
+ zone->present_pages -= nr_pages;
pgdat_resize_lock(zone->zone_pgdat, &flags);
- zone->zone_pgdat->node_present_pages -= offlined_pages;
+ zone->zone_pgdat->node_present_pages -= nr_pages;
pgdat_resize_unlock(zone->zone_pgdat, &flags);
init_per_zone_wmark_min();
_
Patches currently in -mm which might be from david@xxxxxxxxxx are
mm-page_alloc-tweak-comments-in-has_unmovable_pages.patch
mm-page_isolation-exit-early-when-pageblock-is-isolated-in-set_migratetype_isolate.patch
mm-page_isolation-drop-warn_on_once-in-set_migratetype_isolate.patch
mm-page_isolation-cleanup-set_migratetype_isolate.patch
virtio-mem-dont-special-case-zone_movable.patch
mm-document-semantics-of-zone_movable.patch
mm-memory_hotplug-inline-__offline_pages-into-offline_pages.patch
mm-memory_hotplug-enforce-section-granularity-when-onlining-offlining.patch
mm-memory_hotplug-simplify-page-offlining.patch
mm-page_alloc-simplify-__offline_isolated_pages.patch
mm-memory_hotplug-drop-nr_isolate_pageblock-in-offline_pages.patch
mm-page_isolation-simplify-return-value-of-start_isolate_page_range.patch
mm-memory_hotplug-simplify-page-onlining.patch
mm-page_alloc-drop-stale-pageblock-comment-in-memmap_init_zone.patch
mm-pass-migratetype-into-memmap_init_zone-and-move_pfn_range_to_zone.patch
mm-memory_hotplug-mark-pageblocks-migrate_isolate-while-onlining-memory.patch
