Commit 0a1a9a00 authored by David Hildenbrand's avatar David Hildenbrand Committed by Linus Torvalds

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.

[akpm@linux-foundation.org: patch conflict resolution]
Signed-off-by: default avatarDavid Hildenbrand <david@redhat.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Reviewed-by: default avatarOscar Salvador <osalvador@suse.de>
Acked-by: default avatarMichal Hocko <mhocko@suse.com>
Cc: Wei Yang <richard.weiyang@linux.alibaba.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Cc: Charan Teja Reddy <charante@codeaurora.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michel Lespinasse <walken@google.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Tony Luck <tony.luck@intel.com>
Link: https://lkml.kernel.org/r/20200819175957.28465-4-david@redhat.comSigned-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 4986fac1
......@@ -1384,28 +1384,6 @@ do_migrate_range(unsigned long start_pfn, unsigned long end_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;
......@@ -1492,7 +1470,7 @@ static int count_system_ram_pages_cb(unsigned long start_pfn,
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;
......@@ -1590,9 +1568,7 @@ int __ref offline_pages(unsigned long start_pfn, unsigned long nr_pages)
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);
/*
* per-cpu pages are drained in start_isolate_page_range, but if
* there are still pages that are not free, make sure that we
......@@ -1605,15 +1581,15 @@ int __ref offline_pages(unsigned long start_pfn, unsigned long nr_pages)
* because has_unmovable_pages explicitly checks for
* PageBuddy on freed pages on other zones.
*/
ret = test_pages_isolated(start_pfn, end_pfn, MEMORY_OFFLINE);
if (ret)
drain_all_pages(zone);
} 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);
/* 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
......@@ -1624,11 +1600,11 @@ int __ref offline_pages(unsigned long start_pfn, unsigned long nr_pages)
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();
......
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