From: Oscar Salvador <osalvador@suse.de>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: David Hildenbrand <david@redhat.com>,
Dave Hansen <dave.hansen@linux.intel.com>,
Michal Hocko <mhocko@kernel.org>,
Anshuman Khandual <anshuman.khandual@arm.com>,
Vlastimil Babka <vbabka@suse.cz>,
Pavel Tatashin <pasha.tatashin@soleen.com>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
Oscar Salvador <osalvador@suse.de>
Subject: [PATCH v2 1/3] mm,page_alloc: Use {get,put}_online_mems() to get stable zone's values
Date: Wed, 2 Jun 2021 11:14:55 +0200 [thread overview]
Message-ID: <20210602091457.17772-2-osalvador@suse.de> (raw)
In-Reply-To: <20210602091457.17772-1-osalvador@suse.de>
Currently, page_outside_zone_boundaries() takes zone's span_seqlock
when reading zone_start_pfn and spanned_pages so those values are
stable vs memory hotplug operations.
move_pfn_range_to_zone() and remove_pfn_range_from_zone(), which are
the functions that can change zone's values are serialized by
mem_hotplug_lock by mem_hotplug_{begin,done}, so we can just use
{get,put}_online_mems() on the readers.
This will allow us to completely kill span_seqlock lock as no users
will remain after this series.
Signed-off-by: Oscar Salvador <osalvador@suse.de>
---
mm/page_alloc.c | 14 ++++++--------
1 file changed, 6 insertions(+), 8 deletions(-)
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index aaa1655cf682..296cb00802b4 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -582,17 +582,15 @@ void set_pageblock_migratetype(struct page *page, int migratetype)
static int page_outside_zone_boundaries(struct zone *zone, struct page *page)
{
int ret = 0;
- unsigned seq;
unsigned long pfn = page_to_pfn(page);
unsigned long sp, start_pfn;
- do {
- seq = zone_span_seqbegin(zone);
- start_pfn = zone->zone_start_pfn;
- sp = zone->spanned_pages;
- if (!zone_spans_pfn(zone, pfn))
- ret = 1;
- } while (zone_span_seqretry(zone, seq));
+ get_online_mems();
+ start_pfn = zone->zone_start_pfn;
+ sp = zone->spanned_pages;
+ if (!zone_spans_pfn(zone, pfn))
+ ret = 1;
+ put_online_mems();
if (ret)
pr_err("page 0x%lx outside node %d zone %s [ 0x%lx - 0x%lx ]\n",
--
2.16.3
next prev parent reply other threads:[~2021-06-02 15:19 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-02 9:14 [PATCH v2 0/3] Memory hotplug locking cleanup Oscar Salvador
2021-06-02 9:14 ` Oscar Salvador [this message]
2021-06-02 18:37 ` [PATCH v2 1/3] mm,page_alloc: Use {get,put}_online_mems() to get stable zone's values David Hildenbrand
2021-06-02 19:45 ` Oscar Salvador
2021-06-03 8:38 ` Oscar Salvador
2021-06-03 12:45 ` Michal Hocko
2021-06-04 7:41 ` Oscar Salvador
2021-06-07 7:52 ` Oscar Salvador
2021-06-07 8:49 ` David Hildenbrand
2021-06-07 10:23 ` Oscar Salvador
2021-06-08 10:42 ` Oscar Salvador
2021-06-08 15:00 ` David Hildenbrand
2021-06-09 9:42 ` David Hildenbrand
2021-06-07 8:42 ` Michal Hocko
2021-06-03 2:32 ` [mm,page_alloc] [confidence: ] acb5758bf4: BUG:sleeping_function_called_from_invalid_context_at_include/linux/percpu-rwsem.h kernel test robot
2021-06-02 9:14 ` [PATCH v2 2/3] mm,memory_hotplug: Drop unneeded locking Oscar Salvador
2021-06-03 12:52 ` Michal Hocko
2021-06-02 9:14 ` [PATCH v2 3/3] mm,memory_hotplug: Remove unneeded declarations Oscar Salvador
2021-06-02 18:38 ` David Hildenbrand
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