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| author | Arun KS | 2018-12-28 09:34:24 +0100 |
|---|---|---|
| committer | Linus Torvalds | 2018-12-28 21:11:47 +0100 |
| commit | 9705bea5f833f4fc21d5bef5fce7348427f76ea4 (patch) | |
| tree | 37604aa5b680736eb176283f970e1c1d7d27bbf3 /mm/vmstat.c | |
| parent | mm: reference totalram_pages and managed_pages once per function (diff) | |
| download | kernel-qcow2-linux-9705bea5f833f4fc21d5bef5fce7348427f76ea4.tar.gz kernel-qcow2-linux-9705bea5f833f4fc21d5bef5fce7348427f76ea4.tar.xz kernel-qcow2-linux-9705bea5f833f4fc21d5bef5fce7348427f76ea4.zip | |
mm: convert zone->managed_pages to atomic variable
totalram_pages, zone->managed_pages and totalhigh_pages updates are
protected by managed_page_count_lock, but readers never care about it.
Convert these variables to atomic to avoid readers potentially seeing a
store tear.
This patch converts zone->managed_pages. Subsequent patches will convert
totalram_panges, totalhigh_pages and eventually managed_page_count_lock
will be removed.
Main motivation was that managed_page_count_lock handling was complicating
things. It was discussed in length here,
https://lore.kernel.org/patchwork/patch/995739/#1181785 So it seemes
better to remove the lock and convert variables to atomic, with preventing
poteintial store-to-read tearing as a bonus.
Link: http://lkml.kernel.org/r/1542090790-21750-3-git-send-email-arunks@codeaurora.org
Signed-off-by: Arun KS <arunks@codeaurora.org>
Suggested-by: Michal Hocko <mhocko@suse.com>
Suggested-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Reviewed-by: David Hildenbrand <david@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/vmstat.c')
| -rw-r--r-- | mm/vmstat.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/mm/vmstat.c b/mm/vmstat.c index 9c624595e904..83b30edc2f7f 100644 --- a/mm/vmstat.c +++ b/mm/vmstat.c @@ -227,7 +227,7 @@ int calculate_normal_threshold(struct zone *zone) * 125 1024 10 16-32 GB 9 */ - mem = zone->managed_pages >> (27 - PAGE_SHIFT); + mem = zone_managed_pages(zone) >> (27 - PAGE_SHIFT); threshold = 2 * fls(num_online_cpus()) * (1 + fls(mem)); @@ -1569,7 +1569,7 @@ static void zoneinfo_show_print(struct seq_file *m, pg_data_t *pgdat, high_wmark_pages(zone), zone->spanned_pages, zone->present_pages, - zone->managed_pages); + zone_managed_pages(zone)); seq_printf(m, "\n protection: (%ld", |