diff options
| author | Mel Gorman <mgorman@techsingularity.net> | 2021-05-04 18:39:30 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2021-05-05 11:27:26 -0700 |
| commit | 8ca559132a2d9b56732d35e2b947af96acb9b80b (patch) | |
| tree | 37f21af4ddc0a8aecb62388736c9967c8685b39f /drivers | |
| parent | e44605a8b1aa13d892addc59ec3d416cb186c77b (diff) | |
| download | linux-8ca559132a2d9b56732d35e2b947af96acb9b80b.tar.bz2 | |
mm/memory_hotplug: remove broken locking of zone PCP structures during hot remove
zone_pcp_reset allegedly protects against a race with drain_pages using
local_irq_save but this is bogus. local_irq_save only operates on the
local CPU. If memory hotplug is running on CPU A and drain_pages is
running on CPU B, disabling IRQs on CPU A does not affect CPU B and
offers no protection.
This patch deletes IRQ disable/enable on the grounds that IRQs protect
nothing and assumes the existing hotplug paths guarantees the PCP cannot
be used after zone_pcp_enable(). That should be the case already
because all the pages have been freed and there is no page to put on the
PCP lists.
Link: https://lkml.kernel.org/r/20210412090346.GQ3697@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers')
0 files changed, 0 insertions, 0 deletions