[PATCH 4.14.y] mm/page_owner.c: remove drain_all_pages from init_early_allocated_pages

[Nick Desaulniers]

From: Oscar Salvador <osalvador at techadventures.net>

commit u6bec6ad77fac3d29aed0d8e0b7526daedc964970 upstream.

When setting page_owner = on, the following warning can be seen in the
boot log:

  WARNING: CPU: 0 PID: 0 at mm/page_alloc.c:2537 drain_all_pages+0x171/0x1a0
  Modules linked in:
  CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.15.0-rc7-next-20180109-1-default+ #7
  Hardware name: Dell Inc. Latitude E7470/0T6HHJ, BIOS 1.11.3 11/09/2016
  RIP: 0010:drain_all_pages+0x171/0x1a0
  Call Trace:
    init_page_owner+0x4e/0x260
    start_kernel+0x3e6/0x4a6
    ? set_init_arg+0x55/0x55
    secondary_startup_64+0xa5/0xb0
  Code: c5 ed ff 89 df 48 c7 c6 20 3b 71 82 e8 f9 4b 52 00 3b 05 d7 0b f8 00 89 c3 72 d5 5b 5d 41 5

This warning is shown because we are calling drain_all_pages() in
init_early_allocated_pages(), but mm_percpu_wq is not up yet, it is being
set up later on in kernel_init_freeable() -> init_mm_internals().

Link: http://lkml.kernel.org/r/20180109153921.GA13070@techadventures.net
Signed-off-by: Oscar Salvador <osalvador at techadventures.net>
Acked-by: Joonsoo Kim <iamjoonsoo.kim at lge.com>
Cc: Vlastimil Babka <vbabka at suse.cz>
Cc: Michal Hocko <mhocko at suse.com>
Cc: Ayush Mittal <ayush.m at samsung.com>
Signed-off-by: Andrew Morton <akpm at linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds at linux-foundation.org>
Signed-off-by: Nick Desaulniers <ndesaulniers at google.com>
---
Fixes an easliy reproduced WARN_ON_ONCE observed with
CONFIG_PAGE_OWNER=y and page_owner=on boot param.  Looks like this
landed in v4.15-rc9 but hasn't been backported yet. Thanks to
Miles Chen <miles.chen at mediatek.com> for the report.

 mm/page_owner.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/mm/page_owner.c b/mm/page_owner.c
index 6ac05a6ff2d1..4753b317ef7b 100644
--- a/mm/page_owner.c
+++ b/mm/page_owner.c
@@ -617,7 +617,6 @@ static void init_early_allocated_pages(void)
 {
 	pg_data_t *pgdat;
 
-	drain_all_pages(NULL);
 	for_each_online_pgdat(pgdat)
 		init_zones_in_node(pgdat);
 }
-- 
2.28.0.rc0.142.g3c755180ce-goog