+ mm-thp-dont-count-zone_movable-as-the-target-for-freepage-reserving.patch added to -mm tree

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



The patch titled
     Subject: mm/thp: don't count ZONE_MOVABLE as the target for freepage reserving
has been added to the -mm tree.  Its filename is
     mm-thp-dont-count-zone_movable-as-the-target-for-freepage-reserving.patch

This patch should soon appear at
    http://ozlabs.org/~akpm/mmots/broken-out/mm-thp-dont-count-zone_movable-as-the-target-for-freepage-reserving.patch
and later at
    http://ozlabs.org/~akpm/mmotm/broken-out/mm-thp-dont-count-zone_movable-as-the-target-for-freepage-reserving.patch

Before you just go and hit "reply", please:
   a) Consider who else should be cc'ed
   b) Prefer to cc a suitable mailing list as well
   c) Ideally: find the original patch on the mailing list and do a
      reply-to-all to that, adding suitable additional cc's

*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***

The -mm tree is included into linux-next and is updated
there every 3-4 working days

------------------------------------------------------
From: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
Subject: mm/thp: don't count ZONE_MOVABLE as the target for freepage reserving

There was a regression report for "mm/cma: manage the memory of the CMA
area by using the ZONE_MOVABLE"
(lkml.kernel.org/r/20180102063528.GG30397%20()%20yexl-desktop) and I think
that it is related to this problem.  CMA patchset makes the system use
one more zone (ZONE_MOVABLE) and then increases min_free_kbytes.  It
reduces usable memory and it could cause regression.

ZONE_MOVABLE only has movable pages so we don't need to keep enough
freepages to avoid or deal with fragmentation.  So, don't count it.

This changes min_free_kbytes and thus min_watermark greatly if
ZONE_MOVABLE is used.  It will make the user uses more memory.

o System
22GB ram, fakenuma, 2 nodes. 5 zones are used.

o Before
min_free_kbytes: 112640

zone_info (min_watermark):
Node 0, zone      DMA
        min      19
Node 0, zone    DMA32
        min      3778
Node 0, zone   Normal
        min      10191
Node 0, zone  Movable
        min      0
Node 0, zone   Device
        min      0
Node 1, zone      DMA
        min      0
Node 1, zone    DMA32
        min      0
Node 1, zone   Normal
        min      14043
Node 1, zone  Movable
        min      127
Node 1, zone   Device
        min      0

o After
min_free_kbytes: 90112

zone_info (min_watermark):
Node 0, zone      DMA
        min      15
Node 0, zone    DMA32
        min      3022
Node 0, zone   Normal
        min      8152
Node 0, zone  Movable
        min      0
Node 0, zone   Device
        min      0
Node 1, zone      DMA
        min      0
Node 1, zone    DMA32
        min      0
Node 1, zone   Normal
        min      11234
Node 1, zone  Movable
        min      102
Node 1, zone   Device
        min      0

Link: http://lkml.kernel.org/r/1522913236-15776-1-git-send-email-iamjoonsoo.kim@xxxxxxx
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxxxx>
Cc: "Kirill A . Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---

 mm/khugepaged.c |   10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff -puN mm/khugepaged.c~mm-thp-dont-count-zone_movable-as-the-target-for-freepage-reserving mm/khugepaged.c
--- a/mm/khugepaged.c~mm-thp-dont-count-zone_movable-as-the-target-for-freepage-reserving
+++ a/mm/khugepaged.c
@@ -1879,8 +1879,16 @@ static void set_recommended_min_free_kby
 	int nr_zones = 0;
 	unsigned long recommended_min;
 
-	for_each_populated_zone(zone)
+	for_each_populated_zone(zone) {
+		/*
+		 * We don't need to worry about fragmentation of
+		 * ZONE_MOVABLE since it only has movable pages.
+		 */
+		if (zone_idx(zone) > gfp_zone(GFP_USER))
+			continue;
+
 		nr_zones++;
+	}
 
 	/* Ensure 2 pageblocks are free to assist fragmentation avoidance */
 	recommended_min = pageblock_nr_pages * nr_zones * 2;
_

Patches currently in -mm which might be from iamjoonsoo.kim@xxxxxxx are

mm-page_alloc-dont-reserve-zone_highmem-for-zone_movable-request.patch
mm-cma-manage-the-memory-of-the-cma-area-by-using-the-zone_movable.patch
mm-cma-remove-alloc_cma.patch
arm-cma-avoid-double-mapping-to-the-cma-area-if-config_highmem-=-y.patch
mm-thp-dont-count-zone_movable-as-the-target-for-freepage-reserving.patch

--
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html



[Index of Archives]     [Kernel Archive]     [IETF Annouce]     [DCCP]     [Netdev]     [Networking]     [Security]     [Bugtraq]     [Yosemite]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Linux SCSI]

  Powered by Linux