From: js1304@gmail.com
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Michal Hocko <mhocko@suse.com>, Vlastimil Babka <vbabka@suse.cz>,
Mel Gorman <mgorman@techsingularity.net>,
Johannes Weiner <hannes@cmpxchg.org>,
"Aneesh Kumar K . V" <aneesh.kumar@linux.vnet.ibm.com>,
Minchan Kim <minchan@kernel.org>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
Joonsoo Kim <iamjoonsoo.kim@lge.com>
Subject: [PATCH] mm/page_alloc: don't reserve ZONE_HIGHMEM for ZONE_MOVABLE request
Date: Thu, 24 Aug 2017 14:45:46 +0900 [thread overview]
Message-ID: <1503553546-27450-1-git-send-email-iamjoonsoo.kim@lge.com> (raw)
From: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Freepage on ZONE_HIGHMEM doesn't work for kernel memory so it's not that
important to reserve. When ZONE_MOVABLE is used, this problem would
theorectically cause to decrease usable memory for GFP_HIGHUSER_MOVABLE
allocation request which is mainly used for page cache and anon page
allocation. So, fix it.
And, defining sysctl_lowmem_reserve_ratio array by MAX_NR_ZONES - 1 size
makes code complex. For example, if there is highmem system, following
reserve ratio is activated for *NORMAL ZONE* which would be easyily
misleading people.
#ifdef CONFIG_HIGHMEM
32
#endif
This patch also fix this situation by defining sysctl_lowmem_reserve_ratio
array by MAX_NR_ZONES and place "#ifdef" to right place.
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
---
include/linux/mmzone.h | 2 +-
mm/page_alloc.c | 11 ++++++-----
2 files changed, 7 insertions(+), 6 deletions(-)
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index e7e92c8..e5f134b 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -882,7 +882,7 @@ int min_free_kbytes_sysctl_handler(struct ctl_table *, int,
void __user *, size_t *, loff_t *);
int watermark_scale_factor_sysctl_handler(struct ctl_table *, int,
void __user *, size_t *, loff_t *);
-extern int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES-1];
+extern int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES];
int lowmem_reserve_ratio_sysctl_handler(struct ctl_table *, int,
void __user *, size_t *, loff_t *);
int percpu_pagelist_fraction_sysctl_handler(struct ctl_table *, int,
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 90b1996..6faa53d 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -202,17 +202,18 @@ static void __free_pages_ok(struct page *page, unsigned int order);
* TBD: should special case ZONE_DMA32 machines here - in those we normally
* don't need any ZONE_NORMAL reservation
*/
-int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES-1] = {
+int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES] = {
#ifdef CONFIG_ZONE_DMA
- 256,
+ [ZONE_DMA] = 256,
#endif
#ifdef CONFIG_ZONE_DMA32
- 256,
+ [ZONE_DMA32] = 256,
#endif
+ [ZONE_NORMAL] = 32,
#ifdef CONFIG_HIGHMEM
- 32,
+ [ZONE_HIGHMEM] = INT_MAX,
#endif
- 32,
+ [ZONE_MOVABLE] = INT_MAX,
};
EXPORT_SYMBOL(totalram_pages);
--
2.7.4
--
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next reply other threads:[~2017-08-24 5:46 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-08-24 5:45 js1304 [this message]
2017-08-24 9:30 ` [PATCH] mm/page_alloc: don't reserve ZONE_HIGHMEM for ZONE_MOVABLE request Michal Hocko
2017-08-25 0:15 ` Joonsoo Kim
2017-08-25 7:33 ` Michal Hocko
2017-08-24 9:41 ` Vlastimil Babka
2017-08-25 0:20 ` Joonsoo Kim
2017-08-25 7:38 ` Michal Hocko
2017-08-28 0:15 ` Joonsoo Kim
2017-08-28 9:56 ` Michal Hocko
2017-08-29 0:45 ` Joonsoo Kim
2017-08-29 13:39 ` Michal Hocko
2017-08-31 1:45 ` Joonsoo Kim
2017-08-25 7:56 ` Vlastimil Babka
2017-08-28 0:28 ` Joonsoo Kim
2017-08-28 6:45 ` Vlastimil Babka
2017-08-29 0:36 ` Joonsoo Kim
2017-08-29 7:00 ` Vlastimil Babka
2017-09-06 4:35 js1304
2017-09-06 7:54 ` Vlastimil Babka
2017-09-14 13:24 ` Michal Hocko
2018-04-04 0:24 ` Joonsoo Kim
2018-04-12 12:01 ` Michal Hocko
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