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| author | Michal Hocko <mhocko@suse.cz> | 2013-07-09 03:00:40 +0400 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-07-09 21:33:25 +0400 |
| commit | 5f12733e9d976132e6cbbae9d08f71406fdacdfb (patch) | |
| tree | 144cda4e157dcbedd28757796f40c2a4cb52c92f /mm | |
| parent | 465939a1fa283cf2a5194362c5accf4429c99c42 (diff) | |
| download | linux-5f12733e9d976132e6cbbae9d08f71406fdacdfb.tar.xz | |
mm: honor min_free_kbytes set by user
min_free_kbytes is updated during memory hotplug (by
init_per_zone_wmark_min) currently which is right thing to do in most
cases but this could be unexpected if admin increased the value to
prevent from allocation failures and the new min_free_kbytes would be
decreased as a result of memory hotadd.
This patch saves the user defined value and allows updating
min_free_kbytes only if it is higher than the saved one.
A warning is printed when the new value is ignored.
Signed-off-by: Michal Hocko <mhocko@suse.cz>
Cc: Mel Gorman <mgorman@suse.de>
Acked-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/page_alloc.c | 24 |
1 files changed, 17 insertions, 7 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c index b5855e545eec..b100255dedda 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -204,6 +204,7 @@ static char * const zone_names[MAX_NR_ZONES] = { }; int min_free_kbytes = 1024; +int user_min_free_kbytes; static unsigned long __meminitdata nr_kernel_pages; static unsigned long __meminitdata nr_all_pages; @@ -5589,14 +5590,21 @@ static void __meminit setup_per_zone_inactive_ratio(void) int __meminit init_per_zone_wmark_min(void) { unsigned long lowmem_kbytes; + int new_min_free_kbytes; lowmem_kbytes = nr_free_buffer_pages() * (PAGE_SIZE >> 10); - - min_free_kbytes = int_sqrt(lowmem_kbytes * 16); - if (min_free_kbytes < 128) - min_free_kbytes = 128; - if (min_free_kbytes > 65536) - min_free_kbytes = 65536; + new_min_free_kbytes = int_sqrt(lowmem_kbytes * 16); + + if (new_min_free_kbytes > user_min_free_kbytes) { + min_free_kbytes = new_min_free_kbytes; + if (min_free_kbytes < 128) + min_free_kbytes = 128; + if (min_free_kbytes > 65536) + min_free_kbytes = 65536; + } else { + pr_warn("min_free_kbytes is not updated to %d because user defined value %d is preferred\n", + new_min_free_kbytes, user_min_free_kbytes); + } setup_per_zone_wmarks(); refresh_zone_stat_thresholds(); setup_per_zone_lowmem_reserve(); @@ -5614,8 +5622,10 @@ int min_free_kbytes_sysctl_handler(ctl_table *table, int write, void __user *buffer, size_t *length, loff_t *ppos) { proc_dointvec(table, write, buffer, length, ppos); - if (write) + if (write) { + user_min_free_kbytes = min_free_kbytes; setup_per_zone_wmarks(); + } return 0; } |