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authorArve Hjønnevåg <arve@android.com>2009-02-17 14:51:02 -0800
committerDan Willemsen <dwillemsen@nvidia.com>2011-11-30 21:37:50 -0800
commita841be8af78880e00c8ae57f8440b67a1d128365 (patch)
tree4031c4abc43038ff28f19cb1c81da489e4db1f84
parentfe6c31c6f60272e8eda705fdc4428c3b5f06dbc5 (diff)
mm: Add min_free_order_shift tunable.
By default the kernel tries to keep half as much memory free at each order as it does for one order below. This can be too agressive when running without swap. Change-Id: I5efc1a0b50f41ff3ac71e92d2efd175dedd54ead Signed-off-by: Arve Hjønnevåg <arve@android.com>
-rw-r--r--kernel/sysctl.c8
-rw-r--r--mm/page_alloc.c3
2 files changed, 10 insertions, 1 deletions
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 11d65b531e50..fd15163f360a 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -96,6 +96,7 @@ extern char core_pattern[];
extern unsigned int core_pipe_limit;
extern int pid_max;
extern int min_free_kbytes;
+extern int min_free_order_shift;
extern int pid_max_min, pid_max_max;
extern int sysctl_drop_caches;
extern int percpu_pagelist_fraction;
@@ -1189,6 +1190,13 @@ static struct ctl_table vm_table[] = {
.extra1 = &zero,
},
{
+ .procname = "min_free_order_shift",
+ .data = &min_free_order_shift,
+ .maxlen = sizeof(min_free_order_shift),
+ .mode = 0644,
+ .proc_handler = &proc_dointvec
+ },
+ {
.procname = "percpu_pagelist_fraction",
.data = &percpu_pagelist_fraction,
.maxlen = sizeof(percpu_pagelist_fraction),
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 6e8ecb6e021c..41253539b32a 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -176,6 +176,7 @@ static char * const zone_names[MAX_NR_ZONES] = {
};
int min_free_kbytes = 1024;
+int min_free_order_shift = 1;
static unsigned long __meminitdata nr_kernel_pages;
static unsigned long __meminitdata nr_all_pages;
@@ -1469,7 +1470,7 @@ static bool __zone_watermark_ok(struct zone *z, int order, unsigned long mark,
free_pages -= z->free_area[o].nr_free << o;
/* Require fewer higher order pages to be free */
- min >>= 1;
+ min >>= min_free_order_shift;
if (free_pages <= min)
return false;