From fc479982487578c18e9a3c05d5633a5b17e56289 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Arve=20Hj=C3=B8nnev=C3=A5g?= Date: Tue, 17 Feb 2009 14:51:02 -0800 Subject: [PATCH] mm: Add min_free_order_shift tunable. MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit 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 --- kernel/sysctl.c | 8 ++++++++ mm/page_alloc.c | 3 ++- 2 files changed, 10 insertions(+), 1 deletion(-) diff --git a/kernel/sysctl.c b/kernel/sysctl.c index f175d98..ea468b1 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 0f50cdb..517d7ab 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; @@ -1487,7 +1488,7 @@ 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; -- 2.7.4