diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 0d949c517412..79d527a99561 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -79,6 +79,7 @@ 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; @@ -1228,6 +1229,14 @@ static struct ctl_table vm_table[] = { .strategy = &sysctl_intvec, .extra1 = &zero, }, + { + .ctl_name = CTL_UNNUMBERED, + .procname = "min_free_order_shift", + .data = &min_free_order_shift, + .maxlen = sizeof(min_free_order_shift), + .mode = 0644, + .proc_handler = &proc_dointvec + }, { .ctl_name = VM_PERCPU_PAGELIST_FRACTION, .procname = "percpu_pagelist_fraction", diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 2bc2ac63f41e..70d43bf00dc6 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -122,6 +122,7 @@ 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; @@ -1379,7 +1380,7 @@ int 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 0;