hugetlb: override default huge page size
Allow configurations with the default huge page size which is different to
the traditional HPAGE_SIZE size. The default huge page size is the one
represented in the legacy /proc ABIs, SHM, and which is defaulted to when
mounting hugetlbfs filesystems.
This is implemented with a new kernel option default_hugepagesz=, which
defaults to HPAGE_SIZE if not specified.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 107c1ce..2a2f6e8 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -34,6 +34,7 @@
/* for command line parsing */
static struct hstate * __initdata parsed_hstate;
static unsigned long __initdata default_hstate_max_huge_pages;
+static unsigned long __initdata default_hstate_size;
#define for_each_hstate(h) \
for ((h) = hstates; (h) < &hstates[max_hstate]; (h)++)
@@ -1288,11 +1289,14 @@
{
BUILD_BUG_ON(HPAGE_SHIFT == 0);
- if (!size_to_hstate(HPAGE_SIZE)) {
- hugetlb_add_hstate(HUGETLB_PAGE_ORDER);
- parsed_hstate->max_huge_pages = default_hstate_max_huge_pages;
+ if (!size_to_hstate(default_hstate_size)) {
+ default_hstate_size = HPAGE_SIZE;
+ if (!size_to_hstate(default_hstate_size))
+ hugetlb_add_hstate(HUGETLB_PAGE_ORDER);
}
- default_hstate_idx = size_to_hstate(HPAGE_SIZE) - hstates;
+ default_hstate_idx = size_to_hstate(default_hstate_size) - hstates;
+ if (default_hstate_max_huge_pages)
+ default_hstate.max_huge_pages = default_hstate_max_huge_pages;
hugetlb_init_hstates();
@@ -1332,7 +1336,7 @@
parsed_hstate = h;
}
-static int __init hugetlb_setup(char *s)
+static int __init hugetlb_nrpages_setup(char *s)
{
unsigned long *mhp;
static unsigned long *last_mhp;
@@ -1367,7 +1371,14 @@
return 1;
}
-__setup("hugepages=", hugetlb_setup);
+__setup("hugepages=", hugetlb_nrpages_setup);
+
+static int __init hugetlb_default_setup(char *s)
+{
+ default_hstate_size = memparse(s, &s);
+ return 1;
+}
+__setup("default_hugepagesz=", hugetlb_default_setup);
static unsigned int cpuset_mems_nr(unsigned int *array)
{