From: Nick Piggin 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 Signed-off-by: Andrew Morton --- Documentation/kernel-parameters.txt | 7 +++++++ mm/hugetlb.c | 25 ++++++++++++++++++------- 2 files changed, 25 insertions(+), 7 deletions(-) diff -puN Documentation/kernel-parameters.txt~hugetlb-override-default-huge-page-size Documentation/kernel-parameters.txt --- a/Documentation/kernel-parameters.txt~hugetlb-override-default-huge-page-size +++ a/Documentation/kernel-parameters.txt @@ -770,6 +770,13 @@ and is between 256 and 4096 characters. CPU supports the "pdpe1gb" cpuinfo flag) Note that 1GB pages can only be allocated at boot time using hugepages= and not freed afterwards. + default_hugepagesz= + [same as hugepagesz=] The size of the default + HugeTLB page size. This is the size represented by + the legacy /proc/ hugepages APIs, used for SHM, and + default size when mounting hugetlbfs filesystems. + Defaults to the default architecture's huge page size + if not specified. i8042.direct [HW] Put keyboard port into non-translated mode i8042.dumbkbd [HW] Pretend that controller can only read data from diff -puN mm/hugetlb.c~hugetlb-override-default-huge-page-size mm/hugetlb.c --- a/mm/hugetlb.c~hugetlb-override-default-huge-page-size +++ a/mm/hugetlb.c @@ -34,6 +34,7 @@ struct hstate hstates[HUGE_MAX_HSTATE]; /* 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 = HPAGE_SIZE; #define for_each_hstate(h) \ for ((h) = hstates; (h) < &hstates[max_hstate]; (h)++) @@ -1209,11 +1210,14 @@ static int __init hugetlb_init(void) { 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; - } - default_hstate_idx = size_to_hstate(HPAGE_SIZE) - hstates; + 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(default_hstate_size) - hstates; + if (default_hstate_max_huge_pages) + default_hstate.max_huge_pages = default_hstate_max_huge_pages; hugetlb_init_hstates(); @@ -1253,7 +1257,7 @@ void __init hugetlb_add_hstate(unsigned 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; @@ -1288,7 +1292,14 @@ static int __init hugetlb_setup(char *s) 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) { _