From: Nick Piggin Date: Thu, 24 Jul 2008 04:27:52 +0000 (-0700) Subject: hugetlb: override default huge page size X-Git-Tag: v2.6.27-rc1~784 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e11bfbfcb08ef4223b863799897c19cdf7c5bc00;p=linux-2.6 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 Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index d55fd88fd0..30278e9e52 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -783,6 +783,13 @@ and is between 256 and 4096 characters. It is defined in the file 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 --git a/mm/hugetlb.c b/mm/hugetlb.c index 107c1ce223..2a2f6e8694 100644 --- a/mm/hugetlb.c +++ b/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; #define for_each_hstate(h) \ for ((h) = hstates; (h) < &hstates[max_hstate]; (h)++) @@ -1288,11 +1289,14 @@ 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; + 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 @@ void __init hugetlb_add_hstate(unsigned order) 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 @@ 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) {