On 03/18/2015 02:41 PM, Andrew Morton wrote:
On Mon, 16 Mar 2015 16:53:29 -0700 Mike Kravetz <mike.kravetz@xxxxxxxxxx> wrote:Update documentation for the hugetlbfs min_size mount option. Signed-off-by: Mike Kravetz <mike.kravetz@xxxxxxxxxx> --- Documentation/vm/hugetlbpage.txt | 21 ++++++++++++++------- 1 file changed, 14 insertions(+), 7 deletions(-) diff --git a/Documentation/vm/hugetlbpage.txt b/Documentation/vm/hugetlbpage.txt index f2d3a10..83c0305 100644 --- a/Documentation/vm/hugetlbpage.txt +++ b/Documentation/vm/hugetlbpage.txt @@ -267,8 +267,8 @@ call, then it is required that system administrator mount a file system of type hugetlbfs: mount -t hugetlbfs \ - -o uid=<value>,gid=<value>,mode=<value>,size=<value>,nr_inodes=<value> \ - none /mnt/huge + -o uid=<value>,gid=<value>,mode=<value>,size=<value>,min_size=<value>, \ + nr_inodes=<value> none /mnt/huge This command mounts a (pseudo) filesystem of type hugetlbfs on the directory /mnt/huge. Any files created on /mnt/huge uses huge pages. The uid and gid @@ -277,11 +277,18 @@ the uid and gid of the current process are taken. The mode option sets the mode of root of file system to value & 01777. This value is given in octal. By default the value 0755 is picked. The size option sets the maximum value of memory (huge pages) allowed for that filesystem (/mnt/huge). The size is -rounded down to HPAGE_SIZE. The option nr_inodes sets the maximum number of -inodes that /mnt/huge can use. If the size or nr_inodes option is not -provided on command line then no limits are set. For size and nr_inodes -options, you can use [G|g]/[M|m]/[K|k] to represent giga/mega/kilo. For -example, size=2K has the same meaning as size=2048. +rounded down to HPAGE_SIZE. The min_size option sets the minimum value of +memory (huge pages) allowed for the filesystem. Like the size option, +min_size is rounded down to HPAGE_SIZE. At mount time, the number of huge +pages specified by min_size are reserved for use by the filesystem. If +there are not enough free huge pages available, the mount will fail. As +huge pages are allocated to the filesystem and freed, the reserve count +is adjusted so that the sum of allocated and reserved huge pages is always +at least min_size. The option nr_inodes sets the maximum number of +inodes that /mnt/huge can use. If the size, min_size or nr_inodes option +is not provided on command line then no limits are set. For size, min_size +and nr_inodes options, you can use [G|g]/[M|m]/[K|k] to represent +giga/mega/kilo. For example, size=2K has the same meaning as size=2048.Nowhere here is the reader told the units of "size". We should at least describe that, and maybe even rename the thing to min_bytes.
Ok, I will add that the size is in unit of bytes. My choice of 'min_size' as a name for the new mount option was influenced by the existing 'size' mount option. I'm open to any suggestions for the name of this new mount option. -- Mike Kravetz -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>