Update documentation for the hugetlbfs reserved mount option. Signed-off-by: Mike Kravetz <mike.kravetz@xxxxxxxxxx> --- Documentation/vm/hugetlbpage.txt | 18 +++++++++++------- 1 file changed, 11 insertions(+), 7 deletions(-) diff --git a/Documentation/vm/hugetlbpage.txt b/Documentation/vm/hugetlbpage.txt index f2d3a10..1d88bfb 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>,reserved,\ + 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 +277,15 @@ 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. If the size option is specified, the reserved +option may also be specified to reserve the number of huge pages required for +the maximum filesystem size. This number of huge pages is reserved at mount +time and will be available for exclusive use by the filesystem. If not enough +huge pages are available, the mount will fail. 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. While read system calls are supported on files that reside on hugetlb file systems, write system calls are not. -- 2.1.0 -- 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>