From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933513AbbCRVlL (ORCPT ); Wed, 18 Mar 2015 17:41:11 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:38889 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933101AbbCRVlJ (ORCPT ); Wed, 18 Mar 2015 17:41:09 -0400 Date: Wed, 18 Mar 2015 14:41:08 -0700 From: Andrew Morton To: Mike Kravetz Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Davidlohr Bueso , Aneesh Kumar , Joonsoo Kim Subject: Re: [PATCH V2 4/4] hugetlbfs: document min_size mount option Message-Id: <20150318144108.e235862e0be30ff626e01820@linux-foundation.org> In-Reply-To: <3c82f2203e5453ddf3b29431863034afc7699303.1426549011.git.mike.kravetz@oracle.com> References: <3c82f2203e5453ddf3b29431863034afc7699303.1426549011.git.mike.kravetz@oracle.com> X-Mailer: Sylpheed 3.4.1 (GTK+ 2.24.23; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 16 Mar 2015 16:53:29 -0700 Mike Kravetz wrote: > Update documentation for the hugetlbfs min_size mount option. > > Signed-off-by: Mike Kravetz > --- > 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=,gid=,mode=,size=,nr_inodes= \ > - none /mnt/huge > + -o uid=,gid=,mode=,size=,min_size=, \ > + nr_inodes= 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.