From: "Kirill A. Shutemov" <kirill@shutemov.name>
Subject: Re: [PATCHv1, RFC 00/33] ext4: support of huge pages
Date: Tue, 26 Jul 2016 22:12:12 +0300
Message-ID: <20160726191212.GA11776@node.shutemov.name>
References: <1469493335-3622-1-git-send-email-kirill.shutemov@linux.intel.com>
 <20160726172938.GA9284@thunk.org>
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To: Theodore Ts'o <tytso@mit.edu>,
	"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
	Andreas Dilger <adilger.kernel@dilger.ca>, Jan Kara <jack@suse.com>,
	Alexander Viro <viro@zeniv.linux.org.uk>,
	Hugh Dickins <hughd@google.com>,
	Andrea Arcangeli <aarcange@redhat.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	Dave Hansen <dave.hansen@intel.com>,
	Vlastimil Babka <vbabka@suse.cz>,
	Matthew Wilcox <willy@infradead.org>,
	Ross Zwisler <ross.zwisler@linux.intel.com>,
	linux-ext4@vger.kernel.org, linux-fsdevel@vger.kernel.org,
	linux-kernel@vger.kernel.org, linux-mm@kvack.org,
	linux-block@vger.kernel.org
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On Tue, Jul 26, 2016 at 01:29:38PM -0400, Theodore Ts'o wrote:
> On Tue, Jul 26, 2016 at 03:35:02AM +0300, Kirill A. Shutemov wrote:
> > Here's the first version of my patchset which intended to bring huge pages
> > to ext4. It's not yet ready for applying or serious use, but good enough
> > to show the approach.
> 
> Thanks.  The major issues I noticed when doing a quick scan of the
> patches you've already mentioned here.  I'll try to take a closer look
> in the next week or so when I have time.

Thanks.

> One random question --- in the huge=always approach, how much
> additional work would be needed to support file systems with a 64k
> block size on a system with 4k pages?

I think it's totally different story.

Here I have block size smaller than page size and it's not new to the
filesystem -- similar to 1k block size with 4k page size. So I was able to
re-use most of infrastructure to handle the situation.

Block size bigger than page size is backward task. I don't think I know
enough to understand how hard it would be. I guess not easy. :)

-- 
 Kirill A. Shutemov

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