From: William Kucharski <william.kucharski@oracle.com>
To: Matthew Wilcox <willy@infradead.org>
Cc: lsf-pc@lists.linux-foundation.org, Linux-MM <linux-mm@kvack.org>,
linux-fsdevel@vger.kernel.org
Subject: Re: [LSF/MM TOPIC ][LSF/MM ATTEND] Read-only Mapping of Program Text using Large THP Pages
Date: Wed, 20 Feb 2019 07:07:29 -0700 [thread overview]
Message-ID: <07B3B085-C844-4A13-96B1-3DB0F1AF26F5@oracle.com> (raw)
In-Reply-To: <20190220134454.GF12668@bombadil.infradead.org>
> On Feb 20, 2019, at 6:44 AM, Matthew Wilcox <willy@infradead.org> wrote:
>
> That interface would need to have some hint from the VFS as to what
> range of file offsets it's looking for, and which page is the critical
> one. Maybe that's as simple as passing in pgoff and order, where pgoff is
> not necessarily aligned to 1<<order. Or maybe we want to explicitly
> pass in start, end, critical.
The order is especially important, as I think it's vital that the FS can
tell the difference between a caller wanting 2M in PAGESIZE pages
(something that could be satisfied by taking multiple trips through the
existing readahead) or needing to transfer ALL the content for a 2M page
as the fault can't be satisfied until the operation is complete. It also
won't be long before reading 1G at a time to map PUD-sized pages becomes
more important, plus the need to support various sizes in-between for
architectures like ARM that support them (see the non-standard size THP
discussion for more on that.)
I'm also hoping the conference would have enough "mixer" time that MM folks
can have a nice discussion with the FS folks to get their input - or at the
very least these mail threads will get that ball rolling.
next prev parent reply other threads:[~2019-02-20 14:09 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-20 11:17 [LSF/MM TOPIC ][LSF/MM ATTEND] Read-only Mapping of Program Text using Large THP Pages William Kucharski
2019-02-20 12:10 ` Michal Hocko
2019-02-20 13:18 ` William Kucharski
2019-02-20 13:27 ` Michal Hocko
2019-02-20 13:44 ` Matthew Wilcox
2019-02-20 14:07 ` William Kucharski [this message]
2019-02-20 14:43 ` Matthew Wilcox
2019-02-20 16:39 ` Keith Busch
2019-02-20 17:19 ` Matthew Wilcox
2019-04-08 11:36 ` William Kucharski
2019-04-28 20:08 ` Song Liu
2019-04-30 12:12 ` William Kucharski
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