From: Christoph Hellwig <hch-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org>
To: Dan Williams <dan.j.williams-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Cc: "linux-nvdimm-hn68Rpc1hR1g9hUCZPvPmw@public.gmane.org"
<linux-nvdimm-y27Ovi1pjclAfugRpC6u6w@public.gmane.org>,
Linux Kernel Mailing List
<linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
linux-f2fs-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org,
Christoph Hellwig <hch-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org>,
linux-fsdevel
<linux-fsdevel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
Jaegeuk Kim <jaegeuk-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>,
sunqiuyang <sunqiuyang-hv44wF8Li93QT0dZR+AlfA@public.gmane.org>
Subject: Re: [PATCH v8 1/1] f2fs: dax: implement direct access
Date: Wed, 26 Jul 2017 13:11:36 -0700 [thread overview]
Message-ID: <20170726201136.GA30039@infradead.org> (raw)
In-Reply-To: <CAPcyv4hdk8XyYJ5pYvAgUZRoE-SzACNprQm1xaM1KUqBONC8Qw-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
On Wed, Jul 26, 2017 at 12:16:11PM -0700, Dan Williams wrote:
> Silently turn on DAX if HMAT says its ok?
Yes, absolutely. I want my system to do the right thing by default,
and if HMAT says bypassing the page cache is a clear advatange it
should be the default.
> I think we would instead
> want a "-o autodax" for that case and then "-o dax" and "-o nodax" for
> the force cases.
Why?
> I think it's easier to administer than the dax mount option. If
> someone wants dax on only in a sub-tree they can set the flag on that
> parent directory and have a policy in dax filesystems that children
> inherit the dax policy from the parent. That seems a better
> administrative model than trying to get it all right globally at mount
> time.
And why exactly? If DAX is faster for file a in directory X it will
be just as fast for a file b in directory Y.
next prev parent reply other threads:[~2017-07-26 20:11 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-07-20 12:10 [PATCH v8 1/1] f2fs: dax: implement direct access sunqiuyang
2017-07-22 0:34 ` Jaegeuk Kim
2017-07-24 12:03 ` Sun Qiuyang
[not found] ` <1500552639-18523-1-git-send-email-sunqiuyang-hv44wF8Li93QT0dZR+AlfA@public.gmane.org>
2017-07-26 0:15 ` Dan Williams
2017-07-26 2:16 ` Jaegeuk Kim
2017-07-26 6:47 ` sunqiuyang
[not found] ` <CAA9_cmeyVXgu1-ozb7b346ANq+P3e3ATWYfoVGkAKrn5cmo=Hw-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2017-07-26 7:26 ` Christoph Hellwig
2017-07-26 16:53 ` Dan Williams
2017-07-26 17:01 ` Christoph Hellwig
[not found] ` <20170726170147.GA31930-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org>
2017-07-26 17:11 ` Dan Williams
[not found] ` <CAPcyv4iNP0qxL5vToffBivkQWyUquD7HrgNmvYXQW9ejhFrAmA-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2017-07-26 17:20 ` Christoph Hellwig
2017-07-26 19:16 ` Dan Williams
[not found] ` <CAPcyv4hdk8XyYJ5pYvAgUZRoE-SzACNprQm1xaM1KUqBONC8Qw-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2017-07-26 20:11 ` Christoph Hellwig [this message]
2017-07-26 20:29 ` Dan Williams
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