From: Dan Williams <dan.j.williams@intel.com>
To: Jan Kara <jack@suse.cz>
Cc: Dave Jiang <dave.jiang@intel.com>,
Andrew Morton <akpm@linux-foundation.org>,
Dave Hansen <dave.hansen@linux.intel.com>,
Matthew Wilcox <mawilcox@microsoft.com>,
"linux-nvdimm@lists.01.org" <linux-nvdimm@lists.01.org>,
Linux MM <linux-mm@kvack.org>, Vlastimil Babka <vbabka@suse.cz>,
Jan Kara <jack@suse.com>,
Ross Zwisler <ross.zwisler@linux.intel.com>,
"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Subject: Re: [PATCH 0/3] 1G transparent hugepage support for device dax
Date: Tue, 24 Jan 2017 10:26:54 -0800 [thread overview]
Message-ID: <CAPcyv4gW7cho=eE4BQZQ69J7ehREurP6CPbQX3z6eW7BUVT3Bw@mail.gmail.com> (raw)
In-Reply-To: <20170124111248.GC20153@quack2.suse.cz>
On Tue, Jan 24, 2017 at 3:12 AM, Jan Kara <jack@suse.cz> wrote:
> On Mon 23-01-17 16:47:18, Dave Jiang wrote:
>> The following series implements support for 1G trasparent hugepage on
>> x86 for device dax. The bulk of the code was written by Mathew Wilcox
>> a while back supporting transparent 1G hugepage for fs DAX. I have
>> forward ported the relevant bits to 4.10-rc. The current submission has
>> only the necessary code to support device DAX.
>
> Well, you should really explain why do we want this functionality... Is
> anybody going to use it? Why would he want to and what will he gain by
> doing so? Because so far I haven't heard of a convincing usecase.
>
So the motivation and intended user of this functionality mirrors the
motivation and users of 1GB page support in hugetlbfs. Given expected
capacities of persistent memory devices an in-memory database may want
to reduce tlb pressure beyond what they can already achieve with 2MB
mappings of a device-dax file. We have customer feedback to that
effect as Willy mentioned in his previous version of these patches
[1].
[1]: https://lkml.org/lkml/2016/1/31/52
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next prev parent reply other threads:[~2017-01-24 18:26 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-01-23 23:47 Dave Jiang
2017-01-23 23:47 ` [PATCH 1/3] mm,fs,dax: Change ->pmd_fault to ->huge_fault Dave Jiang
2017-01-23 23:47 ` [PATCH 2/3] mm, x86: Add support for PUD-sized transparent hugepages Dave Jiang
2017-01-23 23:47 ` [PATCH 3/3] dax: Support for transparent PUD pages for device DAX Dave Jiang
2017-01-24 11:12 ` [PATCH 0/3] 1G transparent hugepage support for device dax Jan Kara
2017-01-24 18:26 ` Dan Williams [this message]
2017-01-24 21:24 ` Konrad Rzeszutek Wilk
2017-01-24 21:35 ` Nilesh Choudhury
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to='CAPcyv4gW7cho=eE4BQZQ69J7ehREurP6CPbQX3z6eW7BUVT3Bw@mail.gmail.com' \
--to=dan.j.williams@intel.com \
--cc=akpm@linux-foundation.org \
--cc=dave.hansen@linux.intel.com \
--cc=dave.jiang@intel.com \
--cc=jack@suse.com \
--cc=jack@suse.cz \
--cc=kirill.shutemov@linux.intel.com \
--cc=linux-mm@kvack.org \
--cc=linux-nvdimm@lists.01.org \
--cc=mawilcox@microsoft.com \
--cc=ross.zwisler@linux.intel.com \
--cc=vbabka@suse.cz \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox