From: Roman Gushchin <guro@fb.com>
To: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>, Zi Yan <ziy@nvidia.com>,
<linux-mm@kvack.org>, Rik van Riel <riel@surriel.com>,
Kirill A.Shutemov <kirill.shutemov@linux.intel.com>,
Matthew Wilcox <willy@infradead.org>,
Shakeel Butt <shakeelb@google.com>,
Yang Shi <yang.shi@linux.alibaba.com>,
David Nellans <dnellans@nvidia.com>,
<linux-kernel@vger.kernel.org>
Subject: Re: [RFC PATCH 00/16] 1GB THP support on x86_64
Date: Thu, 3 Sep 2020 14:06:01 -0700 [thread overview]
Message-ID: <20200903210601.GI60440@carbon.dhcp.thefacebook.com> (raw)
In-Reply-To: <d64a67fd-17e0-644d-7b2b-2a557f0e35f7@oracle.com>
On Thu, Sep 03, 2020 at 01:57:54PM -0700, Mike Kravetz wrote:
> On 9/3/20 9:25 AM, Roman Gushchin wrote:
> > On Thu, Sep 03, 2020 at 09:32:54AM +0200, Michal Hocko wrote:
> >> On Wed 02-09-20 14:06:12, Zi Yan wrote:
> >>> From: Zi Yan <ziy@nvidia.com>
> >>>
> >>> Hi all,
> >>>
> >>> This patchset adds support for 1GB THP on x86_64. It is on top of
> >>> v5.9-rc2-mmots-2020-08-25-21-13.
> >>>
> >>> 1GB THP is more flexible for reducing translation overhead and increasing the
> >>> performance of applications with large memory footprint without application
> >>> changes compared to hugetlb.
> >>
> >> Please be more specific about usecases. This better have some strong
> >> ones because THP code is complex enough already to add on top solely
> >> based on a generic TLB pressure easing.
> >
> > Hello, Michal!
> >
> > We at Facebook are using 1 GB hugetlbfs pages and are getting noticeable
> > performance wins on some workloads.
> >
> > Historically we allocated gigantic pages at the boot time, but recently moved
> > to cma-based dynamic approach. Still, hugetlbfs interface requires more management
> > than we would like to do. 1 GB THP seems to be a better alternative. So I definitely
> > see it as a very useful feature.
> >
> > Given the cost of an allocation, I'm slightly skeptical about an automatic
> > heuristics-based approach, but if an application can explicitly mark target areas
> > with madvise(), I don't see why it wouldn't work.
> >
> > In our case we'd like to have a reliable way to get 1 GB THPs at some point
> > (usually at the start of an application), and transparently destroy them on
> > the application exit.
>
> Hi Roman,
>
> In your current use case at Facebook, are you adding 1G hugetlb pages to
> the hugetlb pool and then using them within applications? Or, are you
> dynamically allocating them at fault time (hugetlb overcommit/surplus)?
>
> Latency time for use of such pages includes:
> - Putting together 1G contiguous
> - Clearing 1G memory
>
> In the 'allocation at fault time' mode you incur both costs at fault time.
> If using pages from the pool, your only cost at fault time is clearing the
> page.
Hi Mike,
We're using a pool. Under dynamic I mean that gigantic pages are not
allocated at a boot time.
Thanks!
next prev parent reply other threads:[~2020-09-03 21:06 UTC|newest]
Thread overview: 82+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-02 18:06 Zi Yan
2020-09-02 18:06 ` [RFC PATCH 01/16] mm: add pagechain container for storing multiple pages Zi Yan
2020-09-02 20:29 ` Randy Dunlap
2020-09-02 20:48 ` Zi Yan
2020-09-03 3:15 ` Matthew Wilcox
2020-09-07 12:22 ` Kirill A. Shutemov
2020-09-07 15:11 ` Zi Yan
2020-09-09 13:46 ` Kirill A. Shutemov
2020-09-09 14:15 ` Zi Yan
2020-09-02 18:06 ` [RFC PATCH 02/16] mm: thp: 1GB anonymous page implementation Zi Yan
2020-09-02 18:06 ` [RFC PATCH 03/16] mm: proc: add 1GB THP kpageflag Zi Yan
2020-09-09 13:46 ` Kirill A. Shutemov
2020-09-02 18:06 ` [RFC PATCH 04/16] mm: thp: 1GB THP copy on write implementation Zi Yan
2020-09-02 18:06 ` [RFC PATCH 05/16] mm: thp: handling 1GB THP reference bit Zi Yan
2020-09-09 14:09 ` Kirill A. Shutemov
2020-09-09 14:36 ` Zi Yan
2020-09-02 18:06 ` [RFC PATCH 06/16] mm: thp: add 1GB THP split_huge_pud_page() function Zi Yan
2020-09-09 14:18 ` Kirill A. Shutemov
2020-09-09 14:19 ` Zi Yan
2020-09-02 18:06 ` [RFC PATCH 07/16] mm: stats: make smap stats understand PUD THPs Zi Yan
2020-09-02 18:06 ` [RFC PATCH 08/16] mm: page_vma_walk: teach it about PMD-mapped PUD THP Zi Yan
2020-09-02 18:06 ` [RFC PATCH 09/16] mm: thp: 1GB THP support in try_to_unmap() Zi Yan
2020-09-02 18:06 ` [RFC PATCH 10/16] mm: thp: split 1GB THPs at page reclaim Zi Yan
2020-09-02 18:06 ` [RFC PATCH 11/16] mm: thp: 1GB THP follow_p*d_page() support Zi Yan
2020-09-02 18:06 ` [RFC PATCH 12/16] mm: support 1GB THP pagemap support Zi Yan
2020-09-02 18:06 ` [RFC PATCH 13/16] mm: thp: add a knob to enable/disable 1GB THPs Zi Yan
2020-09-02 18:06 ` [RFC PATCH 14/16] mm: page_alloc: >=MAX_ORDER pages allocation an deallocation Zi Yan
2020-09-02 18:06 ` [RFC PATCH 15/16] hugetlb: cma: move cma reserve function to cma.c Zi Yan
2020-09-02 18:06 ` [RFC PATCH 16/16] mm: thp: use cma reservation for pud thp allocation Zi Yan
2020-09-02 18:40 ` [RFC PATCH 00/16] 1GB THP support on x86_64 Jason Gunthorpe
2020-09-02 18:45 ` Zi Yan
2020-09-02 18:48 ` Jason Gunthorpe
2020-09-02 19:05 ` Zi Yan
2020-09-02 19:57 ` Jason Gunthorpe
2020-09-02 20:29 ` Zi Yan
2020-09-03 16:40 ` Jason Gunthorpe
2020-09-03 16:55 ` Matthew Wilcox
2020-09-03 17:08 ` Jason Gunthorpe
2020-09-03 7:32 ` Michal Hocko
2020-09-03 16:25 ` Roman Gushchin
2020-09-03 16:50 ` Jason Gunthorpe
2020-09-03 17:01 ` Matthew Wilcox
2020-09-03 17:18 ` Jason Gunthorpe
2020-09-03 20:57 ` Mike Kravetz
2020-09-03 21:06 ` Roman Gushchin [this message]
2020-09-04 7:42 ` Michal Hocko
2020-09-04 21:10 ` Roman Gushchin
2020-09-07 7:20 ` Michal Hocko
2020-09-08 15:09 ` Zi Yan
2020-09-08 19:58 ` Roman Gushchin
2020-09-09 4:01 ` John Hubbard
2020-09-09 7:15 ` Michal Hocko
2020-09-03 14:23 ` Kirill A. Shutemov
2020-09-03 16:30 ` Roman Gushchin
2020-09-08 11:57 ` David Hildenbrand
2020-09-08 14:05 ` Zi Yan
2020-09-08 14:22 ` David Hildenbrand
2020-09-08 15:36 ` Zi Yan
2020-09-08 14:27 ` Matthew Wilcox
2020-09-08 15:50 ` Zi Yan
2020-09-09 12:11 ` Jason Gunthorpe
2020-09-09 12:32 ` Matthew Wilcox
2020-09-09 13:14 ` Jason Gunthorpe
2020-09-09 13:27 ` David Hildenbrand
2020-09-10 10:02 ` William Kucharski
2020-09-08 14:35 ` Michal Hocko
2020-09-08 14:41 ` Rik van Riel
2020-09-08 15:02 ` David Hildenbrand
2020-09-09 7:04 ` Michal Hocko
2020-09-09 13:19 ` Rik van Riel
2020-09-09 13:43 ` David Hildenbrand
2020-09-09 13:49 ` Rik van Riel
2020-09-09 13:54 ` David Hildenbrand
2020-09-10 7:32 ` Michal Hocko
2020-09-10 8:27 ` David Hildenbrand
2020-09-10 14:21 ` Zi Yan
2020-09-10 14:34 ` David Hildenbrand
2020-09-10 14:41 ` Zi Yan
2020-09-10 15:15 ` David Hildenbrand
2020-09-10 13:32 ` Rik van Riel
2020-09-10 14:30 ` Zi Yan
2020-09-09 13:59 ` Michal Hocko
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=20200903210601.GI60440@carbon.dhcp.thefacebook.com \
--to=guro@fb.com \
--cc=dnellans@nvidia.com \
--cc=kirill.shutemov@linux.intel.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mhocko@suse.com \
--cc=mike.kravetz@oracle.com \
--cc=riel@surriel.com \
--cc=shakeelb@google.com \
--cc=willy@infradead.org \
--cc=yang.shi@linux.alibaba.com \
--cc=ziy@nvidia.com \
/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