From: David Hildenbrand <david@redhat.com>
To: Oscar Salvador <osalvador@suse.de>,
Mike Kravetz <mike.kravetz@oracle.com>
Cc: Muchun Song <songmuchun@bytedance.com>,
Michal Hocko <mhocko@kernel.org>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [RFC PATCH 1/2] mm,page_alloc: Make alloc_contig_range handle in-use hugetlb pages
Date: Wed, 10 Feb 2021 09:56:37 +0100 [thread overview]
Message-ID: <6aa21eb3-7bee-acff-8f3c-7c13737066ba@redhat.com> (raw)
In-Reply-To: <20210208103812.32056-2-osalvador@suse.de>
On 08.02.21 11:38, Oscar Salvador wrote:
> alloc_contig_range is not prepared to handle hugetlb pages and will
> fail if it ever sees one, but since they can be migrated as any other
> page (LRU and Movable), it makes sense to also handle them.
>
> For now, do it only when coming from alloc_contig_range.
>
> Signed-off-by: Oscar Salvador <osalvador@suse.de>
> ---
> mm/compaction.c | 17 +++++++++++++++++
> mm/vmscan.c | 5 +++--
> 2 files changed, 20 insertions(+), 2 deletions(-)
>
> diff --git a/mm/compaction.c b/mm/compaction.c
> index e5acb9714436..89cd2e60da29 100644
> --- a/mm/compaction.c
> +++ b/mm/compaction.c
> @@ -940,6 +940,22 @@ isolate_migratepages_block(struct compact_control *cc, unsigned long low_pfn,
> goto isolate_fail;
> }
>
> + /*
> + * Handle hugetlb pages only when coming from alloc_contig
> + */
> + if (PageHuge(page) && cc->alloc_contig) {
> + if (page_count(page)) {
I wonder if we should care about races here. What if someone
concurrently allocates/frees?
Note that PageHuge() succeeds on tail pages, isolate_huge_page() not, i
assume we'll have to handle that as well.
I wonder if it would make sense to move some of the magic to hugetlb
code and handle it there with less chances for races (isolate if used,
alloc-and-dissolve if not).
> + /*
> + * Hugetlb page in-use. Isolate and migrate.
> + */
> + if (isolate_huge_page(page, &cc->migratepages)) {
> + low_pfn += compound_nr(page) - 1;
> + goto isolate_success_no_list;
> + }
> + }
--
Thanks,
David / dhildenb
next prev parent reply other threads:[~2021-02-10 8:56 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-08 10:38 [RFC PATCH 0/2] Make alloc_contig_range handle Hugetlb pages Oscar Salvador
2021-02-08 10:38 ` [RFC PATCH 1/2] mm,page_alloc: Make alloc_contig_range handle in-use hugetlb pages Oscar Salvador
2021-02-10 8:56 ` David Hildenbrand [this message]
2021-02-10 14:09 ` Oscar Salvador
2021-02-10 14:11 ` David Hildenbrand
2021-02-10 14:14 ` Oscar Salvador
2021-02-10 14:22 ` David Hildenbrand
2021-02-11 0:56 ` Mike Kravetz
2021-02-11 10:40 ` David Hildenbrand
2021-02-08 10:38 ` [RFC PATCH 2/2] mm,page_alloc: Make alloc_contig_range handle free " Oscar Salvador
2021-02-10 8:23 ` David Hildenbrand
2021-02-10 14:24 ` Oscar Salvador
2021-02-10 14:36 ` David Hildenbrand
2021-02-25 21:43 ` Mike Kravetz
2021-02-25 22:15 ` David Hildenbrand
2021-02-11 1:16 ` Mike Kravetz
2021-02-11 21:38 ` Oscar Salvador
2021-02-08 10:39 ` [RFC PATCH 0/2] Make alloc_contig_range handle Hugetlb pages Oscar Salvador
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=6aa21eb3-7bee-acff-8f3c-7c13737066ba@redhat.com \
--to=david@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mhocko@kernel.org \
--cc=mike.kravetz@oracle.com \
--cc=osalvador@suse.de \
--cc=songmuchun@bytedance.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;
as well as URLs for NNTP newsgroup(s).