From: Michal Hocko <mhocko@suse.com>
To: David Hildenbrand <david@redhat.com>
Cc: Barry Song <21cnbao@gmail.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
Yafang Shao <laoar.shao@gmail.com>,
akpm@linux-foundation.org, linux-mm@kvack.org,
42.hyeyoo@gmail.com, cl@linux.com, hailong.liu@oppo.com,
hch@infradead.org, iamjoonsoo.kim@lge.com, penberg@kernel.org,
rientjes@google.com, roman.gushchin@linux.dev, urezki@gmail.com,
v-songbaohua@oppo.com, vbabka@suse.cz,
virtualization@lists.linux.dev
Subject: Re: [PATCH v3 0/4] mm: clarify nofail memory allocation
Date: Thu, 22 Aug 2024 11:11:17 +0200 [thread overview]
Message-ID: <ZscAtVskxgONe3gT@tiehlicka> (raw)
In-Reply-To: <bc952d89-1219-41e9-9a8b-cfe2a758d585@redhat.com>
On Thu 22-08-24 10:39:09, David Hildenbrand wrote:
[...]
> But then the question is: does it really make sense to differentiate
> difference between an NOFAIL allocation under memory pressure of MAX_ORDER
> compared to MAX_ORDER+1 (Linus also touched on that)? It could well take
> minutes/hours/days to satisfy a very large NOFAIL allocation. So callers
> should be prepared to run into effective lockups ... :/
As pointed out in other subthread. We shouldn't really pretend we
support NOFAIL for order > 0, or at least anything > A_SMALL_ORDER and
encourage kvmalloc for those users.
A nofail order 2 allocation can kill most of the userspace on terribly
fragmented system that is kernel allocation heavy.
> NOFAIL shouldn't exist, or at least not used to that degree.
Let's put whishful thinking aside. Unless somebody manages to go over
all existing NOFAIL users and fix them then we should better focus on
providing a reasonable clearly documented and enforced semantic.
--
Michal Hocko
SUSE Labs
next prev parent reply other threads:[~2024-08-22 9:11 UTC|newest]
Thread overview: 101+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-08-17 6:24 [PATCH v3 0/4] mm: clarify nofail memory allocation Barry Song
2024-08-17 6:24 ` [PATCH v3 1/4] vduse: avoid using __GFP_NOFAIL Barry Song
2024-08-17 6:24 ` [PATCH v3 2/4] mm: document __GFP_NOFAIL must be blockable Barry Song
2024-08-17 6:24 ` [PATCH v3 3/4] mm: BUG_ON to avoid NULL deference while __GFP_NOFAIL fails Barry Song
2024-08-19 9:43 ` David Hildenbrand
2024-08-19 9:47 ` Barry Song
2024-08-19 9:55 ` David Hildenbrand
2024-08-19 10:02 ` Barry Song
2024-08-19 12:33 ` David Hildenbrand
2024-08-19 12:48 ` Barry Song
2024-08-19 12:49 ` David Hildenbrand
2024-08-19 17:12 ` Michal Hocko
2024-08-19 17:17 ` Linus Torvalds
2024-08-19 20:24 ` David Hildenbrand
2024-08-19 20:35 ` Linus Torvalds
2024-08-19 21:57 ` David Hildenbrand
2024-08-19 22:13 ` Linus Torvalds
2024-08-20 6:17 ` Michal Hocko
2024-08-19 12:49 ` Christoph Hellwig
2024-08-19 12:51 ` David Hildenbrand
2024-08-19 12:53 ` Christoph Hellwig
2024-08-19 13:14 ` David Hildenbrand
2024-08-19 13:05 ` Barry Song
2024-08-19 13:10 ` David Hildenbrand
2024-08-19 13:19 ` Barry Song
2024-08-19 13:22 ` David Hildenbrand
2024-08-17 6:24 ` [PATCH v3 4/4] mm: prohibit NULL deference exposed for unsupported non-blockable __GFP_NOFAIL Barry Song
2024-08-18 2:55 ` Yafang Shao
2024-08-18 3:48 ` Barry Song
2024-08-18 5:51 ` Yafang Shao
2024-08-18 6:27 ` Barry Song
2024-08-18 6:45 ` Barry Song
2024-08-18 7:07 ` Yafang Shao
2024-08-18 7:25 ` Barry Song
2024-08-19 7:51 ` Michal Hocko
2024-08-19 7:50 ` Michal Hocko
2024-08-19 9:25 ` Yafang Shao
2024-08-19 9:39 ` Barry Song
2024-08-19 9:45 ` Yafang Shao
2024-08-19 10:10 ` Barry Song
2024-08-19 11:56 ` Yafang Shao
2024-08-19 12:09 ` Michal Hocko
2024-08-19 12:17 ` Yafang Shao
2024-08-19 14:01 ` Michal Hocko
2024-08-19 10:17 ` Michal Hocko
2024-08-19 11:56 ` Yafang Shao
2024-08-19 12:04 ` Michal Hocko
2024-08-19 9:44 ` David Hildenbrand
2024-08-19 10:19 ` Michal Hocko
2024-08-19 12:48 ` David Hildenbrand
2024-08-19 13:02 ` [PATCH v3 0/4] mm: clarify nofail memory allocation David Hildenbrand
2024-08-19 16:05 ` Linus Torvalds
2024-08-19 19:23 ` Barry Song
2024-08-19 19:33 ` Linus Torvalds
2024-08-19 21:48 ` Barry Song
2024-08-20 6:24 ` Michal Hocko
2024-08-21 12:40 ` Yafang Shao
2024-08-21 22:59 ` Linus Torvalds
2024-08-22 6:21 ` Michal Hocko
2024-08-22 6:40 ` Linus Torvalds
2024-08-22 6:56 ` Linus Torvalds
2024-08-22 7:47 ` Michal Hocko
2024-08-22 7:57 ` Barry Song
2024-08-22 8:24 ` Michal Hocko
2024-08-22 8:39 ` David Hildenbrand
2024-08-22 9:08 ` Linus Torvalds
2024-08-22 9:16 ` Michal Hocko
2024-08-22 9:24 ` Linus Torvalds
2024-08-22 9:11 ` Michal Hocko [this message]
2024-08-22 9:18 ` Linus Torvalds
2024-08-22 9:33 ` Michal Hocko
2024-08-22 9:44 ` Linus Torvalds
2024-08-22 9:59 ` Michal Hocko
2024-08-22 10:30 ` Linus Torvalds
2024-08-22 10:46 ` Michal Hocko
2024-08-22 9:27 ` David Hildenbrand
2024-08-22 9:34 ` Linus Torvalds
2024-08-22 9:43 ` David Hildenbrand
2024-08-22 9:53 ` Linus Torvalds
2024-08-22 11:58 ` Johannes Weiner
2024-08-26 12:10 ` Vlastimil Babka
2024-08-27 6:57 ` Linus Torvalds
2024-08-27 7:15 ` Barry Song
2024-08-27 7:38 ` Vlastimil Babka
2024-08-27 7:50 ` Barry Song
2024-08-29 10:24 ` Vlastimil Babka
2024-08-29 11:53 ` Barry Song
2024-08-29 13:20 ` Michal Hocko
2024-08-29 21:27 ` Barry Song
2024-08-29 22:31 ` Barry Song
2024-08-30 7:24 ` Michal Hocko
2024-08-30 7:37 ` Vlastimil Babka
2024-08-22 9:41 ` Michal Hocko
2024-08-22 9:42 ` David Hildenbrand
2024-08-22 7:01 ` Gao Xiang
2024-08-22 7:54 ` Michal Hocko
2024-08-22 8:04 ` Gao Xiang
2024-08-22 14:35 ` Yafang Shao
2024-08-22 15:02 ` Gao Xiang
2024-08-22 6:37 ` Barry Song
2024-08-22 14:22 ` Yafang Shao
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=ZscAtVskxgONe3gT@tiehlicka \
--to=mhocko@suse.com \
--cc=21cnbao@gmail.com \
--cc=42.hyeyoo@gmail.com \
--cc=akpm@linux-foundation.org \
--cc=cl@linux.com \
--cc=david@redhat.com \
--cc=hailong.liu@oppo.com \
--cc=hch@infradead.org \
--cc=iamjoonsoo.kim@lge.com \
--cc=laoar.shao@gmail.com \
--cc=linux-mm@kvack.org \
--cc=penberg@kernel.org \
--cc=rientjes@google.com \
--cc=roman.gushchin@linux.dev \
--cc=torvalds@linux-foundation.org \
--cc=urezki@gmail.com \
--cc=v-songbaohua@oppo.com \
--cc=vbabka@suse.cz \
--cc=virtualization@lists.linux.dev \
/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).