From: David Hildenbrand <david@redhat.com>
To: Michal Hocko <mhocko@suse.com>, Evan Green <evgreen@chromium.org>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Pavel Machek <pavel@ucw.cz>, Alex Shi <alexs@kernel.org>,
Alistair Popple <apopple@nvidia.com>,
Jens Axboe <axboe@kernel.dk>,
Johannes Weiner <hannes@cmpxchg.org>,
Joonsoo Kim <iamjoonsoo.kim@lge.com>,
"Matthew Wilcox (Oracle)" <willy@infradead.org>,
Miaohe Lin <linmiaohe@huawei.com>,
Minchan Kim <minchan@kernel.org>,
Vlastimil Babka <vbabka@suse.cz>,
linux-kernel@vger.kernel.org, linux-mm@kvack.org,
linux-api@vger.kernel.org
Subject: Re: [PATCH v2] mm: Enable suspend-only swap spaces
Date: Mon, 12 Jul 2021 09:41:26 +0200 [thread overview]
Message-ID: <30dddfb1-388c-a593-0987-73e821216da9@redhat.com> (raw)
In-Reply-To: <YOvpVRSMJe8NQuS2@dhcp22.suse.cz>
On 12.07.21 09:03, Michal Hocko wrote:
> [Cc linux-api]
>
> On Fri 09-07-21 10:50:48, Evan Green wrote:
>> Currently it's not possible to enable hibernation without also enabling
>> generic swap for a given swap area. These two use cases are not the
>> same. For example there may be users who want to enable hibernation,
>> but whose drives don't have the write endurance for generic swap
>> activities.
>>
>> Add a new SWAP_FLAG_NOSWAP that adds a swap region but refuses to allow
>> generic swapping to it. This region can still be wired up for use in
>> suspend-to-disk activities, but will never have regular pages swapped to
>> it.
>
> Could you expand some more on why a strict exclusion is really
> necessary? I do understand that one might not want to have swap storage
> available all the time but considering that swapon is really a light
> operation so something like the following should be a reasonable
> workaround, no?
> swapon storage/file
> s2disk
> swapoff storage
I'm certainly not a hibernation expert, but I'd guess this can also be
triggered by HW events, so from the kernel and not only from user space
where your workaround would apply.
--
Thanks,
David / dhildenb
next prev parent reply other threads:[~2021-07-12 7:43 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20210709105012.v2.1.I09866d90c6de14f21223a03e9e6a31f8a02ecbaf@changeid>
2021-07-12 7:03 ` [PATCH v2] mm: Enable suspend-only swap spaces Michal Hocko
2021-07-12 7:41 ` David Hildenbrand [this message]
2021-07-14 5:43 ` Michal Hocko
2021-07-14 7:51 ` David Hildenbrand
2021-07-14 8:00 ` Michal Hocko
2021-07-27 12:04 ` Pavel Machek
2021-07-27 12:19 ` David Hildenbrand
2021-07-27 12:01 ` Pavel Machek
2021-07-12 21:32 ` Evan Green
2021-07-14 5:41 ` Michal Hocko
2021-07-14 22:39 ` Evan Green
2021-07-27 12:10 ` Pavel Machek
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=30dddfb1-388c-a593-0987-73e821216da9@redhat.com \
--to=david@redhat.com \
--cc=akpm@linux-foundation.org \
--cc=alexs@kernel.org \
--cc=apopple@nvidia.com \
--cc=axboe@kernel.dk \
--cc=evgreen@chromium.org \
--cc=hannes@cmpxchg.org \
--cc=iamjoonsoo.kim@lge.com \
--cc=linmiaohe@huawei.com \
--cc=linux-api@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mhocko@suse.com \
--cc=minchan@kernel.org \
--cc=pavel@ucw.cz \
--cc=vbabka@suse.cz \
--cc=willy@infradead.org \
/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).