LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
From: Hugh Dickins <hughd@google.com>
To: Yang Shi <shy828301@gmail.com>
Cc: Hugh Dickins <hughd@google.com>,
	Matthew Wilcox <willy@infradead.org>,
	"Huang, Ying" <ying.huang@intel.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	David Hildenbrand <david@redhat.com>,
	Linux MM <linux-mm@kvack.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Miaohe Lin <linmiaohe@huawei.com>,
	Johannes Weiner <hannes@cmpxchg.org>,
	Michal Hocko <mhocko@suse.com>,
	Joonsoo Kim <iamjoonsoo.kim@lge.com>,
	Minchan Kim <minchan@kernel.org>
Subject: Re: [PATCH] mm,shmem: Fix a typo in shmem_swapin_page()
Date: Thu, 5 Aug 2021 23:01:27 -0700 (PDT)	[thread overview]
Message-ID: <d1c768c-8b6-6a9d-ddde-39ac51286927@google.com> (raw)
In-Reply-To: <CAHbLzkrShKORwU-Zrf5_5c6_o_iVwoXRTT+7ABZALLj7p0w-Ug@mail.gmail.com>

On Thu, 5 Aug 2021, Yang Shi wrote:
> On Tue, Aug 3, 2021 at 10:34 PM Hugh Dickins <hughd@google.com> wrote:
> >
> > I've never seen the swapoff race claimed by Miaohe, and don't expect to;
> > but he's probably right, given the current code.  I just dislike adding
> > unnecessary complexity, and siting it in the wrong place (mm/shmem.c).
> >
> > Yang, is it possible that 5.1 commit 8fd2e0b505d1 ("mm: swap: check if
> > swap backing device is congested or not") was actually developed and
> > measured on 4.1 or earlier, which still had blk_set_queue_congested()?
> 
> I forgot the exact version, but definitely not 4.1 or earlier. Maybe
> 4.19 or earlier. I'm not familiar with how block layer detect
> congestion, if the logic was changed, hence the optimization doesn't
> stand anymore nowadays, I'm totally fine to remove it.

You drove me back to look more closely.  blk_set_queue_congested()
vanished from include/linux/blkdev.h in 4.2, but blk_set_congested()
appeared then in block/blk-core.c to replace it.  blk_set_congested()
vanished (along with all references to "congested" in blk-core.c) in
5.0, then your commit (most probably tested on 4.19) went into 5.1 -
just after it had become redundant!

Thanks, yes, let's revert that and Miaohe's and Huang's, later on.

Hugh

  reply	other threads:[~2021-08-06  6:20 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-07-23  8:00 Huang Ying
2021-07-23 11:10 ` David Hildenbrand
2021-07-23 20:23 ` Hugh Dickins
2021-07-23 21:53   ` Matthew Wilcox
2021-08-03  8:14     ` Huang, Ying
2021-08-03 12:01       ` Matthew Wilcox
2021-08-04  5:34         ` Hugh Dickins
2021-08-04  9:04           ` Huang, Ying
2021-08-05 23:08           ` Yang Shi
2021-08-06  6:01             ` Hugh Dickins [this message]
2021-08-06 20:37               ` Yang Shi
2021-08-09 21:26                 ` Yang Shi
2021-08-09 23:43                   ` Huang, Ying
2021-08-10  1:11                     ` Yang Shi
2021-08-04  9:01         ` Huang, Ying
2021-07-28 13:03   ` huang ying
2021-08-03  8:06     ` Huang, Ying
2021-08-03 11:59       ` Matthew Wilcox
2021-08-04  4:28       ` Hugh Dickins
2021-08-04  6:42     ` Hugh Dickins
2021-08-04  8:59       ` Huang, Ying

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=d1c768c-8b6-6a9d-ddde-39ac51286927@google.com \
    --to=hughd@google.com \
    --cc=akpm@linux-foundation.org \
    --cc=david@redhat.com \
    --cc=hannes@cmpxchg.org \
    --cc=iamjoonsoo.kim@lge.com \
    --cc=linmiaohe@huawei.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=mhocko@suse.com \
    --cc=minchan@kernel.org \
    --cc=shy828301@gmail.com \
    --cc=willy@infradead.org \
    --cc=ying.huang@intel.com \
    --subject='Re: [PATCH] mm,shmem: Fix a typo in shmem_swapin_page()' \
    /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

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).