linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Chris Down <chris@chrisdown.name>
To: Shakeel Butt <shakeelb@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
	Johannes Weiner <hannes@cmpxchg.org>, Tejun Heo <tj@kernel.org>,
	Michal Hocko <mhocko@kernel.org>, Linux MM <linux-mm@kvack.org>,
	Cgroups <cgroups@vger.kernel.org>,
	LKML <linux-kernel@vger.kernel.org>,
	Kernel Team <kernel-team@fb.com>
Subject: Re: [PATCH] mm, memcg: reclaim more aggressively before high allocator throttling
Date: Thu, 28 May 2020 20:48:31 +0100	[thread overview]
Message-ID: <20200528194831.GA2017@chrisdown.name> (raw)
In-Reply-To: <CALvZod7rSeAKXKq_V0SggZWn4aL8pYWJiej4NdRd8MmuwUzPEw@mail.gmail.com>

Shakeel Butt writes:
>What was the initial reason to have different behavior in the first place?

This differing behaviour is simply a mistake, it was never intended to be this 
deviate from what happens elsewhere. To that extent this patch is as much a bug 
fix as it is an improvement.

>>  static void high_work_func(struct work_struct *work)
>> @@ -2378,16 +2384,20 @@ void mem_cgroup_handle_over_high(void)
>>  {
>>         unsigned long penalty_jiffies;
>>         unsigned long pflags;
>> +       unsigned long nr_reclaimed;
>>         unsigned int nr_pages = current->memcg_nr_pages_over_high;
>
>Is there any benefit to keep current->memcg_nr_pages_over_high after
>this change? Why not just use SWAP_CLUSTER_MAX?

I don't feel strongly either way, but current->memcg_nr_pages_over_high can be 
very large for large allocations.

That said, maybe we should just reclaim `max(SWAP_CLUSTER_MAX, current - high)` 
for each loop? I agree that with this design it looks like perhaps we don't 
need it any more.

Johannes, what do you think?

  reply	other threads:[~2020-05-28 19:48 UTC|newest]

Thread overview: 40+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-05-20 14:37 [PATCH] mm, memcg: reclaim more aggressively before high allocator throttling Chris Down
2020-05-20 16:07 ` Michal Hocko
2020-05-20 16:51   ` Johannes Weiner
2020-05-20 17:04     ` Michal Hocko
2020-05-20 17:51       ` Johannes Weiner
2020-05-21  7:32         ` Michal Hocko
2020-05-21 13:51           ` Johannes Weiner
2020-05-21 14:22             ` Johannes Weiner
2020-05-21 14:35             ` Michal Hocko
2020-05-21 15:02               ` Chris Down
2020-05-21 16:38               ` Johannes Weiner
2020-05-21 17:37                 ` Michal Hocko
2020-05-21 18:45                   ` Johannes Weiner
2020-05-28 16:31                     ` Michal Hocko
2020-05-28 16:48                       ` Chris Down
2020-05-29  7:31                         ` Michal Hocko
2020-05-29 10:08                           ` Chris Down
2020-05-29 10:14                             ` Michal Hocko
2020-05-28 20:11                       ` Johannes Weiner
2020-05-20 20:26   ` Chris Down
2020-05-21  7:19     ` Michal Hocko
2020-05-21 11:27       ` Chris Down
2020-05-21 12:04         ` Michal Hocko
2020-05-21 12:23           ` Chris Down
2020-05-21 12:24             ` Chris Down
2020-05-21 12:37             ` Michal Hocko
2020-05-21 12:57               ` Chris Down
2020-05-21 13:05                 ` Chris Down
2020-05-21 13:28                   ` Michal Hocko
2020-05-21 13:21                 ` Michal Hocko
2020-05-21 13:41                   ` Chris Down
2020-05-21 13:58                     ` Michal Hocko
2020-05-21 14:22                       ` Chris Down
2020-05-21 12:28         ` Michal Hocko
2020-05-28 18:02 ` Shakeel Butt
2020-05-28 19:48   ` Chris Down [this message]
2020-05-28 20:29     ` Johannes Weiner
2020-05-28 21:02       ` Shakeel Butt
2020-05-28 21:14       ` Chris Down
2020-05-29  7:25       ` 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=20200528194831.GA2017@chrisdown.name \
    --to=chris@chrisdown.name \
    --cc=akpm@linux-foundation.org \
    --cc=cgroups@vger.kernel.org \
    --cc=hannes@cmpxchg.org \
    --cc=kernel-team@fb.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=mhocko@kernel.org \
    --cc=shakeelb@google.com \
    --cc=tj@kernel.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).