All of lore.kernel.org
 help / color / mirror / Atom feed
From: Andrew Morton <akpm@linux-foundation.org>
To: Yosry Ahmed <yosryahmed@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>,
	Michal Hocko <mhocko@kernel.org>,
	Shakeel Butt <shakeelb@google.com>,
	David Rientjes <rientjes@google.com>, Tejun Heo <tj@kernel.org>,
	Zefan Li <lizefan.x@bytedance.com>,
	Roman Gushchin <roman.gushchin@linux.dev>,
	cgroups@vger.kernel.org, linux-doc@vger.kernel.org,
	linux-kernel@vger.kernel.org, linux-mm@kvack.org,
	Jonathan Corbet <corbet@lwn.net>, Yu Zhao <yuzhao@google.com>,
	Dave Hansen <dave.hansen@linux.intel.com>,
	Wei Xu <weixugc@google.com>, Greg Thelen <gthelen@google.com>
Subject: Re: [PATCH resend] memcg: introduce per-memcg reclaim interface
Date: Thu, 31 Mar 2022 17:33:50 -0700	[thread overview]
Message-ID: <20220331173350.1fe09370479a4a6f916b477d@linux-foundation.org> (raw)
In-Reply-To: <20220331084151.2600229-1-yosryahmed@google.com>

On Thu, 31 Mar 2022 08:41:51 +0000 Yosry Ahmed <yosryahmed@google.com> wrote:

> --- a/mm/memcontrol.c
> +++ b/mm/memcontrol.c
> @@ -6355,6 +6355,38 @@ static ssize_t memory_oom_group_write(struct kernfs_open_file *of,
>  	return nbytes;
>  }
>  
> +static ssize_t memory_reclaim(struct kernfs_open_file *of, char *buf,
> +			      size_t nbytes, loff_t off)
> +{
> +	struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of));
> +	unsigned int nr_retries = MAX_RECLAIM_RETRIES;
> +	unsigned long nr_to_reclaim, nr_reclaimed = 0;
> +	int err;
> +
> +	buf = strstrip(buf);
> +	err = page_counter_memparse(buf, "", &nr_to_reclaim);
> +	if (err)
> +		return err;
> +
> +	while (nr_reclaimed < nr_to_reclaim) {
> +		unsigned long reclaimed;
> +
> +		if (signal_pending(current))
> +			break;
> +
> +		reclaimed = try_to_free_mem_cgroup_pages(memcg,
> +						nr_to_reclaim - nr_reclaimed,
> +						GFP_KERNEL, true);
> +
> +		if (!reclaimed && !nr_retries--)
> +			break;
> +
> +		nr_reclaimed += reclaimed;
> +	}

Is there any way in which this can be provoked into triggering the
softlockup detector?

Is it optimal to do the MAX_RECLAIM_RETRIES loop in the kernel? 
Would additional flexibility be gained by letting userspace handle
retrying?



WARNING: multiple messages have this Message-ID (diff)
From: Andrew Morton <akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org>
To: Yosry Ahmed <yosryahmed-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
Cc: Johannes Weiner <hannes-druUgvl0LCNAfugRpC6u6w@public.gmane.org>,
	Michal Hocko <mhocko-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>,
	Shakeel Butt <shakeelb-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>,
	David Rientjes <rientjes-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>,
	Tejun Heo <tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>,
	Zefan Li <lizefan.x-EC8Uxl6Npydl57MIdRCFDg@public.gmane.org>,
	Roman Gushchin
	<roman.gushchin-fxUVXftIFDnyG1zEObXtfA@public.gmane.org>,
	cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	linux-doc-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org,
	Jonathan Corbet <corbet-T1hC0tSOHrs@public.gmane.org>,
	Yu Zhao <yuzhao-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>,
	Dave Hansen <dave.hansen-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>,
	Wei Xu <weixugc-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>,
	Greg Thelen <gthelen-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
Subject: Re: [PATCH resend] memcg: introduce per-memcg reclaim interface
Date: Thu, 31 Mar 2022 17:33:50 -0700	[thread overview]
Message-ID: <20220331173350.1fe09370479a4a6f916b477d@linux-foundation.org> (raw)
In-Reply-To: <20220331084151.2600229-1-yosryahmed-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>

On Thu, 31 Mar 2022 08:41:51 +0000 Yosry Ahmed <yosryahmed-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org> wrote:

> --- a/mm/memcontrol.c
> +++ b/mm/memcontrol.c
> @@ -6355,6 +6355,38 @@ static ssize_t memory_oom_group_write(struct kernfs_open_file *of,
>  	return nbytes;
>  }
>  
> +static ssize_t memory_reclaim(struct kernfs_open_file *of, char *buf,
> +			      size_t nbytes, loff_t off)
> +{
> +	struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of));
> +	unsigned int nr_retries = MAX_RECLAIM_RETRIES;
> +	unsigned long nr_to_reclaim, nr_reclaimed = 0;
> +	int err;
> +
> +	buf = strstrip(buf);
> +	err = page_counter_memparse(buf, "", &nr_to_reclaim);
> +	if (err)
> +		return err;
> +
> +	while (nr_reclaimed < nr_to_reclaim) {
> +		unsigned long reclaimed;
> +
> +		if (signal_pending(current))
> +			break;
> +
> +		reclaimed = try_to_free_mem_cgroup_pages(memcg,
> +						nr_to_reclaim - nr_reclaimed,
> +						GFP_KERNEL, true);
> +
> +		if (!reclaimed && !nr_retries--)
> +			break;
> +
> +		nr_reclaimed += reclaimed;
> +	}

Is there any way in which this can be provoked into triggering the
softlockup detector?

Is it optimal to do the MAX_RECLAIM_RETRIES loop in the kernel? 
Would additional flexibility be gained by letting userspace handle
retrying?



  parent reply	other threads:[~2022-04-01  0:33 UTC|newest]

Thread overview: 81+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-03-31  8:41 [PATCH resend] memcg: introduce per-memcg reclaim interface Yosry Ahmed
2022-03-31 17:25 ` Roman Gushchin
2022-04-01  6:01   ` Wei Xu
2022-04-01  6:01     ` Wei Xu
2022-04-01  9:11   ` Yosry Ahmed
2022-04-01  9:11     ` Yosry Ahmed
2022-04-01 18:39     ` Roman Gushchin
2022-04-01 21:13       ` Johannes Weiner
2022-04-01 21:13         ` Johannes Weiner
2022-04-01 21:21         ` Roman Gushchin
2022-04-01 21:38           ` Wei Xu
2022-04-01 21:51           ` Johannes Weiner
2022-04-04 17:14             ` Shakeel Butt
2022-04-04 17:13       ` Yosry Ahmed
2022-04-04 17:55         ` Roman Gushchin
2022-04-01  9:15   ` Yosry Ahmed
2022-04-01  9:15     ` Yosry Ahmed
2022-04-01 15:41     ` Shakeel Butt
2022-04-01 13:49   ` Michal Hocko
2022-04-01 16:58     ` Roman Gushchin
2022-04-04  8:44       ` Michal Hocko
2022-04-04 18:25         ` Roman Gushchin
2022-03-31 19:25 ` Johannes Weiner
2022-04-01  0:33 ` Andrew Morton [this message]
2022-04-01  0:33   ` Andrew Morton
2022-04-01  3:38   ` Wei Xu
2022-04-01  9:17     ` Yosry Ahmed
2022-04-01  9:17       ` Yosry Ahmed
2022-04-01 13:03       ` Michal Hocko
2022-04-01 13:03         ` Michal Hocko
2022-04-01  3:05 ` Chen Wandun
2022-04-01  3:05   ` Chen Wandun
2022-04-01  9:20   ` Yosry Ahmed
2022-04-01  9:48     ` Chen Wandun
2022-04-01  9:48       ` Chen Wandun
2022-04-01 10:02       ` Yosry Ahmed
2022-04-01  4:05 ` Wei Xu
2022-04-01  4:05   ` Wei Xu
2022-04-01  9:22   ` Yosry Ahmed
2022-04-01  9:22     ` Yosry Ahmed
2022-04-01 15:22   ` Johannes Weiner
2022-04-01 20:14     ` Wei Xu
2022-04-01 21:07       ` Johannes Weiner
2022-04-01 21:07         ` Johannes Weiner
2022-04-04 17:08       ` Shakeel Butt
2022-04-05  2:30         ` Wei Xu
2022-04-05 10:09         ` Michal Koutný
2022-04-01  8:39 ` Vaibhav Jain
2022-04-01  9:23   ` Yosry Ahmed
2022-04-04  3:50     ` Vaibhav Jain
2022-04-04 17:18       ` Yosry Ahmed
2022-04-01 13:54 ` Michal Hocko
2022-04-01 16:56   ` Wei Xu
2022-04-01 16:56     ` Wei Xu
2022-04-02  8:13     ` Huang, Ying
2022-04-03  6:46       ` Wei Xu
2022-04-03  6:56       ` Wei Xu
2022-04-06  0:48         ` Huang, Ying
2022-04-06  1:07           ` Wei Xu
2022-04-06  1:07             ` Wei Xu
2022-04-06  2:49             ` Huang, Ying
2022-04-06  2:49               ` Huang, Ying
2022-04-06  5:02               ` Wei Xu
2022-04-06  6:32                 ` Huang, Ying
2022-04-06  7:05                   ` Wei Xu
2022-04-06  8:49                     ` Huang, Ying
2022-04-06  8:49                       ` Huang, Ying
2022-04-06 20:16                       ` Wei Xu
2022-04-06 20:16                         ` Wei Xu
2022-04-07  7:35                   ` Michal Hocko
2022-04-07 21:26               ` Tim Chen
2022-04-07 22:07                 ` Wei Xu
2022-04-07 22:12                 ` Wei Xu
2022-04-07 22:12                   ` Wei Xu
2022-04-07 23:11                   ` Tim Chen
2022-04-08  2:10                     ` Wei Xu
2022-04-08  2:10                       ` Wei Xu
2022-04-08  3:08                       ` Huang, Ying
2022-04-08  4:10                         ` Wei Xu
2022-04-08  4:10                           ` Wei Xu
2022-04-04 17:09   ` Yosry Ahmed

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=20220331173350.1fe09370479a4a6f916b477d@linux-foundation.org \
    --to=akpm@linux-foundation.org \
    --cc=cgroups@vger.kernel.org \
    --cc=corbet@lwn.net \
    --cc=dave.hansen@linux.intel.com \
    --cc=gthelen@google.com \
    --cc=hannes@cmpxchg.org \
    --cc=linux-doc@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=lizefan.x@bytedance.com \
    --cc=mhocko@kernel.org \
    --cc=rientjes@google.com \
    --cc=roman.gushchin@linux.dev \
    --cc=shakeelb@google.com \
    --cc=tj@kernel.org \
    --cc=weixugc@google.com \
    --cc=yosryahmed@google.com \
    --cc=yuzhao@google.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.