From: "Huang, Ying" <ying.huang@intel.com>
To: Wei Xu <weixugc@google.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>,
Michal Hocko <mhocko@suse.com>,
Yosry Ahmed <yosryahmed@google.com>,
Johannes Weiner <hannes@cmpxchg.org>,
Shakeel Butt <shakeelb@google.com>,
Andrew Morton <akpm@linux-foundation.org>,
David Rientjes <rientjes@google.com>, Tejun Heo <tj@kernel.org>,
Zefan Li <lizefan.x@bytedance.com>,
Roman Gushchin <roman.gushchin@linux.dev>,
Cgroups <cgroups@vger.kernel.org>,
"open list:DOCUMENTATION" <linux-doc@vger.kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Linux MM <linux-mm@kvack.org>, Jonathan Corbet <corbet@lwn.net>,
Yu Zhao <yuzhao@google.com>,
Dave Hansen <dave.hansen@linux.intel.com>,
Greg Thelen <gthelen@google.com>
Subject: Re: [PATCH resend] memcg: introduce per-memcg reclaim interface
Date: Fri, 08 Apr 2022 11:08:28 +0800 [thread overview]
Message-ID: <87y20gtgpf.fsf@yhuang6-desk2.ccr.corp.intel.com> (raw)
In-Reply-To: <CAAPL-u-oF5HQ26w1czNCmA5VadXOfC54GbGpSppva86YEkefyA@mail.gmail.com> (Wei Xu's message of "Thu, 7 Apr 2022 19:10:20 -0700")
Wei Xu <weixugc@google.com> writes:
> On Thu, Apr 7, 2022 at 4:11 PM Tim Chen <tim.c.chen@linux.intel.com> wrote:
>>
>> On Thu, 2022-04-07 at 15:12 -0700, Wei Xu wrote:
>>
>> >
>> > (resending in plain-text, sorry).
>> >
>> > memory.demote can work with any level of memory tiers if a nodemask
>> > argument (or a tier argument if there is a more-explicitly defined,
>> > userspace visible tiering representation) is provided. The semantics
>> > can be to demote X bytes from these nodes to their next tier.
>> >
>>
>> We do need some kind of userspace visible tiering representation.
>> Will be nice if I can tell the memory type, nodemask of nodes in tier Y with
>>
>> cat memory.tier_Y
>>
>>
>> > memory_dram/memory_pmem assumes the hardware for a particular memory
>> > tier, which is undesirable. For example, it is entirely possible that
>> > a slow memory tier is implemented by a lower-cost/lower-performance
>> > DDR device connected via CXL.mem, not by PMEM. It is better for this
>> > interface to speak in either the NUMA node abstraction or a new tier
>> > abstraction.
>>
>> Just from the perspective of memory.reclaim and memory.demote, I think
>> they could work with nodemask. For ease of management,
>> some kind of abstraction of tier information like nodemask, memory type
>> and expected performance should be readily accessible by user space.
>>
>
> I agree. The tier information should be provided at the system level.
> One suggestion is to have a new directory "/sys/devices/system/tier/"
> for tiers, e.g.:
>
> /sys/devices/system/tier/tier0/memlist: all memory nodes in tier 0.
> /sys/devices/system/tier/tier1/memlist: all memory nodes in tier 1.
I think that it may be sufficient to make tier an attribute of "node".
Some thing like,
/sys/devices/system/node/nodeX/memory_tier
Best Regards,
Huang, Ying
> We can discuss this tier representation in a new thread.
>
>> Tim
>>
>> >
>> > It is also desirable to make this interface stateless, i.e. not to
>> > require the setting of memory_dram.reclaim_policy. Any policy can be
>> > specified as arguments to the request itself and should only affect
>> > that particular request.
>> >
>> > Wei
>>
next prev parent reply other threads:[~2022-04-08 3:08 UTC|newest]
Thread overview: 61+ 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 9:11 ` Yosry Ahmed
2022-04-01 18:39 ` Roman Gushchin
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 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
2022-04-01 3:38 ` Wei Xu
2022-04-01 9:17 ` Yosry Ahmed
2022-04-01 13:03 ` Michal Hocko
2022-04-01 3:05 ` Chen Wandun
2022-04-01 9:20 ` Yosry Ahmed
2022-04-01 9:48 ` Chen Wandun
2022-04-01 10:02 ` Yosry Ahmed
2022-04-01 4:05 ` Wei Xu
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
2022-04-04 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
2022-04-02 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 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 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 23:11 ` Tim Chen
2022-04-08 2:10 ` Wei Xu
2022-04-08 3:08 ` Huang, Ying [this message]
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=87y20gtgpf.fsf@yhuang6-desk2.ccr.corp.intel.com \
--to=ying.huang@intel.com \
--cc=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@suse.com \
--cc=rientjes@google.com \
--cc=roman.gushchin@linux.dev \
--cc=shakeelb@google.com \
--cc=tim.c.chen@linux.intel.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 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).