From: Aneesh Kumar K V <aneesh.kumar@linux.ibm.com>
To: "ying.huang@intel.com" <ying.huang@intel.com>,
Wei Xu <weixugc@google.com>,
Andrew Morton <akpm@linux-foundation.org>,
Greg Thelen <gthelen@google.com>, Yang Shi <shy828301@gmail.com>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Jagdish Gediya <jvgediya@linux.ibm.com>,
Michal Hocko <mhocko@kernel.org>,
Tim C Chen <tim.c.chen@intel.com>,
Dave Hansen <dave.hansen@intel.com>,
Alistair Popple <apopple@nvidia.com>,
Baolin Wang <baolin.wang@linux.alibaba.com>,
Feng Tang <feng.tang@intel.com>,
Jonathan Cameron <Jonathan.Cameron@huawei.com>,
Davidlohr Bueso <dave@stgolabs.net>,
Dan Williams <dan.j.williams@intel.com>,
David Rientjes <rientjes@google.com>,
Linux MM <linux-mm@kvack.org>,
Brice Goglin <brice.goglin@gmail.com>,
Hesham Almatary <hesham.almatary@huawei.com>
Subject: Re: RFC: Memory Tiering Kernel Interfaces (v2)
Date: Thu, 12 May 2022 12:42:02 +0530 [thread overview]
Message-ID: <c5d55131-76ff-7354-2954-7cfac365a9a5@linux.ibm.com> (raw)
In-Reply-To: <56b41ce6922ed5f640d9bd46a603fa27576532a9.camel@intel.com>
On 5/12/22 12:33 PM, ying.huang@intel.com wrote:
> On Wed, 2022-05-11 at 23:22 -0700, Wei Xu wrote:
>> Sysfs Interfaces
>> ================
>>
>> * /sys/devices/system/memtier/memtierN/nodelist
>>
>> where N = 0, 1, 2 (the kernel supports only 3 tiers for now).
>>
>> Format: node_list
>>
>> Read-only. When read, list the memory nodes in the specified tier.
>>
>> Tier 0 is the highest tier, while tier 2 is the lowest tier.
>>
>> The absolute value of a tier id number has no specific meaning.
>> What matters is the relative order of the tier id numbers.
>>
>> When a memory tier has no nodes, the kernel can hide its memtier
>> sysfs files.
>>
>> * /sys/devices/system/node/nodeN/memtier
>>
>> where N = 0, 1, ...
>>
>> Format: int or empty
>>
>> When read, list the memory tier that the node belongs to. Its value
>> is empty for a CPU-only NUMA node.
>>
>> When written, the kernel moves the node into the specified memory
>> tier if the move is allowed. The tier assignment of all other nodes
>> are not affected.
>>
>> Initially, we can make this interface read-only.
>
> It seems that "/sys/devices/system/node/nodeN/memtier" has all
> information we needed. Do we really need
> "/sys/devices/system/memtier/memtierN/nodelist"?
>
> That can be gotten via a simple shell command line,
>
> $ grep . /sys/devices/system/node/nodeN/memtier | sort -n -k 2 -t ':'
>
It will be really useful to fetch the memory tier node list in an easy
fashion rather than reading multiple sysfs directories. If we don't have
other attributes for memorytier, we could keep
"/sys/devices/system/memtier/memtierN" a NUMA node list there by
avoiding /sys/devices/system/memtier/memtierN/nodelist
-aneesh
next prev parent reply other threads:[~2022-05-12 7:12 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-05-12 6:22 RFC: Memory Tiering Kernel Interfaces (v2) Wei Xu
2022-05-12 7:03 ` ying.huang
2022-05-12 7:12 ` Aneesh Kumar K V [this message]
2022-05-12 7:18 ` ying.huang
2022-05-12 7:22 ` Wei Xu
2022-05-12 7:36 ` Aneesh Kumar K.V
2022-05-12 8:15 ` Wei Xu
2022-05-12 8:37 ` ying.huang
2022-05-13 2:52 ` ying.huang
2022-05-13 7:00 ` Wei Xu
2022-05-16 1:57 ` ying.huang
2022-05-12 21:12 ` Tim Chen
2022-05-12 21:31 ` Wei Xu
2022-05-12 15:00 ` Jonathan Cameron
2022-05-18 7:09 ` Wei Xu
2022-05-18 12:00 ` Jonathan Cameron
2022-05-24 7:36 ` Wei Xu
2022-05-24 13:26 ` Aneesh Kumar K.V
2022-05-25 5:27 ` Wei Xu
2022-05-25 7:47 ` Alistair Popple
2022-05-25 11:48 ` Jonathan Cameron
2022-05-25 15:32 ` Wei Xu
2022-05-20 3:06 ` Ying Huang
2022-05-24 7:04 ` Wei Xu
2022-05-24 8:24 ` Ying Huang
2022-05-25 5:32 ` Wei Xu
2022-05-25 9:03 ` Ying Huang
2022-05-25 10:01 ` Aneesh Kumar K V
2022-05-25 11:36 ` Mika Penttilä
2022-05-25 15:33 ` Wei Xu
2022-05-25 17:27 ` Wei Xu
2022-05-26 9:32 ` Jonathan Cameron
2022-05-26 20:30 ` Wei Xu
2022-05-27 9:26 ` Aneesh Kumar K V
2022-05-25 15:36 ` Wei Xu
2022-05-26 1:09 ` Ying Huang
2022-05-26 3:53 ` Wei Xu
2022-05-26 6:54 ` Ying Huang
2022-05-26 7:08 ` Wei Xu
2022-05-26 7:39 ` Ying Huang
2022-05-26 20:55 ` Wei Xu
2022-05-27 9:10 ` Jonathan Cameron
2022-05-30 6:54 ` Ying Huang
2022-05-13 3:25 ` ying.huang
2022-05-13 6:36 ` Wei Xu
2022-05-13 7:04 ` ying.huang
2022-05-13 7:21 ` Wei Xu
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=c5d55131-76ff-7354-2954-7cfac365a9a5@linux.ibm.com \
--to=aneesh.kumar@linux.ibm.com \
--cc=Jonathan.Cameron@huawei.com \
--cc=akpm@linux-foundation.org \
--cc=apopple@nvidia.com \
--cc=baolin.wang@linux.alibaba.com \
--cc=brice.goglin@gmail.com \
--cc=dan.j.williams@intel.com \
--cc=dave.hansen@intel.com \
--cc=dave@stgolabs.net \
--cc=feng.tang@intel.com \
--cc=gthelen@google.com \
--cc=hesham.almatary@huawei.com \
--cc=jvgediya@linux.ibm.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mhocko@kernel.org \
--cc=rientjes@google.com \
--cc=shy828301@gmail.com \
--cc=tim.c.chen@intel.com \
--cc=weixugc@google.com \
--cc=ying.huang@intel.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).