From: "Huang, Ying" <ying.huang@intel.com>
To: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>,
Wei Xu <weixugc@google.com>,
Johannes Weiner <hannes@cmpxchg.org>
Cc: linux-mm@kvack.org, akpm@linux-foundation.org,
Yang Shi <shy828301@gmail.com>,
Davidlohr Bueso <dave@stgolabs.net>,
Tim C Chen <tim.c.chen@intel.com>,
Michal Hocko <mhocko@kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Hesham Almatary <hesham.almatary@huawei.com>,
Dave Hansen <dave.hansen@intel.com>,
Jonathan Cameron <Jonathan.Cameron@huawei.com>,
Alistair Popple <apopple@nvidia.com>,
Dan Williams <dan.j.williams@intel.com>,
jvgediya.oss@gmail.com, Bharata B Rao <bharata@amd.com>
Subject: Re: [PATCH v3 updated] mm/demotion: Expose memory tier details via sysfs
Date: Thu, 01 Sep 2022 15:01:39 +0800 [thread overview]
Message-ID: <87tu5rzigc.fsf@yhuang6-desk2.ccr.corp.intel.com> (raw)
In-Reply-To: <20220830081736.119281-1-aneesh.kumar@linux.ibm.com> (Aneesh Kumar K. V.'s message of "Tue, 30 Aug 2022 13:47:36 +0530")
"Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com> writes:
> This patch adds /sys/devices/virtual/memory_tiering/ where all memory tier
> related details can be found. All allocated memory tiers will be listed
> there as /sys/devices/virtual/memory_tiering/memory_tierN/
>
> The nodes which are part of a specific memory tier can be listed via
> /sys/devices/virtual/memory_tiering/memory_tierN/nodes
I think "memory_tier" is a better subsystem/bus name than
memory_tiering. Because we have a set of memory_tierN devices inside.
"memory_tier" sounds more natural. I know this is subjective, just my
preference.
>
> A directory hierarchy looks like
> :/sys/devices/virtual/memory_tiering$ tree memory_tier4/
> memory_tier4/
> ├── nodes
> ├── subsystem -> ../../../../bus/memory_tiering
> └── uevent
>
> All toptier nodes are listed via
> /sys/devices/virtual/memory_tiering/toptier_nodes
>
> :/sys/devices/virtual/memory_tiering$ cat toptier_nodes
> 0,2
> :/sys/devices/virtual/memory_tiering$ cat memory_tier4/nodes
> 0,2
I don't think that it is a good idea to show toptier information in user
space interface. Because it is just a in kernel implementation
details. Now, we only promote pages from !toptier to toptier. But
there may be multiple memory tiers in toptier and !toptier, we may
change the implementation in the future. For example, we may promote
pages from DRAM to HBM in the future.
Do we need a way to show the default memory tier in sysfs? That is, the
memory tier that the DRAM nodes belong to.
Best Regards,
Huang, Ying
> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
> ---
>
> Changes from v2:
> * update macro to static inline
> * Fix build error with CONFIG_MIGRATION disabled
> * drop abstract_distance
> * update commit message
>
>
[snip]
next prev parent reply other threads:[~2022-09-01 7:01 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-08-30 8:17 Aneesh Kumar K.V
2022-09-01 7:01 ` Huang, Ying [this message]
2022-09-01 8:24 ` Aneesh Kumar K V
2022-09-02 0:29 ` Huang, Ying
2022-09-02 5:09 ` Wei Xu
2022-09-02 5:15 ` Huang, Ying
2022-09-02 5:23 ` Aneesh Kumar K V
2022-09-02 5:40 ` Huang, Ying
2022-09-02 5:46 ` Aneesh Kumar K V
2022-09-02 6:12 ` Huang, Ying
2022-09-02 6:31 ` Aneesh Kumar K V
2022-09-02 6:40 ` Huang, Ying
2022-09-02 6:44 ` Aneesh Kumar K V
2022-09-02 7:02 ` Wei Xu
2022-09-02 7:57 ` Huang, Ying
2022-09-02 8:48 ` Aneesh Kumar K V
2022-09-02 9:04 ` Huang, Ying
2022-09-02 9:44 ` Aneesh Kumar K V
2022-09-05 1:52 ` Huang, Ying
2022-09-05 3:50 ` Aneesh Kumar K V
2022-09-05 5:13 ` Huang, Ying
2022-09-05 5:27 ` Aneesh Kumar K V
2022-09-05 5:53 ` Huang, Ying
2022-09-05 6:14 ` Aneesh Kumar K V
2022-09-05 6:24 ` 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=87tu5rzigc.fsf@yhuang6-desk2.ccr.corp.intel.com \
--to=ying.huang@intel.com \
--cc=Jonathan.Cameron@huawei.com \
--cc=akpm@linux-foundation.org \
--cc=aneesh.kumar@linux.ibm.com \
--cc=apopple@nvidia.com \
--cc=bharata@amd.com \
--cc=dan.j.williams@intel.com \
--cc=dave.hansen@intel.com \
--cc=dave@stgolabs.net \
--cc=hannes@cmpxchg.org \
--cc=hesham.almatary@huawei.com \
--cc=jvgediya.oss@gmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mhocko@kernel.org \
--cc=shy828301@gmail.com \
--cc=tim.c.chen@intel.com \
--cc=weixugc@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