From: Michal Hocko <mhocko@kernel.org>
To: Yang Shi <yang.shi@linux.alibaba.com>
Cc: Dan Williams <dan.j.williams@intel.com>,
Mel Gorman <mgorman@techsingularity.net>,
Rik van Riel <riel@surriel.com>,
Johannes Weiner <hannes@cmpxchg.org>,
Andrew Morton <akpm@linux-foundation.org>,
Dave Hansen <dave.hansen@intel.com>,
Keith Busch <keith.busch@intel.com>,
Fengguang Wu <fengguang.wu@intel.com>,
"Du, Fan" <fan.du@intel.com>,
"Huang, Ying" <ying.huang@intel.com>,
Linux MM <linux-mm@kvack.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [RFC PATCH 0/10] Another Approach to Use PMEM as NUMA Node
Date: Thu, 28 Mar 2019 20:12:06 +0100 [thread overview]
Message-ID: <20190328191206.GC7155@dhcp22.suse.cz> (raw)
In-Reply-To: <6487e0f5-aee4-3fea-00f5-c12602b8ad2b@linux.alibaba.com>
On Thu 28-03-19 11:58:57, Yang Shi wrote:
>
>
> On 3/27/19 11:58 PM, Michal Hocko wrote:
> > On Wed 27-03-19 19:09:10, Yang Shi wrote:
> > > One question, when doing demote and promote we need define a path, for
> > > example, DRAM <-> PMEM (assume two tier memory). When determining what nodes
> > > are "DRAM" nodes, does it make sense to assume the nodes with both cpu and
> > > memory are DRAM nodes since PMEM nodes are typically cpuless nodes?
> > Do we really have to special case this for PMEM? Why cannot we simply go
> > in the zonelist order? In other words why cannot we use the same logic
> > for a larger NUMA machine and instead of swapping simply fallback to a
> > less contended NUMA node? It can be a regular DRAM, PMEM or whatever
> > other type of memory node.
>
> Thanks for the suggestion. It makes sense. However, if we don't specialize a
> pmem node, its fallback node may be a DRAM node, then the memory reclaim may
> move the inactive page to the DRAM node, it sounds not make too much sense
> since memory reclaim would prefer to move downwards (DRAM -> PMEM -> Disk).
There are certainly many details to sort out. One thing is how to handle
cpuless nodes (e.g. PMEM). Those shouldn't get any direct allocations
without an explicit binding, right? My first naive idea would be to only
migrate-on-reclaim only from the preferred node. We might need
additional heuristics but I wouldn't special case PMEM from other
cpuless NUMA nodes.
--
Michal Hocko
SUSE Labs
next prev parent reply other threads:[~2019-03-28 19:12 UTC|newest]
Thread overview: 58+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-23 4:44 [RFC PATCH 0/10] Another Approach to Use PMEM as NUMA Node Yang Shi
2019-03-23 4:44 ` [PATCH 01/10] mm: control memory placement by nodemask for two tier main memory Yang Shi
2019-03-23 17:21 ` Dan Williams
2019-03-25 19:28 ` Yang Shi
2019-03-25 23:18 ` Dan Williams
2019-03-25 23:36 ` Yang Shi
2019-03-25 23:42 ` Dan Williams
2019-03-23 4:44 ` [PATCH 02/10] mm: mempolicy: introduce MPOL_HYBRID policy Yang Shi
2019-03-23 4:44 ` [PATCH 03/10] mm: mempolicy: promote page to DRAM for MPOL_HYBRID Yang Shi
2019-03-23 4:44 ` [PATCH 04/10] mm: numa: promote pages to DRAM when it is accessed twice Yang Shi
2019-03-29 0:31 ` kbuild test robot
2019-03-23 4:44 ` [PATCH 05/10] mm: page_alloc: make find_next_best_node could skip DRAM node Yang Shi
2019-03-23 4:44 ` [PATCH 06/10] mm: vmscan: demote anon DRAM pages to PMEM node Yang Shi
2019-03-23 6:03 ` Zi Yan
2019-03-25 21:49 ` Yang Shi
2019-03-24 22:20 ` Keith Busch
2019-03-25 19:49 ` Yang Shi
2019-03-27 0:35 ` Keith Busch
2019-03-27 3:41 ` Yang Shi
2019-03-27 13:08 ` Keith Busch
2019-03-27 17:00 ` Zi Yan
2019-03-27 17:05 ` Dave Hansen
2019-03-27 17:48 ` Zi Yan
2019-03-27 18:00 ` Dave Hansen
2019-03-27 20:37 ` Zi Yan
2019-03-27 20:42 ` Dave Hansen
2019-03-28 21:59 ` Yang Shi
2019-03-28 22:45 ` Keith Busch
2019-03-23 4:44 ` [PATCH 07/10] mm: vmscan: add page demotion counter Yang Shi
2019-03-23 4:44 ` [PATCH 08/10] mm: numa: add page promotion counter Yang Shi
2019-03-23 4:44 ` [PATCH 09/10] doc: add description for MPOL_HYBRID mode Yang Shi
2019-03-23 4:44 ` [PATCH 10/10] doc: elaborate the PMEM allocation rule Yang Shi
2019-03-25 16:15 ` [RFC PATCH 0/10] Another Approach to Use PMEM as NUMA Node Brice Goglin
2019-03-25 16:56 ` Dan Williams
2019-03-25 17:45 ` Brice Goglin
2019-03-25 19:29 ` Dan Williams
2019-03-25 23:09 ` Brice Goglin
2019-03-25 23:37 ` Dan Williams
2019-03-26 12:19 ` Jonathan Cameron
2019-03-25 20:04 ` Yang Shi
2019-03-26 13:58 ` Michal Hocko
2019-03-26 18:33 ` Yang Shi
2019-03-26 18:37 ` Michal Hocko
2019-03-27 2:58 ` Yang Shi
2019-03-27 9:01 ` Michal Hocko
2019-03-27 17:34 ` Dan Williams
2019-03-27 18:59 ` Yang Shi
2019-03-27 20:09 ` Michal Hocko
2019-03-28 2:09 ` Yang Shi
2019-03-28 6:58 ` Michal Hocko
2019-03-28 18:58 ` Yang Shi
2019-03-28 19:12 ` Michal Hocko [this message]
2019-03-28 19:40 ` Yang Shi
2019-03-28 20:40 ` Michal Hocko
2019-03-28 8:21 ` Dan Williams
2019-03-27 20:14 ` Dave Hansen
2019-03-27 20:35 ` Matthew Wilcox
2019-03-27 20:40 ` Dave Hansen
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=20190328191206.GC7155@dhcp22.suse.cz \
--to=mhocko@kernel.org \
--cc=akpm@linux-foundation.org \
--cc=dan.j.williams@intel.com \
--cc=dave.hansen@intel.com \
--cc=fan.du@intel.com \
--cc=fengguang.wu@intel.com \
--cc=hannes@cmpxchg.org \
--cc=keith.busch@intel.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mgorman@techsingularity.net \
--cc=riel@surriel.com \
--cc=yang.shi@linux.alibaba.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).