From: Gregory Price <gregory.price@memverge.com>
To: Dan Williams <dan.j.williams@intel.com>
Cc: "Viacheslav A.Dubeyko" <viacheslav.dubeyko@bytedance.com>,
Adam Manzanares <a.manzanares@samsung.com>,
Mike Rapoport <rppt@kernel.org>,
Kyungsan Kim <ks0204.kim@samsung.com>,
"lsf-pc@lists.linux-foundation.org"
<lsf-pc@lists.linux-foundation.org>,
"linux-mm@kvack.org" <linux-mm@kvack.org>,
"linux-fsdevel@vger.kernel.org" <linux-fsdevel@vger.kernel.org>,
"linux-cxl@vger.kernel.org" <linux-cxl@vger.kernel.org>,
"seungjun.ha@samsung.com" <seungjun.ha@samsung.com>,
"wj28.lee@samsung.com" <wj28.lee@samsung.com>
Subject: Re: [External] RE(2): FW: [LSF/MM/BPF TOPIC] SMDK inspired MM changes for CXL
Date: Tue, 4 Apr 2023 22:34:27 -0400 [thread overview]
Message-ID: <ZCzeM7IUehlrWR9E@memverge.com> (raw)
In-Reply-To: <642cb7ec58c71_21a829453@dwillia2-xfh.jf.intel.com.notmuch>
On Tue, Apr 04, 2023 at 04:51:08PM -0700, Dan Williams wrote:
> Gregory Price wrote:
> [..]
> > More generally, I think a cxl-swap (cswap? ;V) would be useful exactly to
> > help identify when watch-and-wait tiering becomes more performant than
> > promote-on-first-use. If you can't beat a simple fast-swap, why bother?
>
> I think it is instructive to look at what happened with PMEM, i.e. a
> "pswap" idea never entered the discourse. The moment the memory is not
> byte-addressable, it might as well be an NVME device where it can
> support a queue-depth and async-dma.
touché, but then did pmem hit latencies as high as 1.5-2us?
(I honestly don't know).
I'm just wondering how useful a 2mb page of memory at 1.5us per fetch
is, and whether we'll find it's almost always beneficial to promote that
page one first/second/third cache line fetch in some interval. If you
always promote on first use, it's basically just super-swap - even if
the memory is still itself still byte-addressable.
next prev parent reply other threads:[~2023-04-05 2:34 UTC|newest]
Thread overview: 68+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CGME20230221014114epcas2p1687db1d75765a8f9ed0b3495eab1154d@epcas2p1.samsung.com>
2023-02-21 1:41 ` [LSF/MM/BPF TOPIC] SMDK inspired MM changes for CXL Kyungsan Kim
2023-02-27 23:14 ` Dan Williams
2023-02-28 4:35 ` Kyungsan Kim
2023-03-03 6:07 ` Huang, Ying
2023-03-22 4:33 ` FW: " Kyungsan Kim
2023-03-22 22:03 ` Dan Williams
2023-03-23 10:51 ` RE(2): " Kyungsan Kim
2023-03-23 12:25 ` David Hildenbrand
2023-03-24 9:09 ` RE(4): " Kyungsan Kim
2023-03-24 9:12 ` David Hildenbrand
2023-03-24 9:27 ` RE(2): " Kyungsan Kim
2023-03-24 9:30 ` David Hildenbrand
2023-03-24 9:50 ` RE(3): " Kyungsan Kim
2023-03-24 13:08 ` Jørgen Hansen
2023-03-24 22:33 ` David Hildenbrand
2023-03-31 11:42 ` Kyungsan Kim
2023-03-31 13:42 ` Matthew Wilcox
2023-03-31 15:56 ` Frank van der Linden
2023-04-03 8:34 ` David Hildenbrand
2023-04-05 2:16 ` Kyungsan Kim
2023-04-05 2:06 ` Re: " Kyungsan Kim
2023-04-05 5:00 ` Dan Williams
2023-04-05 2:01 ` Kyungsan Kim
2023-04-05 3:11 ` Matthew Wilcox
2023-04-03 8:28 ` David Hildenbrand
2023-04-05 2:09 ` Kyungsan Kim
2023-03-31 11:31 ` RE: RE(3): " Kyungsan Kim
2023-03-24 0:41 ` RE(2): " Huang, Ying
2023-03-24 8:48 ` RE(4): " Kyungsan Kim
2023-03-24 13:46 ` Gregory Price
2023-03-31 11:34 ` Kyungsan Kim
2023-03-31 15:53 ` Gregory Price
2023-04-05 2:02 ` Kyungsan Kim
2023-03-24 14:55 ` RE(2): " Matthew Wilcox
2023-03-24 17:49 ` Matthew Wilcox
2023-03-31 11:37 ` Kyungsan Kim
2023-03-31 12:54 ` Matthew Wilcox
2023-04-05 2:00 ` Kyungsan Kim
2023-04-05 4:48 ` Dan Williams
2023-04-05 18:12 ` Matthew Wilcox
2023-04-05 19:42 ` Dan Williams
2023-04-06 12:27 ` David Hildenbrand
2023-04-07 9:30 ` Kyungsan Kim
2023-03-31 11:38 ` Re: RE(2): " Kyungsan Kim
2023-03-26 7:21 ` Mike Rapoport
2023-03-30 22:03 ` Dragan Stancevic
2023-04-03 8:44 ` Mike Rapoport
2023-04-04 4:27 ` Dragan Stancevic
2023-04-04 6:47 ` Huang, Ying
2023-04-06 22:27 ` Dragan Stancevic
2023-04-07 0:58 ` Huang, Ying
2023-04-07 9:29 ` Kyungsan Kim
2023-04-07 14:35 ` Dragan Stancevic
2023-04-05 10:18 ` Kyungsan Kim
2023-03-31 11:45 ` RE: RE(2): " Kyungsan Kim
2023-04-04 8:31 ` Mike Rapoport
2023-04-04 17:58 ` Adam Manzanares
2023-04-01 10:51 ` Gregory Price
2023-04-04 18:59 ` [External] " Viacheslav A.Dubeyko
2023-04-01 11:51 ` Gregory Price
2023-04-04 21:09 ` Viacheslav A.Dubeyko
2023-04-04 23:51 ` Dan Williams
2023-04-05 2:34 ` Gregory Price [this message]
2023-04-05 10:18 ` Kyungsan Kim
2023-03-30 22:02 ` Dragan Stancevic
2023-03-31 11:46 ` Kyungsan Kim
2023-04-14 8:41 ` FW: " Kyungsan Kim
2023-05-09 18:45 ` MTK
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