From: Nicholas Piggin <npiggin@gmail.com>
To: Shijie Huang <shijie@amperemail.onmicrosoft.com>,
Matthew Wilcox <willy@infradead.org>
Cc: akpm@linux-foundation.org, linux-kernel@vger.kernel.org,
linux-mm@kvack.org, song.bao.hua@hisilicon.com,
torvalds@linux-foundation.org, viro@zeniv.linux.org.uk,
Frank Wang <zwang@amperecomputing.com>
Subject: Re: Is it possible to implement the per-node page cache for programs/libraries?
Date: Thu, 02 Sep 2021 13:25:36 +1000 [thread overview]
Message-ID: <1630552995.2mupnzoqzs.astroid@bobo.none> (raw)
In-Reply-To: <YS7yjcqA6txFHd99@casper.infradead.org>
Excerpts from Matthew Wilcox's message of September 1, 2021 1:25 pm:
> On Wed, Sep 01, 2021 at 11:07:41AM +0800, Shijie Huang wrote:
>> In the NUMA, we only have one page cache for each file. For the
>> program/shared libraries, the
>> remote-access delays longer then the local-access.
>>
>> So, is it possible to implement the per-node page cache for
>> programs/libraries?
>
> At this point, we have no way to support text replication within a
> process. So what you're suggesting (if implemented) would work for
> processes which limit themselves to a single node. That is, if you
> have a system with CPUs 0-3 on node 0 and CPUs 4-7 on node 1, a process
> which only works on node 0 or only works on node 1 will get text on the
> appropriate node.
>
> If there's a process which runs on both nodes 0 and 1, there's no support
> for per-node PGDs. So it will get a mix of pages from nodes 0 and 1,
> and that doesn't necessarily seem like a big win. I haven't yet dived
> into how hard it would be to make mm->pgd a per-node allocation.
>
> I have been thinking about this a bit; one of our internal performance
> teams flagged the potential performance win to me a few months ago.
> I don't have a concrete design for text replication yet; there have been
> various attempts over the years, but none were particularly compelling.
What was not compelling about it?
https://lists.openwall.net/linux-kernel/2007/07/27/112
What are the other attempts?
Thanks,
Nick
next prev parent reply other threads:[~2021-09-02 3:25 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-01 3:07 Is it possible to implement the per-node page cache for programs/libraries? Shijie Huang
2021-09-01 2:09 ` Barry Song
2021-09-01 3:25 ` Matthew Wilcox
2021-09-01 13:30 ` Huang Shijie
2021-09-01 14:25 ` Huang Shijie
2021-09-01 11:32 ` Matthew Wilcox
2021-09-01 23:58 ` Matthew Wilcox
2021-09-02 0:15 ` Barry Song
2021-09-02 1:13 ` Linus Torvalds
2021-09-02 10:16 ` Huang Shijie
2021-09-02 3:25 ` Nicholas Piggin [this message]
2021-09-02 10:17 ` Matthew Wilcox
2021-09-03 7:10 ` Nicholas Piggin
2021-09-03 19:01 ` Matthew Wilcox
2021-09-03 19:08 ` Linus Torvalds
2021-09-06 9:56 ` Huang Shijie
2021-09-03 23:42 ` Nicholas Piggin
2021-09-01 4:55 ` Al Viro
2021-09-01 13:10 ` Huang Shijie
2021-09-01 17:24 ` Linus Torvalds
2021-09-01 17:29 ` Linus Torvalds
2021-09-01 22:56 ` Barry Song
2021-09-02 10:12 ` Huang Shijie
2021-09-02 10:08 ` Huang Shijie
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