From: SeongJae Park <sj38.park@gmail.com>
To: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>,
"Kirill A. Shutemov" <kirill@shutemov.name>,
Matthew Wilcox <willy@infradead.org>,
linux-mm@kvack.org, Peter Zijlstra <peterz@infradead.org>
Subject: Re: Re: Splitting the mmap_sem
Date: Thu, 9 Jan 2020 18:32:06 +0100 [thread overview]
Message-ID: <20200109173206.3731-1-sj38.park@gmail.com> (raw)
In-Reply-To: <20200109170715.GV4951@dhcp22.suse.cz>
On Thu, 9 Jan 2020 18:07:15 +0100 Michal Hocko <mhocko@suse.com> wrote:
> On Thu 09-01-20 18:03:25, Michal Hocko wrote:
> > I might misremember but RCU based VMA handling has
> > been considered in the past. I do not remember details but there were
> > some problems and page tables allocation is not the biggest one.
>
> I have found https://pdos.csail.mit.edu/papers/rcuvm:asplos12.pdf in my
> notes. I managed to forget everything but maybe it will be useful for a
> reference.
The subsequent work from the authors
(https://people.csail.mit.edu/nickolai/papers/clements-radixvm-2014-08-05.pdf)
might be also useful for the understanding of the limitations found from the
work.
I also forgot many details but as far as I remember, the biggest problem with
the rcuvm was the update side scalability limitation that results from the
single updater lock and the TLB invalidations. I has also internally
implemented another RCU based vm that utilizing fine-grained update side
synchronization. The write side performance of my version was therefore much
improved, but it also dropped the performance at the end with heavily
write-intensive workloads due to the TLB flush overhead.
Page table allocations weren't bothered me at that time.
Thanks,
SeongJae Park
> --
> Michal Hocko
> SUSE Labs
>
>
next prev parent reply other threads:[~2020-01-09 17:32 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-03 22:21 Splitting the mmap_sem Matthew Wilcox
2019-12-05 17:21 ` Jerome Glisse
2019-12-06 5:13 ` Matthew Wilcox
2019-12-06 17:30 ` Jerome Glisse
2019-12-09 3:33 ` Matthew Wilcox
2019-12-09 14:17 ` Jerome Glisse
2019-12-10 15:26 ` Vlastimil Babka
2019-12-10 16:07 ` Jerome Glisse
2019-12-10 18:09 ` Vlastimil Babka
2019-12-12 14:24 ` Kirill A. Shutemov
2019-12-12 15:40 ` Matthew Wilcox
2019-12-12 15:46 ` Kirill A. Shutemov
2019-12-13 14:33 ` Matthew Wilcox
2019-12-13 18:06 ` Kirill A. Shutemov
2019-12-13 18:21 ` Matthew Wilcox
2020-01-06 22:09 ` Matthew Wilcox
2020-01-07 12:34 ` Kirill A. Shutemov
2020-01-07 13:54 ` Matthew Wilcox
2020-01-07 14:27 ` Kirill A. Shutemov
2020-01-09 13:56 ` Vlastimil Babka
2020-01-09 17:03 ` Michal Hocko
2020-01-09 17:07 ` Michal Hocko
2020-01-09 17:32 ` SeongJae Park [this message]
2020-01-09 20:13 ` Matthew Wilcox
2020-02-06 13:59 ` Peter Zijlstra
2020-02-06 20:15 ` Matthew Wilcox
2020-02-06 20:55 ` Peter Zijlstra
2020-02-06 21:20 ` Matthew Wilcox
2020-02-07 8:52 ` Peter Zijlstra
2020-02-10 22:00 ` Matthew Wilcox
2020-02-19 17:14 ` Laurent Dufour
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