From: Oleksandr Natalenko <oleksandr@natalenko.name>
To: ValdikSS <iam@valdikss.org.ru>,
Andrew Morton <akpm@linux-foundation.org>
Cc: Alexey Avramov <hakavlad@inbox.lv>,
linux-mm@kvack.org, linux-doc@vger.kernel.org,
linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
corbet@lwn.net, mcgrof@kernel.org, keescook@chromium.org,
yzaikin@google.com, kernel@xanmod.org, aros@gmx.com,
hakavlad@gmail.com, Yu Zhao <yuzhao@google.com>
Subject: Re: [PATCH] mm/vmscan: add sysctl knobs for protecting the working set
Date: Fri, 03 Dec 2021 15:01:08 +0100 [thread overview]
Message-ID: <4776971.31r3eYUQgx@natalenko.name> (raw)
In-Reply-To: <20211202135824.33d2421bf5116801cfa2040d@linux-foundation.org>
Hello.
On čtvrtek 2. prosince 2021 22:58:24 CET Andrew Morton wrote:
> On Thu, 2 Dec 2021 21:05:01 +0300 ValdikSS <iam@valdikss.org.ru> wrote:
> > This patchset is surprisingly effective and very useful for low-end PC
> > with slow HDD, single-board ARM boards with slow storage, cheap Android
> > smartphones with limited amount of memory. It almost completely prevents
> > thrashing condition and aids in fast OOM killer invocation.
> >
> > The similar file-locking patch is used in ChromeOS for nearly 10 years
> > but not on stock Linux or Android. It would be very beneficial for
> > lower-performance Android phones, SBCs, old PCs and other devices.
> >
> > With this patch, combined with zram, I'm able to run the following
> > software on an old office PC from 2007 with __only 2GB of RAM__
> >
> > simultaneously:
> > * Firefox with 37 active tabs (all data in RAM, no tab unloading)
> > * Discord
> > * Skype
> > * LibreOffice with the document opened
> > * Two PDF files (14 and 47 megabytes in size)
> >
> > And the PC doesn't crawl like a snail, even with 2+ GB in zram!
> > Without the patch, this PC is barely usable.
> > Please watch the video:
> > https://notes.valdikss.org.ru/linux-for-old-pc-from-2007/en/
>
> This is quite a condemnation of the current VM. It shouldn't crawl
> like a snail.
>
> The patch simply sets hard limits on page reclaim's malfunctioning.
> I'd prefer that reclaim not malfunction :(
>
> That being said, I can see that a blunt instrument like this would be
> useful.
>
> I don't think that the limits should be "N bytes on the current node".
> Nodes can have different amounts of memory so I expect it should scale
> the hard limits on a per-node basis. And of course, the various zones
> have different size as well.
Probably not. To my understanding, the limits should roughly correspond to
what you see after executing this:
```
$ echo 1 | sudo tee /proc/sys/vm/drop_caches; grep -F 'Active(file)' /proc/
meminfo
```
IMO, this has nothing to do with the size of the node.
> We do already have a lot of sysctls for controlling these sort of
> things. Was much work put into attempting to utilize the existing
> sysctls to overcome these issues?
--
Oleksandr Natalenko (post-factum)
next prev parent reply other threads:[~2021-12-03 14:01 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-30 11:16 [PATCH] mm/vmscan: add sysctl knobs for protecting the working set Alexey Avramov
2021-11-30 15:28 ` Luis Chamberlain
2021-11-30 18:56 ` Oleksandr Natalenko
2021-12-01 15:51 ` Alexey Avramov
2021-12-02 18:05 ` ValdikSS
2021-12-02 21:58 ` Andrew Morton
2021-12-03 11:59 ` Vlastimil Babka
2021-12-03 13:27 ` Alexey Avramov
2021-12-06 9:59 ` Michal Hocko
2022-01-09 22:59 ` Barry Song
2021-12-03 14:01 ` Oleksandr Natalenko [this message]
2021-12-12 20:15 ` Alexey Avramov
2021-12-13 9:06 ` Barry Song
2021-12-13 9:07 ` Michal Hocko
2021-12-13 8:38 ` Barry Song
2022-01-25 8:19 ` ValdikSS
2022-02-12 0:01 ` Barry Song
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