From: Miklos Szeredi <miklos@szeredi.hu>
To: Michael Stapelberg <stapelberg+linux@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
linux-kernel@vger.kernel.org, linux-mm <linux-mm@kvack.org>,
linux-fsdevel@vger.kernel.org, Tejun Heo <tj@kernel.org>,
Dennis Zhou <dennis@kernel.org>, Jens Axboe <axboe@kernel.dk>,
Roman Gushchin <guro@fb.com>,
Johannes Thumshirn <johannes.thumshirn@wdc.com>,
Jan Kara <jack@suse.cz>, Song Liu <song@kernel.org>,
David Sterba <dsterba@suse.com>
Subject: Re: [PATCH] backing_dev_info: introduce min_bw/max_bw limits
Date: Fri, 18 Jun 2021 16:41:58 +0200 [thread overview]
Message-ID: <CAJfpegu0prjjHVhBzwZBVk5N+avHvUcyi4ovhKbf+F7GEuVkmw@mail.gmail.com> (raw)
In-Reply-To: <CAH9Oa-ZcG0+08d=D5-rbzY-v1cdUcuW0E7D_GcwjDoC1Phf+0g@mail.gmail.com>
On Fri, 18 Jun 2021 at 10:31, Michael Stapelberg
<stapelberg+linux@google.com> wrote:
> Maybe, but I don’t have the expertise, motivation or time to
> investigate this any further, let alone commit to get it done.
> During our previous discussion I got the impression that nobody else
> had any cycles for this either:
> https://lore.kernel.org/linux-fsdevel/CANnVG6n=ySfe1gOr=0ituQidp56idGARDKHzP0hv=ERedeMrMA@mail.gmail.com/
>
> Have you had a look at the China LSF report at
> http://bardofschool.blogspot.com/2011/?
> The author of the heuristic has spent significant effort and time
> coming up with what we currently have in the kernel:
>
> """
> Fengguang said he draw more than 10K performance graphs and read even
> more in the past year.
> """
>
> This implies that making changes to the heuristic will not be a quick fix.
Having a piece of kernel code sitting there that nobody is willing to
fix is certainly not a great situation to be in.
And introducing band aids is not going improve the above situation,
more likely it will prolong it even further.
Thanks,
Miklos
next prev parent reply other threads:[~2021-06-18 14:42 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-17 9:53 [PATCH] backing_dev_info: introduce min_bw/max_bw limits Michael Stapelberg
2021-06-18 8:18 ` Miklos Szeredi
2021-06-18 8:31 ` Michael Stapelberg
2021-06-18 9:12 ` Hillf Danton
2021-06-18 14:41 ` Miklos Szeredi [this message]
2021-06-21 9:20 ` Michael Stapelberg
2021-06-22 12:12 ` Jan Kara
2021-06-22 12:29 ` Michael Stapelberg
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