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From: Tejun Heo <tj@kernel.org>
To: Weiping Zhang <zwp10758@gmail.com>
Cc: Jens Axboe <axboe@kernel.dk>,
	linux-block@vger.kernel.org, cgroups@vger.kernel.org
Subject: Re: [RFC 0/3] blkcg: add blk-iotrack
Date: Tue, 31 Mar 2020 10:19:16 -0400
Message-ID: <20200331141916.GR162390@mtj.duckdns.org> (raw)
In-Reply-To: <CAA70yB66fBdAOnv+8rXauwbuPu+UY+gr9ZKeSsQNgq+ZHhJn3Q@mail.gmail.com>

Hello, Weiping.

On Fri, Mar 27, 2020 at 12:27:11AM +0800, Weiping Zhang wrote:
> I really appreciate that if you help review blk-iotrack.c, or just
> drop io.iotrakc.stat
> and append these  statistics to the io.stat? I think these metrics is usefull,

So, the problem is that you can get the same exact and easily more information
using bpf. There definitely are benefits to baking in some stastics in terms of
overhead and accessbility but I'm not sure what's being proposed is generic
and/or flexible enough to bake into the interface at this point.

Something which can be immediately useful would be cgroup-aware bpf progs which
expose these statistics. Can you please take a look at the followings?

  https://github.com/iovisor/bcc/blob/master/tools/biolatency.py
  https://github.com/iovisor/bcc/blob/master/tools/biolatency_example.txt

They aren't cgroup aware but can be made so and can provide a lot more detailed
statistics than something we can hardcode into the kernel.

Thanks.

-- 
tejun

  reply index

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-03-21  1:20 Weiping Zhang
2020-03-21  1:21 ` [RFC 1/3] update the real issue size when bio_split Weiping Zhang
2020-03-21  1:21 ` [RFC 2/3] bio: track timestamp of submitting bio the disk driver Weiping Zhang
2020-03-21  1:21 ` [RFC 3/3] blkcg: add blk-iotrack Weiping Zhang
2020-03-24 18:27 ` [RFC 0/3] " Tejun Heo
2020-03-25 12:49   ` Weiping Zhang
2020-03-25 14:12     ` Tejun Heo
2020-03-25 16:45       ` Weiping Zhang
2020-03-26 15:08         ` Weiping Zhang
2020-03-26 16:14           ` Tejun Heo
2020-03-26 16:27             ` Weiping Zhang
2020-03-31 14:19               ` Tejun Heo [this message]
2020-03-27  6:27 ` [RFC PATCH v2 " Weiping Zhang

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