From: Andrew Morton <akpm@linux-foundation.org>
To: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org,
cgroups@vger.kernel.org, linux-fsdevel@vger.kernel.org,
Tejun Heo <tj@kernel.org>, Jens Axboe <axboe@kernel.dk>,
Johannes Weiner <hannes@cmpxchg.org>,
Michal Hocko <mhocko@kernel.org>
Subject: Re: [PATCH] mm/backing-dev: show state of all bdi_writeback in debugfs
Date: Tue, 23 Jul 2019 13:07:29 -0700 [thread overview]
Message-ID: <20190723130729.522976a1f075d748fc946ff6@linux-foundation.org> (raw)
In-Reply-To: <156388617236.3608.2194886130557491278.stgit@buzz>
On Tue, 23 Jul 2019 15:49:32 +0300 Konstantin Khlebnikov <khlebnikov@yandex-team.ru> wrote:
> Currently /sys/kernel/debug/bdi/$maj:$min/stats shows only root bdi wb.
> With CONFIG_CGROUP_WRITEBACK=y there is one for each memory cgroup.
>
> This patch shows here state of each bdi_writeback in form:
>
> <global state>
>
> Id: 1
> Cgroup: /
> <root wb state>
>
> Id: xxx
> Cgroup: /path
> <cgroup wb state>
>
> Id: yyy
> Cgroup: /path2
> <cgroup wb state>
Why is this considered useful? What are the use cases. ie, why should
we add this to Linux?
> mm/backing-dev.c | 106 +++++++++++++++++++++++++++++++++++++++++++++++-------
> 1 file changed, 93 insertions(+), 13 deletions(-)
No documentation because it's debugfs, right?
I'm struggling to understand why this is a good thing :(. If it's
there and people use it then we should document it for them. If it's
there and people don't use it then we should delete the code.
next prev parent reply other threads:[~2019-07-23 20:07 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-23 12:49 Konstantin Khlebnikov
2019-07-23 20:07 ` Andrew Morton [this message]
2019-07-23 21:24 ` Konstantin Khlebnikov
2019-07-23 22:36 ` Tejun Heo
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