Date: Tue, 16 Jan 2018 10:08:09 +0100
From: Lars Ellenberg <lars.ellenberg@linbit.com>
To: Eric Wheeler <drbd-dev@lists.ewheeler.net>
Cc: drbd-dev@lists.linbit.com, Eric Wheeler <git@linux.ewheeler.net>,
        Eric Wheeler <drbd@linux.ewheeler.net>,
        Philipp Reisner <philipp.reisner@linbit.com>,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH] drbd: standardize kthread/workqueue thread naming to
 include drbd minor number
Message-ID: <20180116090809.GC4107@soda.linbit>
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        Eric Wheeler <drbd@linux.ewheeler.net>,
        Philipp Reisner <philipp.reisner@linbit.com>,
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On Mon, Jan 15, 2018 at 03:52:15PM -0800, Eric Wheeler wrote:
> From: Eric Wheeler <git@linux.ewheeler.net>
> 
> For DRBD resources with long names that start with the same prefix,
> it was difficult to find all process pids for that minor since names
> are truncated to the task_struct's comm field (16 bytes).
> 
> This patch names all processes associated with a DRBD device as drbdN_*
> where N is the DRBD minor in the same ways that the drbdN_submit workqueue
> is named.  Userspace tools can then lookup the name=>minor=>pid mapping
> and for all pids and use tools like chrt, ioprio, nice, add pids to
> cgroups, or for other useful purpose.


DRBD can do "multi volume" resources, which means most threads
are associated not with one, but with many minors.

"does not work just like that"

    Lars