To agk@sourceware.org
cc: dm-devel@redhat.com, linux-kernel@vger.kernel.org
Subject: [RFC][PATCH 0/10] I/O context inheritance
From: Hirokazu Takahashi <taka@valinux.co.jp>
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Hi,
This series of patches make the block I/O layer and the I/O schedulers
be able to determine the right io_context of every I/O.
The current implementation of the block I/O layer and the I/O schedulers
assume that the current process is the one which issued the given I/O,
then use the io_context of this process to control the I/O.
But this assumption isn't quite right because several kernel threads
will handle I/O requests on behalf of the processes which originated them.
This often happens when you want to use device mapper modules.
The patches make every bio has a pointer to an io_context, which will
be set when it is allocated or cloned. So it makes it possible to find
the right io_context from any bio at any place.
I'm waiting for your comments.
Thank you,
Hirokazu Takahashi.
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