[dm-devel] Re: [RFC][PATCH 0/10] I/O context inheritance

[Hirokazu Takahashi]

Hi,

Sorry, these patches are for linux-2.6.25.

> 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.