Re: [RFC 5/5] pm: remove kernel thread freezing

From: Bart Van Assche
Date: Tue Oct 03 2017 - 21:04:08 EST


On Wed, 2017-10-04 at 02:47 +0200, Luis R. Rodriguez wrote:
> 3) Lookup for kthreads which seem to generate IO -- address / review if
> removal of the freezer API can be done somehow with a quescing. This
> is currently for example being done on SCSI / md.
> 4) Only after all the above is done should we consider this patch or some
> form of it.

After having given this more thought, I think we should omit these last two
steps. Modifying the md driver such that it does not submit I/O requests while
processes are frozen requires either to use the freezer API or to open-code it.
I think there is general agreement in the kernel community that open-coding a
single mechanism in multiple drivers is wrong. Does this mean that instead of
removing the freezer API we should keep it and review all its users instead?

Bart.