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

From: Luis R. Rodriguez
Date: Wed Nov 29 2017 - 18:05:43 EST


On Wed, Oct 04, 2017 at 01:03:54AM +0000, Bart Van Assche wrote:
> 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?

Agreed.

Luis