Re: [PATCH] sched: make struct task_struct::state 32-bit

[Alexey Dobriyan]

On Tue, Sep 03, 2019 at 06:29:06PM +0100, Valentin Schneider wrote:
> On 02/09/2019 22:05, Alexey Dobriyan wrote:
> > 32-bit accesses are shorter than 64-bit accesses on x86_64.
> > Nothing uses 64-bitness of ->state.

> It looks like you missed a few places. There's a long prev_state in
> sched/core.c::finish_task_switch() for instance.
> 
> I suppose that's where coccinelle oughta help but I'm really not fluent
> in that. Is there a way to make it match p.state accesses with p task_struct?
> And if so, can we make it change the type of the variable being read from
> / written to?

Coccinelle is interesting: basic

	- foo
	+ bar

doesn't find "foo" in function arguments.

I'm scared of coccinelle.

> How did you come up with this changeset, did you pickaxe for some regexp?

No, manually, backtracking up to the call chain.
Maybe I missed a few places.