Re: [PATCH 0/2] pipe: Fixes [ver #2]

From: Linus Torvalds
Date: Fri Dec 06 2019 - 22:50:36 EST


On Fri, Dec 6, 2019 at 1:04 PM Linus Torvalds
<torvalds@xxxxxxxxxxxxxxxxxxxx> wrote:
>
> It doesn't fix my "kernel compiles go single-threaded" issue.

I ended up just bisecting it.

The "make goes slow" problem bisects down to b667b8673443 ("pipe:
Advance tail pointer inside of wait spinlock in pipe_read()").

I assume it's the added "do_wakeup = 0" (not the spinlock) that ends
up having some subtle issue.

Very strange, but there it is.

Linus