Re: [PATCH AUTOSEL 5.5 542/542] pipe: use exclusive waits when reading or writing

From: Linus Torvalds
Date: Tue Feb 18 2020 - 13:54:04 EST

On Fri, Feb 14, 2020 at 8:00 AM Sasha Levin <sashal@xxxxxxxxxx> wrote:
> From: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
> [ Upstream commit 0ddad21d3e99c743a3aa473121dc5561679e26bb ]
> This makes the pipe code use separate wait-queues and exclusive waiting
> for readers and writers, [..]

Oh, and since I didn't react initially, let me react now that Andrei
found a bug here: why was this patch auto-selected for 5.5 stable in
the first place?

It wasn't really a fix, and there's no Fixes: tag or stable tag in
there. Yeah, there's a reference to an old commit, but that one isn't
even a kernel commit.

Yeah, the performance improvements are quite nice if you hit the case
this matters for, but still..