Re: pagecache locking (was: bcachefs status update) merged)
From: Linus Torvalds
Date: Sat Jun 15 2019 - 00:06:49 EST
On Thu, Jun 13, 2019 at 5:08 PM Linus Torvalds
> I do not believe that posix itself actually requires that at all,
> although extended standards may.
So I tried to see if I could find what this perhaps alludes to.
And I suspect it's not in the read/write thing, but the pthreads side
talks about atomicity.
Interesting, but I doubt if that's actually really intentional, since
the non-thread read/write behavior specifically seems to avoid the
whole concurrency issue.
The pthreads atomicity thing seems to be about not splitting up IO and
doing it in chunks when you have m:n threading models, but can be
(mis-)construed to have threads given higher atomicity guarantees than