Re: [PATCH] lib/genalloc: use try_cmpxchg in {set,clear}_bits_ll
From: Mateusz Guzik
Date: Tue Jan 24 2023 - 01:48:56 EST
On 1/24/23, Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> wrote:
> On Mon, Jan 23, 2023 at 4:11 PM Mateusz Guzik <mjguzik@xxxxxxxxx> wrote:
>>
>> On another point how to end up dealing with lockref less, I have to
>> note glibc switched fstat(fd, buf) to use newfstatat(fd, "", buf,
>> AT_EMPTY_PATH) internally.
>
> Yeah, that's just plain stupid.
>
> I don't know what the thinking (or rather, lack-thereof) was inside
> glibc for that one.
>
To my reading the fstat system call is now legacy so they switched to
something else. There is a lot to say about the stat situation (going
past the fd vs lookup issue), which I'm going to do on fsdevel (perhaps
next week).
All flaming aside, I think Uros is still waiting for an answer what
should be done in cmpxchg loops and someone else will have to provide
it.
I stated my case for the best course of action being to do nothing
(for x86-64 anyway), but I'm not an authority figure.
--
Mateusz Guzik <mjguzik gmail.com>