From: Peter Zijlstra <peterz@infradead.org>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: "André Almeida" <andrealmeid@collabora.com>,
"Ingo Molnar" <mingo@redhat.com>,
"Darren Hart" <dvhart@infradead.org>,
linux-kernel@vger.kernel.org,
"Steven Rostedt" <rostedt@goodmis.org>,
"Sebastian Andrzej Siewior" <bigeasy@linutronix.de>,
kernel@collabora.com, krisman@collabora.com,
linux-api@vger.kernel.org, libc-alpha@sourceware.org,
mtk.manpages@gmail.com, "Davidlohr Bueso" <dave@stgolabs.net>
Subject: Re: [PATCH 2/4] futex2: Implement vectorized wait
Date: Wed, 18 Aug 2021 18:20:34 +0200 [thread overview]
Message-ID: <20210818162034.GA26408@worktop.programming.kicks-ass.net> (raw)
In-Reply-To: <87v94310gm.ffs@tglx>
On Wed, Aug 18, 2021 at 01:00:57PM +0200, Thomas Gleixner wrote:
> > +/**
> > + * struct futex_waitv - A waiter for vectorized wait
> > + * @val: Expected value at uaddr
> > + * @uaddr: User address to wait on
> > + * @flags: Flags for this waiter
> > + */
> > +struct futex_waitv {
> > + __u64 val;
>
> Again. Why u64?
So I think the idea was that if we're going to do new syscalls, we
should cater for future extentions, one of which was 64bit futexes (for
64bit archs) (along with u{8,16,32})
The previous set of patches implemented a more complete replacement ABI
-- which I rather liked, however the implementation was completely
disjoint from the existing futexes, which was a non-starter for me.
Anyway, yes, current futexes are u32, but if we want to ever do u64
futexes, we should either do this syscall with a u64, or already plan to
retire the whole syscall.
Obiously this would've made good Changelog material, but alas it wasn't
there.
next prev parent reply other threads:[~2021-08-18 16:22 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-05 19:04 [PATCH 0/4] futex2: Add wait on multiple futexes syscall André Almeida
2021-08-05 19:04 ` [PATCH 1/4] futex: Prepare for futex_wait_multiple() André Almeida
2021-08-18 8:22 ` Thomas Gleixner
2021-08-05 19:04 ` [PATCH 2/4] futex2: Implement vectorized wait André Almeida
2021-08-05 23:48 ` kernel test robot
2021-08-06 0:17 ` kernel test robot
2021-08-06 0:20 ` kernel test robot
2021-08-06 7:06 ` kernel test robot
2021-08-18 11:00 ` Thomas Gleixner
2021-08-18 16:20 ` Peter Zijlstra [this message]
2021-08-18 16:34 ` André Almeida
2021-08-18 19:45 ` Thomas Gleixner
2021-08-19 3:38 ` André Almeida
2021-08-05 19:04 ` [PATCH 3/4] selftests: futex2: Add waitv test André Almeida
2021-08-05 19:04 ` [PATCH 4/4] futex2: Documentation: Document futex_waitv() uAPI André Almeida
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20210818162034.GA26408@worktop.programming.kicks-ass.net \
--to=peterz@infradead.org \
--cc=andrealmeid@collabora.com \
--cc=bigeasy@linutronix.de \
--cc=dave@stgolabs.net \
--cc=dvhart@infradead.org \
--cc=kernel@collabora.com \
--cc=krisman@collabora.com \
--cc=libc-alpha@sourceware.org \
--cc=linux-api@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@redhat.com \
--cc=mtk.manpages@gmail.com \
--cc=rostedt@goodmis.org \
--cc=tglx@linutronix.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.