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From: Arnd Bergmann <arnd@arndb.de>
To: "André Almeida" <andrealmeid@collabora.com>
Cc: Arnd Bergmann <arnd@arndb.de>,
	Alistair Francis <alistair.francis@opensource.wdc.com>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Alistair Francis <alistair23@gmail.com>,
	linux-riscv <linux-riscv@lists.infradead.org>,
	Namhyung Kim <namhyung@kernel.org>, Jiri Olsa <jolsa@redhat.com>,
	linux-perf-users@vger.kernel.org,
	Alexander Shishkin <alexander.shishkin@linux.intel.com>,
	Mark Rutland <mark.rutland@arm.com>,
	Arnaldo Carvalho de Melo <acme@kernel.org>,
	Davidlohr Bueso <dave@stgolabs.net>,
	Darren Hart <dvhart@infradead.org>,
	Peter Zijlstra <peterz@infradead.org>,
	Ingo Molnar <mingo@redhat.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Atish Patra <atish.patra@wdc.com>,
	Alistair Francis <alistair.francis@wdc.com>
Subject: Re: [PATCH v3 2/2] perf bench: Add support for 32-bit systems with 64-bit time_t
Date: Wed, 22 Sep 2021 13:26:16 +0200	[thread overview]
Message-ID: <CAK8P3a0LsxOTYeM-o=Ee=XFD6zN7ESV_dhGmAOFSj_zJ8pBDgA@mail.gmail.com> (raw)
In-Reply-To: <9db8c79a-f704-84ce-360b-84335f926a48@collabora.com>

On Wed, Sep 22, 2021 at 1:06 AM André Almeida <andrealmeid@collabora.com> wrote:
> Às 05:08 de 21/09/21, Arnd Bergmann escreveu:
> > I would love to see the wrapper that Alistair wrote as part of some kernel
> > uapi header provided to user space. futex is used by tons of applications,
> > and we never had a library abstraction for it, so everyone has to do these
> > by hand, and they all get them slightly wrong in different ways.
>
> Why we don't have a futex() wrapper at glibc as we do have for others
> syscalls?

I think mainly because there was no agreement on what the calling
conventions should be:

The raw syscall is awkward because of the argument overloading that cannot
easily be expressed in standard C in a typesafe way. Having a per-operation
interface would avoid that problem but requires specifying what that
particular interface has to be, and there is no standard to fall back on for
this syscall.

       Arnd

  reply	other threads:[~2021-09-22 11:26 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-09-17  6:10 [PATCH v3 1/2] perf benchmark: Call the futex syscall from a function Alistair Francis
2021-09-17  6:10 ` [PATCH v3 2/2] perf bench: Add support for 32-bit systems with 64-bit time_t Alistair Francis
2021-09-17  7:33   ` Arnd Bergmann
2021-09-17 18:33   ` Davidlohr Bueso
2021-09-20 22:47   ` André Almeida
2021-09-21  8:08     ` Arnd Bergmann
2021-09-21 23:06       ` André Almeida
2021-09-22 11:26         ` Arnd Bergmann [this message]
2021-09-22 11:27         ` Arnd Bergmann
2021-09-24  4:34       ` Alistair Francis
2021-09-24  4:34     ` Alistair Francis
2021-09-26 21:32       ` André Almeida
2021-09-17 18:21 ` [PATCH v3 1/2] perf benchmark: Call the futex syscall from a function Davidlohr Bueso

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