Date:   Sat, 11 Dec 2021 08:28:59 -0300
From:   Arnaldo Carvalho de Melo <acme@kernel.org>
To:     Arnd Bergmann <arnd@arndb.de>
Cc:     Alistair Francis <alistair.francis@opensource.wdc.com>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Davidlohr Bueso <dave@stgolabs.net>,
        Darren Hart <dvhart@infradead.org>,
        Alistair Francis <alistair23@gmail.com>,
        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>,
        Ingo Molnar <mingo@redhat.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Alistair Francis <alistair.francis@wdc.com>,
        Atish Patra <atish.patra@wdc.com>,
        linux-riscv <linux-riscv@lists.infradead.org>,
        Arnaldo Carvalho de Melo <acme@redhat.com>
Subject: Re: [PATCH v5 1/6] perf bench futex: Add support for 32-bit systems
 with 64-bit time_t
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Em Fri, Dec 10, 2021 at 03:23:42PM +0100, Arnd Bergmann escreveu:
> On Fri, Dec 10, 2021 at 2:44 PM Arnaldo Carvalho de Melo
> <acme@kernel.org> wrote:
> > Em Fri, Dec 10, 2021 at 10:36:30AM -0300, Arnaldo Carvalho de Melo escreveu:
> > > Em Fri, Dec 10, 2021 at 09:58:52AM +1000, Alistair Francis escreveu:
> > > > From: Alistair Francis <alistair.francis@wdc.com>

> > > > Some 32-bit architectures (such are 32-bit RISC-V) only have a 64-bit
> > > > time_t and as such don't have the SYS_futex syscall. This patch will
> > > > allow us to use the SYS_futex_time64 syscall on those platforms.

> > > > This also converts the futex calls to be y2038 safe (when built for a
> > > > 5.1+ kernel).

> > > > This is a revert of commit ba4026b09d83acf56c040b6933eac7916c27e728
> > > > "Revert "perf bench futex: Add support for 32-bit systems with 64-bit time_t"".

> > > > The original commit was reverted as including linux/time_types.h would
> > > > fail to compile on older kernels. This commit doesn't include
> > > > linux/time_types.h to avoid this issue.

> > >   10     9.99 alpine:3.12                   : FAIL gcc version 9.3.0 (Alpine 9.3.0)
> > >     In file included from bench/futex-hash.c:29:
> > >     bench/futex.h:37:2: error: unknown type name '__kernel_old_time_t'
> > >        37 |  __kernel_old_time_t tv_sec;  /* seconds */
> > >           |  ^~~~~~~~~~~~~~~~~~~
> > >     In file included from bench/futex-wake.c:25:
 
> It looks like we need to add include/uapi/linux/time_types.h to
> tools/include/linux/ and update tools/include/linux/types.h
> in order to address this.

And make sure it is found before the system ones, yes, that would fix
the issues. I'll try to do it these days.

- Arnaldo