From: Peter Zijlstra <peterz@infradead.org>
To: Jens Axboe <axboe@kernel.dk>
Cc: "Carter Li 李通洲" <carter.li@eoitek.com>,
"Pavel Begunkov" <asml.silence@gmail.com>,
io-uring <io-uring@vger.kernel.org>,
"Oleg Nesterov" <oleg@redhat.com>,
"Mark Rutland" <mark.rutland@arm.com>,
linux-kernel@vger.kernel.org, "Will Deacon" <will@kernel.org>
Subject: Re: [PATCH] asm-generic/atomic: Add try_cmpxchg() fallbacks
Date: Tue, 18 Feb 2020 15:40:37 +0100 [thread overview]
Message-ID: <20200218144037.GC14946@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <20200218142700.GB14946@hirez.programming.kicks-ass.net>
On Tue, Feb 18, 2020 at 03:27:00PM +0100, Peter Zijlstra wrote:
> diff --git a/scripts/atomic/gen-atomic-fallback.sh b/scripts/atomic/gen-atomic-fallback.sh
> index b6c6f5d306a7..3c9be8d550e0 100755
> --- a/scripts/atomic/gen-atomic-fallback.sh
> +++ b/scripts/atomic/gen-atomic-fallback.sh
> @@ -140,6 +140,32 @@ cat <<EOF
> EOF
> }
>
> +gen_try_cmpxchg_fallback()
> +{
> + local order="$1"; shift;
> +
> +cat <<EOF
> +#ifndef try_cmpxchg${order}
> +#define try_cmpxchg${order}(_ptr, _oldp, _new) \\
> +({ \\
> + typeof(*ptr) ___r, ___o = *(_oldp); \\
*(_ptr)
> + ___r = cmpxchg${order}((_ptr), ___o, (_new)); \\
> + if (unlikely(___r != ___o)) \\
> + *(_old) = ___r; \\
*(_oldp)
> + likely(___r == ___o); \\
> +})
> +#endif /* try_cmpxchg${order} */
And it actually builds, as tested on an ARM build.
next prev parent reply other threads:[~2020-02-18 14:40 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <5995f84e-8a6c-e774-6bb5-5b9b87a9cd3c@kernel.dk>
[not found] ` <7c4c3996-4886-eb58-cdee-fe0951907ab5@kernel.dk>
[not found] ` <addcd44e-ed9b-5f82-517d-c1ed3ee2d85c@kernel.dk>
[not found] ` <b8069e62-7ea4-c7f3-55a3-838241951068@kernel.dk>
[not found] ` <20200217120920.GQ14914@hirez.programming.kicks-ass.net>
[not found] ` <53de3581-b902-89ba-3f53-fd46b052df40@kernel.dk>
[not found] ` <43c066d1-a892-6a02-82e7-7be850d9454d@kernel.dk>
[not found] ` <20200217174610.GU14897@hirez.programming.kicks-ass.net>
[not found] ` <592cf069-41ee-0bc1-1f83-e058e5dd53ff@kernel.dk>
[not found] ` <20200218131310.GZ14914@hirez.programming.kicks-ass.net>
2020-02-18 14:27 ` Peter Zijlstra
2020-02-18 14:40 ` Peter Zijlstra [this message]
2020-02-20 10:30 ` Will Deacon
2020-02-20 10:37 ` Peter Zijlstra
2020-02-20 10:39 ` Will Deacon
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