From: Thomas Monjalon <thomas@monjalon.net>
To: Joyce Kong <joyce.kong@arm.com>
Cc: Ruifeng Wang <ruifeng.wang@arm.com>,
Bruce Richardson <bruce.richardson@intel.com>,
dev@dpdk.org, nd@arm.com
Subject: Re: [PATCH v2] config/arm: support ldapr on neoverse n1
Date: Tue, 21 Mar 2023 12:16:48 +0100 [thread overview]
Message-ID: <3212656.N7aMVyhfb1@thomas> (raw)
In-Reply-To: <20230321094433.736943-1-joyce.kong@arm.com>
21/03/2023 10:44, Joyce Kong:
> Armv8.3 introduced a LDAPR instruction that has weaker guarantees,
> just sufficient to implement memory_order_acq_rel. LDAPR does not
> wait for previous STLR to complete. And if the same location is
> used in both, it does not force the write to be globally observed.
> The new instruction can avoid some costs associated with LDAR.
>
> GCC13.0 has supported LDAPR.
> For Armv8.3 and higher, LDAPR is default.
> For Armv8.2 such as neoverse n1, LDAPR is supported with enabling
> rcpc feature.
> For Armv8.1 and lower, LDAPR is not supported.
>
> Signed-off-by: Joyce Kong <joyce.kong@arm.com>
> Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>
Applied, thanks.
prev parent reply other threads:[~2023-03-21 11:16 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-03-20 3:26 [PATCH] config/arm: enable rcpc feature " Joyce Kong
2023-03-20 16:10 ` Thomas Monjalon
2023-03-21 2:13 ` Joyce Kong
2023-03-21 9:44 ` [PATCH v2] config/arm: support ldapr " Joyce Kong
2023-03-21 11:16 ` Thomas Monjalon [this message]
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