From mboxrd@z Thu Jan 1 00:00:00 1970 From: pwalmsley@nvidia.com (Paul Walmsley) Date: Wed, 30 Oct 2013 08:53:08 -0700 Subject: [GIT PULL] prefetch support for 3.13 In-Reply-To: <20131030152553.GD16735@n2100.arm.linux.org.uk> References: <20131009171312.GJ8378@mudshark.cambridge.arm.com> <527124B3.9090305@nvidia.com> <20131030152553.GD16735@n2100.arm.linux.org.uk> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi Russell, On Wed, 30 Oct 2013, Russell King - ARM Linux wrote: > On Wed, Oct 30, 2013 at 08:24:35AM -0700, Paul Walmsley wrote: >> Hi Will et al., >> >> On 10/09/2013 10:13 AM, Will Deacon wrote: >>> Hi Russell, >>> >>> Please pull the following patches for 3.13. They add support for the pldw >>> instruction (prefetch with intent to modify) in ARMv7 SMP cores, which is >>> then used to gain a measurable performance boost for particular atomic >>> sequences. >> >> Looks like the pldw changes require binutils >= 2.21. Might be worth >> considering a patch to update Documentation/Changes? > > Not really - because that says "for all architectures the minimum > requirement is now 2.21 or later" and that's certainly not the case. > > It's only ARMv7 which requires this. Would you consider something like the following? - Paul From: Paul Walmsley Date: Wed, 30 Oct 2013 08:51:26 -0700 Subject: [PATCH] Documentation/Changes: update binutils version requirement for ARMv7 builds ARMv7 builds now make use of the pldw opcode and the ".arch_extension mp" pragma. These aren't supported in binutils prior to 2.21. So, update Documentation/Changes accordingly. Signed-off-by: Paul Walmsley Cc: Will Deacon Cc: Russell King Cc: Stephen Warren Cc: Thierry Reding --- Documentation/Changes | 3 +++ 1 file changed, 3 insertions(+) diff --git a/Documentation/Changes b/Documentation/Changes index b175808..97fcbdf 100644 --- a/Documentation/Changes +++ b/Documentation/Changes @@ -67,6 +67,9 @@ assembling the 16-bit boot code, removing the need for as86 to compile your kernel. This change does, however, mean that you need a recent release of binutils. +ARMv7 builds require binutils 2.21 or later due to the use of the pldw +opcode and ".arch_extension mp". + Perl ---- -- 1.8.1.5