From mboxrd@z Thu Jan 1 00:00:00 1970 From: mzoran@crowfest.net (Michael Zoran) Date: Sun, 22 Jan 2017 01:33:50 -0800 Subject: ARM64: Disabling warnings about deprecated armv8 instructions In-Reply-To: References: <1485072424.14066.2.camel@crowfest.net> <9647813.NZ2c5cYUSH@localhost> <1485075528.14345.1.camel@crowfest.net> Message-ID: <1485077630.1308.0.camel@crowfest.net> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Sun, 2017-01-22 at 09:09 +0000, Ard Biesheuvel wrote: > On 22 January 2017 at 08:58, Michael Zoran > wrote: > > On Sun, 2017-01-22 at 09:52 +0100, Alexander Stein wrote: > > > Hi Michael, > > > > > > On Sunday, January 22, 2017, 12:07:04 AM CET Michael Zoran wrote: > > > > I'm not sure if this if the correct place to be asking > > > > this.???The > > > > RPI > > > > 3 running ARM64 is slowly reaching the point of being about to > > > > seriously run a 32 bit vender OS like Raspbian.??When running > > > > Raspbian, > > > > I'm seeing a very large number(thousands) of kernel log > > > > messages > > > > about > > > > deprecated instructions especially setend and barrier > > > > instuctions. > > > > This can be very annoying and is completely filling the kernel > > > > log. > > > > > > > > I'm considering submitting a patch to add a Kconfig option to > > > > disable > > > > these warnings with the default being to keep the warnings > > > > enabled.??I > > > > was wondering if such a patch could be seriously considered. > > > > > > Could you please provide an example of those warning an what is > > > trigging > > > those? > > > > > > Thanks and best regards, > > > Alexander > > > > Sure, here is a snipped from dmesg.??I think this is happening > > because > > the entire Raspbian OS is compiled with a custom gcc compiler that > > is > > targeting arm6+VFP. > > > > I can double check, but I think the instructions are being emulated > > in > > hardware so they are just filling the log and slowing things down. > > > > You can disable the emulation by doing > > echo 2 >/proc/sys/abi/setend > echo 2 >/proc/sys/abi/cp15_barrier I don't want to disable the emulation since I want to run old binaries. I just want to disable the warning...