From mboxrd@z Thu Jan 1 00:00:00 1970 From: "acme@redhat.com" Subject: Re: [RFC] perf: fix building for ARCv1 Date: Fri, 5 Feb 2016 13:10:27 -0300 Message-ID: <20160205161027.GG28242@kernel.org> References: <20151019095157.GM3816@twins.programming.kicks-ass.net> <20151020101133.GA17308@twins.programming.kicks-ass.net> <1446134296.3203.27.camel@synopsys.com> <1454516455.2811.4.camel__10775.5710989752$1454516490$gmane$org@synopsys.com> <56B2CFF2.4030503@synopsys.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-snps-arc" Errors-To: linux-snps-arc-bounces+gla-linux-snps-arc=m.gmane.org@lists.infradead.org To: Noam Camus Cc: "peterz@infradead.org" , Vineet Gupta , Alexey Brodkin , "linux-kernel@vger.kernel.org" , "linux-perf-users@vger.kernel.org" , "andi@firstfloor.org" , "dsahern@gmail.com" , "tglx@linutronix.de" , "linux-snps-arc@lists.infradead.org" , "dvhart@linux.intel.com" , Gilad Ben Yossef List-Id: linux-perf-users.vger.kernel.org Em Fri, Feb 05, 2016 at 11:18:52AM +0000, Noam Camus escreveu: > Well here for EZchip I also see the: > undefined reference to `__sync_add_and_fetch_4' > undefined reference to `__sync_sub_and_fetch_4' Yeah, because there is no: tools/arch/arc/include/asm/atomic.h, can't you guys adapt arch/arc/include/asm/atomic.h to use in userspace? - Arnaldo > This is since at file tools/include/asm/atomic.h we use the generic implementation > If for ARC I could use just like x86 my own header file then functions like: > atomic_inc() > atomic_dec_and_test() > Are easy to implement and you may see an example for such atomic methods in my patch set for the new platform. > > You however wants to use some GCC flag -matomic which I assume somehow will implement the above __sync*. > I can't find the implementation but if it uses LLSC then it won't work for me since I am not supporting LLSC. > So seem that either I have my own header at kernel or that I need to > change the GCC implementation for __sync* to use my atomic > instructions. I am personally tend to the x86 solution and not the > generic one since changing GCC will require to have new compiler > dependency.