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[35.185.214.157]) by smtp.gmail.com with ESMTPSA id h21sm6580708pfc.118.2021.09.17.09.53.56 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 17 Sep 2021 09:53:56 -0700 (PDT) Date: Fri, 17 Sep 2021 16:53:52 +0000 From: Sean Christopherson To: Peter Zijlstra Subject: Re: [PATCH v2 00/13] perf: KVM: Fix, optimize, and clean up callbacks Message-ID: References: <20210828003558.713983-1-seanjc@google.com> <20210828201336.GD4353@worktop.programming.kicks-ass.net> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: X-Mailman-Approved-At: Sun, 19 Sep 2021 06:09:08 -0400 Cc: Wanpeng Li , kvm@vger.kernel.org, Alexander Shishkin , Catalin Marinas , Guo Ren , "H. Peter Anvin" , linux-riscv@lists.infradead.org, Vincent Chen , Jiri Olsa , Boris Ostrovsky , Stefano Stabellini , xen-devel@lists.xenproject.org, Marc Zyngier , Joerg Roedel , x86@kernel.org, linux-csky@vger.kernel.org, kvmarm@lists.cs.columbia.edu, Ingo Molnar , Like Xu , Albert Ou , Zhu Lingshan , Will Deacon , Arnaldo Carvalho de Melo , Borislav Petkov , Greentime Hu , Paul Walmsley , Namhyung Kim , Thomas Gleixner , Artem Kashkanov , linux-arm-kernel@lists.infradead.org, Jim Mattson , Juergen Gross , Nick Hu , linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, Palmer Dabbelt , Paolo Bonzini , Vitaly Kuznetsov X-BeenThere: kvmarm@lists.cs.columbia.edu X-Mailman-Version: 2.1.14 Precedence: list List-Id: Where KVM/ARM decisions are made List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu On Fri, Sep 17, 2021, Peter Zijlstra wrote: > On Thu, Sep 16, 2021 at 09:37:43PM +0000, Sean Christopherson wrote: > So I don't mind exporting __static_call_return0, but exporting a raw > static_call is much like exporting a function pointer :/ Ya, that part is quite gross. > > The unregister path would also need its own synchronize_rcu(). In general, I > > don't love duplicating the logic, but it's not the end of the world. > > > > Either way works for me. Paolo or Peter, do either of you have a preference? > > Can we de-feature kvm as a module and only have this PT functionality > when built-in? :-) I agree that many of the for-KVM exports are ugly, especially several of the perf exports, but I will fight tooth and nail to keep KVM-as-a-module. It is invaluable for development and testing, and in the not-too-distant future there is KVM-maintenance related functionality that we'd like to implement that relies on KVM being a module. I would be more than happy to help explore approaches that reduce the for-KVM exports, but I am strongly opposed to defeaturing KVM-as-a-module. I have a few nascent ideas for eliminating a handful of a random exports, but no clever ideas for eliminating perf's for-KVM exports. _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm