From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Zijlstra Subject: Re: [PATCH 2/2] arm64: bpf: add BPF XADD instruction Date: Wed, 11 Nov 2015 20:23:52 +0100 Message-ID: <20151111192352.GT17308@twins.programming.kicks-ass.net> References: <56436420.9090401@iogearbox.net> <20151111162341.GN9562@arm.com> <20151111172659.GA86334@ast-mbp.thefacebook.com> <20151111.123548.1039494689070388545.davem@davemloft.net> <20151111175741.GR17308@twins.programming.kicks-ass.net> <20151111181132.GA90947@ast-mbp.thefacebook.com> <20151111183128.GS17308@twins.programming.kicks-ass.net> <56438DE7.4080300@iogearbox.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Alexei Starovoitov , David Miller , will.deacon@arm.com, arnd@arndb.de, yang.shi@linaro.org, linaro-kernel@lists.linaro.org, eric.dumazet@gmail.com, zlim.lnx@gmail.com, ast@kernel.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, xi.wang@gmail.com, catalin.marinas@arm.com, linux-arm-kernel@lists.infradead.org, yhs@plumgrid.com, bblanco@plumgrid.com To: Daniel Borkmann Return-path: Content-Disposition: inline In-Reply-To: <56438DE7.4080300@iogearbox.net> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Wed, Nov 11, 2015 at 07:50:15PM +0100, Daniel Borkmann wrote: > Well, on that note, it's not like you just change the target to bpf in your > Makefile and can compile (& load into the kernel) anything you want with it. > You do have to write small, restricted programs from scratch for a specific > use-case with the limited set of helper functions and intrinsics that are > available from the kernel. So I don't think that "Programs that used to work > will now no longer work." holds if you regard it as such. So I don't get this argument. If everything is so targeted, then why are the BPF instructions an ABI. If OTOH you're expected to be able to transfer these small proglets, then too I would expect to transfer the source of these proglets. You cannot argue both ways.