From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Paul E. McKenney" Subject: Re: [PATCH v4 0/7] kernel tinification: optionally compile out splice family of syscalls (splice, vmsplice, tee and sendfile) Date: Tue, 25 Nov 2014 10:10:32 -0800 Message-ID: <20141125181032.GJ5050@linux.vnet.ibm.com> References: <1416870079-15254-1-git-send-email-pieter@boesman.nl> <5474ABB6.3030400@infradead.org> <20141125.121305.2094097848188324942.davem@davemloft.net> Reply-To: paulmck@linux.vnet.ibm.com Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20141125.121305.2094097848188324942.davem@davemloft.net> Sender: linux-kernel-owner@vger.kernel.org To: David Miller Cc: rdunlap@infradead.org, pieter@boesman.nl, josh@joshtriplett.org, alexander.h.duyck@intel.com, viro@zeniv.linux.org.uk, ast@plumgrid.com, akpm@linux-foundation.org, beber@meleeweb.net, catalina.mocanu@gmail.com, dborkman@redhat.com, edumazet@google.com, ebiederm@xmission.com, fabf@skynet.be, fuse-devel@lists.sourceforge.net, geert@linux-m68k.org, hughd@google.com, iulia.manda21@gmail.com, JBeulich@suse.com, bfields@fieldses.org, jlayton@poochiereds.net, linux-api@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-nfs@vger.kernel.org, mcgrof@suse.com, mattst88@gmail.com, mgorman@suse.de, mst@redhat.com, miklos@szeredi.hu, netdev@vger.kernel.org, oleg@redhat.com, Paul.Durrant@citrix.com, pefoley2@pefoley.com, tgraf@suug.ch, therbert@google.com, trond.myklebust@primarydata.com, willemb@google.com, xiaoguangrong@linux.vnet.ibm.com, zhenglong List-Id: linux-api@vger.kernel.org On Tue, Nov 25, 2014 at 12:13:05PM -0500, David Miller wrote: > From: Randy Dunlap > Date: Tue, 25 Nov 2014 08:17:58 -0800 > > > Is the splice family of syscalls the only one that tiny has identified > > for optional building or can we expect similar treatment for other > > syscalls? > > > > Why will many embedded systems not need these syscalls? You know > > exactly what apps they run and you are positive that those apps do > > not use splice? > > I think starting to compile out system calls is a very slippery > slope we should not begin the journey down. > > This changes the forward facing interface to userspace. I certainly sympathize with this concern, given the importance of software portability. However, the tiny-hardware alternative appears ot some sort of special-purpose embedded OS, which most definitely will suffer from software compatibility issues. I guess that the good news is that much of the tiny hardware that used to be 8 or 16 bits is now 32 bits, which means that it has at least some chance of running some form of Linux. ;-) Thanx, Paul