From mboxrd@z Thu Jan 1 00:00:00 1970 From: James Hogan Subject: Re: [PATCH v2 00/44] Meta Linux Kernel Port Date: Tue, 18 Dec 2012 16:09:02 +0000 Message-ID: <50D0951E.7060503@imgtec.com> References: <1354723742-6195-1-git-send-email-james.hogan@imgtec.com> <20121205171131.GV4939@ZenIV.linux.org.uk> <20121205183923.GY4939@ZenIV.linux.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit Return-path: Received: from multi.imgtec.com ([194.200.65.239]:55637 "EHLO multi.imgtec.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755122Ab2LRQJE (ORCPT ); Tue, 18 Dec 2012 11:09:04 -0500 In-Reply-To: <20121205183923.GY4939@ZenIV.linux.org.uk> Sender: linux-arch-owner@vger.kernel.org List-ID: To: Al Viro Cc: linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, Arnd Bergmann On 05/12/12 18:39, Al Viro wrote: > On Wed, Dec 05, 2012 at 05:11:32PM +0000, Al Viro wrote: >> On Wed, Dec 05, 2012 at 04:08:18PM +0000, James Hogan wrote: >> >>> other work not included: >>> * switch to generic kernel_{thread,execve} (will be posted separately to >>> aid review) >> >>> other changes: >> ... >>> * switch to generic sys_execve >> >> ... which should've broken your kernel_execve(). > > BTW, one general note: lose the magical 7th argument. In the few syscalls > that do need pt_regs, you can bloody well use current_pt_regs() instead; > it's what, (register & constant) + constant? Passing it as explicit > argument is saving at most two arithmetical insns on those syscalls. > Moreover, for fork/clone/vfork we really don't need it until copy_thread(); > one of the changes in -next kills passing pt_regs * to do_fork() and through > all that call chain (furthermore, if you make that > childregs->ctx.AX[0].U0 = ALIGN(usp, 8); > in copy_thread() conditional on usp != 0, you can go with generic > variants from kernel/fork.c; again, see linux-next for examples of that). > What's left? sigreturn and sigaltstack? > > Seriously, drop that struct pt_regs *; it makes things uglier, (slightly) > hurts the syscall overhead and doesn't help the few syscalls that even > look at that argument. > Done (with generic clone), thanks for pointing out the linux-next changes. I'll base the next patchset on -next. Thanks for all the review comments so far, they're much appreciated. Cheers James