Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758725Ab2JSRag (ORCPT ); Fri, 19 Oct 2012 13:30:36 -0400 Received: from zeniv.linux.org.uk ([195.92.253.2]:35065 "EHLO ZenIV.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753744Ab2JSRae (ORCPT ); Fri, 19 Oct 2012 13:30:34 -0400 Date: Fri, 19 Oct 2012 18:30:29 +0100 From: Al Viro To: "Luck, Tony" Cc: "linux-kernel@vger.kernel.org" , "linux-arch@vger.kernel.org" , Linus Torvalds , Catalin Marinas , Haavard Skinnemoen , Mike Frysinger , Jesper Nilsson , David Howells , Benjamin Herrenschmidt , Hirokazu Takata , Geert Uytterhoeven , Michal Simek , Jonas Bonn , "James E.J. Bottomley" , Richard Kuo , Martin Schwidefsky , Lennox Wu , "David S. Miller" , Paul Mundt , Chris Zankel , Chris Metcalf , Yoshinori Sato , Guan Xuetao Subject: Re: new execve/kernel_thread design Message-ID: <20121019173029.GO2616@ZenIV.linux.org.uk> References: <20121016223508.GR2616@ZenIV.linux.org.uk> <20121019154901.GK2616@ZenIV.linux.org.uk> <3908561D78D1C84285E8C5FCA982C28F19D57A82@ORSMSX108.amr.corp.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <3908561D78D1C84285E8C5FCA982C28F19D57A82@ORSMSX108.amr.corp.intel.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1556 Lines: 38 On Fri, Oct 19, 2012 at 05:16:50PM +0000, Luck, Tony wrote: > > Surprisingly enough, ia64 one seems to work on actual hardware; I have sent > > Tony an incremental patch cleaning copy_thread() up, waiting for results of > > testing that on SMP box. > > Tiny bit faster than plain 3.7-rc1. lmbench3 reports fork+execve test at between > 558 to 567 usec with the new code, compared with 562-572 usec with the old. Are you OK with the state of comments in call_payload() in the current form of that sucker? Right now in #arch-ia64 is looks so: ENTRY(call_payload) .prologue ASM_UNW_PRLG_RP|ASM_UNW_PRLG_PFS, ASM_UNW_PRLG_GRSAVE(0) /* call the kernel_thread payload; fn is in r4, arg - in r5 */ alloc loc1=ar.pfs,0,3,1,0 mov loc0=rp mov loc2=gp mov out0=r5 // arg ld8 r14 = [r4], 8 // fn.address ;; mov b6 = r14 ld8 gp = [r4] // fn.gp ;; br.call.sptk.many rp=b6 // fn(arg) .ret12: mov gp=loc2 mov rp=loc0 mov ar.pfs=loc1 /* ... and if it has returned, we are going to userland */ cmp.ne pKStk,pUStk=r0,r0 br.ret.sptk.many rp END(call_payload) IIRC, the lack of comments on function with unusual calling conventions was the last remaining issue... -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/