From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8A2EEC4332B for ; Mon, 1 Feb 2021 11:01:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5A29A64E96 for ; Mon, 1 Feb 2021 11:01:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233451AbhBALBO (ORCPT ); Mon, 1 Feb 2021 06:01:14 -0500 Received: from elvis.franken.de ([193.175.24.41]:43229 "EHLO elvis.franken.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233145AbhBALAZ (ORCPT ); Mon, 1 Feb 2021 06:00:25 -0500 Received: from uucp (helo=alpha) by elvis.franken.de with local-bsmtp (Exim 3.36 #1) id 1l6Wv9-00087b-00; Mon, 01 Feb 2021 11:59:03 +0100 Received: by alpha.franken.de (Postfix, from userid 1000) id 8C857C0CC6; Mon, 1 Feb 2021 11:43:38 +0100 (CET) Date: Mon, 1 Feb 2021 11:43:38 +0100 From: Thomas Bogendoerfer To: Tiezhu Yang Cc: Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Mark Rutland , Alexander Shishkin , Jiri Olsa , Namhyung Kim , linux-mips@vger.kernel.org, linux-kernel@vger.kernel.org, Xuefeng Li , David Daney , Ralf Baechle , Archer Yan Subject: Re: [PATCH 1/3] MIPS: kernel: Support extracting off-line stack traces from user-space with perf Message-ID: <20210201104338.GA6484@alpha.franken.de> References: <1609246561-5474-1-git-send-email-yangtiezhu@loongson.cn> <1609246561-5474-2-git-send-email-yangtiezhu@loongson.cn> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1609246561-5474-2-git-send-email-yangtiezhu@loongson.cn> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Dec 29, 2020 at 08:55:59PM +0800, Tiezhu Yang wrote: > +++ b/arch/mips/include/uapi/asm/perf_regs.h > @@ -0,0 +1,42 @@ > +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ > +#ifndef _ASM_MIPS_PERF_REGS_H > +#define _ASM_MIPS_PERF_REGS_H > + > +enum perf_event_mips_regs { > + PERF_REG_MIPS_PC, > + PERF_REG_MIPS_R1, > + PERF_REG_MIPS_R2, > + PERF_REG_MIPS_R3, > + PERF_REG_MIPS_R4, > + PERF_REG_MIPS_R5, > + PERF_REG_MIPS_R6, > + PERF_REG_MIPS_R7, > + PERF_REG_MIPS_R8, > + PERF_REG_MIPS_R9, > + PERF_REG_MIPS_R10, > + PERF_REG_MIPS_R11, > + PERF_REG_MIPS_R12, > + PERF_REG_MIPS_R13, > + PERF_REG_MIPS_R14, > + PERF_REG_MIPS_R15, > + PERF_REG_MIPS_R16, > + PERF_REG_MIPS_R17, > + PERF_REG_MIPS_R18, > + PERF_REG_MIPS_R19, > + PERF_REG_MIPS_R20, > + PERF_REG_MIPS_R21, > + PERF_REG_MIPS_R22, > + PERF_REG_MIPS_R23, > + PERF_REG_MIPS_R24, > + PERF_REG_MIPS_R25, > + /* > + * 26 and 27 are k0 and k1, they are always clobbered thus not > + * stored. > + */ haveing this hole here make all code more complicated. Does it hurt to have R26 and R27 in the list ? Thomas. -- Crap can work. Given enough thrust pigs will fly, but it's not necessarily a good idea. [ RFC1925, 2.3 ]