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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7A80EC433EF for ; Thu, 24 Feb 2022 05:37:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230291AbiBXFhe (ORCPT ); Thu, 24 Feb 2022 00:37:34 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54846 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229903AbiBXFhe (ORCPT ); Thu, 24 Feb 2022 00:37:34 -0500 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 970B570F4E; Wed, 23 Feb 2022 21:37:03 -0800 (PST) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 28E7F106F; Wed, 23 Feb 2022 21:37:03 -0800 (PST) Received: from p8cg001049571a15.arm.com (unknown [10.163.48.178]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id C497E3F66F; Wed, 23 Feb 2022 21:36:58 -0800 (PST) From: Anshuman Khandual To: linux-kernel@vger.kernel.org Cc: Anshuman Khandual , Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Mark Rutland , Alexander Shishkin , Jiri Olsa , Namhyung Kim , Thomas Gleixner , Will Deacon , linux-arm-kernel@lists.infradead.org, linux-perf-users@vger.kernel.org Subject: [PATCH] perf: Add irq and exception return branch types Date: Thu, 24 Feb 2022 11:06:54 +0530 Message-Id: <1645681014-3346-1-git-send-email-anshuman.khandual@arm.com> X-Mailer: git-send-email 2.7.4 Precedence: bulk List-ID: X-Mailing-List: linux-perf-users@vger.kernel.org This expands generic branch type classification by adding two more entries there in i.e irq and exception return. Also updates the x86 implementation to process X86_BR_IRET and X86_BR_IRQ records as appropriate. This changes branch types reported to user space on x86 platform but it should not be a problem. The possible scenarios and impacts are enumerated here. -------------------------------------------------------------------------- | kernel | perf tool | Impact | -------------------------------------------------------------------------- | old | old | Works as before | -------------------------------------------------------------------------- | old | new | PERF_BR_UNKNOWN is processed | -------------------------------------------------------------------------- | new | old | PERF_BR_ERET/IRQ are blocked via old PERF_BR_MAX | -------------------------------------------------------------------------- | new | new | PERF_BR_ERET/IRQ are recognized | -------------------------------------------------------------------------- When PERF_BR_ERET/IRQ are blocked via old PERF_BR_MAX (new kernel with old perf tool) the user space might throw up an warning complaining about some unrecognized branch types being reported, but it is expected. PERF_BR_ERET and PERF_BR_IRQ branch types will be used for BRBE implementation on arm64 platform. Cc: Peter Zijlstra Cc: Ingo Molnar Cc: Arnaldo Carvalho de Melo Cc: Mark Rutland Cc: Alexander Shishkin Cc: Jiri Olsa Cc: Namhyung Kim Cc: Thomas Gleixner Cc: Will Deacon Cc: linux-arm-kernel@lists.infradead.org Cc: linux-perf-users@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Anshuman Khandual --- This applies on v5.17-rc5 These two new branch types expands generic branch type classification but still leaves another three entries in 'type' field for later. Please refer a previous discussion [1] for some further context. [1] https://lore.kernel.org/all/1643348653-24367-1-git-send-email-anshuman.khandual@arm.com/ arch/x86/events/intel/lbr.c | 4 ++-- include/uapi/linux/perf_event.h | 2 ++ tools/include/uapi/linux/perf_event.h | 2 ++ tools/perf/util/branch.c | 4 +++- 4 files changed, 9 insertions(+), 3 deletions(-) diff --git a/arch/x86/events/intel/lbr.c b/arch/x86/events/intel/lbr.c index 669c2be14784..fe1742c4ca49 100644 --- a/arch/x86/events/intel/lbr.c +++ b/arch/x86/events/intel/lbr.c @@ -1329,10 +1329,10 @@ static int branch_map[X86_BR_TYPE_MAP_MAX] = { PERF_BR_SYSCALL, /* X86_BR_SYSCALL */ PERF_BR_SYSRET, /* X86_BR_SYSRET */ PERF_BR_UNKNOWN, /* X86_BR_INT */ - PERF_BR_UNKNOWN, /* X86_BR_IRET */ + PERF_BR_ERET, /* X86_BR_IRET */ PERF_BR_COND, /* X86_BR_JCC */ PERF_BR_UNCOND, /* X86_BR_JMP */ - PERF_BR_UNKNOWN, /* X86_BR_IRQ */ + PERF_BR_IRQ, /* X86_BR_IRQ */ PERF_BR_IND_CALL, /* X86_BR_IND_CALL */ PERF_BR_UNKNOWN, /* X86_BR_ABORT */ PERF_BR_UNKNOWN, /* X86_BR_IN_TX */ diff --git a/include/uapi/linux/perf_event.h b/include/uapi/linux/perf_event.h index 82858b697c05..d37629dbad72 100644 --- a/include/uapi/linux/perf_event.h +++ b/include/uapi/linux/perf_event.h @@ -251,6 +251,8 @@ enum { PERF_BR_SYSRET = 8, /* syscall return */ PERF_BR_COND_CALL = 9, /* conditional function call */ PERF_BR_COND_RET = 10, /* conditional function return */ + PERF_BR_ERET = 11, /* exception return */ + PERF_BR_IRQ = 12, /* irq */ PERF_BR_MAX, }; diff --git a/tools/include/uapi/linux/perf_event.h b/tools/include/uapi/linux/perf_event.h index 82858b697c05..d37629dbad72 100644 --- a/tools/include/uapi/linux/perf_event.h +++ b/tools/include/uapi/linux/perf_event.h @@ -251,6 +251,8 @@ enum { PERF_BR_SYSRET = 8, /* syscall return */ PERF_BR_COND_CALL = 9, /* conditional function call */ PERF_BR_COND_RET = 10, /* conditional function return */ + PERF_BR_ERET = 11, /* exception return */ + PERF_BR_IRQ = 12, /* irq */ PERF_BR_MAX, }; diff --git a/tools/perf/util/branch.c b/tools/perf/util/branch.c index 2285b1eb3128..a9a909db8cc7 100644 --- a/tools/perf/util/branch.c +++ b/tools/perf/util/branch.c @@ -49,7 +49,9 @@ const char *branch_type_name(int type) "SYSCALL", "SYSRET", "COND_CALL", - "COND_RET" + "COND_RET", + "ERET", + "IRQ" }; if (type >= 0 && type < PERF_BR_MAX) -- 2.25.1