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=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 B478DC1B0D9 for ; Mon, 14 Dec 2020 08:46:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 72F6B225AB for ; Mon, 14 Dec 2020 08:46:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731394AbgLNIqI (ORCPT ); Mon, 14 Dec 2020 03:46:08 -0500 Received: from foss.arm.com ([217.140.110.172]:44556 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2407115AbgLNIqG (ORCPT ); Mon, 14 Dec 2020 03:46:06 -0500 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 97C6E1FB; Mon, 14 Dec 2020 00:45:16 -0800 (PST) Received: from e121896.arm.com (unknown [10.57.30.226]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id CC4BC3F66E; Mon, 14 Dec 2020 00:45:13 -0800 (PST) From: James Clark To: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, will@kernel.org, leo.yan@linaro.org Cc: James Clark , Mark Rutland , Al Grant , John Garry , Suzuki K Poulose , Mathieu Poirier , Catalin Marinas Subject: [PATCH v2] drivers/perf: Enable PID_IN_CONTEXTIDR with SPE Date: Mon, 14 Dec 2020 10:45:02 +0200 Message-Id: <20201214084502.19954-1-james.clark@arm.com> X-Mailer: git-send-email 2.28.0 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-perf-users@vger.kernel.org Enable PID_IN_CONTEXTIDR by default when Arm SPE is enabled. This flag is required to get PID data in the SPE trace. Without it the perf tool will report 0 for PID which isn't very useful, especially when doing system wide profiling or profiling applications that fork. There is a small performance overhead when enabling PID_IN_CONTEXTIDR, but SPE itself is optional and not enabled by default so the impact is minimised. Cc: Will Deacon Cc: Mark Rutland Cc: Al Grant Cc: Leo Yan Cc: John Garry Cc: Suzuki K Poulose Cc: Mathieu Poirier Cc: Catalin Marinas Signed-off-by: James Clark --- arch/arm64/Kconfig.debug | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/arm64/Kconfig.debug b/arch/arm64/Kconfig.debug index 265c4461031f..b030bb21a0bb 100644 --- a/arch/arm64/Kconfig.debug +++ b/arch/arm64/Kconfig.debug @@ -2,6 +2,7 @@ config PID_IN_CONTEXTIDR bool "Write the current PID to the CONTEXTIDR register" + default y if ARM_SPE_PMU help Enabling this option causes the kernel to write the current PID to the CONTEXTIDR register, at the expense of some additional -- 2.28.0