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=-13.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,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 A81E4C55178 for ; Tue, 27 Oct 2020 15:16:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 53FAF2225E for ; Tue, 27 Oct 2020 15:16:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603811780; bh=IAiyoMSp5eobg2tYTlH1ydz13QN9WNKa7GSzZyxSfPY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=ocfPqKAWYMW62PnmB0bGZsw21vXWy4C2VEV4/Dtx283NV7YPdHzmz1WiZt8UmkQg8 uv9q7OK3JIRk7C2QsAfCipaG6aiiU5C0oSJNZPORvJdRKM33P8XZTGvbvYanB6KJ/r 2NcQvOIJBvb0425GoBHc6+B6KB8gsjq4aKZN2ISk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1795006AbgJ0POv (ORCPT ); Tue, 27 Oct 2020 11:14:51 -0400 Received: from mail.kernel.org ([198.145.29.99]:44354 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1793898AbgJ0PI5 (ORCPT ); Tue, 27 Oct 2020 11:08:57 -0400 Received: from localhost.localdomain (i16-lef01-ix2-212-195-25-126.ft.lns.abo.bbox.fr [212.195.25.126]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 89BFF20657; Tue, 27 Oct 2020 15:08:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603811337; bh=IAiyoMSp5eobg2tYTlH1ydz13QN9WNKa7GSzZyxSfPY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=yelSqX+njT/MlciL+fm4HSbY42RzztO0ZWOK+6jadfytp2t9KrGZMFitRyUeLQzwd JbIYRxP/4OL5LXoGFl3IFUwp//Hj/OcXxT0f8ezW4ZZvc8odwlgF8+WTgd5eddI88W FgjtUy0mzmRKhqZr9tCvm5Qy1rtz2Bv3owHUhN58= From: Frederic Weisbecker To: Peter Zijlstra Cc: LKML , Frederic Weisbecker , "Paul E . McKenney" , Thomas Gleixner , Phil Auld , Marcelo Tosatti Subject: [PATCH 4/5] context_tracking: Only define schedule_user() on !HAVE_CONTEXT_TRACKING_OFFSTACK archs Date: Tue, 27 Oct 2020 16:08:26 +0100 Message-Id: <20201027150827.148821-5-frederic@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20201027150827.148821-1-frederic@kernel.org> References: <20201027150827.148821-1-frederic@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org schedule_user() was traditionally used by the entry code's tail to preempt userspace after the call to user_enter(). Indeed the call to user_enter() used to be performed upon syscall exit slow path which was right before the last opportunity to schedule() while resuming to userspace. The context tracking state had to be saved on the task stack and set back to CONTEXT_KERNEL temporarily in order to safely switch to another task. Only a few archs use it now and those implementing HAVE_CONTEXT_TRACKING_OFFSTACK definetly can't rely on it. Signed-off-by: Frederic Weisbecker Cc: Marcelo Tosatti Cc: Paul E. McKenney Cc: Peter Zijlstra Cc: Phil Auld Cc: Thomas Gleixner --- kernel/sched/core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index c23d7cb5aee3..44426e5acde2 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -4631,7 +4631,7 @@ void __sched schedule_idle(void) } while (need_resched()); } -#ifdef CONFIG_CONTEXT_TRACKING +#if defined(CONFIG_CONTEXT_TRACKING) && !defined(CONFIG_HAVE_CONTEXT_TRACKING_OFFSTACK) asmlinkage __visible void __sched schedule_user(void) { /* -- 2.25.1