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=-13.8 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 0A7E2C4363A for ; Mon, 5 Oct 2020 10:49:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C1F9920796 for ; Mon, 5 Oct 2020 10:49:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1601894984; bh=cmNfiTiEFaEzS7i7+ax6M+OfXWovFZb9x0YWXzxnWvo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=YgQA+xA+I9ML5al5GNnvzQKHn7Fd/0c2QVcmejdeyE3pxf+B+Mrk8buzNjQVA+L61 Lv5RCGfxlOJvU8NyV354KFtkQ0nqzeF8q+r26J9R/92cauh8SIdbxl0vk484zTnQeD HMZZgyfuRtGpcf3VxGIXdmGqqDdm1YwqCKSCmot8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726053AbgJEKtn (ORCPT ); Mon, 5 Oct 2020 06:49:43 -0400 Received: from mail.kernel.org ([198.145.29.99]:38692 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725981AbgJEKtd (ORCPT ); Mon, 5 Oct 2020 06:49:33 -0400 Received: from localhost.localdomain (unknown [94.238.213.162]) (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 AD1192078E; Mon, 5 Oct 2020 10:49:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1601894973; bh=cmNfiTiEFaEzS7i7+ax6M+OfXWovFZb9x0YWXzxnWvo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=erITJzNW4V7UGb3B7N2gnPLIiplPHW9b5ubcVs6MxVmDGaMyzr0qMl1CYNDmUHjW5 Wzd6L65RNlYnu7Fw67p+Ns97brjm9wsva32n99b+IRI6KgLM3qfHflkb/2GkYErB3F 1YGmexU0F08yZpnTOmD2IGlQhRgbJKRQZndYKBys= From: Frederic Weisbecker To: LKML Cc: Frederic Weisbecker , Peter Zijlstra , "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: Mon, 5 Oct 2020 12:49:18 +0200 Message-Id: <20201005104919.5250-5-frederic@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20201005104919.5250-1-frederic@kernel.org> References: <20201005104919.5250-1-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 d31a79e073e3..cb7afcfbb809 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -4632,7 +4632,7 @@ 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