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=-8.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED, USER_AGENT_MUTT 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 14C10C282D8 for ; Fri, 1 Feb 2019 10:22:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DC0DA2086C for ; Fri, 1 Feb 2019 10:22:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728774AbfBAKV7 (ORCPT ); Fri, 1 Feb 2019 05:21:59 -0500 Received: from foss.arm.com ([217.140.101.70]:57472 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726450AbfBAKV6 (ORCPT ); Fri, 1 Feb 2019 05:21:58 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 2D47715BE; Fri, 1 Feb 2019 02:21:58 -0800 (PST) Received: from fuggles.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.72.51.249]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 82F5F3F71E; Fri, 1 Feb 2019 02:21:56 -0800 (PST) Date: Fri, 1 Feb 2019 10:21:54 +0000 From: Will Deacon To: Valentin Schneider Cc: linux-kernel@vger.kernel.org, Julien Thierry , Catalin Marinas , Mark Rutland , Marc Zyngier , Julien Grall , Thomas Gleixner , linux-arm-kernel@lists.infradead.org Subject: Re: [RFC PATCH 1/3] arm64: entry: Remove unneeded need_resched() loop Message-ID: <20190201102154.GB26637@fuggles.cambridge.arm.com> References: <20190131182339.9835-1-valentin.schneider@arm.com> <20190131182339.9835-2-valentin.schneider@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190131182339.9835-2-valentin.schneider@arm.com> User-Agent: Mutt/1.11.1+86 (6f28e57d73f2) () Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jan 31, 2019 at 06:23:37PM +0000, Valentin Schneider wrote: > Since the enabling and disabling of IRQs within preempt_schedule_irq() > is contained in a need_resched() loop, we don't need the outer arch > code loop. > > Reported-by: Julien Thierry > Reported-by: Will Deacon > Signed-off-by: Valentin Schneider > Cc: Catalin Marinas > Cc: Will Deacon > Cc: Mark Rutland > Cc: Marc Zyngier > Cc: Julien Grall > Cc: Julien Thierry > Cc: Thomas Gleixner > Cc: linux-arm-kernel@lists.infradead.org > --- > arch/arm64/kernel/entry.S | 11 +---------- > 1 file changed, 1 insertion(+), 10 deletions(-) > > diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S > index 0ec0c46b2c0c..4d0c81f29a60 100644 > --- a/arch/arm64/kernel/entry.S > +++ b/arch/arm64/kernel/entry.S > @@ -611,7 +611,7 @@ el1_irq: > #ifdef CONFIG_PREEMPT > ldr x24, [tsk, #TSK_TI_PREEMPT] // get preempt count > cbnz x24, 1f // preempt count != 0 > - bl el1_preempt > + bl preempt_schedule_irq // irq en/disable is done inside > 1: > #endif > #ifdef CONFIG_TRACE_IRQFLAGS > @@ -620,15 +620,6 @@ el1_irq: > kernel_exit 1 > ENDPROC(el1_irq) > > -#ifdef CONFIG_PREEMPT > -el1_preempt: > - mov x24, lr > -1: bl preempt_schedule_irq // irq en/disable is done inside > - ldr x0, [tsk, #TSK_TI_FLAGS] // get new tasks TI_FLAGS > - tbnz x0, #TIF_NEED_RESCHED, 1b // needs rescheduling? > - ret x24 > -#endif > - Acked-by: Will Deacon Catalin can pick this up for 5.1. Will