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 E5FDBC678D4 for ; Tue, 7 Mar 2023 17:43:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231799AbjCGRnX (ORCPT ); Tue, 7 Mar 2023 12:43:23 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53990 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232071AbjCGRmu (ORCPT ); Tue, 7 Mar 2023 12:42:50 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8E094900BB for ; Tue, 7 Mar 2023 09:38:48 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 65DFDB819A6 for ; Tue, 7 Mar 2023 17:38:39 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A03C9C4339B; Tue, 7 Mar 2023 17:38:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1678210718; bh=MHvVvHcFFxtRpvQ1ATNLFyUwyZ4h6QIJd3v05fBfveY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=oT6XP1/uqniNJHyy8O3XTr/S6dNN6cgtA7vAZiXdFOdMElpo8io7+LZPQOVlh3pVS TJhQSnSZo4DX4WiJzDlE7sNFjuwctcbyeevGZODHjMWlJojVggEwQdAQo+8necRoMe Nhw4i04ixj+A76+Xwd5aXySSdKs2h6k8y5dOIATM= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Jens Axboe , Ingo Molnar , Peter Zijlstra , Sasha Levin Subject: [PATCH 6.2 0632/1001] x86/fpu: Dont set TIF_NEED_FPU_LOAD for PF_IO_WORKER threads Date: Tue, 7 Mar 2023 17:56:44 +0100 Message-Id: <20230307170049.001634066@linuxfoundation.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230307170022.094103862@linuxfoundation.org> References: <20230307170022.094103862@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Jens Axboe [ Upstream commit cb3ea4b7671b7cfbac3ee609976b790aebd0bbda ] We don't set it on PF_KTHREAD threads as they never return to userspace, and PF_IO_WORKER threads are identical in that regard. As they keep running in the kernel until they die, skip setting the FPU flag on them. More of a cosmetic thing that was found while debugging and issue and pondering why the FPU flag is set on these threads. Signed-off-by: Jens Axboe Signed-off-by: Ingo Molnar Acked-by: Peter Zijlstra Link: https://lore.kernel.org/r/560c844c-f128-555b-40c6-31baff27537f@kernel.dk Signed-off-by: Sasha Levin --- arch/x86/include/asm/fpu/sched.h | 2 +- arch/x86/kernel/fpu/context.h | 2 +- arch/x86/kernel/fpu/core.c | 2 +- 3 files changed, 3 insertions(+), 3 deletions(-) diff --git a/arch/x86/include/asm/fpu/sched.h b/arch/x86/include/asm/fpu/sched.h index b2486b2cbc6e0..c2d6cd78ed0c2 100644 --- a/arch/x86/include/asm/fpu/sched.h +++ b/arch/x86/include/asm/fpu/sched.h @@ -39,7 +39,7 @@ extern void fpu_flush_thread(void); static inline void switch_fpu_prepare(struct fpu *old_fpu, int cpu) { if (cpu_feature_enabled(X86_FEATURE_FPU) && - !(current->flags & PF_KTHREAD)) { + !(current->flags & (PF_KTHREAD | PF_IO_WORKER))) { save_fpregs_to_fpstate(old_fpu); /* * The save operation preserved register state, so the diff --git a/arch/x86/kernel/fpu/context.h b/arch/x86/kernel/fpu/context.h index 958accf2ccf07..9fcfa5c4dad79 100644 --- a/arch/x86/kernel/fpu/context.h +++ b/arch/x86/kernel/fpu/context.h @@ -57,7 +57,7 @@ static inline void fpregs_restore_userregs(void) struct fpu *fpu = ¤t->thread.fpu; int cpu = smp_processor_id(); - if (WARN_ON_ONCE(current->flags & PF_KTHREAD)) + if (WARN_ON_ONCE(current->flags & (PF_KTHREAD | PF_IO_WORKER))) return; if (!fpregs_state_valid(fpu, cpu)) { diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c index dccce58201b7c..caf33486dc5ee 100644 --- a/arch/x86/kernel/fpu/core.c +++ b/arch/x86/kernel/fpu/core.c @@ -426,7 +426,7 @@ void kernel_fpu_begin_mask(unsigned int kfpu_mask) this_cpu_write(in_kernel_fpu, true); - if (!(current->flags & PF_KTHREAD) && + if (!(current->flags & (PF_KTHREAD | PF_IO_WORKER)) && !test_thread_flag(TIF_NEED_FPU_LOAD)) { set_thread_flag(TIF_NEED_FPU_LOAD); save_fpregs_to_fpstate(¤t->thread.fpu); -- 2.39.2