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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 42AC2C433F5 for ; Wed, 17 Nov 2021 18:29:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 284D161BD3 for ; Wed, 17 Nov 2021 18:29:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239109AbhKQSch (ORCPT ); Wed, 17 Nov 2021 13:32:37 -0500 Received: from Galois.linutronix.de ([193.142.43.55]:33262 "EHLO galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233890AbhKQScg (ORCPT ); Wed, 17 Nov 2021 13:32:36 -0500 Date: Wed, 17 Nov 2021 18:29:35 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1637173776; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=nOVhcHgI8g7zN42nh4pVJOp1nfrcdr3b6IpdBIKlais=; b=wE04mu2twkM9aqGqNMRzVKtlPXqFt3ClWwGohclTHZfDA2MNNMLnRZNV2s9x4OV92LxIac BhrI2veE/e3x8SGBZY9Ht9ycTYhPGSr4Cre6a2MVjbjBO1G9Uawdn6x4zErhaL93iqgjDu SsaLHgNdsFPjb3HDwFcneyx4zLSzGS4qy/cud3tkWDNoToNH5YGC2oT0YrXb7Lfe6DNH/3 7XXiGSNyA7xfv6H4buTK4tUoBobeeY/eeiaubiPfxBoN0uytd29mA/3+iqILEt3QG/5d/M txPUtWP+jr485POmM0VJVi/djWi4MV9rUTudVCkIBmsIrZBk7SbjM929d8GpLw== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1637173776; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=nOVhcHgI8g7zN42nh4pVJOp1nfrcdr3b6IpdBIKlais=; b=jdh+M2kvkP1kXilkcOPbajYPMrg/W94s0Rf+t3tLFMZbCDK5ChAiafjT9/ZN5J/Ll0OW0R +XW5G5OHWfzJaPAg== From: "tip-bot2 for Noah Goldstein" Sender: tip-bot2@linutronix.de Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: x86/fpu] x86/fpu: Correct AVX512 state tracking Cc: Noah Goldstein , Borislav Petkov , x86@kernel.org, linux-kernel@vger.kernel.org In-Reply-To: <20210920053951.4093668-1-goldstein.w.n@gmail.com> References: <20210920053951.4093668-1-goldstein.w.n@gmail.com> MIME-Version: 1.0 Message-ID: <163717377532.11128.15112806017937850586.tip-bot2@tip-bot2> Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The following commit has been merged into the x86/fpu branch of tip: Commit-ID: 0fe4ff885f8a50082d9dc241b657472894caba16 Gitweb: https://git.kernel.org/tip/0fe4ff885f8a50082d9dc241b657472894caba16 Author: Noah Goldstein AuthorDate: Tue, 16 Nov 2021 17:14:21 +01:00 Committer: Borislav Petkov CommitterDate: Tue, 16 Nov 2021 17:19:41 +01:00 x86/fpu: Correct AVX512 state tracking Add a separate, local mask for tracking AVX512 usage which does not include the opmask xfeature set. Opmask registers usage does not cause frequency throttling so it is a completely unnecessary false positive. While at it, carve it out into a separate function to keep that abomination extracted out. [ bp: Rediff and cleanup ontop of 5.16-rc1. ] Signed-off-by: Noah Goldstein Signed-off-by: Borislav Petkov Link: https://lore.kernel.org/r/20210920053951.4093668-1-goldstein.w.n@gmail.com --- arch/x86/kernel/fpu/core.c | 21 ++++++++++++++------- 1 file changed, 14 insertions(+), 7 deletions(-) diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c index 8ea306b..dd3777a 100644 --- a/arch/x86/kernel/fpu/core.c +++ b/arch/x86/kernel/fpu/core.c @@ -99,6 +99,19 @@ bool irq_fpu_usable(void) EXPORT_SYMBOL(irq_fpu_usable); /* + * Track AVX512 state use because it is known to slow the max clock + * speed of the core. + */ +static void update_avx_timestamp(struct fpu *fpu) +{ + +#define AVX512_TRACKING_MASK (XFEATURE_MASK_ZMM_Hi256 | XFEATURE_MASK_Hi16_ZMM) + + if (fpu->fpstate->regs.xsave.header.xfeatures & AVX512_TRACKING_MASK) + fpu->avx512_timestamp = jiffies; +} + +/* * Save the FPU register state in fpu->fpstate->regs. The register state is * preserved. * @@ -116,13 +129,7 @@ void save_fpregs_to_fpstate(struct fpu *fpu) { if (likely(use_xsave())) { os_xsave(fpu->fpstate); - - /* - * AVX512 state is tracked here because its use is - * known to slow the max clock speed of the core. - */ - if (fpu->fpstate->regs.xsave.header.xfeatures & XFEATURE_MASK_AVX512) - fpu->avx512_timestamp = jiffies; + update_avx_timestamp(fpu); return; }