From nobody Fri Dec 19 19:00:42 2025 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 80BEDC43334 for ; Tue, 12 Jul 2022 23:13:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233849AbiGLXNx (ORCPT ); Tue, 12 Jul 2022 19:13:53 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41872 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233884AbiGLXNc (ORCPT ); Tue, 12 Jul 2022 19:13:32 -0400 Received: from mga04.intel.com (mga04.intel.com [192.55.52.120]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4DEA7CC03D for ; Tue, 12 Jul 2022 16:13:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1657667610; x=1689203610; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=KcHlgajuJie/y+gq2EtP0KVLDLxzLO/XCoJPUGPXJSQ=; b=C3yEBht7s0joBeCa4xRR7g/TJXVNBc2qPPncpMNfLx92VYuCdnV6zNuY /Tcalduqk+jJX97rHzETmNM80yL9WanNgiQkN05+YXUezTCj3jv0w7WaK 83DMUHfDxwxyP2Oav3CyNn3br4IXMaaUHx2Pupk7eDT7D7XF7Zs7X66/9 rQrJLHfsYcXVVd1kq7C5tUsDNefV9mINFkn3dHIFFmdFEet+6LiWO887q FNa3HkftkajfhqqA7sbo3bfU8msTbD9JwQlOieL58g/sakTI+tTaAbZWx q0RipOfRAYs8VY+qursthGbLk9dNhdjLBUHSnkBlNgCidp950EJKt6D8o A==; X-IronPort-AV: E=McAfee;i="6400,9594,10406"; a="283818841" X-IronPort-AV: E=Sophos;i="5.92,266,1650956400"; d="scan'208";a="283818841" Received: from fmsmga007.fm.intel.com ([10.253.24.52]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 12 Jul 2022 16:13:30 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.92,266,1650956400"; d="scan'208";a="599542524" Received: from black.fi.intel.com ([10.237.72.28]) by fmsmga007.fm.intel.com with ESMTP; 12 Jul 2022 16:13:26 -0700 Received: by black.fi.intel.com (Postfix, from userid 1000) id 0693C4B0; Wed, 13 Jul 2022 02:13:30 +0300 (EEST) From: "Kirill A. Shutemov" To: Dave Hansen , Andy Lutomirski , Peter Zijlstra Cc: x86@kernel.org, Kostya Serebryany , Andrey Ryabinin , Andrey Konovalov , Alexander Potapenko , Taras Madan , Dmitry Vyukov , "H . J . Lu" , Andi Kleen , Rick Edgecombe , linux-mm@kvack.org, linux-kernel@vger.kernel.org, "Kirill A. Shutemov" Subject: [PATCHv5 07/13] x86: Expose untagging mask in /proc/$PID/arch_status Date: Wed, 13 Jul 2022 02:13:22 +0300 Message-Id: <20220712231328.5294-8-kirill.shutemov@linux.intel.com> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220712231328.5294-1-kirill.shutemov@linux.intel.com> References: <20220712231328.5294-1-kirill.shutemov@linux.intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Add a line in /proc/$PID/arch_status to report untag_mask. It can be used to find out LAM status of the process from the outside. It is useful for debuggers. Signed-off-by: Kirill A. Shutemov Tested-by: Alexander Potapenko --- arch/x86/include/asm/mmu_context.h | 10 +++++ arch/x86/kernel/Makefile | 2 + arch/x86/kernel/fpu/xstate.c | 47 ----------------------- arch/x86/kernel/proc.c | 60 ++++++++++++++++++++++++++++++ 4 files changed, 72 insertions(+), 47 deletions(-) create mode 100644 arch/x86/kernel/proc.c diff --git a/arch/x86/include/asm/mmu_context.h b/arch/x86/include/asm/mmu_= context.h index 5bd3d46685dc..b0e9ea23758b 100644 --- a/arch/x86/include/asm/mmu_context.h +++ b/arch/x86/include/asm/mmu_context.h @@ -103,6 +103,11 @@ static inline void dup_lam(struct mm_struct *oldmm, st= ruct mm_struct *mm) mm->context.untag_mask =3D oldmm->context.untag_mask; } =20 +static inline unsigned long mm_untag_mask(struct mm_struct *mm) +{ + return mm->context.untag_mask; +} + static inline void mm_reset_untag_mask(struct mm_struct *mm) { mm->context.untag_mask =3D -1UL; @@ -119,6 +124,11 @@ static inline void dup_lam(struct mm_struct *oldmm, st= ruct mm_struct *mm) { } =20 +static inline unsigned long mm_untag_mask(struct mm_struct *mm) +{ + return -1UL; +} + static inline void mm_reset_untag_mask(struct mm_struct *mm) { } diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile index 4c8b6ae802ac..313f1d8e7783 100644 --- a/arch/x86/kernel/Makefile +++ b/arch/x86/kernel/Makefile @@ -141,6 +141,8 @@ obj-$(CONFIG_UNWINDER_GUESS) +=3D unwind_guess.o =20 obj-$(CONFIG_AMD_MEM_ENCRYPT) +=3D sev.o =20 +obj-$(CONFIG_PROC_FS) +=3D proc.o + ### # 64 bit specific files ifeq ($(CONFIG_X86_64),y) diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c index c8340156bfd2..838a6f0627fd 100644 --- a/arch/x86/kernel/fpu/xstate.c +++ b/arch/x86/kernel/fpu/xstate.c @@ -10,8 +10,6 @@ #include #include #include -#include -#include #include =20 #include @@ -1745,48 +1743,3 @@ long fpu_xstate_prctl(int option, unsigned long arg2) return -EINVAL; } } - -#ifdef CONFIG_PROC_PID_ARCH_STATUS -/* - * Report the amount of time elapsed in millisecond since last AVX512 - * use in the task. - */ -static void avx512_status(struct seq_file *m, struct task_struct *task) -{ - unsigned long timestamp =3D READ_ONCE(task->thread.fpu.avx512_timestamp); - long delta; - - if (!timestamp) { - /* - * Report -1 if no AVX512 usage - */ - delta =3D -1; - } else { - delta =3D (long)(jiffies - timestamp); - /* - * Cap to LONG_MAX if time difference > LONG_MAX - */ - if (delta < 0) - delta =3D LONG_MAX; - delta =3D jiffies_to_msecs(delta); - } - - seq_put_decimal_ll(m, "AVX512_elapsed_ms:\t", delta); - seq_putc(m, '\n'); -} - -/* - * Report architecture specific information - */ -int proc_pid_arch_status(struct seq_file *m, struct pid_namespace *ns, - struct pid *pid, struct task_struct *task) -{ - /* - * Report AVX512 state if the processor and build option supported. - */ - if (cpu_feature_enabled(X86_FEATURE_AVX512F)) - avx512_status(m, task); - - return 0; -} -#endif /* CONFIG_PROC_PID_ARCH_STATUS */ diff --git a/arch/x86/kernel/proc.c b/arch/x86/kernel/proc.c new file mode 100644 index 000000000000..9765b4d05ce4 --- /dev/null +++ b/arch/x86/kernel/proc.c @@ -0,0 +1,60 @@ +// SPDX-License-Identifier: GPL-2.0-only +#include +#include +#include +#include +#include + +/* + * Report the amount of time elapsed in millisecond since last AVX512 + * use in the task. + */ +static void avx512_status(struct seq_file *m, struct task_struct *task) +{ + unsigned long timestamp =3D READ_ONCE(task->thread.fpu.avx512_timestamp); + long delta; + + if (!timestamp) { + /* + * Report -1 if no AVX512 usage + */ + delta =3D -1; + } else { + delta =3D (long)(jiffies - timestamp); + /* + * Cap to LONG_MAX if time difference > LONG_MAX + */ + if (delta < 0) + delta =3D LONG_MAX; + delta =3D jiffies_to_msecs(delta); + } + + seq_put_decimal_ll(m, "AVX512_elapsed_ms:\t", delta); + seq_putc(m, '\n'); +} + +/* + * Report architecture specific information + */ +int proc_pid_arch_status(struct seq_file *m, struct pid_namespace *ns, + struct pid *pid, struct task_struct *task) +{ + struct mm_struct *mm; + unsigned long untag_mask =3D -1UL; + + /* + * Report AVX512 state if the processor and build option supported. + */ + if (cpu_feature_enabled(X86_FEATURE_AVX512F)) + avx512_status(m, task); + + mm =3D get_task_mm(task); + if (mm) { + untag_mask =3D mm_untag_mask(task->mm); + mmput(mm); + } + + seq_printf(m, "untag_mask:\t%#lx\n", untag_mask); + + return 0; +} --=20 2.35.1