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=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 BF959C10F14 for ; Tue, 16 Apr 2019 06:35:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 99B112073F for ; Tue, 16 Apr 2019 06:35:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728423AbfDPGfK (ORCPT ); Tue, 16 Apr 2019 02:35:10 -0400 Received: from mga04.intel.com ([192.55.52.120]:15139 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726857AbfDPGfI (ORCPT ); Tue, 16 Apr 2019 02:35:08 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga003.jf.intel.com ([10.7.209.27]) by fmsmga104.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 15 Apr 2019 23:35:08 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.60,355,1549958400"; d="scan'208";a="143098772" Received: from aubrey-lkp.sh.intel.com ([10.239.97.113]) by orsmga003.jf.intel.com with ESMTP; 15 Apr 2019 23:35:05 -0700 From: Aubrey Li To: tglx@linutronix.de, mingo@redhat.com, peterz@infradead.org, hpa@zytor.com Cc: ak@linux.intel.com, tim.c.chen@linux.intel.com, dave.hansen@intel.com, arjan@linux.intel.com, adobriyan@gmail.com, akpm@linux-foundation.org, aubrey.li@intel.com, linux-api@vger.kernel.org, linux-kernel@vger.kernel.org, Aubrey Li Subject: [PATCH v15 3/3] Documentation/filesystems/proc.txt: add AVX512_elapsed_ms Date: Tue, 16 Apr 2019 14:32:50 +0800 Message-Id: <20190416063250.7514-3-aubrey.li@linux.intel.com> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190416063250.7514-1-aubrey.li@linux.intel.com> References: <20190416063250.7514-1-aubrey.li@linux.intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Added AVX512_elapsed_ms in /proc//status. Report it in Documentation/filesystems/proc.txt Signed-off-by: Aubrey Li Cc: Peter Zijlstra Cc: Andi Kleen Cc: Tim Chen Cc: Dave Hansen Cc: Arjan van de Ven Cc: Linux API Cc: Alexey Dobriyan Cc: Andrew Morton --- Documentation/filesystems/proc.txt | 29 ++++++++++++++++++++++++++++- 1 file changed, 28 insertions(+), 1 deletion(-) diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt index 66cad5c86171..c4a9e48681ad 100644 --- a/Documentation/filesystems/proc.txt +++ b/Documentation/filesystems/proc.txt @@ -207,6 +207,7 @@ read the file /proc/PID/status: Speculation_Store_Bypass: thread vulnerable voluntary_ctxt_switches: 0 nonvoluntary_ctxt_switches: 1 + AVX512_elapsed_ms: 8 This shows you nearly the same information you would get if you viewed it with the ps command. In fact, ps uses the proc file system to obtain its @@ -224,7 +225,7 @@ asynchronous manner and the value may not be very precise. To see a precise snapshot of a moment, you can see /proc//smaps file and scan page table. It's slow but very precise. -Table 1-2: Contents of the status files (as of 4.19) +Table 1-2: Contents of the status files (as of 5.1) .............................................................................. Field Content Name filename of the executable @@ -289,6 +290,32 @@ Table 1-2: Contents of the status files (as of 4.19) Mems_allowed_list Same as previous, but in "list format" voluntary_ctxt_switches number of voluntary context switches nonvoluntary_ctxt_switches number of non voluntary context switches + AVX512_elapsed_ms time elapsed since last AVX512 usage recorded + + AVX512_elapsed_ms: + ------------------ + If AVX512 is supported on the machine, this entry shows the milliseconds + elapsed since the last time AVX512 usage was recorded. The recording + happens on a best effort basis when a task is scheduled out. This means + that the value depends on two factors: + + 1) The time which the task spent on the CPU without being scheduled + out. With CPU isolation and a single runnable task this can take + several seconds. + + 2) The time since the task was scheduled out last. Depending on the + reason for being scheduled out (time slice exhausted, syscall ...) + this can be arbitrary long time. + + As a consequence the value cannot be considered precise and authoritative + information. The application which uses this information has to be aware + of the overall scenario on the system in order to determine whether a + task is a real AVX512 user or not. + + A special value of '-1' indicates that no AVX512 usage was recorded, thus + the task is unlikely an AVX512 user, but depends on the workload and the + scheduling scenario, it also could be a false negative mentioned above. + .............................................................................. Table 1-3: Contents of the statm files (as of 2.6.8-rc3) -- 2.21.0