From patchwork Tue Jan 31 08:39:52 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Byungchul Park X-Patchwork-Id: 13122481 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 585D9C38142 for ; Tue, 31 Jan 2023 08:44:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229973AbjAaIoY (ORCPT ); Tue, 31 Jan 2023 03:44:24 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54842 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230162AbjAaImf (ORCPT ); Tue, 31 Jan 2023 03:42:35 -0500 Received: from lgeamrelo11.lge.com (lgeamrelo11.lge.com [156.147.23.51]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id EA8DD474C8 for ; Tue, 31 Jan 2023 00:40:12 -0800 (PST) Received: from unknown (HELO lgeamrelo04.lge.com) (156.147.1.127) by 156.147.23.51 with ESMTP; 31 Jan 2023 17:40:02 +0900 X-Original-SENDERIP: 156.147.1.127 X-Original-MAILFROM: max.byungchul.park@gmail.com Received: from unknown (HELO localhost.localdomain) (10.177.244.38) by 156.147.1.127 with ESMTP; 31 Jan 2023 17:40:02 +0900 X-Original-SENDERIP: 10.177.244.38 X-Original-MAILFROM: max.byungchul.park@gmail.com From: Byungchul Park To: linux-kernel@vger.kernel.org Cc: torvalds@linux-foundation.org, damien.lemoal@opensource.wdc.com, linux-ide@vger.kernel.org, adilger.kernel@dilger.ca, linux-ext4@vger.kernel.org, mingo@redhat.com, peterz@infradead.org, will@kernel.org, tglx@linutronix.de, rostedt@goodmis.org, joel@joelfernandes.org, sashal@kernel.org, daniel.vetter@ffwll.ch, duyuyang@gmail.com, johannes.berg@intel.com, tj@kernel.org, tytso@mit.edu, willy@infradead.org, david@fromorbit.com, amir73il@gmail.com, gregkh@linuxfoundation.org, kernel-team@lge.com, linux-mm@kvack.org, akpm@linux-foundation.org, mhocko@kernel.org, minchan@kernel.org, hannes@cmpxchg.org, vdavydov.dev@gmail.com, sj@kernel.org, jglisse@redhat.com, dennis@kernel.org, cl@linux.com, penberg@kernel.org, rientjes@google.com, vbabka@suse.cz, ngupta@vflare.org, linux-block@vger.kernel.org, paolo.valente@linaro.org, josef@toxicpanda.com, linux-fsdevel@vger.kernel.org, viro@zeniv.linux.org.uk, jack@suse.cz, jlayton@kernel.org, dan.j.williams@intel.com, hch@infradead.org, djwong@kernel.org, dri-devel@lists.freedesktop.org, rodrigosiqueiramelo@gmail.com, melissa.srw@gmail.com, hamohammed.sa@gmail.com, 42.hyeyoo@gmail.com, chris.p.wilson@intel.com, gwan-gyeong.mun@intel.com, max.byungchul.park@gmail.com, boqun.feng@gmail.com, longman@redhat.com, hdanton@sina.com Subject: [PATCH v9 23/25] dept: Record the latest one out of consecutive waits of the same class Date: Tue, 31 Jan 2023 17:39:52 +0900 Message-Id: <1675154394-25598-24-git-send-email-max.byungchul.park@gmail.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1675154394-25598-1-git-send-email-max.byungchul.park@gmail.com> References: <1675154394-25598-1-git-send-email-max.byungchul.park@gmail.com> Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org The current code records all the waits for later use to track relation between waits and events in each context. However, since the same class is handled the same way, it'd be okay to record only one on behalf of the others if they all have the same class. Even though it's the ideal to search the whole history buffer for that, since it'd cost too high, alternatively, let's keep the latest one at least when the same class'ed waits consecutively appear. Signed-off-by: Byungchul Park --- kernel/dependency/dept.c | 21 ++++++++++++++++++++- 1 file changed, 20 insertions(+), 1 deletion(-) diff --git a/kernel/dependency/dept.c b/kernel/dependency/dept.c index 3ab999f..2887858 100644 --- a/kernel/dependency/dept.c +++ b/kernel/dependency/dept.c @@ -1522,9 +1522,28 @@ static inline struct dept_wait_hist *new_hist(void) return wh; } +static inline struct dept_wait_hist *last_hist(void) +{ + int pos_n = hist_pos_next(); + struct dept_wait_hist *wh_n = hist(pos_n); + + /* + * This is the first try. + */ + if (!pos_n && !wh_n->wait) + return NULL; + + return hist(pos_n + DEPT_MAX_WAIT_HIST - 1); +} + static void add_hist(struct dept_wait *w, unsigned int wg, unsigned int ctxt_id) { - struct dept_wait_hist *wh = new_hist(); + struct dept_wait_hist *wh; + + wh = last_hist(); + + if (!wh || wh->wait->class != w->class || wh->ctxt_id != ctxt_id) + wh = new_hist(); if (likely(wh->wait)) put_wait(wh->wait);