From patchwork Fri Jan 27 01:19:16 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Byungchul Park X-Patchwork-Id: 13118119 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 B12ADC61DA4 for ; Fri, 27 Jan 2023 01:53:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233708AbjA0BxN (ORCPT ); Thu, 26 Jan 2023 20:53:13 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33000 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233546AbjA0BvP (ORCPT ); Thu, 26 Jan 2023 20:51:15 -0500 Received: from lgeamrelo11.lge.com (lgeamrelo12.lge.com [156.147.23.52]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id EAA0A761CE for ; Thu, 26 Jan 2023 17:49:52 -0800 (PST) Received: from unknown (HELO lgemrelse7q.lge.com) (156.147.1.151) by 156.147.23.52 with ESMTP; 27 Jan 2023 10:19:44 +0900 X-Original-SENDERIP: 156.147.1.151 X-Original-MAILFROM: max.byungchul.park@gmail.com Received: from unknown (HELO localhost.localdomain) (10.177.244.38) by 156.147.1.151 with ESMTP; 27 Jan 2023 10:19:44 +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 v8 23/25] dept: Record the latest one out of consecutive waits of the same class Date: Fri, 27 Jan 2023 10:19:16 +0900 Message-Id: <1674782358-25542-24-git-send-email-max.byungchul.park@gmail.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1674782358-25542-1-git-send-email-max.byungchul.park@gmail.com> References: <1674782358-25542-1-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 4f66c7f..d84a9b0 100644 --- a/kernel/dependency/dept.c +++ b/kernel/dependency/dept.c @@ -1521,9 +1521,28 @@ 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);