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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7C6EDC54FB3 for ; Mon, 2 Jun 2025 02:59:18 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 6EE146B024B; Sun, 1 Jun 2025 22:59:17 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 69DFD6B024C; Sun, 1 Jun 2025 22:59:17 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 58D0E6B024D; Sun, 1 Jun 2025 22:59:17 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) by kanga.kvack.org (Postfix) with ESMTP id 393456B024B for ; Sun, 1 Jun 2025 22:59:17 -0400 (EDT) Received: from smtpin29.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay04.hostedemail.com (Postfix) with ESMTP id 9841B1A1C82 for ; Mon, 2 Jun 2025 02:59:16 +0000 (UTC) X-FDA: 83508954312.29.10DBB13 Received: from invmail4.hynix.com (exvmail4.hynix.com [166.125.252.92]) by imf16.hostedemail.com (Postfix) with ESMTP id EA75A180005 for ; Mon, 2 Jun 2025 02:59:13 +0000 (UTC) Authentication-Results: imf16.hostedemail.com; dkim=none; dmarc=none; spf=pass (imf16.hostedemail.com: domain of byungchul@sk.com designates 166.125.252.92 as permitted sender) smtp.mailfrom=byungchul@sk.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1748833155; h=from:from:sender: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: in-reply-to:in-reply-to:references:references; bh=cGk8oD/fMHHhj/PFnsrGlNcjKlGvxXVSj0D6mRka+lw=; b=zXkzOy53WVLQVUO5Ig+3vRGNI137/NEapAyMTXi6oy6XFwNktPaNUEzqxaeLwPMNqI+Lvv eb+LRo/D7e4Rc3/PjNOWDyxX6298VrKkykrtts77jxuAIy2a9i2GX4vOIsaQxC3cAAMwNC f2VyvVPmYHU8+uDU6jy/WPNxqDkQoQ8= ARC-Authentication-Results: i=1; imf16.hostedemail.com; dkim=none; dmarc=none; spf=pass (imf16.hostedemail.com: domain of byungchul@sk.com designates 166.125.252.92 as permitted sender) smtp.mailfrom=byungchul@sk.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1748833155; a=rsa-sha256; cv=none; b=32xebkWsrCdwW3QTjyp+kMN0li3hhbJts5JBH1Q7ukC2Qo+AtW3RZQEn5H19FalSyCD9mL xhu+sc+ad2nkGiKkH9Ej51P51kDoY/xzBzHKllgeByymrAULXYZUQCmry1rcCbv/ZaFiZ6 71QkudA5GQ0SUJWIq9/D73pWIIeZL8M= X-AuditID: a67dfc5b-669ff7000002311f-6b-683d137fccc7 Date: Mon, 2 Jun 2025 11:59:06 +0900 From: Byungchul Park To: Yeo Reum Yun Cc: "kernel_team@skhynix.com" , "linux-ide@vger.kernel.org" , "kernel-team@lge.com" , "open list:MEMORY MANAGEMENT" , "harry.yoo@oracle.com" , "yskelg@gmail.com" , "her0gyugyu@gmail.com" , "max.byungchul.park@gmail.com" , Andrew Morton , Linux Kernel Mailing List Subject: Re: [RFC DEPT v16] Question for dept. 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EA75A180005 X-Stat-Signature: typ5steoryaaiqet36u4qf7uuskpxuwo X-Rspam-User: X-HE-Tag: 1748833153-922944 X-HE-Meta: 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 WsiaHq/B dpegbelxiy4odbtgcflLJwmuQN4+o7tzRFrseP0WmLA/GP+RFdukCyOiJZDFiavy3qywxqDb/WT9r59qRx0WQF0lOWfpMuPYGRM8NGF+eRtYUAbM= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Fri, May 30, 2025 at 11:27:48AM +0000, Yeo Reum Yun wrote: > Hi Byungchul, > > Thanks for your great work for the latest dept patch. > > But I have a some quetions with the below dept log supplied from > Yunseong Kim > > ... > [13304.604203] context A > [13304.604209] [S] lock(&uprobe->register_rwsem:0) > [13304.604217] [W] __wait_rcu_gp(:0) > [13304.604226] [E] unlock(&uprobe->register_rwsem:0) > [13304.604234] > [13304.604239] context B > [13304.604244] [S] lock(event_mutex:0) > [13304.604252] [W] lock(&uprobe->register_rwsem:0) > [13304.604261] [E] unlock(event_mutex:0) > [13304.604269] > [13304.604274] context C > [13304.604279] [S] lock(&ctx->mutex:0) > [13304.604287] [W] lock(event_mutex:0) > [13304.604295] [E] unlock(&ctx->mutex:0) > [13304.604303] > [13304.604308] context D > [13304.604313] [S] lock(&sig->exec_update_lock:0) > [13304.604322] [W] lock(&ctx->mutex:0) > [13304.604330] [E] unlock(&sig->exec_update_lock:0) > [13304.604338] > [13304.604343] context E > [13304.604348] [S] lock(&f->f_pos_lock:0) > [13304.604356] [W] lock(&sig->exec_update_lock:0) > [13304.604365] [E] unlock(&f->f_pos_lock:0) > [13304.604373] > [13304.604378] context F > [13304.604383] [S] (unknown)(:0) > [13304.604391] [W] lock(&f->f_pos_lock:0) > [13304.604399] [E] try_to_wake_up(:0) > [13304.604408] > [13304.604413] context G > [13304.604418] [S] lock(btrfs_trans_num_writers:0) > [13304.604427] [W] btrfs_commit_transaction(:0) > [13304.604436] [E] unlock(btrfs_trans_num_writers:0) > [13304.604445] > [13304.604449] context H > [13304.604455] [S] (unknown)(:0) > [13304.604463] [W] lock(btrfs_trans_num_writers:0) > [13304.604471] [E] try_to_wake_up(:0) > [13304.604484] context I > [13304.604490] [S] (unknown)(:0) > [13304.604498] [W] synchronize_rcu_expedited_wait_once(:0) > [13304.604507] --------------- >8 timeout --------------- > [13304.604527] context J > [13304.604533] [S] (unknown)(:0) > [13304.604541] [W] synchronize_rcu_expedited(:0) > [13304.604549] [E] try_to_wake_up(:0) What a long circle! Dept is working great! However, this is a false positive that comes from rcu waits that haven't been classified properly yet, the fix of which is in progress by Yunseong Kim. We should wait for him to complete the fix :( > [end of circular] > ... > > 1. I wonder how context A could be printed with > [13304.604217] [W] __wait_rcu_gp(:0) > since, the completion's dept map will be initailized with > sdt_might_sleep_start_timeout((x)->dmap, -1L); > > I think last dept_task's stage_sched_map affects this wrong print. No. It's working as it should. Since (x)->dmap is NULL in this case, it's supposed to print . > Should this be fixed with: > > @@ -2713,6 +2713,7 @@ void dept_stage_wait(struct dept_map *m, struct dept_key *k, > if (m) { > dt->stage_m = *m; > dt->stage_real_m = m; > + dt->stage_sched_map = false; It should already be false since sdt_might_sleep_end() reset this value to false. DEPT_WARN_ON(dt->stage_sched_map) in here might make more sense. > /* > * Ensure dt->stage_m.keys != NULL and it works with the > > 2. Whenever prints the dependency which initalized with sdt_might_sleep_start_timeout() currently it prints > (unknown)(:0) only. > Would it much better to print task information? (pid, comm and other). Thanks for such a valuable feedback. I will add it to to-do. Byungchul > > Thanks.