From patchwork Fri Mar 4 07:06:19 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Byungchul Park X-Patchwork-Id: 12768605 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 49497C433FE for ; Fri, 4 Mar 2022 07:07:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238648AbiCDHIC (ORCPT ); Fri, 4 Mar 2022 02:08:02 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36424 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238469AbiCDHH5 (ORCPT ); Fri, 4 Mar 2022 02:07:57 -0500 Received: from lgeamrelo11.lge.com (lgeamrelo11.lge.com [156.147.23.51]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 2F91818FAC5 for ; Thu, 3 Mar 2022 23:07:07 -0800 (PST) Received: from unknown (HELO lgemrelse6q.lge.com) (156.147.1.121) by 156.147.23.51 with ESMTP; 4 Mar 2022 16:07:06 +0900 X-Original-SENDERIP: 156.147.1.121 X-Original-MAILFROM: byungchul.park@lge.com Received: from unknown (HELO localhost.localdomain) (10.177.244.38) by 156.147.1.121 with ESMTP; 4 Mar 2022 16:07:05 +0900 X-Original-SENDERIP: 10.177.244.38 X-Original-MAILFROM: byungchul.park@lge.com From: Byungchul Park To: torvalds@linux-foundation.org Cc: damien.lemoal@opensource.wdc.com, linux-ide@vger.kernel.org, adilger.kernel@dilger.ca, linux-ext4@vger.kernel.org, mingo@redhat.com, linux-kernel@vger.kernel.org, peterz@infradead.org, will@kernel.org, tglx@linutronix.de, rostedt@goodmis.org, joel@joelfernandes.org, sashal@kernel.org, daniel.vetter@ffwll.ch, chris@chris-wilson.co.uk, duyuyang@gmail.com, johannes.berg@intel.com, tj@kernel.org, tytso@mit.edu, willy@infradead.org, david@fromorbit.com, amir73il@gmail.com, bfields@fieldses.org, 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, jack@suse.com, jlayton@kernel.org, dan.j.williams@intel.com, hch@infradead.org, djwong@kernel.org, dri-devel@lists.freedesktop.org, airlied@linux.ie, rodrigosiqueiramelo@gmail.com, melissa.srw@gmail.com, hamohammed.sa@gmail.com Subject: [PATCH v4 00/24] DEPT(Dependency Tracker) Date: Fri, 4 Mar 2022 16:06:19 +0900 Message-Id: <1646377603-19730-1-git-send-email-byungchul.park@lge.com> X-Mailer: git-send-email 1.9.1 Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org Hi Linus and folks, I've been developing a tool for detecting deadlock possibilities by tracking wait/event rather than lock(?) acquisition order to try to cover all synchonization machanisms. It's done on v5.17-rc1 tag. https://github.com/lgebyungchulpark/linux-dept/commits/dept1.14_on_v5.17-rc1 Benifit: 0. Works with all lock primitives. 1. Works with wait_for_completion()/complete(). 2. Works with 'wait' on PG_locked. 3. Works with 'wait' on PG_writeback. 4. Works with swait/wakeup. 5. Works with waitqueue. 6. Multiple reports are allowed. 7. Deduplication control on multiple reports. 8. Withstand false positives thanks to 6. 9. Easy to tag any wait/event. Future work: 0. To make it more stable. 1. To separates Dept from Lockdep. 2. To improves performance in terms of time and space. 3. To use Dept as a dependency engine for Lockdep. 4. To add any missing tags of wait/event in the kernel. 5. To deduplicate stack trace. How to interpret reports: 1. E(event) in each context cannot be triggered because of the W(wait) that cannot be woken. 2. The stack trace helping find the problematic code is located in each conext's detail. Thanks, Byungchul --- Changes from v3: 1. Dept shouldn't create dependencies between different depths of a class that were indicated by *_lock_nested(). Dept normally doesn't but it does once another lock class comes in. So fixed it. (feedback from Hyeonggon) 2. Dept considered a wait as a real wait once getting to __schedule() even if it has been set to TASK_RUNNING by wake up sources in advance. Fixed it so that Dept doesn't consider the case as a real wait. (feedback from Jan Kara) 3. Stop tracking dependencies with a map once the event associated with the map has been handled. Dept will start to work with the map again, on the next sleep. Changes from v2: 1. Disable Dept on bit_wait_table[] in sched/wait_bit.c reporting a lot of false positives, which is my fault. Wait/event for bit_wait_table[] should've been tagged in a higher layer for better work, which is a future work. (feedback from Jan Kara) 2. Disable Dept on crypto_larval's completion to prevent a false positive. Changes from v1: 1. Fix coding style and typo. (feedback from Steven) 2. Distinguish each work context from another in workqueue. 3. Skip checking lock acquisition with nest_lock, which is about correct lock usage that should be checked by Lockdep. Changes from RFC: 1. Prevent adding a wait tag at prepare_to_wait() but __schedule(). (feedback from Linus and Matthew) 2. Use try version at lockdep_acquire_cpus_lock() annotation. 3. Distinguish each syscall context from another. Byungchul Park (24): llist: Move llist_{head,node} definition to types.h dept: Implement Dept(Dependency Tracker) dept: Embed Dept data in Lockdep dept: Add a API for skipping dependency check temporarily dept: Apply Dept to spinlock dept: Apply Dept to mutex families dept: Apply Dept to rwlock dept: Apply Dept to wait_for_completion()/complete() dept: Apply Dept to seqlock dept: Apply Dept to rwsem dept: Add proc knobs to show stats and dependency graph dept: Introduce split map concept and new APIs for them dept: Apply Dept to wait/event of PG_{locked,writeback} dept: Apply SDT to swait dept: Apply SDT to wait(waitqueue) locking/lockdep, cpu/hotplus: Use a weaker annotation in AP thread dept: Distinguish each syscall context from another dept: Distinguish each work from another dept: Disable Dept within the wait_bit layer by default dept: Add nocheck version of init_completion() dept: Disable Dept on struct crypto_larval's completion for now dept: Don't create dependencies between different depths in any case dept: Let it work with real sleeps in __schedule() dept: Disable Dept on that map once it's been handled until next turn crypto/api.c | 7 +- include/linux/completion.h | 50 +- include/linux/dept.h | 535 +++++++ include/linux/dept_page.h | 78 ++ include/linux/dept_sdt.h | 62 + include/linux/hardirq.h | 3 + include/linux/irqflags.h | 33 +- include/linux/llist.h | 8 - include/linux/lockdep.h | 158 ++- include/linux/lockdep_types.h | 3 + include/linux/mutex.h | 33 + include/linux/page-flags.h | 45 +- include/linux/pagemap.h | 7 +- include/linux/percpu-rwsem.h | 10 +- include/linux/rtmutex.h | 7 + include/linux/rwlock.h | 52 + include/linux/rwlock_api_smp.h | 8 +- include/linux/rwlock_types.h | 7 + include/linux/rwsem.h | 33 + include/linux/sched.h | 7 + include/linux/seqlock.h | 59 +- include/linux/spinlock.h | 26 + include/linux/spinlock_types_raw.h | 13 + include/linux/swait.h | 4 + include/linux/types.h | 8 + include/linux/wait.h | 6 +- init/init_task.c | 2 + init/main.c | 4 + kernel/Makefile | 1 + kernel/cpu.c | 2 +- kernel/dependency/Makefile | 4 + kernel/dependency/dept.c | 2716 ++++++++++++++++++++++++++++++++++++ kernel/dependency/dept_hash.h | 10 + kernel/dependency/dept_internal.h | 26 + kernel/dependency/dept_object.h | 13 + kernel/dependency/dept_proc.c | 92 ++ kernel/entry/common.c | 3 + kernel/exit.c | 1 + kernel/fork.c | 2 + kernel/locking/lockdep.c | 12 +- kernel/module.c | 2 + kernel/sched/completion.c | 12 +- kernel/sched/core.c | 8 + kernel/sched/swait.c | 10 + kernel/sched/wait.c | 16 + kernel/sched/wait_bit.c | 5 +- kernel/softirq.c | 6 +- kernel/trace/trace_preemptirq.c | 19 +- kernel/workqueue.c | 3 + lib/Kconfig.debug | 21 + mm/filemap.c | 68 + mm/page_ext.c | 5 + 52 files changed, 4266 insertions(+), 59 deletions(-) create mode 100644 include/linux/dept.h create mode 100644 include/linux/dept_page.h create mode 100644 include/linux/dept_sdt.h create mode 100644 kernel/dependency/Makefile create mode 100644 kernel/dependency/dept.c create mode 100644 kernel/dependency/dept_hash.h create mode 100644 kernel/dependency/dept_internal.h create mode 100644 kernel/dependency/dept_object.h create mode 100644 kernel/dependency/dept_proc.c