From patchwork Thu Apr 25 09:45:12 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thomas Gleixner X-Patchwork-Id: 10916631 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 284431805 for ; Thu, 25 Apr 2019 10:00:27 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 176BC28C50 for ; Thu, 25 Apr 2019 10:00:27 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 0A6CE28C55; Thu, 25 Apr 2019 10:00:27 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 776E128C53 for ; Thu, 25 Apr 2019 10:00:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728431AbfDYKAV (ORCPT ); Thu, 25 Apr 2019 06:00:21 -0400 Received: from Galois.linutronix.de ([146.0.238.70]:57973 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728739AbfDYKAU (ORCPT ); Thu, 25 Apr 2019 06:00:20 -0400 Received: from localhost ([127.0.0.1] helo=nanos.tec.linutronix.de) by Galois.linutronix.de with esmtp (Exim 4.80) (envelope-from ) id 1hJbA9-0001vH-Ry; Thu, 25 Apr 2019 11:59:30 +0200 Message-Id: <20190425094802.891724020@linutronix.de> User-Agent: quilt/0.65 Date: Thu, 25 Apr 2019 11:45:12 +0200 From: Thomas Gleixner To: LKML Cc: Josh Poimboeuf , x86@kernel.org, Andy Lutomirski , Steven Rostedt , Alexander Potapenko , Alexey Dobriyan , Andrew Morton , Christoph Lameter , Pekka Enberg , linux-mm@kvack.org, David Rientjes , Catalin Marinas , Dmitry Vyukov , Andrey Ryabinin , kasan-dev@googlegroups.com, Mike Rapoport , Akinobu Mita , Christoph Hellwig , iommu@lists.linux-foundation.org, Robin Murphy , Marek Szyprowski , Johannes Thumshirn , David Sterba , Chris Mason , Josef Bacik , linux-btrfs@vger.kernel.org, dm-devel@redhat.com, Mike Snitzer , Alasdair Kergon , Daniel Vetter , intel-gfx@lists.freedesktop.org, Joonas Lahtinen , Maarten Lankhorst , dri-devel@lists.freedesktop.org, David Airlie , Jani Nikula , Rodrigo Vivi , Tom Zanussi , Miroslav Benes , linux-arch@vger.kernel.org Subject: [patch V3 19/29] lockdep: Simplify stack trace handling References: <20190425094453.875139013@linutronix.de> MIME-Version: 1.0 Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Replace the indirection through struct stack_trace by using the storage array based interfaces and storing the information is a small lockdep specific data structure. Signed-off-by: Thomas Gleixner Acked-by: Peter Zijlstra (Intel) --- include/linux/lockdep.h | 9 +++++-- kernel/locking/lockdep.c | 55 +++++++++++++++++++++++------------------------ 2 files changed, 35 insertions(+), 29 deletions(-) --- a/include/linux/lockdep.h +++ b/include/linux/lockdep.h @@ -66,6 +66,11 @@ struct lock_class_key { extern struct lock_class_key __lockdep_no_validate__; +struct lock_trace { + unsigned int nr_entries; + unsigned int offset; +}; + #define LOCKSTAT_POINTS 4 /* @@ -100,7 +105,7 @@ struct lock_class { * IRQ/softirq usage tracking bits: */ unsigned long usage_mask; - struct stack_trace usage_traces[XXX_LOCK_USAGE_STATES]; + struct lock_trace usage_traces[XXX_LOCK_USAGE_STATES]; /* * Generation counter, when doing certain classes of graph walking, @@ -188,7 +193,7 @@ struct lock_list { struct list_head entry; struct lock_class *class; struct lock_class *links_to; - struct stack_trace trace; + struct lock_trace trace; int distance; /* --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -434,18 +434,14 @@ static void print_lockdep_off(const char #endif } -static int save_trace(struct stack_trace *trace) +static int save_trace(struct lock_trace *trace) { - trace->nr_entries = 0; - trace->max_entries = MAX_STACK_TRACE_ENTRIES - nr_stack_trace_entries; - trace->entries = stack_trace + nr_stack_trace_entries; - - trace->skip = 3; - - save_stack_trace(trace); - - trace->max_entries = trace->nr_entries; + unsigned long *entries = stack_trace + nr_stack_trace_entries; + unsigned int max_entries; + trace->offset = nr_stack_trace_entries; + max_entries = MAX_STACK_TRACE_ENTRIES - nr_stack_trace_entries; + trace->nr_entries = stack_trace_save(entries, max_entries, 3); nr_stack_trace_entries += trace->nr_entries; if (nr_stack_trace_entries >= MAX_STACK_TRACE_ENTRIES-1) { @@ -1196,7 +1192,7 @@ static struct lock_list *alloc_list_entr static int add_lock_to_list(struct lock_class *this, struct lock_class *links_to, struct list_head *head, unsigned long ip, int distance, - struct stack_trace *trace) + struct lock_trace *trace) { struct lock_list *entry; /* @@ -1415,6 +1411,13 @@ static inline int __bfs_backwards(struct * checking. */ +static void print_lock_trace(struct lock_trace *trace, unsigned int spaces) +{ + unsigned long *entries = stack_trace + trace->offset; + + stack_trace_print(entries, trace->nr_entries, spaces); +} + /* * Print a dependency chain entry (this is only done when a deadlock * has been detected): @@ -1427,8 +1430,7 @@ print_circular_bug_entry(struct lock_lis printk("\n-> #%u", depth); print_lock_name(target->class); printk(KERN_CONT ":\n"); - print_stack_trace(&target->trace, 6); - + print_lock_trace(&target->trace, 6); return 0; } @@ -1740,7 +1742,7 @@ static void print_lock_class_header(stru len += printk("%*s %s", depth, "", usage_str[bit]); len += printk(KERN_CONT " at:\n"); - print_stack_trace(class->usage_traces + bit, len); + print_lock_trace(class->usage_traces + bit, len); } } printk("%*s }\n", depth, ""); @@ -1765,7 +1767,7 @@ print_shortest_lock_dependencies(struct do { print_lock_class_header(entry->class, depth); printk("%*s ... acquired at:\n", depth, ""); - print_stack_trace(&entry->trace, 2); + print_lock_trace(&entry->trace, 2); printk("\n"); if (depth == 0 && (entry != root)) { @@ -1878,14 +1880,14 @@ print_bad_irq_dependency(struct task_str print_lock_name(backwards_entry->class); pr_warn("\n... which became %s-irq-safe at:\n", irqclass); - print_stack_trace(backwards_entry->class->usage_traces + bit1, 1); + print_lock_trace(backwards_entry->class->usage_traces + bit1, 1); pr_warn("\nto a %s-irq-unsafe lock:\n", irqclass); print_lock_name(forwards_entry->class); pr_warn("\n... which became %s-irq-unsafe at:\n", irqclass); pr_warn("..."); - print_stack_trace(forwards_entry->class->usage_traces + bit2, 1); + print_lock_trace(forwards_entry->class->usage_traces + bit2, 1); pr_warn("\nother info that might help us debug this:\n\n"); print_irq_lock_scenario(backwards_entry, forwards_entry, @@ -2158,7 +2160,7 @@ check_deadlock(struct task_struct *curr, */ static int check_prev_add(struct task_struct *curr, struct held_lock *prev, - struct held_lock *next, int distance, struct stack_trace *trace) + struct held_lock *next, int distance, struct lock_trace *trace) { struct lock_list *uninitialized_var(target_entry); struct lock_list *entry; @@ -2196,7 +2198,7 @@ check_prev_add(struct task_struct *curr, this.parent = NULL; ret = check_noncircular(&this, hlock_class(prev), &target_entry); if (unlikely(!ret)) { - if (!trace->entries) { + if (!trace->nr_entries) { /* * If save_trace fails here, the printing might * trigger a WARN but because of the !nr_entries it @@ -2252,7 +2254,7 @@ check_prev_add(struct task_struct *curr, return print_bfs_bug(ret); - if (!trace->entries && !save_trace(trace)) + if (!trace->nr_entries && !save_trace(trace)) return 0; /* @@ -2284,14 +2286,9 @@ check_prev_add(struct task_struct *curr, static int check_prevs_add(struct task_struct *curr, struct held_lock *next) { + struct lock_trace trace = { .nr_entries = 0 }; int depth = curr->lockdep_depth; struct held_lock *hlock; - struct stack_trace trace = { - .nr_entries = 0, - .max_entries = 0, - .entries = NULL, - .skip = 0, - }; /* * Debugging checks. @@ -2719,6 +2716,10 @@ static inline int validate_chain(struct { return 1; } + +static void print_lock_trace(struct lock_trace *trace, unsigned int spaces) +{ +} #endif /* @@ -2815,7 +2816,7 @@ print_usage_bug(struct task_struct *curr print_lock(this); pr_warn("{%s} state was registered at:\n", usage_str[prev_bit]); - print_stack_trace(hlock_class(this)->usage_traces + prev_bit, 1); + print_lock_trace(hlock_class(this)->usage_traces + prev_bit, 1); print_irqtrace_events(curr); pr_warn("\nother info that might help us debug this:\n");