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 X-Spam-Level: X-Spam-Status: No, score=-6.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D11C0C2D0B1 for ; Thu, 6 Feb 2020 15:24:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A2F1C24682 for ; Thu, 6 Feb 2020 15:24:43 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="XfsHeHXv" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727922AbgBFPYn (ORCPT ); Thu, 6 Feb 2020 10:24:43 -0500 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:38784 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727806AbgBFPYe (ORCPT ); Thu, 6 Feb 2020 10:24:34 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1581002673; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:in-reply-to:in-reply-to:references:references; bh=lNAPArXbNovHkR2AMewAPMmBXHpx4HCht8HvJkIov8w=; b=XfsHeHXvDpC0HtCdrkWIXu7n7R0GtA5rAfbqhwvspbiQ2K1e41537W0vn0r3b1Zu6EtbJT yhJ4cUTRmUnh+DKTJtVIrIKwwJpb2MKt7LLdjYq7vR/X0RcPsY/8HiwF0h83TGbXWBSy8g zP8uIZMoHdQc23ym/YnwvC8AFdZi6rI= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-417-OVyt5JHpMdmaCnjKIFD2AA-1; Thu, 06 Feb 2020 10:24:25 -0500 X-MC-Unique: OVyt5JHpMdmaCnjKIFD2AA-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 36F168C3492; Thu, 6 Feb 2020 15:24:24 +0000 (UTC) Received: from llong.com (ovpn-124-223.rdu2.redhat.com [10.10.124.223]) by smtp.corp.redhat.com (Postfix) with ESMTP id 5DB301001B05; Thu, 6 Feb 2020 15:24:23 +0000 (UTC) From: Waiman Long To: Peter Zijlstra , Ingo Molnar , Will Deacon Cc: linux-kernel@vger.kernel.org, Bart Van Assche , Waiman Long Subject: [PATCH v6 3/6] locking/lockdep: Track number of zapped classes Date: Thu, 6 Feb 2020 10:24:05 -0500 Message-Id: <20200206152408.24165-4-longman@redhat.com> In-Reply-To: <20200206152408.24165-1-longman@redhat.com> References: <20200206152408.24165-1-longman@redhat.com> X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The whole point of the lockdep dynamic key patch is to allow unused locks to be removed from the lockdep data buffers so that existing buffer space can be reused. However, there is no way to find out how many unused locks are zapped and so we don't know if the zapping process is working properly. Add a new nr_zapped_classes counter to track that and show it in /proc/lockdep_stats. Signed-off-by: Waiman Long --- kernel/locking/lockdep.c | 2 ++ kernel/locking/lockdep_internals.h | 1 + kernel/locking/lockdep_proc.c | 6 ++++++ 3 files changed, 9 insertions(+) diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c index 35449f5b79fb..28222d03345f 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -147,6 +147,7 @@ static DECLARE_BITMAP(list_entries_in_use, MAX_LOCKDEP_ENTRIES); #define KEYHASH_SIZE (1UL << KEYHASH_BITS) static struct hlist_head lock_keys_hash[KEYHASH_SIZE]; unsigned long nr_lock_classes; +unsigned long nr_zapped_classes; #ifndef CONFIG_DEBUG_LOCKDEP static #endif @@ -4880,6 +4881,7 @@ static void zap_class(struct pending_free *pf, struct lock_class *class) } remove_class_from_lock_chains(pf, class); + nr_zapped_classes++; } static void reinit_class(struct lock_class *class) diff --git a/kernel/locking/lockdep_internals.h b/kernel/locking/lockdep_internals.h index a525368b8cf6..76db80446a32 100644 --- a/kernel/locking/lockdep_internals.h +++ b/kernel/locking/lockdep_internals.h @@ -130,6 +130,7 @@ extern const char *__get_key_name(const struct lockdep_subclass_key *key, struct lock_class *lock_chain_get_class(struct lock_chain *chain, int i); extern unsigned long nr_lock_classes; +extern unsigned long nr_zapped_classes; extern unsigned long nr_list_entries; long lockdep_next_lockchain(long i); unsigned long lock_chain_count(void); diff --git a/kernel/locking/lockdep_proc.c b/kernel/locking/lockdep_proc.c index 0f6842bcfba8..453e497b6124 100644 --- a/kernel/locking/lockdep_proc.c +++ b/kernel/locking/lockdep_proc.c @@ -343,6 +343,12 @@ static int lockdep_stats_show(struct seq_file *m, void *v) seq_printf(m, " debug_locks: %11u\n", debug_locks); + /* + * Zappped classes and lockdep data buffers reuse statistics. + */ + seq_puts(m, "\n"); + seq_printf(m, " zapped classes: %11lu\n", + nr_zapped_classes); return 0; } -- 2.18.1