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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 1FB55C55186 for ; Wed, 22 Apr 2020 10:02:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E967220774 for ; Wed, 22 Apr 2020 10:02:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587549767; bh=8W1vFSWViNeHhEhT1gm4IAWUjpSWJW1aRrND3K87PAI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=2h/WzCQ31VJ9gwT+Pz8Ryiypf2SAOVunUFdl1mL38SV/KaII6OKZdehGqeDTFJHO2 2A26aB/dPaqGag2d8SxMwjfPx1PsyeYQtqs37v5dWtTgdE9gHVF+Ysd51CEeU8U1nV 8DbImvxWNJD7pgP01/L7lbhZBOc0eNTYVILgFank= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727049AbgDVKCp (ORCPT ); Wed, 22 Apr 2020 06:02:45 -0400 Received: from mail.kernel.org ([198.145.29.99]:51926 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727034AbgDVKCm (ORCPT ); Wed, 22 Apr 2020 06:02:42 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 3140320787; Wed, 22 Apr 2020 10:02:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587549761; bh=8W1vFSWViNeHhEhT1gm4IAWUjpSWJW1aRrND3K87PAI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=xzNZokm1Za+Azl4pahFDePvsuYuqxKmQwva2LgTGc+K9LjPMzLWOMww/LWHJjGW27 mVYQZVj4zUMZDLcVb+gJSyNW82/Psq6SqdiwUvCAvd6TFq51suk7kg5Zv4No0EHyxt 46JnY0T4/TlPjAyk3blu20YU1N6dAI7CXl+1j+q0= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Will Deacon , "Paul E. McKenney" , Davidlohr Bueso , Josh Triplett , Peter Zijlstra Subject: [PATCH 4.4 095/100] locktorture: Print ratio of acquisitions, not failures Date: Wed, 22 Apr 2020 11:57:05 +0200 Message-Id: <20200422095040.045537728@linuxfoundation.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200422095022.476101261@linuxfoundation.org> References: <20200422095022.476101261@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Paul E. McKenney commit 80c503e0e68fbe271680ab48f0fe29bc034b01b7 upstream. The __torture_print_stats() function in locktorture.c carefully initializes local variable "min" to statp[0].n_lock_acquired, but then compares it to statp[i].n_lock_fail. Given that the .n_lock_fail field should normally be zero, and given the initialization, it seems reasonable to display the maximum and minimum number acquisitions instead of miscomputing the maximum and minimum number of failures. This commit therefore switches from failures to acquisitions. And this turns out to be not only a day-zero bug, but entirely my own fault. I hate it when that happens! Fixes: 0af3fe1efa53 ("locktorture: Add a lock-torture kernel module") Reported-by: Will Deacon Signed-off-by: Paul E. McKenney Acked-by: Will Deacon Cc: Davidlohr Bueso Cc: Josh Triplett Cc: Peter Zijlstra Signed-off-by: Greg Kroah-Hartman --- kernel/locking/locktorture.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) --- a/kernel/locking/locktorture.c +++ b/kernel/locking/locktorture.c @@ -655,10 +655,10 @@ static void __torture_print_stats(char * if (statp[i].n_lock_fail) fail = true; sum += statp[i].n_lock_acquired; - if (max < statp[i].n_lock_fail) - max = statp[i].n_lock_fail; - if (min > statp[i].n_lock_fail) - min = statp[i].n_lock_fail; + if (max < statp[i].n_lock_acquired) + max = statp[i].n_lock_acquired; + if (min > statp[i].n_lock_acquired) + min = statp[i].n_lock_acquired; } page += sprintf(page, "%s: Total: %lld Max/Min: %ld/%ld %s Fail: %d %s\n",