From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on dcvr.yhbt.net X-Spam-Level: X-Spam-ASN: AS31976 209.132.180.0/23 X-Spam-Status: No, score=-4.0 required=3.0 tests=AWL,BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI shortcircuit=no autolearn=ham autolearn_force=no version=3.4.2 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by dcvr.yhbt.net (Postfix) with ESMTP id E4F711F453 for ; Fri, 8 Feb 2019 19:11:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727212AbfBHTLF (ORCPT ); Fri, 8 Feb 2019 14:11:05 -0500 Received: from cloud.peff.net ([104.130.231.41]:37916 "HELO cloud.peff.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1726852AbfBHTLF (ORCPT ); Fri, 8 Feb 2019 14:11:05 -0500 Received: (qmail 13962 invoked by uid 109); 8 Feb 2019 19:11:05 -0000 Received: from Unknown (HELO peff.net) (10.0.1.2) by cloud.peff.net (qpsmtpd/0.94) with SMTP; Fri, 08 Feb 2019 19:11:05 +0000 Authentication-Results: cloud.peff.net; auth=none Received: (qmail 26569 invoked by uid 111); 8 Feb 2019 19:11:14 -0000 Received: from sigill.intra.peff.net (HELO sigill.intra.peff.net) (10.0.0.7) by peff.net (qpsmtpd/0.94) with (ECDHE-RSA-AES256-GCM-SHA384 encrypted) SMTP; Fri, 08 Feb 2019 14:11:14 -0500 Authentication-Results: peff.net; auth=none Received: by sigill.intra.peff.net (sSMTP sendmail emulation); Fri, 08 Feb 2019 14:11:03 -0500 Date: Fri, 8 Feb 2019 14:11:03 -0500 From: Jeff King To: SZEDER =?utf-8?B?R8OhYm9y?= Cc: Junio C Hamano , git@vger.kernel.org Subject: Re: [PATCH] test-lib: make '--stress' more bisect-friendly Message-ID: <20190208191103.GD27673@sigill.intra.peff.net> References: <20190208115045.13256-1-szeder.dev@gmail.com> <20190208164732.GA23461@sigill.intra.peff.net> <20190208182319.GY10587@szeder.dev> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20190208182319.GY10587@szeder.dev> Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org On Fri, Feb 08, 2019 at 07:23:19PM +0100, SZEDER Gábor wrote: > > Picking an is tough. Too low and you get a false negative, too high > > and you can wait forever, especially if the script is long. But I don't > > think there's any real way to auto-scale it, except by seeing a few of > > the failing cases and watching how long they take. > > So far I've chosen like this: run the test script with --stress > 3-5 times to trigger the failure, take the highest repetition count > that was necessary for the failure, multiply it by 4-6 to get a round > number, and that's a good ballpark for . And once bisect came up > with the suspect commit, I double checked it by letting the test > script run with --stress on its parent commit for at least 5-10x > repetitions. Heh. That's exactly my process, too. :) > Anyway, I doubt that auto-scaling is worth the effort. Yeah, especially because as a concept it exists outside of the script itself (i.e., you have to checkout a failing version and then run the script a bunch of times; that's not something that test-lib.sh should even know about). So let's go with this for now. It's already a much nicer tool than we had yesterday, so we can take some time to get used to it. -Peff