From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on dcvr.yhbt.net X-Spam-Level: X-Spam-ASN: AS31976 209.132.180.0/23 X-Spam-Status: No, score=-4.8 required=3.0 tests=AWL,BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,RCVD_IN_DNSWL_HI,RP_MATCHES_RCVD shortcircuit=no autolearn=ham autolearn_force=no version=3.4.0 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by dcvr.yhbt.net (Postfix) with ESMTP id D90911FCA9 for ; Wed, 14 Sep 2016 23:55:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1764328AbcINXzw (ORCPT ); Wed, 14 Sep 2016 19:55:52 -0400 Received: from cloud.peff.net ([104.130.231.41]:43460 "EHLO cloud.peff.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1762678AbcINXzv (ORCPT ); Wed, 14 Sep 2016 19:55:51 -0400 Received: (qmail 22730 invoked by uid 109); 14 Sep 2016 23:55:51 -0000 Received: from Unknown (HELO peff.net) (10.0.1.2) by cloud.peff.net (qpsmtpd/0.84) with SMTP; Wed, 14 Sep 2016 23:55:51 +0000 Received: (qmail 5243 invoked by uid 111); 14 Sep 2016 23:56:01 -0000 Received: from Unknown (HELO sigill.intra.peff.net) (10.0.1.3) by peff.net (qpsmtpd/0.84) with SMTP; Wed, 14 Sep 2016 19:56:01 -0400 Received: by sigill.intra.peff.net (sSMTP sendmail emulation); Wed, 14 Sep 2016 16:55:48 -0700 Date: Wed, 14 Sep 2016 16:55:48 -0700 From: Jeff King To: git@vger.kernel.org Subject: Journal of Failed Git Experiments, Volume 1 Message-ID: <20160914235547.h3n2otje2hec6u7k@sigill.intra.peff.net> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org I try a lot of different experiments with git performance, some of them more hare-brained than others. The ones that succeed end up as real patches. But I hate for the ones that fail to die a quiet death. Then nobody learns what _doesn't_ work, and nobody has the opportunity to point out the spot where I made a stupid mistake that invalidates the whole result. Here are two performance experiments that did _not_ turn out. They are in patch form, because I want to document exactly what I did (especially because it helps in the "stupid mistake" case, or if somebody wants to try building on my results). So without further ado: [1/2]: obj_hash: convert to a critbit tree [2/2]: use zstd zlib wrapper -Peff