From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on dcvr.yhbt.net X-Spam-Level: X-Spam-ASN: AS54825 139.178.88.0/22 X-Spam-Status: No, score=-4.0 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED,SPF_HELO_NONE,SPF_PASS shortcircuit=no autolearn=ham autolearn_force=no version=3.4.6 Received: from sv.mirrors.kernel.org (sv.mirrors.kernel.org [139.178.88.99]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by dcvr.yhbt.net (Postfix) with ESMTPS id D70E31F44D for ; Fri, 19 Apr 2024 21:52:28 +0000 (UTC) Authentication-Results: dcvr.yhbt.net; dkim=pass (1024-bit key; unprotected) header.d=80x24.org header.i=@80x24.org header.a=rsa-sha256 header.s=selector1 header.b=sfYe4avb; dkim-atps=neutral Received: from smtp.subspace.kernel.org (wormhole.subspace.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by sv.mirrors.kernel.org (Postfix) with ESMTPS id 7A8FA282865 for ; Fri, 19 Apr 2024 21:52:28 +0000 (UTC) Received: from localhost.localdomain (localhost.localdomain [127.0.0.1]) by smtp.subspace.kernel.org (Postfix) with ESMTP id B1B9A13D256; Fri, 19 Apr 2024 21:52:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=80x24.org header.i=@80x24.org header.b="sfYe4avb" Received: from dcvr.yhbt.net (dcvr.yhbt.net [173.255.242.215]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E53EA2AEF5 for ; Fri, 19 Apr 2024 21:52:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=173.255.242.215 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713563541; cv=none; b=RHSU7DSb8KjDMBt9zw0JiWwoGSFZQ5i2UVEN9ci2RwIaKtOMWCeFbTyihzhuJy13SvK5f6v9QEGBKSrOk8RX5Vek1zMECGDPk570lcxeZdf+DKe7ZcIHnSRXN7hEPhy2DfhJCzkKAI/Sows1WyipubiBWIl5mtOHT2phitTcj2g= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713563541; c=relaxed/simple; bh=Nj8qfAproCROeDwyxxAjMZRAXxz/YgxTP2lH6prm/cY=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=P7PQryCfw9caVLXJxGAwzca9RCHay/OJDFnECVIklJasWTocpNCgbcnr/R3WXXm5UaudipJqfyccCdEVVLyQYprpCUfZTbaFQu/3k0en1IfWH9nF/pngglExKOo1EYGfYqPYymz2gyDOU3zbYJbZkIzNMkGiB5TT1MN98h9LEc4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=80x24.org; spf=pass smtp.mailfrom=80x24.org; dkim=pass (1024-bit key) header.d=80x24.org header.i=@80x24.org header.b=sfYe4avb; arc=none smtp.client-ip=173.255.242.215 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=80x24.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=80x24.org Received: from localhost (dcvr.yhbt.net [127.0.0.1]) by dcvr.yhbt.net (Postfix) with ESMTP id 5544C1F44D; Fri, 19 Apr 2024 21:46:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=80x24.org; s=selector1; t=1713563204; bh=Nj8qfAproCROeDwyxxAjMZRAXxz/YgxTP2lH6prm/cY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=sfYe4avbe9MW60hgF+q7crGthwP9weWL8I3TQCH+/ZpoZ/EysUTw3a3GHDTeTbQjp BkDJb3KzvLzvgfHlqjNZVAkTx+48fMZynibJR4KT9UyME7IWfQe/UeT3tu7zfYUtJF cmmKqL1AvXtyINNH2i6wtLD7HxnEC68odE8WYxCg= Date: Fri, 19 Apr 2024 21:46:44 +0000 From: Eric Wong To: Junio C Hamano Cc: git@vger.kernel.org Subject: Re: [PATCH 0/3] switch to tombstone-free khashl table Message-ID: <20240419214644.M168521@dcvr> References: <20240325230704.262272-1-e@80x24.org> Precedence: bulk X-Mailing-List: git@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: Junio C Hamano wrote: > Junio C Hamano writes: > > Eric Wong writes: > > > >> The memory improvement is minor, but any memory reduction at all > >> is welcome at this point. Fortunately, this set of changes is > >> unintrusive. > >> > >> I have some other ideas that I'll hopefully get to implement before > >> swapping kills all my SSDs (see bottom). > > > > Please describe what this topic aims at to sell the topic better. > > Are we trying to reduce memory footprint? In other words, if this > > topic were to hit a released version of Git, what would the short > > paragraph description for the topic in the release notes look like? > > ... > > So, did anything happened since this exchange? I remember that we > caught and fixed a few minor sparse errors, but other than that, I > am not sure what to do with this topic. Not really... I've been thinking we can beat khashl for our purposes usage by allowing explicit tombstones to be configured and getting rid of the ->used bitmap entirely. One goal is to eventually reuse the code with the open-coded hash table in object.c That said, I've been bogged down by personal crap this year and don't know how/if I'll be able to hack on it this year. > Not that I want to merge loud tree-wide topics down during the > prerelease period... No worries, we can keep it out for now and work on it incrementally or drop it entirely in favor of something else down the line... git's about to turn 20, and I really want to ensure it and the tools around it continue to be usable on computers from 20-25 years ago.