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: AS3215 2.6.0.0/16 X-Spam-Status: No, score=-3.8 required=3.0 tests=AWL,BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS shortcircuit=no autolearn=ham autolearn_force=no version=3.4.2 Received: from out1.vger.email (out1.vger.email [IPv6:2620:137:e000::1:20]) by dcvr.yhbt.net (Postfix) with ESMTP id 697D31F506 for ; Sat, 24 Sep 2022 20:17:14 +0000 (UTC) Authentication-Results: dcvr.yhbt.net; dkim=pass (1024-bit key; unprotected) header.d=pobox.com header.i=@pobox.com header.b="hzxVm4kr"; dkim-atps=neutral Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229558AbiIXURJ (ORCPT ); Sat, 24 Sep 2022 16:17:09 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49934 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229957AbiIXURH (ORCPT ); Sat, 24 Sep 2022 16:17:07 -0400 Received: from pb-smtp2.pobox.com (pb-smtp2.pobox.com [64.147.108.71]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A193432ED7 for ; Sat, 24 Sep 2022 13:17:05 -0700 (PDT) Received: from pb-smtp2.pobox.com (unknown [127.0.0.1]) by pb-smtp2.pobox.com (Postfix) with ESMTP id 76D5414CFE6; Sat, 24 Sep 2022 16:17:04 -0400 (EDT) (envelope-from junio@pobox.com) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed; d=pobox.com; h=from:to:cc :subject:references:date:in-reply-to:message-id:mime-version :content-type:content-transfer-encoding; s=sasl; bh=DIwl/lLvGVTe s5cFfYLgSAydO0cOT5TrPqJkrxdzmxE=; b=hzxVm4kreQzvUFi90aeKdmPZu0MP OanLVUR5d66eC9xnR5Xry+0GMJg6tML/wkMXZgcW04I+6GsZ60aTZ19VNcHdDs8o 9Qfxj699kMKFRprdo6dc2vsfbnJstP4+Jw3X6fzAVhnnSnh8bijWcGZ1BOJd1dG1 EPObaIJxRdYbWoM= Received: from pb-smtp2.nyi.icgroup.com (unknown [127.0.0.1]) by pb-smtp2.pobox.com (Postfix) with ESMTP id 4FB8414CFE5; Sat, 24 Sep 2022 16:17:04 -0400 (EDT) (envelope-from junio@pobox.com) Received: from pobox.com (unknown [34.83.5.33]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by pb-smtp2.pobox.com (Postfix) with ESMTPSA id 8522F14CFE4; Sat, 24 Sep 2022 16:17:03 -0400 (EDT) (envelope-from junio@pobox.com) From: Junio C Hamano To: =?utf-8?B?w4Z2YXIgQXJuZmrDtnLDsA==?= Bjarmason Cc: Calvin Wan , git@vger.kernel.org, emilyshaffer@google.com Subject: Re: [PATCH 4/4] diff-lib: parallelize run_diff_files for submodules References: <20220922232947.631309-1-calvinwan@google.com> <20220922232947.631309-5-calvinwan@google.com> <220923.86o7v64ik0.gmgdl@evledraar.gmail.com> Date: Sat, 24 Sep 2022 13:17:02 -0700 In-Reply-To: <220923.86o7v64ik0.gmgdl@evledraar.gmail.com> (=?utf-8?B?IsOG?= =?utf-8?B?dmFyIEFybmZqw7Zyw7A=?= Bjarmason"'s message of "Fri, 23 Sep 2022 10:06:56 +0200") Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/28.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 X-Pobox-Relay-ID: DA8FBFEC-3C45-11ED-885E-307A8E0A682E-77302942!pb-smtp2.pobox.com Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org =C3=86var Arnfj=C3=B6r=C3=B0 Bjarmason writes: > On Thu, Sep 22 2022, Calvin Wan wrote: > >> +status.parallelSubmodules:: >> + When linkgit:git-status[1] is run in a superproject with >> + submodules, a status subprocess is spawned for every submodule. >> + This option specifies the number of submodule status subprocesses >> + to run in parallel. If unset, it defaults to 1. > > Why do we default to 1, instead of e.g. grep.threads defaulting to the > "cores available"? I would imagine we would want to be able to say: - I do not trust the parallel mode yet, just use the single process method that we have always been using. - I do not know how many cores I have, just use a reasonable default parallelism. - I want to use N processes because I know better than auto-scaling based on num_cpus. And the value of 1 would be a reasonable way to express the first one.