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=-3.3 required=3.0 tests=AWL,BAYES_00,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,RCVD_IN_DNSWL_HI,T_DKIM_INVALID, T_RP_MATCHES_RCVD shortcircuit=no autolearn=no 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 649531F424 for ; Sat, 20 Jan 2018 22:14:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756732AbeATWOz (ORCPT ); Sat, 20 Jan 2018 17:14:55 -0500 Received: from imap.thunk.org ([74.207.234.97]:41206 "EHLO imap.thunk.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756652AbeATWOv (ORCPT ); Sat, 20 Jan 2018 17:14:51 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=thunk.org; s=ef5046eb; h=In-Reply-To:Content-Type:MIME-Version:References:Message-ID: Subject:Cc:To:From:Date:Sender:Reply-To:Content-Transfer-Encoding:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=2e4dqcjMge9DYIPHTxEF2qXFQFb4zvzaSioR4/Z7KlI=; b=JaKtLTLJf2KYAeKRFCpe3h5K7/ 8jLOd6bxCgJU1Hf1pZ8OmBwjFqiSWUxvsUCcSSxRDzeYDRmjaGAhxb8RdwqTec52IzbYo2FIOtrZu fTjFC2Sdz+kpCHl5pzPgdDBau56IurOTS5Ng39AlvJqHUbtPWmyt9qJYVrg8qh18ZiHo=; Received: from root (helo=callcc.thunk.org) by imap.thunk.org with local-esmtp (Exim 4.89) (envelope-from ) id 1ed1PS-00082T-Mq; Sat, 20 Jan 2018 22:14:46 +0000 Received: by callcc.thunk.org (Postfix, from userid 15806) id 057D4C0021E; Sat, 20 Jan 2018 17:14:45 -0500 (EST) Date: Sat, 20 Jan 2018 17:14:45 -0500 From: Theodore Ts'o To: Junio C Hamano Cc: Christoph Hellwig , Linus Torvalds , =?iso-8859-1?Q?=C6var_Arnfj=F6r=F0?= Bjarmason , Git Mailing List , linux-fsdevel , Chris Mason Subject: Re: [PATCH] enable core.fsyncObjectFiles by default Message-ID: <20180120221445.GA4451@thunk.org> References: <20180117184828.31816-1-hch@lst.de> <87h8rki2iu.fsf@evledraar.gmail.com> <20180117235220.GD6948@thunk.org> <20180118162721.GA26078@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.9.2 (2017-12-15) X-SA-Exim-Connect-IP: X-SA-Exim-Mail-From: tytso@thunk.org X-SA-Exim-Scanned: No (on imap.thunk.org); SAEximRunCond expanded to false Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org On Fri, Jan 19, 2018 at 11:08:46AM -0800, Junio C Hamano wrote: > So..., is it fair to say that the one you sent in > > https://public-inbox.org/git/20180117193510.GA30657@lst.de/ > > is the best variant we have seen in this thread so far? I'll keep > that in my inbox so that I do not forget, but I think we would want > to deal with a hotfix for 2.16 on case insensitive platforms before > this topic. It's a simplistic fix, but it will work. There may very well be certain workloads which generate a large number of loose objects (e.g., git repack -A) which will make things go significantly more slowly as a result. It might very well be the case that if nothing else is going on, something like "write all the files without fsync(2), then use syncfs(2)" would be much faster. The downside with that approach is if indeed you were downloading a multi-gigabyte DVD image at the same time, the syncfs(2) will force a writeback of the partially writte DVD image, or some other unrelated files. But if the goal is to just change the default, and then see what shakes out, and then apply other optimizations later, that's certainly a valid result. I've never been fond of the "git repack -A" behavior where it can generate huge numbers of loose files. I'd much prefer it if the other objects ended up in a separate pack file, and then some other provision made for nuking that pack file some time later. But that's expanding the scope significantly over what's currently being discussed. - Ted