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: AS53758 23.128.96.0/24 X-Spam-Status: No, score=-4.2 required=3.0 tests=AWL,BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,RCVD_IN_DNSWL_LOW, SPF_HELO_PASS,SPF_PASS shortcircuit=no autolearn=ham autolearn_force=no version=3.4.2 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by dcvr.yhbt.net (Postfix) with ESMTP id 2F5191F670 for ; Wed, 20 Oct 2021 20:36:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230454AbhJTUjG (ORCPT ); Wed, 20 Oct 2021 16:39:06 -0400 Received: from cloud.peff.net ([104.130.231.41]:43056 "EHLO cloud.peff.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230052AbhJTUjF (ORCPT ); Wed, 20 Oct 2021 16:39:05 -0400 Received: (qmail 10542 invoked by uid 109); 20 Oct 2021 20:36:50 -0000 Received: from Unknown (HELO peff.net) (10.0.1.2) by cloud.peff.net (qpsmtpd/0.94) with ESMTP; Wed, 20 Oct 2021 20:36:50 +0000 Authentication-Results: cloud.peff.net; auth=none Received: (qmail 29285 invoked by uid 111); 20 Oct 2021 20:36:50 -0000 Received: from Unknown (HELO sigill.intra.peff.net) (10.0.1.3) by peff.net (qpsmtpd/0.94) with (TLS_AES_256_GCM_SHA384 encrypted) ESMTPS; Wed, 20 Oct 2021 16:36:50 -0400 Authentication-Results: peff.net; auth=none Date: Wed, 20 Oct 2021 16:36:49 -0400 From: Jeff King To: Junio C Hamano Cc: Kenneth Arnold , Alex Henrie , "git@vger.kernel.org" Subject: Re: "Not possible to fast-forward" when pull.ff=only and new commits on remote Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org On Wed, Oct 20, 2021 at 12:19:19PM -0700, Junio C Hamano wrote: > > Running a sequence of traversals like this can be slow, because we may > > walk over the same history again and again. But I think in the usual > > non-octopus cases we'd only have one entry, so we'd only be adding a > > single extra merge-base traversal in most cases. > > > > It does feel like this could be combined with get_can_ff() somehow so > > that we're not adding even that single traversal. But I expect that may > > be hard to do because of the multiple heads (e.g., we cannot use the > > usual ahead/behind code). > > I'd leave such an optimization as a separate topic. This was meant > to be a regression fix. Yeah, I'm definitely OK with that. You might be making performance a little worse with your patch, but getting correctness right is much more important. -Peff