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: AS31976 209.132.180.0/23 X-Spam-Status: No, score=-4.0 required=3.0 tests=AWL,BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI shortcircuit=no autolearn=ham autolearn_force=no version=3.4.2 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by dcvr.yhbt.net (Postfix) with ESMTP id F0B5A211B6 for ; Wed, 19 Dec 2018 23:22:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729676AbeLSXWC (ORCPT ); Wed, 19 Dec 2018 18:22:02 -0500 Received: from cloud.peff.net ([104.130.231.41]:46288 "HELO cloud.peff.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1728195AbeLSXWC (ORCPT ); Wed, 19 Dec 2018 18:22:02 -0500 Received: (qmail 20768 invoked by uid 109); 19 Dec 2018 23:22:02 -0000 Received: from Unknown (HELO peff.net) (10.0.1.2) by cloud.peff.net (qpsmtpd/0.94) with SMTP; Wed, 19 Dec 2018 23:22:02 +0000 Authentication-Results: cloud.peff.net; auth=none Received: (qmail 26144 invoked by uid 111); 19 Dec 2018 23:21:34 -0000 Received: from sigill.intra.peff.net (HELO sigill.intra.peff.net) (10.0.0.7) by peff.net (qpsmtpd/0.94) with (ECDHE-RSA-AES256-GCM-SHA384 encrypted) SMTP; Wed, 19 Dec 2018 18:21:34 -0500 Authentication-Results: peff.net; auth=none Received: by sigill.intra.peff.net (sSMTP sendmail emulation); Wed, 19 Dec 2018 18:22:00 -0500 Date: Wed, 19 Dec 2018 18:22:00 -0500 From: Jeff King To: Sitsofe Wheeler Cc: git@vger.kernel.org Subject: Re: Periodic hang during git index-pack Message-ID: <20181219232200.GB21283@sigill.intra.peff.net> References: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org On Wed, Dec 19, 2018 at 10:59:30PM +0000, Sitsofe Wheeler wrote: > While using trying to use git to clone a remote repository git > index-pack occasionally goes on to hang: > [...] > Looking at where it is stuck, git is doing read of a pipe: > > #0 0x00007fd1b845034e in __libc_read (fd=fd@entry=0, > buf=buf@entry=0x55ab81e19d40 , nbytes=nbytes@entry=4096) > at ../sysdeps/unix/sysv/linux/read.c:27 > #1 0x000055ab81b51b23 in read (__nbytes=4096, __buf=0x55ab81e19d40 > , __fd=0) > at /usr/include/x86_64-linux-gnu/bits/unistd.h:44 Index-pack is reading the pack on stdin, so it's expecting more bytes. Those bytes should be coming from the git-clone process, which is relaying the bytes from the other side. Check the backtrace of git-clone to see why it isn't feeding more data (but note that it will generally have two threads -- one processing the data from the remote, and one wait()ing for index-pack to finish). My guess, though, is that you'll find that git-clone is simply waiting on another pipe: the one from ssh. -Peff