From owner-svn-src-head@freebsd.org Mon Jun 25 11:46:45 2018 Return-Path: Delivered-To: svn-src-head@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 65E581009D81; Mon, 25 Jun 2018 11:46:45 +0000 (UTC) (envelope-from kostikbel@gmail.com) Received: from kib.kiev.ua (kib.kiev.ua [IPv6:2001:470:d5e7:1::1]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id B59BA7938C; Mon, 25 Jun 2018 11:46:44 +0000 (UTC) (envelope-from kostikbel@gmail.com) Received: from tom.home (kib@localhost [127.0.0.1]) by kib.kiev.ua (8.15.2/8.15.2) with ESMTP id w5PBkY3A094723; Mon, 25 Jun 2018 14:46:37 +0300 (EEST) (envelope-from kostikbel@gmail.com) DKIM-Filter: OpenDKIM Filter v2.10.3 kib.kiev.ua w5PBkY3A094723 Received: (from kostik@localhost) by tom.home (8.15.2/8.15.2/Submit) id w5PBkXb6094721; Mon, 25 Jun 2018 14:46:33 +0300 (EEST) (envelope-from kostikbel@gmail.com) X-Authentication-Warning: tom.home: kostik set sender to kostikbel@gmail.com using -f Date: Mon, 25 Jun 2018 14:46:33 +0300 From: Konstantin Belousov To: Mark Johnston Cc: Steven Hartland , Alan Cox , src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: Re: svn commit: r335171 - head/sys/vm Message-ID: <20180625114633.GE2430@kib.kiev.ua> References: <201806141941.w5EJf2qa069373@repo.freebsd.org> <603230da-cfe2-e3e2-bd9a-f5230b30e371@multiplay.co.uk> <20180615110303.GN2493@kib.kiev.ua> <20180625103020.GF1232@pesky> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180625103020.GF1232@pesky> User-Agent: Mutt/1.10.0 (2018-05-17) X-Spam-Status: No, score=-2.0 required=5.0 tests=ALL_TRUSTED,BAYES_00, DKIM_ADSP_CUSTOM_MED,FREEMAIL_FROM,NML_ADSP_CUSTOM_MED autolearn=no autolearn_force=no version=3.4.1 X-Spam-Checker-Version: SpamAssassin 3.4.1 (2015-04-28) on tom.home X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.26 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 25 Jun 2018 11:46:45 -0000 On Mon, Jun 25, 2018 at 06:30:20AM -0400, Mark Johnston wrote: > On Fri, Jun 15, 2018 at 02:03:03PM +0300, Konstantin Belousov wrote: > > On Fri, Jun 15, 2018 at 11:03:06AM +0100, Steven Hartland wrote: > > > On 15/06/2018 00:07, Alan Cox wrote: > > > > > > > >> On Jun 14, 2018, at 5:54 PM, Steven Hartland > > > >> > > >> > wrote: > > > >> > > > >> Out of interest, how would this exhibit itself? > > > >> > > > > > > > > A panic in vm_page_insert_after(). > > > > > > > So just to confirm this couldn't cause random memory corruption of the > > > parent process? > > > > No, or to put it more sincere, I highly doubt it. > > > > Also, I do not think that this Go issue will be solved serendipitously > > by some FreeBSD bug fix. So far it is indicative that either the > > situation is too unique for the Go runtime so it is not exposed by other > > programs (which is quite doubtful), or this is a bug in Go runtime. > > > > The only way forward is to understand what exactly is broken for the > > situation. This requires at least deep knowledge the Go garbage collector > > internal working, which itself supposes understanding of the Go runtime > > and Go environment. I do not mean explanation of the assert, but the > > root cause that eventually triggers the assert. They are somewhat > > disjoint in time, I believe. > > Is this problem summarized anywhere? In particular, is there a > reasonably minimal test case that reproduces the problem? Go bug report has the reproducer. I do not remember if this is the same snippet that I used. https://github.com/golang/go/issues/15658 When I looked at it, it took tens of minutes to trigger on sandy bridge machine. Note that recent reporters indicate that they need to run the test for a whole day. It might be that there are more then one issues, and some of them are fixed.