From owner-freebsd-hackers@freebsd.org Wed Aug 16 03:38:27 2017 Return-Path: Delivered-To: freebsd-hackers@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 2274DDE3742 for ; Wed, 16 Aug 2017 03:38:27 +0000 (UTC) (envelope-from list@execve.net) Received: from lax012.relay.arandomserver.com (lax012.relay.arandomserver.com [198.252.106.48]) (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 E671E6D72B for ; Wed, 16 Aug 2017 03:38:26 +0000 (UTC) (envelope-from list@execve.net) Received: from sng001.hawkhost.com ([119.81.196.36]) by se003.arandomserver.com with esmtpsa (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.89) (envelope-from ) id 1dhp9q-0005DG-1P for freebsd-hackers@freebsd.org; Tue, 15 Aug 2017 22:38:20 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=execve.net; s=default; h=Content-Type:Cc:To:Subject:Message-ID:Date:From:References: In-Reply-To:MIME-Version: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=2YKvwr+FYwdq35Ewu3rjBXP2K4WfDBmVFxYD40d66IQ=; b=n+mqRxQvf7jAsy29Gc/ZEJb9Mg nTQGHapRxr8Y0pEWcb25gVrUf5lYAEGYi39lBN0TXbdDn0sgj11DTGBxRJj3JrjSFyVYI7L61v9lZ vVhff15wY73f9CiwTF38Eo2xU; Received: from mail-yw0-f169.google.com ([209.85.161.169]:33790) by sng001.hawkhost.com with esmtpsa (TLSv1.2:ECDHE-RSA-AES128-GCM-SHA256:128) (Exim 4.89) (envelope-from ) id 1dhp9m-002WiT-W3 for freebsd-hackers@freebsd.org; Wed, 16 Aug 2017 11:38:11 +0800 Received: by mail-yw0-f169.google.com with SMTP id p68so15716963ywg.0 for ; Tue, 15 Aug 2017 20:38:10 -0700 (PDT) X-Gm-Message-State: AHYfb5gxd+VrwbBGHsHKtRANbxENcANegiRLtYjXFv485yP32sfQMvEW hH3nDOOEdIkh4oWfSVMwnEV8zvFIAA== X-Received: by 10.129.166.130 with SMTP id d124mr248448ywh.342.1502854689406; Tue, 15 Aug 2017 20:38:09 -0700 (PDT) MIME-Version: 1.0 Received: by 10.37.20.135 with HTTP; Tue, 15 Aug 2017 20:38:08 -0700 (PDT) In-Reply-To: References: <598ADB65.8060701@grosbein.net> From: Gautam Date: Wed, 16 Aug 2017 09:08:08 +0530 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: Freebsd 11.0 - system freeze on intensive I/O To: Warner Losh Cc: freebsd-hackers X-Originating-IP: 119.81.196.36 X-SpamExperts-Domain: sng001.hawkhost.com X-SpamExperts-Username: relay Authentication-Results: arandomserver.com; auth=pass (login) smtp.auth=relay@sng001.hawkhost.com X-SpamExperts-Outgoing-Class: ham X-SpamExperts-Outgoing-Evidence: Combined (0.06) X-Recommended-Action: accept X-Filter-ID: PqwsvolAWURa0gwxuN3S5YEa3T7JuZT23fGO2rGt3ZiEh/Q2y0dK8jSMLTE55fwqH0Nprjby6XDb qzVlIOQ03kAwPN4M+BNtq20Hh3O6Az9ismS84NPFas3IWADbmzJ9CZryIsNFvaBrlzs70sT7iKmx j3Zz/WM/IwRyPjIHIwDyYBCz7y6+JbUXRmxDo5gVYAaY7Fh7D0FeMimNXOyfBh5e973vehgRRMJd d1x498Qq4U4e8tvTFrEqtdOukU7DGzcWMr0czofRVh8rMXrt/SyLxLEJIkbWABkyXJwBVLal3W+/ PI81P534n3yak4n7EfJL2hMI4yCDSSr/HxDyN5bD8YyxjFtJAz2loLb4we0tFPPhpWPZ07PAOr0y wYIXuCj9wj08m7429e2ZOl/ZXvNM2/zURZVxzSV/eszOttj6AVIvY+ILsI7br1ka/ZVMCHna6kKG M93r44iJ/OLHS8Ir9uceKeUgExm45FTVrVmVu34H+eqH7iWBpUrKGrffGcXZKnwjnRMG9jJ/knTt +XiA50wwIMuM3BDtnoPm4HpIizaH26GaoEDwTtnQE6q4ZRNP3CPS3YZT5ODGEA+uOpLZY+4z/dwR ocCZGdc1cl9f9x/pKLS918QV+MmO1bAAEgjXIny51RJ3yyIOVX71wEukYspuIwswojsoiyB8OuXo nV+E7OMXRvgtdyMlnmWi9uF4/xGeHumbSXx1nykjkg3q5Go+y6UPrDLg9O+nbQGGK6KbSnjG5GpR nEf9H5gqQnTIgDfxZ2/WGqYvyOVteVOdo6Dvr8fbMJVJ9/erL6/4IvMfhB2h/z0m0D607pH+pWX8 JH76UCDHe+VBXhtjrZr9RUQzcLUz45TvUuLctG5L8ZHLV0zHQOMuxVjpDkV6 X-Report-Abuse-To: spam@se001.arandomserver.com Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Content-Filtered-By: Mailman/MimeDel 2.1.23 X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 16 Aug 2017 03:38:27 -0000 Hi, On Sat, Aug 12, 2017 at 8:53 PM, Warner Losh wrote: > > > On Fri, Aug 11, 2017 at 11:17 PM, Gautam wrote: > >> > =E2=80=8BOne update on this one. I installed a custom stable/11 kernel= and world >> (sched =3D 4BSD was the only change), and the problem >> is no longer seen. From my untrained eyes, it looks like some kind of sw= ap >> request starvation causing a hang when ULE is in use.=E2=80=8B >> > > I did some patches a few years ago that separated out geom requests into > their own uma map, if you wanted and hacked the swap pager to use that to > ensure that it always had BIOs available to do it's I/O. Maybe I should > dust them off and see if they help you. They didn't seem to help me too > much, but didn't hurt too much either. > > There's still the issue of some drivers not pre-allocating requests, whic= h > is what makes the deadlock possible in the first place. > > Warner > > I would be willing to try the patches and report back - although my understanding of FreeBSD inter=E2=80=8Bnals is next to zero; but can surely= try. =E2=80=8BThanks, Gautam =E2=80=8B