From owner-freebsd-hackers@freebsd.org Wed Aug 9 16:54:04 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 772F5DD10AA for ; Wed, 9 Aug 2017 16:54:04 +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 3D55E7CEB2 for ; Wed, 9 Aug 2017 16:54:03 +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 1dfUF2-0006yt-GH for freebsd-hackers@freebsd.org; Wed, 09 Aug 2017 11:54:02 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=execve.net; s=default; h=Content-Type:To:Subject:Message-ID:Date:From:References: In-Reply-To:MIME-Version:Sender:Reply-To:Cc: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=oxnuAhfsrjO6ChYA8wY4F7JSDx013Ov+uwReHBD/6fk=; b=QVadJEk9AupCQ/V15YNPDiP15W wzKt6vqQ8VxhQOBuhBO4aEIbR+IDprTKPQb4pqMbYASvM7a5pXHEBWOD1q/aX6EYjbrzYOizu67LM EWeXEIoc27Na0HdGVi+vuot7R; Received: from mail-ua0-f171.google.com ([209.85.217.171]:36260) by sng001.hawkhost.com with esmtpsa (TLSv1.2:ECDHE-RSA-AES128-GCM-SHA256:128) (Exim 4.89) (envelope-from ) id 1dfUEy-003knS-ID for freebsd-hackers@freebsd.org; Thu, 10 Aug 2017 00:53:52 +0800 Received: by mail-ua0-f171.google.com with SMTP id k43so30897175uaf.3 for ; Wed, 09 Aug 2017 09:53:52 -0700 (PDT) X-Gm-Message-State: AHYfb5gDrZOmJZGCoFs0s5fkUUADpjRkifr1iicVghTXSq4Ppv+6vb6e G5uaCWiowUg34q9UgoVWi3vVmLMITg== X-Received: by 10.159.56.10 with SMTP id p10mr3087778uad.189.1502297631019; Wed, 09 Aug 2017 09:53:51 -0700 (PDT) MIME-Version: 1.0 Received: by 10.159.40.136 with HTTP; Wed, 9 Aug 2017 09:53:50 -0700 (PDT) In-Reply-To: References: <598ADB65.8060701@grosbein.net> From: Gautam Date: Wed, 9 Aug 2017 22:23:50 +0530 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: Freebsd 11.0 - system freeze on intensive I/O To: 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 (0.12) X-Recommended-Action: accept X-Filter-ID: PqwsvolAWURa0gwxuN3S5YEa3T7JuZT23fGO2rGt3ZiEh/Q2y0dK8jSMLTE55fwqH0Nprjby6XDb qzVlIOQ03kAwPN4M+BNtq20Hh3O6Az9ismS84NPFas3IWADbmzJ9CZryIsNFvaBrlzs70sT7iKmx j3Zz/WM/IwRyPjIHIwDPF1ZlofeOwAIM7JgtjyhlpinkyDC41hCHKs1oE2UeMx5e973vehgRRMJd d1x498Tufal7CMGWrqEKEiC/97WgGzcWMr0czofRVh8rMXrt/SyLxLEJIkbWABkyXJwBVLal3W+/ PI81P534n3yak4n7EfJL2hMI4yCDSSr/HxDyN5bD8YyxjFtJAz2loLb4we0tFPPhpWPZ07PAOr0y wYIXuCj9wj08m7429e2ZOl/ZXvNM2/zURZVxzSV/eszOttj6AVIvY+ILsI7br1ka/ZVMg6RdYTdA xY74GsEonmxBjzpKeIF2yKaDUU/b2z0vdzaVu34H+eqH7iWBpUrKGrffGcXZKnwjnRMG9jJ/knTt +XiA50wwIMuM3BDtnoPm4HpIizaH26GaoEDwTtnQE6q4ZRNP3CPS3YZT5ODGEA+uOpLZY+4z/dwR ocCZGdc1cl9f9x/pKLS918QV+MmO1bAAEgjXIny51RJ3yyIOVX71wEukYspuIwswojsoiyB8OuXo nV+E7OMXRvgtdyMlnmWi9uF4/xGeHumbSXx1nykjkg3q5Go+y6UPrDLg9O+nbQFoH9UL1HQ24F+S 4+SX5+akQnTIgDfxZ2/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, 09 Aug 2017 16:54:04 -0000 Hi, On Wed, Aug 9, 2017 at 7:43 PM, Mark Millard wrote: > > Swap files on ZFS are also known to have the problem. > > Quoting bugzilla 206048's comment #7 (which is quoting an older > list message): > > On 2017-Feb-13, at 7:20 PM, Konstantin Belousov > wrote > on the freebsd-arm list: > > . . . > > swapfile write requires the write request to come through the filesystem > write path, which might require the filesystem to allocate more memory > and read some data. E.g. it is known that any ZFS write request > allocates memory, and that write request on large UFS file might require > allocating and reading an indirect block buffer to find the block number > of the written block, if the indirect block was not yet read. > > As result, swapfile swapping is more prone to the trivial and unavoidable > deadlocks where the pagedaemon thread, which produces free memory, needs > more free memory to make a progress. Swap write on the raw partition ove= r > simple partitioning scheme directly over HBA are usually safe, while e.g. > zfs over geli over umass is the worst construction. > > =E2=80=8BFirstly, thanks all for the responses. I just want to comment, that when I tested it there was absolutely no need for any swap usage. I tried the test on a laptop with 8GB RAM and did it from the console mode. But it does seem that there might be some request (read/write) to swap which =E2=80=8Bcauses a lock up to the system.=E2=80=8B =E2=80=8BThanks, Gautam =E2=80=8B