From owner-freebsd-current@freebsd.org Thu Sep 13 13:18:38 2018 Return-Path: Delivered-To: freebsd-current@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 2615A108D7D5 for ; Thu, 13 Sep 2018 13:18:38 +0000 (UTC) (envelope-from eric@vangyzen.net) Received: from smtp.vangyzen.net (hotblack.vangyzen.net [IPv6:2607:fc50:1000:7400:216:3eff:fe72:314f]) (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 C91CD705F0; Thu, 13 Sep 2018 13:18:37 +0000 (UTC) (envelope-from eric@vangyzen.net) Received: from hammy.vangyzen.net (unknown [70.97.188.230]) by smtp.vangyzen.net (Postfix) with ESMTPSA id 9C9405646F; Thu, 13 Sep 2018 08:18:36 -0500 (CDT) To: freebsd-current , markj@FreeBSD.org From: Eric van Gyzen Subject: arc_reclaim_thread running hot Message-ID: <0cdba37f-6b47-0929-fb72-dcca7e70a05a@vangyzen.net> Date: Thu, 13 Sep 2018 08:18:17 -0500 User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:60.0) Gecko/20100101 Thunderbird/60.0 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.27 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 13 Sep 2018 13:18:38 -0000 This morning, I found the arc_reclaim_thread running hot on my laptop running 12.0-ALPHA5 r338572. vfs.zfs.arc_max="4294967296" <-- 4 GiB last pid: 13288; load averages: 1.32, 1.26, 1.16 Mem: 456M Active, 3837M Inact, 743M Laundry, 2563M Wired, 167M Free ARC: 1131M Total, 304M MFU, 145M MRU, 1344K Anon, 9116K Header, 671M Other 89M Compressed, 361M Uncompressed, 4.03:1 Ratio 22 root -8 - 0 256K CPU2 2 309:20 99.75% zfskern{arc_reclaim_thread} zfs_arc_meta_strategy is still the default of 1. I sampled the thread's stacks with for N in `jot 1000`; do procstat -kk 100101; done | grep 100101 and put the results here: https://people.freebsd.org/~vangyzen/arc_reclaim_thread_stacks.txt I'm happy to help debug this. Just let me know what you need. Eric