From owner-freebsd-fs@freebsd.org Tue Mar 29 08:18:19 2016 Return-Path: Delivered-To: freebsd-fs@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 AA3B2AE1F42 for ; Tue, 29 Mar 2016 08:18:19 +0000 (UTC) (envelope-from sobomax@sippysoft.com) Received: from mail-ob0-x22b.google.com (mail-ob0-x22b.google.com [IPv6:2607:f8b0:4003:c01::22b]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 70CE218F7 for ; Tue, 29 Mar 2016 08:18:19 +0000 (UTC) (envelope-from sobomax@sippysoft.com) Received: by mail-ob0-x22b.google.com with SMTP id fp4so6042914obb.2 for ; Tue, 29 Mar 2016 01:18:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sippysoft-com.20150623.gappssmtp.com; s=20150623; h=mime-version:sender:in-reply-to:references:date:message-id:subject :from:to:cc; bh=SWN6fNnscw0XX4jPjmXHvmBPW0sLZq41LiX2I/tETAc=; b=zwoBGSQTCTtCi7mAQFmtsOoeF69Zjjn8DLI5aeGBO8UtT8gHa97Sv2DWLcQ4ysGMUY QRNQH9K8Aa+fHvn4yEZMwH1XglvMfKlI9fHWhbbHkCPn2w6m7XWE5EVQuIAwsRYhUHe9 56XHCSC9IWaHd9mJY9adR8/FyrzoBztRi96/StK01eVbwahr+tCf757gts0OYFTDFjzX 4B/wRgwxCKz/6mq7A0Fu6edOTMqj1mNvJcf41tyNvGVYLU3IXZ+EUdyX6VByVUJxwkZr 74om3rzkeDqpLzI5Szxr2kr0GSwKbjsPGmDrOuB7Ugd1kgJUzTHX5KKBZkLGQiN6MD+t ZgzQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:sender:in-reply-to:references:date :message-id:subject:from:to:cc; bh=SWN6fNnscw0XX4jPjmXHvmBPW0sLZq41LiX2I/tETAc=; b=ZCv7i2zgWuJNJ+f7NmKaibZvXAptKBQ9LvNUuXYkmSpxHELPUBvBZohGohuVWu4azS v4dx07p5/yu/4vTaERZgDVEzBm5A78iFlaOKsjJHp1GE+NDlg5nHESxK+O5LZN3QHL71 AddD/D3y7gKNDmm8WXG/VhLELPIf+zvmKjmH3Fdiur7IHmHnXhKm0nbbHB1yDdFBxF/g eFW6R5WeyFxEueUZKekcIqzsNIcYzk2NV3f3VvWVgWMTm/oI5dT38gvZkbNyVfOuWKKo keIAfA/cqpYZ5NRue/rfsYYeHfbormXRtuCrdet/iUdUFkZU8R5ZXZ4c0VyYp7EttJSs CTgA== X-Gm-Message-State: AD7BkJIEFL4qY4qNZfqVPa7UYhbZYDlqwZAPDgcTLmUzZ0XRQkfA66+byuZ5iK7bb/ESpFOpoQMTYE7Ip2ID6vh/ MIME-Version: 1.0 X-Received: by 10.60.60.3 with SMTP id d3mr345478oer.66.1459239498544; Tue, 29 Mar 2016 01:18:18 -0700 (PDT) Sender: sobomax@sippysoft.com Received: by 10.157.11.143 with HTTP; Tue, 29 Mar 2016 01:18:18 -0700 (PDT) In-Reply-To: References: Date: Tue, 29 Mar 2016 01:18:18 -0700 X-Google-Sender-Auth: CBR6IHtKFmM7iRis-Rba3Ci97rk Message-ID: Subject: Re: Process stuck in "vnread" From: Maxim Sobolev To: Adrian Chadd Cc: "stable@freebsd.org" , FreeBSD Filesystems , Pawel Jakub Dawidek , Kirk McKusick , Konstantin Belousov Content-Type: text/plain; charset=UTF-8 X-Content-Filtered-By: Mailman/MimeDel 2.1.21 X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 29 Mar 2016 08:18:19 -0000 Hey Adrian, unfortunately, this is kinda our production build/test box, it's not particularly beefy and we also run some heavily contended apps on it too just to see how it performs on this size of machine, so we would not really want to put any heavy debug into kernel unless it's some issue that can be triggered quickly. This particular deadlock has been popping up every few weeks, annoying but not severely critical to jump to guns. I think, thanks to @kib and @avg we might be on the right track. At least that sounds plausible and kinda fits the pattern. On Mon, Mar 28, 2016 at 9:09 AM, Adrian Chadd wrote: > Hi, > > I think a bunch of the lock order checks with witness get disabled for ZFS > ? > > Maybe compile up a witness kernel so you can get 'show alllocks' in > ddb. That should help narrow down exactly what's going on. > > Thanks! > > > -a > >