From owner-freebsd-geom@FreeBSD.ORG Tue Dec 8 20:26:02 2009 Return-Path: Delivered-To: freebsd-geom@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 83BAD106566B; Tue, 8 Dec 2009 20:26:02 +0000 (UTC) (envelope-from google@vink.pl) Received: from mail-ew0-f211.google.com (mail-ew0-f211.google.com [209.85.219.211]) by mx1.freebsd.org (Postfix) with ESMTP id 4C7FC8FC13; Tue, 8 Dec 2009 20:26:01 +0000 (UTC) Received: by ewy3 with SMTP id 3so67984ewy.13 for ; Tue, 08 Dec 2009 12:26:00 -0800 (PST) Received: by 10.216.86.72 with SMTP id v50mr2845605wee.184.1260303958372; Tue, 08 Dec 2009 12:25:58 -0800 (PST) Received: from mail-ew0-f211.google.com (mail-ew0-f211.google.com [209.85.219.211]) by mx.google.com with ESMTPS id 28sm4762305eye.7.2009.12.08.12.25.57 (version=SSLv3 cipher=RC4-MD5); Tue, 08 Dec 2009 12:25:57 -0800 (PST) Received: by ewy3 with SMTP id 3so67921ewy.13 for ; Tue, 08 Dec 2009 12:25:57 -0800 (PST) MIME-Version: 1.0 Received: by 10.216.93.15 with SMTP id k15mr2921402wef.103.1260303955340; Tue, 08 Dec 2009 12:25:55 -0800 (PST) In-Reply-To: <20091207213408.GE1795@garage.freebsd.pl> References: <2ae8edf30912050724i6f196e53y40ccd06970d59a7a@mail.gmail.com> <20091207213408.GE1795@garage.freebsd.pl> Date: Tue, 8 Dec 2009 21:25:55 +0100 Message-ID: <2ae8edf30912081225i224de5cg3a76beb3fda85ff7@mail.gmail.com> From: Wiktor Niesiobedzki To: Pawel Jakub Dawidek Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Cc: freebsd-geom Subject: Re: geli freezing 8.0 RELEASE and 7.2-STABLE X-BeenThere: freebsd-geom@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: GEOM-specific discussions and implementations List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 08 Dec 2009 20:26:02 -0000 2009/12/7 Pawel Jakub Dawidek : > Hi Wiktor:) > > My guess is that this is because GELI worker threads are running with > too high priority (at least for your configuration). > > If I am right, the patch below should help you: > > =C2=A0 =C2=A0 =C2=A0 =C2=A0http://people.freebsd.org/~pjd/patches/g_eli.c= .2.patch Hi, Yes, it looks like it is thread priority problem. With this patch applied I do not see any freezes nor lags as before. I also did some small check, how this affects the performance, and I see no significant change. I saw some similiar reports here: http://forums.freebsd.org/showthread.php?t=3D6230 (though here it is connected with ZFS and compression). As far as I can imagine, what happens is, that ZFS usually sends data to disks as bulk transfers (every 5-10 seconds), so when I'm using GELI, it has quite a lot of data to encrypt, hence I observe some lagging. But then, I'm not sure, if compression on ZFS could expose this scenario in more aparent way. After having a quick look on http://www.freebsd.org/doc/en/books/arch-handbook/smp-design.html Does it mean, that alawys, when we have a a PRIBIO kthread running (geli thread encrypting data), lower priority processes (esp. userland processes) will not get any CPU? Sounds bit different than what I expected... Cheers, Wiktor Niesiobedzki