From owner-freebsd-current@FreeBSD.ORG Thu Jan 21 19:58:13 2010 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id EF3EA1065676 for ; Thu, 21 Jan 2010 19:58:12 +0000 (UTC) (envelope-from naylor.b.david@gmail.com) Received: from ey-out-2122.google.com (ey-out-2122.google.com [74.125.78.26]) by mx1.freebsd.org (Postfix) with ESMTP id 7730F8FC15 for ; Thu, 21 Jan 2010 19:58:11 +0000 (UTC) Received: by ey-out-2122.google.com with SMTP id 9so106291eyd.9 for ; Thu, 21 Jan 2010 11:58:11 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:from:organization:to:subject :date:user-agent:cc:references:in-reply-to:mime-version:content-type :content-transfer-encoding:message-id; bh=rpU0RmucqWbo6HFyc724SUqxUjH/a1z3KeAQRVnyFKI=; b=dgyQ58d66jBlk6Uf8yj1mKH24igAJqUxjDVRo32tp171OEBZ/tTTVfH6jvBuuu12ru Hrixk6xPBkMtiT2bT6enZfR5m98d5suto3W31CwWBExaDgEGLi7gFHuBp33ho7VWsYJ3 lzpRtEe2aq5rcWbi/QAcKgxW3qLedyvb+aI9c= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=from:organization:to:subject:date:user-agent:cc:references :in-reply-to:mime-version:content-type:content-transfer-encoding :message-id; b=r39Th1J4gx2bT4kVjf4+Z4O5/gTBYm70czGCasTNlRnDFCvsEZbsNqJpWzVAgdv6SN eRPtCtraBeaioPz9CA3VCbVYKLblNex5QBUZOxVqJpH79P+IwKWMUrufseFv+WEOqIzz bmte5X0/c6spzL0ZjWpw9z+ke6uzOhvTAw62A= Received: by 10.213.107.69 with SMTP id a5mr1734234ebp.73.1264103890981; Thu, 21 Jan 2010 11:58:10 -0800 (PST) Received: from dragon.dg ([41.216.197.17]) by mx.google.com with ESMTPS id 5sm1605500eyh.24.2010.01.21.11.58.08 (version=SSLv3 cipher=RC4-MD5); Thu, 21 Jan 2010 11:58:10 -0800 (PST) From: David Naylor Organization: Private To: Andriy Gapon Date: Thu, 21 Jan 2010 21:58:07 +0200 User-Agent: KMail/1.12.3 (FreeBSD/8.0-STABLE; KDE/4.3.3; amd64; ; ) References: <201001201543.15818.naylor.b.david@gmail.com> <201001211952.20202.naylor.b.david@gmail.com> <4B58953F.10404@icyb.net.ua> In-Reply-To: <4B58953F.10404@icyb.net.ua> MIME-Version: 1.0 Content-Type: multipart/signed; boundary="nextPart2244530.oVi6VMMIuN"; protocol="application/pgp-signature"; micalg=pgp-sha1 Content-Transfer-Encoding: 7bit Message-Id: <201001212158.13250.naylor.b.david@gmail.com> Cc: freebsd-current@freebsd.org Subject: Re: stacked unionfs freeze and crash FreeBSD X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 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, 21 Jan 2010 19:58:13 -0000 --nextPart2244530.oVi6VMMIuN Content-Type: Text/Plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable On Thursday 21 January 2010 19:56:15 Andriy Gapon wrote: > on 21/01/2010 19:52 David Naylor said the following: > > On Wednesday 20 January 2010 19:16:59 Andriy Gapon wrote: > >> Double-fault could indicate stack overflow. > > > > Thanks, I bumped KSTACK_PAGES to 32 (just to be on the safe side) and it > > is working fairly well now. Only crash I have had since was related to > > tmpfs. So far I have successfully build a port with 59 stacked unionfs = (1 > > rw, 58 ro). >=20 > Good that you found a workaround, bad that there is no better way to hand= le > this overflow. Or, is there? What would make it easier is having kern.kstack_pages tunable (and having t= he=20 appropriate changes to use that variable). =20 I do not know the internals of the kernel but is it possible for unionfs=20 (assuming it runs in its own thread) to specify a stack size big enough?. = =20 It might even be possible to extend unionfs to mount multiple directories o= nto=20 another, at once (thus eliminating the need for multiple mounts). And=20 probably a measurable performance increase? P.S. Twice I have had processes freeze, these were restricted to directori= es=20 affected by unionfs mounts. --nextPart2244530.oVi6VMMIuN Content-Type: application/pgp-signature; name=signature.asc Content-Description: This is a digitally signed message part. -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.13 (FreeBSD) iEYEABECAAYFAktYsdUACgkQUaaFgP9pFrJ8EgCffURcPPOMn2X/PXngfsWxAMJD n9QAn0NS9hY4fF8y1Wi6Xy85EEd8DTAi =jLmX -----END PGP SIGNATURE----- --nextPart2244530.oVi6VMMIuN--