From owner-freebsd-stable@freebsd.org Tue Nov 10 12:02:19 2015 Return-Path: Delivered-To: freebsd-stable@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 1F40BA2BFFE for ; Tue, 10 Nov 2015 12:02:19 +0000 (UTC) (envelope-from markoml@markoturk.info) Received: from vps.markoturk.info (vps.markoturk.info [95.154.208.14]) by mx1.freebsd.org (Postfix) with ESMTP id E1D001A20 for ; Tue, 10 Nov 2015 12:02:18 +0000 (UTC) (envelope-from markoml@markoturk.info) Received: from vps.markoturk.info (localhost [127.0.0.1]) by vps.markoturk.info (Postfix) with ESMTP id 6B3422738C; Tue, 10 Nov 2015 12:56:52 +0100 (CET) Date: Tue, 10 Nov 2015 12:56:54 +0100 From: Marko Turk To: "Eugene M. Zheganin" Cc: FreeBSD Subject: Re: zfs, mc, mcview and files opening Message-ID: <20151110115654.GA1949@vps.markoturk.info> References: <5641BFC8.9050207@norma.perm.ru> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="h31gzZEtNLTqOjlF" Content-Disposition: inline In-Reply-To: <5641BFC8.9050207@norma.perm.ru> User-Agent: Mutt/1.5.24 (2015-08-30) X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 10 Nov 2015 12:02:19 -0000 --h31gzZEtNLTqOjlF Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi, On Tue, Nov 10, 2015 at 02:58:32PM +0500, Eugene M. Zheganin wrote: > Hi. >=20 > my midnight commander is terribly slow at vieweing files with mcview. > Opening of a file of approximately 10 megabytes takes about 30-40 > seconds. This isn't related with the compression setting, %busy wait or > pool properties- I tested on various machines, it's fully reproducible. > This lag appears on files about 1.5 megs in size, and the lag time is > pretty constant. From my observation, it's the following syscall that's > blocking: >=20 > fstat(4,{ mode=3Dp--------- ,inode=3D41,size=3D0,blksize=3D4096 }) =3D 0 = (0x0) > (observed using `truss mcview maillog`) >=20 > If the file is viewed not by mcview (i.e. it is of a special type and > viewed by the special utility, or mcview is simply not used - for > example more opens same file without lag) - the file is opening fast as > always. When mcview is involved - lag appears. In the same time I've > never seen this lag on filesystems other than zfs. Is this happening on every ZFS FreeBSD install or just some of them? I'm running ZFS on FreeBSD 10-STABLE and I don't see this problem (even for much larger files). BR, Marko > And the most > beautiful detail is that this lag is repeatable on multiple opens of > same file - though you can expect that it will be only first time that > would be that slow, it doesn't happen - same pause occurs on sequential > opens. >=20 > Who's issue is this ? > Can some workaround be used ? >=20 > Thanks. > Eugene. --h31gzZEtNLTqOjlF Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQIcBAEBCAAGBQJWQduFAAoJEHg6bF2mqM2I5i8QAI1apl/l4FByFvlMH7qpUkJX 9h/AtXPB3fzf+dHK7YQwRoWq6oBRlR8gw2UGcWGNHXevHMusb0yC8unYzqtKnVw4 DgFPlMGZcf9RW+UOaMVsYyyxiSSzJRxYLbBDgw0FBlZNWqooFo5qq9lxiRinxtWm /dZ+/hRh9zV6/r/BIB+yWt7/lYNsuUQ/qpRuUvl2tY1aZzz30pTcwuAtrf8YKZcR T4v6vN9ImfLvbx4NuPupDIvK8m7Cp90FE+jQJYuctDned0pIge/jw3g+ob/opn94 CcL3JJ0dMzwMutclyoYQa3AbgW4prtv+OgvsXmPJu6pnIo1FAQ/x4zOxMVmnFL8c CYeZ8OFnf3TztUmMY50YsQPZikbUT5WfI7g+vhamFkiPZAuJBV5pvzWtYTPWDq3/ pPVMnD54kolwhgu+jOh1/dcdxZYipbbDoYMkXzo/VNUr+CU10L+TQSEzwSsLvyRR PX0X75SnEz0KWm5Sk0XkeGZFti2+Fpuapx7YAnGR0E24MuvzNwIG8bq0gM/9jhuj zB3T3YM25ncmTFSckGyvE8ERd70IcM+WMxUxcE+JOPQYiB6uYckzYosfkKd/d8MW ezNc8AtCoMg1TgTpDgjEaLi5crwlAYB3To5sQSn0qwDgHUKJ7W0uC1+jgauYlha8 jePBJoOjlsureDnNdGQn =EFE+ -----END PGP SIGNATURE----- --h31gzZEtNLTqOjlF--