Date: Mon, 28 Apr 2014 13:22:10 +0200 From: Ivan Voras <ivoras@freebsd.org> To: freebsd-hackers@freebsd.org Subject: Re: HAST performance / dtrace / _umtx_op Message-ID: <ljldl2$ag4$1@ger.gmane.org> In-Reply-To: <B044E9557B63332185C7792F@study64.tdx.co.uk> References: <B044E9557B63332185C7792F@study64.tdx.co.uk>
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This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --io2xDFlROGTjil1jNup82J13rFswlJbPF Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable On 26/04/2014 12:30, Karl Pielorz wrote: >=20 > Hi All, >=20 > I've been looking at HAST recently - and noticed there's a huge > performance hit (on 10-STABLE anyway) even if you setup a disk with a > remote of 'none' - switching from the 'raw' disk to '/dev/hast/disk' > shows a 50% performance hit [in testing having an active secondary via > 10Gbit link doesn't seem to show any further performance drop]. HAST is a GEOM_GATE solution so every IO request goes through a round-trip to the userland hastd process. This could be one of the reasons for the slowness. IIRC it is still async, so adding the second remote note would not slow it down additionally since it doesn't wait for the network request. --io2xDFlROGTjil1jNup82J13rFswlJbPF Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.22 (FreeBSD) Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iKYEARECAGYFAlNeOeJfFIAAAAAALgAoaXNzdWVyLWZwckBub3RhdGlvbnMub3Bl bnBncC5maWZ0aGhvcnNlbWFuLm5ldDYxNDE4MkQ3ODMwNDAwMDJFRUIzNDhFNUZE MDhENTA2M0RGRjFEMkMACgkQ/QjVBj3/HSwJoQCfQtmSL/5HoV1ddr2vUApow2tP 9QYAn3GByPXH09RaGK6U9c5blEWK2iPp =5K2q -----END PGP SIGNATURE----- --io2xDFlROGTjil1jNup82J13rFswlJbPF--
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