Date: Fri, 15 Feb 2013 16:10:59 +0200 From: Konstantin Belousov <kostikbel@gmail.com> To: Dag-Erling Sm??rgrav <des@des.no> Cc: arch@freebsd.org Subject: Re: Unmapped I/O Message-ID: <20130215141059.GO2522@kib.kiev.ua> In-Reply-To: <86621trc50.fsf@ds4.des.no> References: <20121219135451.GU71906@kib.kiev.ua> <20130214194731.GK2522@kib.kiev.ua> <86621trc50.fsf@ds4.des.no>
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--fEHni0rYmTqv5Hb6 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, Feb 15, 2013 at 01:32:11PM +0100, Dag-Erling Sm??rgrav wrote: > Konstantin Belousov <kostikbel@gmail.com> writes: > > I consider the current patch ready to be committed into the HEAD. > > Some elements of the design were discussed with Jeff Roberson. The > > patch was tested by Peter Holm, a backport to stable/9 got load > > testing by Scott Long. I see an ~30% reduction in the system time on > > reading large files over UFS/ahci on the 4-core HTT machine. >=20 > That sounds very nice indeed. Have you observed a similar reduction in > buildworld times? I measured the buildworld times with the version of the patch I had a month ago. That time, I did not see any statistically significant difference in either times (user, system, total). On the other hand, the machine I used to measure is netbooted, and despite both src/ and obj/ being on UFS over ahci, I still see a steady and significant amount of the NFS RPC going out, in particular, getattr RPC. From what I saw, this is due to execing /bin/sh and several other utilities from the base system over NFS. I believe that it induces the latency that hides any speed up. =46rom that moment, there were some bug-fixes related to speed, in particul= ar, sometimes clustered reads forced the mapping for the cluster buffer, even if not needed, which could also increase the gain. I probably do not have time to spend to reevaluate the buildworld timings, and definitely I do not see much reason to do it on my hardware. If somebody wants to do the benchmarking, please. --fEHni0rYmTqv5Hb6 Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.19 (FreeBSD) iQIcBAEBAgAGBQJRHkHyAAoJEJDCuSvBvK1BXmYP/jn/iQ3E0tjSWaZytiCUFACw rVgc/SqBYIkQRfLQHA4ZCF8tDnkQc921INUwxSarU1joOFVroWxo9YN+zT5ONEne 0RvqoeKf5PgWneW9Me3QJV984k9Bmnx0sYkReh0CDA39GyEQPF2D5iPNHMstKCrv ZtlWEmSjEJAwlYNwtU3LepF0FmKt6xmrZohrV4pQdFKSAoKoxGZ4zIQEf0tswzrh GNm310XOXfCgiE/DyRqQlhVG8NIU7MJFcb78gMe6ozrqfFKgOtgFZYVYAQa6kVo9 eBSBxEB93cG2jC+s+T8hdj7DZdQwjWlJgaOJMzLpBtaLuJatklQjDYl8myvpZ8I/ ZxLVE2W17h5YRC5MXk0SNH1+HDwyu94eMrEvVzYXYLUbQYj6R7XdvnYqPGBEhZVB SgVwCrwRWEKHiG5sIIoRbslxUTljSscDI9QvUhs2thOpfrkgKNtvoNHy4dzMXT/w h8u134hCj7Sig4mPL1UOe3BYKS8jZvg7ohFuVJCZOW7bMJ+Krb+XbON/On2dykb0 t533zczS9eimqnpgGr7gp/WkIbjXUXoM/S5inr43FHHWtwlxbJCr/wrskWNORpgH xyzohWjB8Fm0yx9DCSbIi0Hc7KXM6GbIf+E9kGAQYhtlIEjq6hsNyFqCyPYQuDf8 +JIfY9wENg87tEHLLqQ4 =gO0q -----END PGP SIGNATURE----- --fEHni0rYmTqv5Hb6--
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