From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lists.gentoo.org ([140.105.134.102] helo=robin.gentoo.org) by nuthatch.gentoo.org with esmtp (Exim 4.62) (envelope-from ) id 1HLisR-00048n-Kw for garchives@archives.gentoo.org; Mon, 26 Feb 2007 16:39:04 +0000 Received: from robin.gentoo.org (localhost [127.0.0.1]) by robin.gentoo.org (8.14.0/8.14.0) with SMTP id l1QGbm3d024010; Mon, 26 Feb 2007 16:37:48 GMT Received: from mail.gmx.net (mail.gmx.net [213.165.64.20]) by robin.gentoo.org (8.14.0/8.14.0) with SMTP id l1QGTNLq011085 for ; Mon, 26 Feb 2007 16:29:23 GMT Received: (qmail invoked by alias); 26 Feb 2007 16:29:22 -0000 X-Provags-ID: V01U2FsdGVkX1/iLIY8qdHiHGcSJAaPzqkNqVI8Gq9yjXKyvTvxPD /luQ== Received: by huxley.mblan (Postfix, from userid 1000) id 47DFD13E32D; Mon, 26 Feb 2007 17:28:35 +0100 (CET) Date: Mon, 26 Feb 2007 17:28:35 +0100 From: Matthias Bethke To: gentoo-user@lists.gentoo.org Subject: Re: [gentoo-user] Performance problem at writing big files and Multitasking Message-ID: <20070226162835.GG4105@huxley> References: <7LFgI-6qK-17@gated-at.bofh.it> <7LFqt-6Eo-27@gated-at.bofh.it> <7LUIK-4Qn-3@gated-at.bofh.it> <45C9F7A1.10806@comcast.net> <45CA4708.9010307@googlemail.com> <6142e6140702100349x55f34bc7hdb4f16fa82075b3d@mail.gmail.com> Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-Id: Gentoo Linux mail X-BeenThere: gentoo-user@gentoo.org Reply-to: gentoo-user@lists.gentoo.org MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="V32M1hWVjliPHW+c" Content-Disposition: inline In-Reply-To: <6142e6140702100349x55f34bc7hdb4f16fa82075b3d@mail.gmail.com> User-Agent: mutt-ng/devel-r804 (Linux) X-Y-GMX-Trusted: 0 X-Archives-Salt: 948f27bc-0975-4ab6-a9fb-2c3c77817c3f X-Archives-Hash: 17d0b06d56f7df39e70ba476dcaa30a7 --V32M1hWVjliPHW+c Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi Daniel, on Saturday, 2007-02-10 at 12:49:14, you wrote: > I will give short overview what i have tried so far. >=20 > 1. Trying different I/O Scheduler ( cfq anticipatory and deadline) > 2. Enabling Low latency kernel and Preemptible kernel > 3. Setting 1000 HZ for timer frequency > 4. Tried the new kernel 2.6.19-gentoo-r6 and even the testing version > 2.6.20-gentoo with core 2 enabled in processor type Oh, so it is a multicore CPU---sorry if you mentioned it already, I had deleted the start of the thread already when I read Benno's advice. In that case, try 100 Hz scheduling period as well. I've had very bad experiences with I/O and 250 Hz or higher on a dual Xeon. My guess is that it was a cache effect and therefore shouldn't happen on the Core2Duo, but it might still be worth a try. > As i am using Xfce i installed the diskperf-plugin which monitors disk > I/O. The monitoring is divided in disk-read and disk-write. > I recognized that every time when reading stops writing starts. So is > this staggering of writing to disk normal as the programs have to read > data they want to write to disk? On my previous machine i didn't > recognize such a behaviour. So you're reading and writing from/to the same disk? I'd expect that behavior then, because the I/O scheduler tries to satisfy requests with as little thrashing as possible. So if there are enough write requests queued up it may keep the HD busy writing for a while before reading the next chunk from somewhere else. cheers! Matthias --=20 I prefer encrypted and signed messages. KeyID: FAC37665 Fingerprint: 8C16 3F0A A6FC DF0D 19B0 8DEF 48D9 1700 FAC3 7665 --V32M1hWVjliPHW+c Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.6 (GNU/Linux) iD8DBQFF4wqzSNkXAPrDdmURAjqxAJ9TLjkgHTedp8W3fuADkKpkN9XC8QCeMX8B cGPBZo0dS6s/xoWyoy0FA4o= =r/0f -----END PGP SIGNATURE----- --V32M1hWVjliPHW+c-- -- gentoo-user@gentoo.org mailing list