From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from pigeon.gentoo.org ([208.92.234.80] helo=lists.gentoo.org) by finch.gentoo.org with esmtp (Exim 4.60) (envelope-from ) id 1MFkLb-000880-AM for garchives@archives.gentoo.org; Sun, 14 Jun 2009 07:41:47 +0000 Received: from pigeon.gentoo.org (localhost [127.0.0.1]) by pigeon.gentoo.org (Postfix) with SMTP id 647C3E02D8; Sun, 14 Jun 2009 07:41:46 +0000 (UTC) Received: from mail-bw0-f223.google.com (mail-bw0-f223.google.com [209.85.218.223]) by pigeon.gentoo.org (Postfix) with ESMTP id 1F95EE02D8 for ; Sun, 14 Jun 2009 07:41:46 +0000 (UTC) Received: by bwz23 with SMTP id 23so2484619bwz.34 for ; Sun, 14 Jun 2009 00:41:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:date:from:to:subject :message-id:in-reply-to:references:x-mailer:mime-version :content-type; bh=3L5MKFk4NEiAURzZHBwLiXtYf/6KgXylvE61B4u4DxA=; b=vcdQCCRBf/L6R/qoTU7lHQ9PcCSxMI+a7q5geXiwNyp5Bj+8et3JAFHIpC7MlBhvwY tP6mJd7dA0vfZowFSj/BQ4aYK3UCP7tkn/gaB1Oj6sz2dTYJj4AC/7D7gwSrWEZ6IgOo ALmJvbuEVXASJdHP6eg2AVtVgfSRlkPh7yr60= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=date:from:to:subject:message-id:in-reply-to:references:x-mailer :mime-version:content-type; b=aST4gFu+zS+G21683YfN4iJdRG3c+xF7swSXR2c1qvCAV61LO2EsW38Q8JKeinBBtj hQQZ5+lSzoOK9JxTnFycldnnQEAuPDZVyeVQIbc1fg+A4sVgMB0nQ/2xcD9rDg1HUzA8 8GvyehySYvrb4wugfBYyMQv6bNJaBxs9k8TuM= Received: by 10.103.1.5 with SMTP id d5mr2855008mui.113.1244965305364; Sun, 14 Jun 2009 00:41:45 -0700 (PDT) Received: from coercion ([91.191.238.58]) by mx.google.com with ESMTPS id j6sm187432mue.31.2009.06.14.00.41.44 (version=TLSv1/SSLv3 cipher=RC4-MD5); Sun, 14 Jun 2009 00:41:45 -0700 (PDT) Date: Sun, 14 Jun 2009 13:39:08 +0600 From: Mike Kazantsev To: gentoo-user@lists.gentoo.org Subject: Re: [gentoo-user] Re: Idle Process Scheduling Message-ID: <20090614133908.4eb978ae@coercion> In-Reply-To: References: <200906132339.57042.saschahlusiak@arcor.de> X-Mailer: Claws Mail 3.7.1 (GTK+ 2.16.1; i686-pc-linux-gnu) Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-Id: Gentoo Linux mail X-BeenThere: gentoo-user@lists.gentoo.org Reply-to: gentoo-user@lists.gentoo.org Mime-Version: 1.0 Content-Type: multipart/signed; micalg=PGP-SHA1; boundary="Sig_/vBMV/EIHEHw9oSknBuJP1sQ"; protocol="application/pgp-signature" X-Archives-Salt: 7843d342-1d8c-4527-9853-8fd67e791e1a X-Archives-Hash: b96b72ac648cbf7787051f7a3c09cea8 --Sig_/vBMV/EIHEHw9oSknBuJP1sQ Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable On Sun, 14 Jun 2009 06:07:16 +0000 (UTC) Jason Lynch wrote: > Thus, I have five processes, four at nice 19, one at nice 0, a load=20 > average of just over 5, but only 3 out of the 4 cores are actually doing= =20 > anything.=20 That's an interesting observation with quite a trivial scenario. So I thought to check it out and ran 8 niced copies "while True: pass" script on 8-core machine, atop showed 799-800% load, 100% for each core. Ninth, non-niced process indeed drops the load to 700-710%, with one core absolutely free. Then, I've tried to remove nice form the equation and load held at 800% with 8, 9, 10 and more processes. Nice-only processes behave similary, loading all eight cores. So I guess the problem (or feature?) is related to nice / non-nice processes' scheduling and exists at least in 2.6.29 kernel. Gotta google it a bit later, bet someone on lkml should've noticed it. --=20 Mike Kazantsev // fraggod.net --Sig_/vBMV/EIHEHw9oSknBuJP1sQ Content-Type: application/pgp-signature; name=signature.asc Content-Disposition: attachment; filename=signature.asc -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.11 (GNU/Linux) iEYEARECAAYFAko0qSEACgkQASbOZpzyXnF81wCfSSWJfAuP6RifmZvWF5sx2MqD 4/cAoNfY0Rz8ATP8ZZ+Z1MFHG8qF7pQW =QMXV -----END PGP SIGNATURE----- --Sig_/vBMV/EIHEHw9oSknBuJP1sQ--