From owner-freebsd-arch@FreeBSD.ORG Wed Feb 25 15:09:52 2015 Return-Path: Delivered-To: freebsd-arch@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 4287FD2B for ; Wed, 25 Feb 2015 15:09:52 +0000 (UTC) Received: from mail-pa0-f41.google.com (mail-pa0-f41.google.com [209.85.220.41]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 0F6C9375 for ; Wed, 25 Feb 2015 15:09:51 +0000 (UTC) Received: by pablf10 with SMTP id lf10so5861874pab.6 for ; Wed, 25 Feb 2015 07:09:45 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:sender:content-type:mime-version:subject:from :in-reply-to:date:cc:content-transfer-encoding:message-id:references :to; bh=OavwdixP7bB85A/vyNLW1YNcun0WuuvLONwrn3rgWFc=; b=LtMO69UiD7J8TxTvmT+92ZZs9vsnxeR6xwf5bdCC2U3+MlYosw8cQh1r/6VDAjKP6z iQ6/WWd90kLbsFUTj9Mp8Hiyn4+IutTgI8w06833hnjBz2Xw/oqsupTYIv/oEzlq8lSD IWDqMmngnOtU7/jwJUuZwdNwstXuSwJjalUpzrVtfEVWUaTlPq24JXU5r4GmJoZrGd2M jkicnz/59VZwKuqyaETg+SXQtZfjKnUl6DzTI0BAreIUQTA9+yWKHtqm2452o884Wc+J hk4yvjsJjw3pneD89zFyhanISgkoPyzW3JJpWcMYBYCckrM3iUPZwkvwCQvYCOVxBwRO 44Qw== X-Gm-Message-State: ALoCoQleCzOZ0xnlDW5LtqvTTgSmLUsZL9u+qBivS8LwfrQ7Syt+3TJZBp5jFtx5OSdTJ7D0+y3Q X-Received: by 10.69.27.15 with SMTP id jc15mr6200532pbd.126.1424876984948; Wed, 25 Feb 2015 07:09:44 -0800 (PST) Received: from macintosh-3c0754232d17.corp.netflix.com ([69.53.236.236]) by mx.google.com with ESMTPSA id mm9sm41519877pbc.76.2015.02.25.07.09.43 (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Wed, 25 Feb 2015 07:09:43 -0800 (PST) Sender: Warner Losh Content-Type: text/plain; charset=utf-8 Mime-Version: 1.0 (Mac OS X Mail 8.2 \(2070.6\)) Subject: Re: locks and kernel randomness... From: Warner Losh In-Reply-To: <20150225085659.GA74514@kib.kiev.ua> Date: Wed, 25 Feb 2015 08:09:39 -0700 Content-Transfer-Encoding: quoted-printable Message-Id: <3A406DF7-E6A1-494D-9B7D-3666D41DBC2B@bsdimp.com> References: <20150224174053.GG46794@funkthat.com> <54ECBD4B.6000007@freebsd.org> <20150224182507.GI46794@funkthat.com> <54ECEA43.2080008@freebsd.org> <20150224231921.GQ46794@funkthat.com> <20150225002301.GS46794@funkthat.com> <54ED80BD.1080603@freebsd.org> <54ED87E9.8030706@astrodoggroup.com> <20150225085659.GA74514@kib.kiev.ua> To: Konstantin Belousov X-Mailer: Apple Mail (2.2070.6) Cc: Harrison Grundy , freebsd-arch@freebsd.org X-BeenThere: freebsd-arch@freebsd.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: Discussion related to FreeBSD architecture List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 25 Feb 2015 15:09:52 -0000 > On Feb 25, 2015, at 1:56 AM, Konstantin Belousov = wrote: > So neither buildworld timing, nor network throughput are adequate > to estimate the change. It is system unresponsivness and loss of > the realtime behaviour up to some degree. Yes. You need to look at the changes affects, if any, on outlier = behavior under load. Without careful monitoring of that, you won=E2=80=99t see the bad = effects. I=E2=80=99ve made several changes over the years to improve performance that I later (usually much = later) had to back out or modify because it made the outlier behavior much worse. So data here isn=E2=80=99t =E2=80=9CI did 3 build worlds and the time = was about the same=E2=80=9D even if ministat(8) says there=E2=80=99s no difference. Warner