From owner-freebsd-current@FreeBSD.ORG Wed May 25 16:30:10 2011 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 459971065676; Wed, 25 May 2011 16:30:10 +0000 (UTC) (envelope-from yanegomi@gmail.com) Received: from mail-vw0-f54.google.com (mail-vw0-f54.google.com [209.85.212.54]) by mx1.freebsd.org (Postfix) with ESMTP id 93F2B8FC20; Wed, 25 May 2011 16:30:09 +0000 (UTC) Received: by vws18 with SMTP id 18so8099084vws.13 for ; Wed, 25 May 2011 09:30:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:in-reply-to:references:date :message-id:subject:from:to:cc:content-type :content-transfer-encoding; bh=jiZgUomQQZNxMqa3ArR2qFKvVvMueYMA4XqALgZ00YA=; b=ZYu5Mv3pwxUSUOLnozeAzKvMTFliAtDF7qgfCcJZI0PQ/ztEUm0qL9MyUISy5zR4cm zHmWxFti4TK0q191akdj3eOBFhCw/lDfW4kJ1czthoEugzQ15P83m97PsgqT2admf7Ek sBt8kB/Ss+Z0BL+Z57Gtxpg9KIefOuEMrqQ+E= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; b=PirJnw+XTnpDiNd1ytc1CQP1zAzVz9kwr509ejvIfQZdMrItkEiStq9stIv4eHGpEh uH9KUiFIDsFoM8pIFq2qqrgSEzE8f9PWRY86halzrL+e7roYpPg41cDaI1UjxkwR6WHY QNPYTjGsGH1F9zQ5TwFaflijCrhP2AqThPdus= MIME-Version: 1.0 Received: by 10.220.105.75 with SMTP id s11mr1597645vco.73.1306341008527; Wed, 25 May 2011 09:30:08 -0700 (PDT) Received: by 10.220.183.11 with HTTP; Wed, 25 May 2011 09:30:08 -0700 (PDT) In-Reply-To: <4DDD2B34.5070702@FreeBSD.org> References: <4DD3F662.9040603@FreeBSD.org> <4DD54C18.8050305@FreeBSD.org> <4DDA8B2A.6010500@FreeBSD.org> <4DDD2B34.5070702@FreeBSD.org> Date: Wed, 25 May 2011 09:30:08 -0700 Message-ID: From: Garrett Cooper To: Andriy Gapon Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Cc: Attilio Rao , "freebsd-current@freebsd.org" , "freebsd-arch@freebsd.org" Subject: Re: [rfc] remove hlt_cpus et al sysctls and related code X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 25 May 2011 16:30:10 -0000 On Wed, May 25, 2011 at 9:15 AM, Andriy Gapon wrote: > on 23/05/2011 19:28 Andriy Gapon said the following: >> I propose the following path for moving forward. >> - use hint.lapic.X.disabled to disable individual CPUs by their APIC ID >> - use machdep.hyperthreading_allowed tunable to disable second logical C= PU on each >> real core >> >> The above should already work as expected. =A0One thing is that currentl= y we have >> handling of machdep.hyperthreading_allowed tunable under SCHED_ULE. =A0I= plan to >> make it unconditional. >> >> Things to remove: >> - all the related sysctls for dynamic onlining/offlining >> - machdep.hlt_logical_cpus tunable (it duplicates hint.lapic.X.disabled) >> >> It's possible to keep machdep.hlt_logical_cpus and just add some code to= convert >> hlt_logical_cpus mask to a set of individual hint.lapic.X.disabled, but = I don't >> see very much value in that. =A0But if there is a good reason to keep th= at tunable, >> I am prepared to jump through this hoop. >> >> If no one objects to this proposal, I will provide a patch soon. > > The patch is here: > http://people.freebsd.org/~avg/cpu-offline-sysctl.diff > It should implement the strategy described above. > > I have mp_watchdog alone for now. =A0It seems to have the same issues wit= h respect > to dynamic CPU state change. =A0Besides its compilation is disabled when = SCHED_ULE > is enabled. =A0mp_watchdog is a nice idea, but I wonder if anyone actuall= y uses it > (with success). I'll have to test out the patch, but at first glance it seems ok (at least the machdep.hyperthreading_allowed changes which $WORK depends upon). Thanks! -Garrett