From owner-freebsd-stable@FreeBSD.ORG Mon Feb 21 20:07:57 2011 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 451AD106566C; Mon, 21 Feb 2011 20:07:57 +0000 (UTC) (envelope-from yanegomi@gmail.com) Received: from mail-ew0-f49.google.com (mail-ew0-f49.google.com [209.85.215.49]) by mx1.freebsd.org (Postfix) with ESMTP id 77FF58FC12; Mon, 21 Feb 2011 20:07:56 +0000 (UTC) Received: by ewy23 with SMTP id 23so720639ewy.8 for ; Mon, 21 Feb 2011 12:07:55 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:sender:in-reply-to:references:date :x-google-sender-auth:message-id:subject:from:to:cc:content-type; bh=1ykyobV8y6187OR5JHXYKP59rNq4eFA5NuE6cm+2eRU=; b=EFEgWHgYRs7ucuISAHzPqZ09+5Au4k3ZFlsgGl4t0DlIoFFesge8r9cMZpKtkpNCnV RFVJFYbLHkCpwn28nYKkaTOc1CYi7zsSwB3QAxVhAvnWRDC1O/ihyW+hc4Jax4j+0PRU 83pny5QOCamsNFLBHOEpA0pywmqNjNwAsqq+Q= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:sender:in-reply-to:references:date :x-google-sender-auth:message-id:subject:from:to:cc:content-type; b=pvLNIjBldpMB7fNY/YT0M3a7RWyy3xjUhFuEOx3xh0zmH/aaFWjIStvoFBPTxYcrLE XcTl5PIcjxQcaeoXayTZuD2vZZJ++NPk9ve+ONXhcDv7sSiqrRIJnBp02rCKjFeP+070 XN6wse8dxxA+70CpoqjYjDz05xChqAuvhlVfs= MIME-Version: 1.0 Received: by 10.216.155.75 with SMTP id i53mr2512006wek.27.1298318875220; Mon, 21 Feb 2011 12:07:55 -0800 (PST) Sender: yanegomi@gmail.com Received: by 10.216.71.200 with HTTP; Mon, 21 Feb 2011 12:07:54 -0800 (PST) In-Reply-To: <4D6292DD.8010704@freebsd.org> References: <8332E9240ECA403480B48D21FA3A8694@multiplay.co.uk> <4D6292DD.8010704@freebsd.org> Date: Mon, 21 Feb 2011 12:07:54 -0800 X-Google-Sender-Auth: wgVU-5gTp7RGTPT4RddyOwFItKI Message-ID: From: Garrett Cooper To: Andriy Gapon Content-Type: text/plain; charset=ISO-8859-1 Cc: freebsd-hackers@freebsd.org, Steven Hartland , freebsd-stable@freebsd.org Subject: Re: machdep.hlt_cpus not safe with ULE? X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 21 Feb 2011 20:07:57 -0000 On Mon, Feb 21, 2011 at 8:29 AM, Andriy Gapon wrote: > on 19/02/2011 14:36 Steven Hartland said the following: >> I'm trying to debug a possibly failing CPU, so I thought it would >> be easy just disable the cores using machdep.hlt_cpus and see if >> we see the panic's we've been seeing. >> >> The problem is it seems ULE doesnt properly support machdep.hlt_cpus >> and still schedules processes onto the halted cpus which obviously >> causes problems. >> >> Can anyone confirm this behaviour? > > Yes, your observations are correct. > Please also see: http://www.freebsd.org/cgi/query-pr.cgi?pr=145385 > >> Should machdep.hlt_cpus and I assume >> the logical counterpart never be used with ULE? As a followup to this and based on discussions with other folks, the fact that it's using hlt to halt CPUs without rescheduling tasks / masking interrupts, etc is not good. So none of the *hlt* sysctls are really doing the right thing on x86. Thanks, -Garrett