From owner-freebsd-hackers@FreeBSD.ORG Wed May 2 21:39:44 2012 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 3698B106566C for ; Wed, 2 May 2012 21:39:44 +0000 (UTC) (envelope-from nparhar@gmail.com) Received: from mail-pb0-f54.google.com (mail-pb0-f54.google.com [209.85.160.54]) by mx1.freebsd.org (Postfix) with ESMTP id 041B78FC12 for ; Wed, 2 May 2012 21:39:43 +0000 (UTC) Received: by pbbro2 with SMTP id ro2so1801756pbb.13 for ; Wed, 02 May 2012 14:39:43 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=sender:message-id:date:from:user-agent:mime-version:to:cc:subject :references:in-reply-to:content-type:content-transfer-encoding; bh=m+dWgsxmWaBRNVvPAsKkbXOQB3jw8o11sRpDgbPweuo=; b=wzUCwiBQx8YrhwenKKMcJ/Ae7VSEwj4fagsfdGn7oLlP43eBNMU+JAgTfbk8IFGXXf TlsvGSnYXBqXFllc1HQUuQKu/vlHaYSkfprxPnx62W7DnaP3jZOlSe+jBkqeMm/VsZWs 58WFGNCCf0YzNV9soZ1FMxY3IiayLs7jkVPJQgmUGsmsISXpVC6Ck+V9CXNIwdbnK9CD 7Bh4nWedu2cr/KI3tT1bwD5gV0LeuWByWWuI2oigP06CNe22gG5ukD7hV15SfA3JIyNf BpGs8nusYNcBQUCISV7eje8sPA9UA+t0YwIfiFOFVN5J+3bXQrhGa39iaUxNjcNyCJy0 mAPA== Received: by 10.68.129.38 with SMTP id nt6mr1224802pbb.38.1335994783560; Wed, 02 May 2012 14:39:43 -0700 (PDT) Received: from [10.192.166.0] (stargate.chelsio.com. [67.207.112.58]) by mx.google.com with ESMTPS id ry4sm3049274pbc.27.2012.05.02.14.39.41 (version=SSLv3 cipher=OTHER); Wed, 02 May 2012 14:39:42 -0700 (PDT) Sender: Navdeep Parhar Message-ID: <4FA1A99D.208@FreeBSD.org> Date: Wed, 02 May 2012 14:39:41 -0700 From: Navdeep Parhar User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:12.0) Gecko/20120502 Thunderbird/12.0.1 MIME-Version: 1.0 To: Ryan Stone References: <4FA1A421.6020601@FreeBSD.org> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: freebsd-hackers@freebsd.org Subject: Re: CPU selection for ithreads on 8.3 X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 02 May 2012 21:39:44 -0000 On 05/02/12 14:28, Ryan Stone wrote: > On Wed, May 2, 2012 at 5:16 PM, Navdeep Parhar wrote: >> There seems to be a regression in 8.3 in the way the kernel selects CPUs >> for interrupts. For example, cxgb(4) on 8.3 ends up with all >> its ithreads on the same CPU (CPU7 in this case). >> >> 12 root -68 - 0K 816K WAIT 7 0:55 0.00% intr{irq279: >> cxgbc0} >> 12 root -68 - 0K 816K WAIT 7 0:52 0.00% intr{irq275: >> cxgbc0} >> 12 root -68 - 0K 816K WAIT 7 0:47 0.00% intr{irq278: >> cxgbc0} >> 12 root -68 - 0K 816K WAIT 7 0:43 0.00% intr{irq277: >> cxgbc0} >> 12 root -68 - 0K 816K WAIT 7 0:43 0.00% intr{irq282: >> cxgbc0} >> 12 root -68 - 0K 816K WAIT 7 0:41 0.00% intr{irq281: >> cxgbc0} >> 12 root -68 - 0K 816K WAIT 7 0:32 0.00% intr{irq276: >> cxgbc0} >> 12 root -68 - 0K 816K WAIT 7 0:31 0.00% intr{irq280: >> cxgbc0} >> >> Back in the day there used to be code in cxgb to bind different >> interrupts to different CPUs but it was removed because the kernel >> distributed them across CPUs anyway. So what changed? This appears 8.3 >> specific. I don't see it on head and I don't have a 9 system readily >> available right now. > > Does r232757 fix this? That just missed 8.3-RELEASE. I will try it. But would this explain why it used to work with 8.2 but broke in 8.3? Navdeep