From owner-freebsd-mips@FreeBSD.ORG Tue Oct 4 02:45:06 2011 Return-Path: Delivered-To: freebsd-mips@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id BA452106566B; Tue, 4 Oct 2011 02:45:06 +0000 (UTC) (envelope-from adrian.chadd@gmail.com) Received: from mail-gy0-f182.google.com (mail-gy0-f182.google.com [209.85.160.182]) by mx1.freebsd.org (Postfix) with ESMTP id 3CE058FC0C; Tue, 4 Oct 2011 02:45:05 +0000 (UTC) Received: by gyf2 with SMTP id 2so47474gyf.13 for ; Mon, 03 Oct 2011 19:45:05 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; 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 :content-transfer-encoding; bh=m6+nehxglakeTA1qylRV1tfYF+ObCCuWZUylmkUWqWM=; b=PiEoRlx/zMo0SF0C9DSL5LFEjzmopPvwQSUedW9S63r2PGiDCEYFp8kDyxXTQf1Iz3 TgdRHxK1SRGUOkOuMnJ6TVoD7+ynzmHKG2ouwkBeKqTkmiH57x2iwc9kt8NsM34X2nqK GGZ9OvV4Sz3vkEgkhaQEaI3j80P/BPlUHvLpM= MIME-Version: 1.0 Received: by 10.236.185.131 with SMTP id u3mr3597020yhm.55.1317696305491; Mon, 03 Oct 2011 19:45:05 -0700 (PDT) Sender: adrian.chadd@gmail.com Received: by 10.236.111.42 with HTTP; Mon, 3 Oct 2011 19:45:05 -0700 (PDT) In-Reply-To: <79147576-6E4F-46C9-8887-0847567A46A7@bsdimp.com> References: <20111002110331.GF1511@deviant.kiev.zoral.com.ua> <79147576-6E4F-46C9-8887-0847567A46A7@bsdimp.com> Date: Tue, 4 Oct 2011 10:45:05 +0800 X-Google-Sender-Auth: EtdkwXini2lxnXKZXK_kKkWKVik Message-ID: From: Adrian Chadd To: Warner Losh Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Cc: "Jayachandran C." , Kostik Belousov , Alexander Motin , "freebsd-mips@freebsd.org" Subject: Re: svn commit: r225892 - head/sys/mips/mips X-BeenThere: freebsd-mips@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Porting FreeBSD to MIPS List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 04 Oct 2011 02:45:06 -0000 On 4 October 2011 10:39, Warner Losh wrote: >> Is one needed after the mtc0 after StartWaitSkip? > > I don't think it matters. =A0The COP0_SYNC is needed when you want to flu= sh the instruction pipeline so that changes to COP0 don't affect them 'rand= omly'. =A0However, in this case. =A0Either we're setting a bit that's alrea= dy set, which won't change anything, or we're setting a bit that's clear, w= hich will just delay the delivery of the interrupt a few cycles. =A0The rac= e where it happens before the wait instruction is handled by the rest of th= e patch. That makes sense. I'll try this patch out soon and let you all know how it = goes. Now, hm. How can I easily instrument whether the hardware is actually spending time in wait or not? Thanks, Adrian