From owner-freebsd-current@FreeBSD.ORG Tue Jan 6 15:57:31 2015 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id E655B261; Tue, 6 Jan 2015 15:57:30 +0000 (UTC) Received: from mail-we0-x22f.google.com (mail-we0-x22f.google.com [IPv6:2a00:1450:400c:c03::22f]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 7990C285A; Tue, 6 Jan 2015 15:57:30 +0000 (UTC) Received: by mail-we0-f175.google.com with SMTP id k11so9880862wes.34; Tue, 06 Jan 2015 07:57:28 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:sender:in-reply-to:references:date:message-id:subject :from:to:cc:content-type; bh=g/blWvkMEWWOjnUyA8cWzNat/dnaSBvep2uZWMFYRsI=; b=ucvJi3+2sFLyP8HQePm8ZX5w6P9YnRh2AlNHKeTltdcDYZEhL2RuD+Lebx+jg6M+LV RQ5JTM8NrTa5xQ1dlzSOwknE24QQSKYivyrR4vwkMIGP9tmh7SjMReDh6ndpr1t18SHU vu82R3vG5xJaopmxSsYFPAsUPljswQcDprlPomIMdeTqvAUUCHvEXEkZrb1tNS8FFELP 06gl6LRRPKX5nTtIA5lljChsPEk5wloZACCFk4i3ldme9OG4gMEthZOlm1lVbnCQ1SaT /x+4n/uPdtQYaTL2I744vrETXxYlmpHTcmn3pmFbPnxE/V7plfasmC1EEEOmVXQBAtk0 w+Uw== MIME-Version: 1.0 X-Received: by 10.194.108.9 with SMTP id hg9mr189340697wjb.68.1420559848802; Tue, 06 Jan 2015 07:57:28 -0800 (PST) Sender: adrian.chadd@gmail.com Received: by 10.216.41.136 with HTTP; Tue, 6 Jan 2015 07:57:28 -0800 (PST) In-Reply-To: <1420559715.14601.25.camel@freebsd.org> References: <54AA8F19.9030300@selasky.org> <54ABF32A.6010409@FreeBSD.org> <1420559715.14601.25.camel@freebsd.org> Date: Tue, 6 Jan 2015 07:57:28 -0800 X-Google-Sender-Auth: eQKsSs6iB3qqDYJNccG1zMZ0Cn0 Message-ID: Subject: Re: [RFC] Start SMP subsystem earlier From: Adrian Chadd To: Ian Lepore Content-Type: text/plain; charset=UTF-8 Cc: Hans Petter Selasky , markb@mellanox.com, FreeBSD Current X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.18-1 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: Tue, 06 Jan 2015 15:57:31 -0000 On 6 January 2015 at 07:55, Ian Lepore wrote: > On Tue, 2015-01-06 at 09:37 -0500, John Baldwin wrote: >> On 1/5/15 8:18 AM, Hans Petter Selasky wrote: >> > Hi, >> > >> > There is a limitiation on the number of interrupt vectors available when >> > only a single processor is running. To have more interrupts available we >> > need to start SMP earlier when building a monotolith kernel and not >> > loading drivers as modules. The driver in question is a network driver >> > and because it cannot be started after SI_SUB_ROOT_CONF due to PXE >> > support I see no other option than to move SI_SUB_SMP earlier. >> > >> > Suggested patch: >> > >> >>[...] >> > >> > This fixes a problem for Mellanox drivers in the OFED layer. Possibly we >> > need to move the SMP even earlier to not miss the generic FreeBSD PCI >> > device enumeration or maybe this is not possible. Does anyone know how >> > early we can start SMP? >> >> We need a lot more work before this is ready. This is one of the goals >> of the multipass new-bus stuff. In particular, we have to enumerate >> enough devices to bring event timer hardware up so that timer interrupts >> work so that tsleep() will actually sleep. In addition, we also need >> idle threads created and working before APs are started as otherwise >> they will have no thread to run initially. This is certainly a desired >> feature, but it is not as simple as moving the sysinit up I'm afraid. >> > > Just an FYI, the ARM world is now using the multipass newbus stuff. It > works well, with some quirks... > > The predefined pass names don't always makes sense for the arm world. > There aren't enough predefined pass names and even though the number > space for them is 4 billion wide all the predefined names are in the > range < 100 and separated by only 10 so it's tricky to wedge things > between the existing names. Maybe we need a RENUM script? :) -adrian > > The strangest bit is when you have interdependent drivers at different > early pass numbers. Sometimes it's necessary to do almost nothing in > the attach() routine and do all the real attach-time type stuff in a > bus_new_pass() routine after the pass number becomes high enough that > your co-dependent driver peers are available. > > -- Ian > > > _______________________________________________ > freebsd-current@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-current > To unsubscribe, send any mail to "freebsd-current-unsubscribe@freebsd.org"