From owner-freebsd-net@FreeBSD.ORG Thu Mar 15 16:07:42 2012 Return-Path: Delivered-To: freebsd-net@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 3121E106564A; Thu, 15 Mar 2012 16:07:42 +0000 (UTC) (envelope-from jfvogel@gmail.com) Received: from mail-wi0-f172.google.com (mail-wi0-f172.google.com [209.85.212.172]) by mx1.freebsd.org (Postfix) with ESMTP id 499958FC21; Thu, 15 Mar 2012 16:07:41 +0000 (UTC) Received: by wibhj6 with SMTP id hj6so7412392wib.13 for ; Thu, 15 Mar 2012 09:07:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type; bh=CQkd3lno8FuLyoYJpAvTne3D7qiRnt+w30t47a1P9lY=; b=SOR+qXMA+QlS0qiJLn0l8hXJ6MbXNOnmoyZOZFjU0hM6sh/b5xqch4Q84raSiQbK4V 1C/0fFC6LSJMjo2EhbCTFkui0RepqVXIV7ORYnzEpEAbeY228HlIY+iHaxHI9cJhoAwm ZhqZ/r/8JaXvsqbdMBNMCb7xeX5eHlCbFmaN5nGF9N55UuLGPgOh3+SfuuWAej70P8rr 8rul9FTBGLa9frnndG1sMEsGDCQ9hHwcb7eMAiqTn0tnHzyNpRy3PioYv8Dcen77khna MRDhFJBnns29DzVBWVMxhtaYPYOTQlc6axjt6iCu+a5zCT6HYXh2qlqPHtpx4lrbeXpR sB3g== MIME-Version: 1.0 Received: by 10.180.81.135 with SMTP id a7mr22015761wiy.16.1331827660489; Thu, 15 Mar 2012 09:07:40 -0700 (PDT) Received: by 10.180.82.168 with HTTP; Thu, 15 Mar 2012 09:07:40 -0700 (PDT) In-Reply-To: References: Date: Thu, 15 Mar 2012 09:07:40 -0700 Message-ID: From: Jack Vogel To: Juli Mallett Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: quoted-printable X-Content-Filtered-By: Mailman/MimeDel 2.1.5 Cc: freebsd-net@freebsd.org Subject: Re: MSI-X + em(4) = Refresh mbufs: hdr dmamap load failure - 22 X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 15 Mar 2012 16:07:42 -0000 You have header split on?? I've not seen this before so something odd is going on. Jack On Thu, Mar 15, 2012 at 12:39 AM, Juli Mallett wrote= : > All, > > On both stable/9 and trunk I see that with one of either the 82571EB > or 82574L I am flooded with messages in the form of: > > Refresh mbufs: hdr dmamap load failure - 22 > > If I disable msix, then the messages go away. I am not sure why msix > vs. non-msix would matter in this case unless in the msix case there's > some kind of case of spurious interrupts causing em_rxeof to be called > without any packets available. If that happens then perhaps > e1000_rx_unrefreshed() is called when no buffers have been processed > and then em_refresh_mbufs wrongly refreshes the whole ring? > > This seems like it would be a problem because the > bus_dmamap_load_mbuf_sg code is called unconditionally, even when a > new mbuf isn't being allocated. In that case, the mapping already > exists. Wouldn't it be necessary to unload and then reload the mbuf? > So either it's a bug that em_refresh_mbufs is being called at all, or > it's naively reusing mbufs in a way that actually guarantees an error, > right? Also, in the case where it frees, only m_free is called =97 is > there never a case where that should be an m_freem? I can imagine > some, but they are likely impossible with the receive path of the > driver. (I don't know for sure because the receive path and the mbuf > refresh code keep changing and I've been unable to keep up.) > > I don't know which part it is, of course, because I don't know what > port it's coming from. Like three other printfs in the driver where > which device is being used matters tremendously, it uses a bare printf > and not a device_printf. I could modify the driver, but for now > disabling msix is easier than continuing to load new kernels to try to > debug the problem. > > Is anyone else seeing this? Has anyone further investigated the > problem? Is there a patch floating around and I just haven't found > the right search terms? > > Thanks in advance, > Juli. > > PS: Yes, I know this is kind of a crappy bug report, sorry. I've had > a limited amount of time to investigate so far, and don't want to > delay reporting it until I am able to get more time with the > problematic hardware. > _______________________________________________ > freebsd-net@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-net > To unsubscribe, send any mail to "freebsd-net-unsubscribe@freebsd.org" >