From owner-freebsd-net@freebsd.org Wed May 2 15:53:22 2018 Return-Path: Delivered-To: freebsd-net@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 4CCC5FAD696 for ; Wed, 2 May 2018 15:53:22 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from mailman.ysv.freebsd.org (mailman.ysv.freebsd.org [IPv6:2001:1900:2254:206a::50:5]) by mx1.freebsd.org (Postfix) with ESMTP id 89C1E7A800 for ; Wed, 2 May 2018 15:53:21 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: by mailman.ysv.freebsd.org (Postfix) id 471DFFAD695; Wed, 2 May 2018 15:53:21 +0000 (UTC) Delivered-To: net@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 27EA2FAD694 for ; Wed, 2 May 2018 15:53:20 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from mxrelay.ysv.freebsd.org (mxrelay.ysv.freebsd.org [IPv6:2001:1900:2254:206a::19:3]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "mxrelay.ysv.freebsd.org", Issuer "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 1B3247A7E8 for ; Wed, 2 May 2018 15:53:20 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org (kenobi.freebsd.org [IPv6:2001:1900:2254:206a::16:76]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mxrelay.ysv.freebsd.org (Postfix) with ESMTPS id 44B3F22708 for ; Wed, 2 May 2018 15:53:19 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org ([127.0.1.118]) by kenobi.freebsd.org (8.15.2/8.15.2) with ESMTP id w42FrJ2l032257 for ; Wed, 2 May 2018 15:53:19 GMT (envelope-from bugzilla-noreply@freebsd.org) Received: (from www@localhost) by kenobi.freebsd.org (8.15.2/8.15.2/Submit) id w42FrJxu032256 for net@FreeBSD.org; Wed, 2 May 2018 15:53:19 GMT (envelope-from bugzilla-noreply@freebsd.org) X-Authentication-Warning: kenobi.freebsd.org: www set sender to bugzilla-noreply@freebsd.org using -f From: bugzilla-noreply@freebsd.org To: net@FreeBSD.org Subject: [Bug 208205] re0 watchdog timeout Date: Wed, 02 May 2018 15:53:16 +0000 X-Bugzilla-Reason: AssignedTo X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: Base System X-Bugzilla-Component: kern X-Bugzilla-Version: 11.1-RELEASE X-Bugzilla-Keywords: needs-qa X-Bugzilla-Severity: Affects Many People X-Bugzilla-Who: aksyom@gmail.com X-Bugzilla-Status: New X-Bugzilla-Resolution: X-Bugzilla-Priority: --- X-Bugzilla-Assigned-To: net@FreeBSD.org X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: cc Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: https://bugs.freebsd.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.25 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 02 May 2018 15:53:22 -0000 https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D208205 Arto Pekkanen changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |aksyom@gmail.com --- Comment #22 from Arto Pekkanen --- I managed to solve this issue by disabling MSI and MSI-X. Put the following lines into /boot/loader.conf hw.re.msi_disable=3D"1" hw.re.msix_disable=3D"1" You see, the MSI/MSI-X interrupt processing supposedly eliminates the need = to perform an extra read from device register after receiving an interrupt whi= ch tells that a DMA write is finished. However, there is some kind of problem either in the driver or the chip itself in the way it handles these interru= pts. By disabling MSI and MSI-X, the driver switches to using the older interrupt filter handler, and thus probably performs and extra read from some device register to wait for the DMA transfer to memory to be ready (according to wikipedia, when using legacy interrupts this is the only way to ensure the = DMA transfer wasn't buffered by the chipset etc). So, I would suggest everybody watching this thread to try if disabling MSI = and MSI-X on their system helps. Might not apply to all Realtek NICs, but on my machine this workaround is valid. PS. the performance is still horrible when transferring to and from the machine, but at least now it doesn't hang sporadically. --=20 You are receiving this mail because: You are the assignee for the bug.=