From owner-svn-src-all@freebsd.org Thu Jan 30 21:12:18 2020 Return-Path: Delivered-To: svn-src-all@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id A977B1FF346; Thu, 30 Jan 2020 21:12:18 +0000 (UTC) (envelope-from hps@selasky.org) Received: from mail.turbocat.net (turbocat.net [IPv6:2a01:4f8:c17:6c4b::2]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) server-signature RSA-PSS (4096 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 487tN244dfz3Bqq; Thu, 30 Jan 2020 21:12:18 +0000 (UTC) (envelope-from hps@selasky.org) Received: from hps2020.home.selasky.org (unknown [62.141.129.235]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits)) (No client certificate requested) by mail.turbocat.net (Postfix) with ESMTPSA id 505A92600F6; Thu, 30 Jan 2020 22:12:09 +0100 (CET) Subject: Re: svn commit: r357293 - head/sys/net To: Gleb Smirnoff Cc: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org References: <202001301204.00UC43Rw022059@repo.freebsd.org> <20200130205629.GK1268@FreeBSD.org> From: Hans Petter Selasky Message-ID: <1bd0ae2c-3b5a-dfd7-747b-75af6f8d4d03@selasky.org> Date: Thu, 30 Jan 2020 22:09:45 +0100 User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:68.0) Gecko/20100101 Thunderbird/68.3.1 MIME-Version: 1.0 In-Reply-To: <20200130205629.GK1268@FreeBSD.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: 487tN244dfz3Bqq X-Spamd-Bar: ----- Authentication-Results: mx1.freebsd.org; none X-Spamd-Result: default: False [-6.00 / 15.00]; NEURAL_HAM_MEDIUM(-1.00)[-0.999,0]; REPLY(-4.00)[]; NEURAL_HAM_LONG(-1.00)[-1.000,0] X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 30 Jan 2020 21:12:18 -0000 On 2020-01-30 21:56, Gleb Smirnoff wrote: > On Thu, Jan 30, 2020 at 12:04:03PM +0000, Hans Petter Selasky wrote: > H> Author: hselasky > H> Date: Thu Jan 30 12:04:02 2020 > H> New Revision: 357293 > H> URL: https://svnweb.freebsd.org/changeset/base/357293 > H> > H> Log: > H> Widen EPOCH(9) usage in netisr. > H> > H> Software interrupt handlers are allowed to sleep. In swi_net() there > H> is a read lock behind NETISR_RLOCK() which in turn ends up calling > H> msleep() which means the whole of swi_net() cannot be protected by an > H> EPOCH(9) section. By default the NETISR_LOCKING feature is disabled. > H> > H> This issue was introduced by r357004. This is a preparation step for > H> replacing the functionality provided by r357004. > H> > H> Found by: kib@ > H> Sponsored by: Mellanox Technologies > > What?! NETISR_RLOCK() which in turn ends up calling msleep()? Can you please > explain this nonsense? > See rms_rlock_fallback() in kern_rmlock.c . --HPS