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[66.29.188.166]) by smtp.gmail.com with ESMTPSA id m19sm1024468pgn.35.2019.01.14.05.26.11 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 14 Jan 2019 05:26:12 -0800 (PST) Subject: Re: [PATCH BUGFIX 0/2] bfq: fix unbalanced decrements causing loss of throughput To: Paolo Valente Cc: linux-block , linux-kernel , Ulf Hansson , Linus Walleij , Mark Brown , bfq-iosched@googlegroups.com, oleksandr@natalenko.name, federico@willer.it References: <20181206181819.11148-1-paolo.valente@linaro.org> <09393ef1-9559-2042-6c83-75ed3fd529d3@kernel.dk> <8753C347-2BFD-40D4-A97E-DA955BC0207C@linaro.org> <16d4065e-c0d1-7a85-3d9a-242bfd92923e@kernel.dk> From: Jens Axboe Message-ID: Date: Mon, 14 Jan 2019 06:26:09 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.2.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 1/14/19 2:09 AM, Paolo Valente wrote: > > >> Il giorno 7 dic 2018, alle ore 15:40, Jens Axboe ha scritto: >> >> On 12/7/18 3:01 AM, Paolo Valente wrote: >>> >>> >>>> Il giorno 7 dic 2018, alle ore 03:23, Jens Axboe ha scritto: >>>> >>>> On 12/6/18 11:18 AM, Paolo Valente wrote: >>>>> Hi Jens, >>>>> the first patch in this series fixes an error in the decrementing of >>>>> the counter of the number of groups with pending I/O. This wrong >>>>> decrement caused loss of throughput or, less likely, of control on >>>>> I/O. The second patch is a fix of some wrong comments, which somehow >>>>> contributed to making the above bug more difficult to find. >>>> >>>> Are you fine with this going into 4.21? I can't quite tell what your >>>> intent is. The first patch has a Fixes for something >>> >>> yep, that fixes a serious error. >>> >>>> that went into >>>> this series, but then patch 2 is a comment update that would not >>>> normally be something to be applied at this stage. >>>> >>> >>> and yes, only comments changed by the second one >>> >>> May it make sense to apply them in two steps, one in the 4.20 and the other one in the 4.21? >> >> I think so, I'll do that. > > Hi Jens, > is the second patch still queued? That got dropped for some reason, I've applied it now. -- Jens Axboe