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[66.29.164.166]) by smtp.gmail.com with ESMTPSA id t2sm124731pgo.61.2019.06.26.15.25.55 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 26 Jun 2019 15:25:56 -0700 (PDT) Subject: Re: [PATCH] block, bfq: Init saved_wr_start_at_switch_to_srt in unlikely case To: Douglas Anderson , Paolo Valente Cc: groeck@chromium.org, drinkcat@chromium.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org References: <20190626195919.107425-1-dianders@chromium.org> From: Jens Axboe Message-ID: <8a108498-77ec-1164-b5ed-80d791f60119@kernel.dk> Date: Wed, 26 Jun 2019 16:25:55 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.7.1 MIME-Version: 1.0 In-Reply-To: <20190626195919.107425-1-dianders@chromium.org> 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 6/26/19 1:59 PM, Douglas Anderson wrote: > Some debug code suggested by Paolo was tripping when I did reboot > stress tests. Specifically in bfq_bfqq_resume_state() > "bic->saved_wr_start_at_switch_to_srt" was later than the current > value of "jiffies". A bit of debugging showed that > "bic->saved_wr_start_at_switch_to_srt" was actually 0 and a bit more > debugging showed that was because we had run through the "unlikely" > case in the bfq_bfqq_save_state() function. > > Let's init "saved_wr_start_at_switch_to_srt" in the unlikely case to > something sane. > > NOTE: this fixes no known real-world errors. Applied, thanks. -- Jens Axboe