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[146.241.36.39]) by smtp.gmail.com with ESMTPSA id o18sm20747276wrg.59.2018.01.13.03.05.31 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sat, 13 Jan 2018 03:05:32 -0800 (PST) From: Paolo Valente To: Jens Axboe Cc: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, ulf.hansson@linaro.org, broonie@kernel.org, linus.walleij@linaro.org, bfq-iosched@googlegroups.com, oleksandr@natalenko.name, Paolo Valente Subject: [PATCH BUGFIX/IMPROVEMENT 0/2] block, bfq: two pending patches Date: Sat, 13 Jan 2018 12:05:16 +0100 Message-Id: <20180113110518.2519-1-paolo.valente@linaro.org> X-Mailer: git-send-email 2.15.1 MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Jens, here are again the two pending patches you asked me to resend [1]. One of them, fixing read-starvation problems, was accompanied by a cover letter. I'm pasting the content of that cover letter below. The patch addresses (serious) starvation problems caused by request-tag exhaustion, as explained in more detail in the commit message. I started from the solution in the function kyber_limit_depth, but then I had to define more articulate limits, to counter starvation also in cases not covered in kyber_limit_depth. If this solution proves to be effective, I'm willing to port it somehow to the other schedulers. Thanks, Paolo [1] https://www.spinics.net/lists/linux-block/msg21586.html Paolo Valente (2): block, bfq: limit tags for writes and async I/O block, bfq: limit sectors served with interactive weight raising block/bfq-iosched.c | 158 +++++++++++++++++++++++++++++++++++++++++++++++++--- block/bfq-iosched.h | 17 ++++++ block/bfq-wf2q.c | 3 + 3 files changed, 169 insertions(+), 9 deletions(-) -- 2.15.1 Tested-by: Oleksandr Natalenko