From mboxrd@z Thu Jan 1 00:00:00 1970 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934207AbeAMLFh (ORCPT + 1 other); Sat, 13 Jan 2018 06:05:37 -0500 Received: from mail-wr0-f195.google.com ([209.85.128.195]:42735 "EHLO mail-wr0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933502AbeAMLFe (ORCPT ); Sat, 13 Jan 2018 06:05:34 -0500 X-Google-Smtp-Source: ACJfBos0outwr8bWm85C0F1X/ceGht8fwN/Tnt4lFFupRM0PD/dE2BinJZH4IB/o1PQ0V3RhFN/rAw== 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 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: 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