From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.5 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 43D07C55189 for ; Wed, 22 Apr 2020 11:29:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 245AA2082E for ; Wed, 22 Apr 2020 11:29:59 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="2+8v67rb" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727871AbgDVL35 (ORCPT ); Wed, 22 Apr 2020 07:29:57 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45824 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1727003AbgDVL3j (ORCPT ); Wed, 22 Apr 2020 07:29:39 -0400 Received: from merlin.infradead.org (unknown [IPv6:2001:8b0:10b:1231::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E84D6C03C1A8 for ; Wed, 22 Apr 2020 04:29:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.20170209; h=Content-Type:MIME-Version:References: Subject:Cc:To:From:Date:Message-Id:Sender:Reply-To:Content-Transfer-Encoding: Content-ID:Content-Description:In-Reply-To; bh=3bAokr5NILG1h/Bx/ZUJG/Nj4cpaotPiRJOOn7QkaIs=; b=2+8v67rb7pJohkSqOLleVrtjVa rvh/jb2TdTbGdK3M9POBH524IRiVIUlSv3ictUOBSQP+H6qnqrqHD11GPcET3yEHNLDY2VfUvbQeb AjhNQpz+T3S3GznmwAbyksiAZ0YyZnzJ9/g+IMJVE1Zz75zmvLMpoHHlxpa8WlKRE36SL/QxNx0Q6 NgLW7MFT+Uu9y+lp0Pg9FczKYNsRNE7eQYMkLDjRKc0NDFolx/NYi6R4hGA7m9Y4lej6NN/kj4n02 IlxOr/rrQeDQX2gbwu+uPzgf6FdUJouAqP085k5Cv/T0iGiZNcEXOhQ5dhSkJd3Eqm+As6aSBoPgQ scefLT/Q==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1jRDYw-0006ql-Ce; Wed, 22 Apr 2020 11:29:06 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 2F17C30783F; Wed, 22 Apr 2020 13:29:03 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 0) id C43D0201946E4; Wed, 22 Apr 2020 13:29:02 +0200 (CEST) Message-Id: <20200422112831.515522261@infradead.org> User-Agent: quilt/0.65 Date: Wed, 22 Apr 2020 13:27:24 +0200 From: Peter Zijlstra To: mingo@kernel.org, linux-kernel@vger.kernel.org Cc: tglx@linutronix.de, rostedt@goodmis.org, qais.yousef@arm.com, juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, bsegall@google.com, mgorman@suse.de, peterz@infradead.org, axboe@kernel.dk Subject: [PATCH 05/23] sched,drbd: Convert to sched_set_fifo*() References: <20200422112719.826676174@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Because SCHED_FIFO is a broken scheduler model (see previous patches) take away the priority field, the kernel can't possibly make an informed decision. In this case, use fifo_low, because it only cares about being above SCHED_NORMAL. Effectively changes prio from 2 to 1. Cc: axboe@kernel.dk Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Ingo Molnar --- drivers/block/drbd/drbd_receiver.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) --- a/drivers/block/drbd/drbd_receiver.c +++ b/drivers/block/drbd/drbd_receiver.c @@ -6020,9 +6020,8 @@ int drbd_ack_receiver(struct drbd_thread unsigned int header_size = drbd_header_size(connection); int expect = header_size; bool ping_timeout_active = false; - struct sched_param param = { .sched_priority = 2 }; - rv = sched_setscheduler(current, SCHED_RR, ¶m); + rv = sched_set_fifo_low(current); if (rv < 0) drbd_err(connection, "drbd_ack_receiver: ERROR set priority, ret=%d\n", rv);