From patchwork Wed Jun 1 14:51:06 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jan Kara X-Patchwork-Id: 12866927 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7D4EACCA478 for ; Wed, 1 Jun 2022 14:51:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346832AbiFAOvQ (ORCPT ); Wed, 1 Jun 2022 10:51:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37918 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233844AbiFAOvP (ORCPT ); Wed, 1 Jun 2022 10:51:15 -0400 Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.220.29]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 971215DD21 for ; Wed, 1 Jun 2022 07:51:12 -0700 (PDT) Received: from relay2.suse.de (relay2.suse.de [149.44.160.134]) by smtp-out2.suse.de (Postfix) with ESMTP id 4BC211F8F6; Wed, 1 Jun 2022 14:51:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1654095071; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=yUduM4lG2q2GY35eSJ4HLE/WEL036XTWEqWZF30BRZA=; b=j6I9ufRf+6qlHq5Ye9C7SShlYxn5Y8nSobvRjrbcQ3JV6LsfZJrKn7oz2LP/uziqTGyXMJ ZWYTR1VtK5K8VOATnlbzcVPumU+ByskpCVfc5idlpoFeY3/OtonXI9zJGLh8Jr8fJ2KxQ3 6oP8W+yqleiMp2wTcEyzZxV0Nm7CI/4= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1654095071; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=yUduM4lG2q2GY35eSJ4HLE/WEL036XTWEqWZF30BRZA=; b=UKQBt1HZTfQJnp4lW3g3OzAaAtC/0kMWmg8YNe2Ugpu47o/OHV1yapNREacYIX0pFl6xZR 4/pZloQc8Q7y4YAw== Received: from quack3.suse.cz (unknown [10.163.28.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by relay2.suse.de (Postfix) with ESMTPS id 133932C145; Wed, 1 Jun 2022 14:51:11 +0000 (UTC) Received: by quack3.suse.cz (Postfix, from userid 1000) id C9F06A0637; Wed, 1 Jun 2022 16:51:10 +0200 (CEST) From: Jan Kara To: Jens Axboe Cc: , Christoph Hellwig , Damien Le Moal , Jan Kara Subject: [PATCH 3/3] block: fix default IO priority handling again Date: Wed, 1 Jun 2022 16:51:06 +0200 Message-Id: <20220601145110.18162-3-jack@suse.cz> X-Mailer: git-send-email 2.35.3 In-Reply-To: <20220601132347.13543-1-jack@suse.cz> References: <20220601132347.13543-1-jack@suse.cz> MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=2229; h=from:subject; bh=F/+79O3vT4YJ18myuAZmNBRsDmfEk3VfFl9MazpsqGQ=; b=owEBbQGS/pANAwAIAZydqgc/ZEDZAcsmYgBil3zaD2Dh0tXPI5QrXiqY5Xj8NIYkL00D+oD9WQcq QdRrANaJATMEAAEIAB0WIQSrWdEr1p4yirVVKBycnaoHP2RA2QUCYpd82gAKCRCcnaoHP2RA2QrBCA DNeuqpwzGyaHeIRCxuFM3ewOcoGjZR217e2DveCBDlnv+hu9MnF7o4f/QgqlZH+dJWbXz4JhKt8/Xt 4KPj62xrhpg4YoTWCV5q/t10cgtbvy51Ar8LfGadwrIdVujrVnIS0cfOD0cYQ5Oty/ftjgMlWKMBTJ KY0d517H8N5KfeOUmXSGG+AZYo+4OXXa3ShfDAcYRatFyrv2uIDlBze/fZkIzfd2o129aZwzLafnri dd3QVXbYlHqCNSkvswJskOvHjRHepyiUavLTX5DrNThyqz5l19yu6NT62E9JEf16L1CyYrOTt38Y9B eY4iVxeB+uyLfoteXbbVq29RD4P6rQ X-Developer-Key: i=jack@suse.cz; a=openpgp; fpr=93C6099A142276A28BBE35D815BC833443038D8C Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org Commit e70344c05995 ("block: fix default IO priority handling") introduced an inconsistency in get_current_ioprio() that tasks without IO context return IOPRIO_DEFAULT priority while tasks with freshly allocated IO context will return 0 (IOPRIO_CLASS_NONE/0) IO priority. Tasks without IO context used to be rare before 5a9d041ba2f6 ("block: move io_context creation into where it's needed") but after this commit they became common because now only BFQ IO scheduler setups task's IO context. Similar inconsistency is there for get_task_ioprio() so this inconsistency is now exposed to userspace and userspace will see different IO priority for tasks operating on devices with BFQ compared to devices without BFQ. Furthemore the changes done by commit e70344c05995 change the behavior when no IO priority is set for BFQ IO scheduler which is also documented in ioprio_set(2) manpage - namely that tasks without set IO priority will use IO priority based on their nice value. So make sure we default to IOPRIO_CLASS_NONE as used to be the case before commit e70344c05995. Also cleanup alloc_io_context() to explicitely set this IO priority for the allocated IO context. Fixes: e70344c05995 ("block: fix default IO priority handling") Signed-off-by: Jan Kara --- block/blk-ioc.c | 2 ++ include/linux/ioprio.h | 2 +- 2 files changed, 3 insertions(+), 1 deletion(-) diff --git a/block/blk-ioc.c b/block/blk-ioc.c index df9cfe4ca532..63fc02042408 100644 --- a/block/blk-ioc.c +++ b/block/blk-ioc.c @@ -247,6 +247,8 @@ static struct io_context *alloc_io_context(gfp_t gfp_flags, int node) INIT_HLIST_HEAD(&ioc->icq_list); INIT_WORK(&ioc->release_work, ioc_release_fn); #endif + ioc->ioprio = IOPRIO_DEFAULT; + return ioc; } diff --git a/include/linux/ioprio.h b/include/linux/ioprio.h index 774bb90ad668..d9dc78a15301 100644 --- a/include/linux/ioprio.h +++ b/include/linux/ioprio.h @@ -11,7 +11,7 @@ /* * Default IO priority. */ -#define IOPRIO_DEFAULT IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, IOPRIO_BE_NORM) +#define IOPRIO_DEFAULT IOPRIO_PRIO_VALUE(IOPRIO_CLASS_NONE, 0) /* * Check that a priority value has a valid class.