From patchwork Tue Sep 17 16:51:47 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paolo Valente X-Patchwork-Id: 11149215 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 32D46912 for ; Tue, 17 Sep 2019 16:52:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 06EF920862 for ; Tue, 17 Sep 2019 16:52:22 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="hHiW8B/Q" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730636AbfIQQwU (ORCPT ); Tue, 17 Sep 2019 12:52:20 -0400 Received: from mail-wr1-f66.google.com ([209.85.221.66]:36587 "EHLO mail-wr1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730620AbfIQQwM (ORCPT ); Tue, 17 Sep 2019 12:52:12 -0400 Received: by mail-wr1-f66.google.com with SMTP id y19so3965381wrd.3 for ; Tue, 17 Sep 2019 09:52:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=D17brve6b6KAv4fqOmqA3INLGXx33zG7oskk+r6jVO8=; b=hHiW8B/QKwHCS22NUzjtEbLG8SCk2S3zBzArHW2Q9oZ8//kdEgusup7MhqecS/2AEB yF6OG6N6oV+f1nDE1wDU+LMtO2czrB56uU2oRX6x+4hPmUxkl0a8vFBZpIoGa3xz48Uv +gc6kHj7G3csBtOnlLWFxsddt8gxaJQhJ3bdoqNriEauIH7KxJcvbFbPNHoEIqRaHXEu 28FafC+evdI7HfXnQMXvkY6ibAMw0fgvvunmPYKCljgkH2xkNdfJwwsxa+Mg3xnJ7p0P z+Zi669gBxRrsg5sUV9Qj5Be2Cxm7XPszByLZoicHHs242Qo8chu3PxPnKH9sEzlphSF EyoQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=D17brve6b6KAv4fqOmqA3INLGXx33zG7oskk+r6jVO8=; b=ND/PergMzfFYrtl1PQx2wFpxz4+5Jx8aXlDWUkTsADojVNbSKKJ2yo4XYDldQX0cpB MPL8YFKHe9JQUV1UNERYmdq/n/UI5fpTlNRBEZ7gZUefgfM0ewgqGy0rVnp0ce3i8DAz xfYa6Bh1MaW55qvduGK8HErlvs7LOoMEQReDKBS4yQNz/9xqe5UVsXSIapQNbO6OMRIu LgE8WWwjirV7GRAv/+0m3BXorC0+/ttTMRLVz6yMKF4HFKCpzWuMvvFAZRqdd4gCU4DD W4X3F2RIzUf48UDds2Hv44XcY4aJrCeXFiJzGjVk3dEWm/fG4pIq2EKevs/vdZyjdEG1 a93A== X-Gm-Message-State: APjAAAU/Hj7/sPp25Vb9sffwptyOZktv+RJQKXTKX+lC8H77UgOhQt+Q oss5LPOY9iBf2IEFcHXnx8KxvQ== X-Google-Smtp-Source: APXvYqz+JIm5NzzIioOZ+1thydASKJ+eQAcvmXAA0O0HwMtzk5VXPo+NJIR6yYpELIXHqYc1wQyNGg== X-Received: by 2002:adf:9d84:: with SMTP id p4mr3668012wre.39.1568739129746; Tue, 17 Sep 2019 09:52:09 -0700 (PDT) Received: from localhost.localdomain (146-241-53-114.dyn.eolo.it. [146.241.53.114]) by smtp.gmail.com with ESMTPSA id g73sm4012378wme.10.2019.09.17.09.52.08 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 17 Sep 2019 09:52:09 -0700 (PDT) From: Paolo Valente To: Jens Axboe Cc: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, ulf.hansson@linaro.org, linus.walleij@linaro.org, bfq-iosched@googlegroups.com, oleksandr@natalenko.name, Tejun Heo , cgroups@vger.kernel.org, Paolo Valente Subject: [PATCH 1/2] blkcg: Make bfq disable iocost when enabled Date: Tue, 17 Sep 2019 18:51:47 +0200 Message-Id: <20190917165148.19146-2-paolo.valente@linaro.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190917165148.19146-1-paolo.valente@linaro.org> References: <20190917165148.19146-1-paolo.valente@linaro.org> MIME-Version: 1.0 Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org From: Tejun Heo Both iocost and bfq implement weight based IO control. Currently, bfq is using io.bfq prefix but wants to drop the bfq part. To avoid interface conflict, make bfq disable iocost when it's selected as the IO scheduler for any block device on the system. iocost is only re-enabled when bfq is built as a module and unloaded. Signed-off-by: Tejun Heo Cc: Paolo Valente --- Documentation/admin-guide/cgroup-v2.rst | 8 ++++--- block/bfq-cgroup.c | 2 ++ block/bfq-iosched.c | 32 +++++++++++++++++++++++++ block/blk-iocost.c | 5 ++-- include/linux/blk-cgroup.h | 5 ++++ kernel/cgroup/cgroup.c | 2 ++ 6 files changed, 48 insertions(+), 6 deletions(-) diff --git a/Documentation/admin-guide/cgroup-v2.rst b/Documentation/admin-guide/cgroup-v2.rst index 3deacdc5e6d2..d4d06a970f8a 100644 --- a/Documentation/admin-guide/cgroup-v2.rst +++ b/Documentation/admin-guide/cgroup-v2.rst @@ -1406,9 +1406,11 @@ IO The "io" controller regulates the distribution of IO resources. This controller implements both weight based and absolute bandwidth or IOPS -limit distribution; however, weight based distribution is available -only if cfq-iosched is in use and neither scheme is available for -blk-mq devices. +limit distribution. Weight based distribution is implemented by +either iocost controller or bfq IO scheduler. When bfq is selected as +the IO scheduler for any block device, iocost is disabled and bfq's +implementation overrides for all devices. If bfq is built as a kernel +module, unloading it re-enables iocost. IO Interface Files diff --git a/block/bfq-cgroup.c b/block/bfq-cgroup.c index 86a607cf19a1..decda96770f4 100644 --- a/block/bfq-cgroup.c +++ b/block/bfq-cgroup.c @@ -1194,7 +1194,9 @@ struct bfq_group *bfq_create_group_hierarchy(struct bfq_data *bfqd, int node) } struct blkcg_policy blkcg_policy_bfq = { +#ifndef CONFIG_BLK_CGROUP_IOCOST .dfl_cftypes = bfq_blkg_files, +#endif .legacy_cftypes = bfq_blkcg_legacy_files, .cpd_alloc_fn = bfq_cpd_alloc, diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c index 0319d6339822..21d1b08610b1 100644 --- a/block/bfq-iosched.c +++ b/block/bfq-iosched.c @@ -6382,6 +6382,36 @@ static void bfq_init_root_group(struct bfq_group *root_group, root_group->sched_data.bfq_class_idle_last_service = jiffies; } +#if defined(CONFIG_BFQ_GROUP_IOSCHED) && defined(CONFIG_BLK_CGROUP_IOCOST) +static bool bfq_enabled = false; + +static void bfq_enable(void) +{ + static DEFINE_MUTEX(bfq_enable_mutex); + + mutex_lock(&bfq_enable_mutex); + if (!bfq_enabled) { + pr_info("bfq-iosched: Overriding iocost\n"); + blkcg_policy_unregister(&blkcg_policy_iocost); + cgroup_add_dfl_cftypes(&io_cgrp_subsys, bfq_blkg_files); + bfq_enabled = true; + } + mutex_unlock(&bfq_enable_mutex); +} + +static void __exit bfq_disable(void) +{ + if (bfq_enabled) { + pr_info("bfq-iosched: Restoring iocost\n"); + cgroup_rm_cftypes(bfq_blkg_files); + blkcg_policy_register(&blkcg_policy_iocost); + } +} +#else +static void bfq_enable(void) {} +static void __exit bfq_disable(void) {} +#endif + static int bfq_init_queue(struct request_queue *q, struct elevator_type *e) { struct bfq_data *bfqd; @@ -6506,6 +6536,7 @@ static int bfq_init_queue(struct request_queue *q, struct elevator_type *e) bfq_init_entity(&bfqd->oom_bfqq.entity, bfqd->root_group); wbt_disable_default(q); + bfq_enable(); return 0; out_free: @@ -6823,6 +6854,7 @@ static void __exit bfq_exit(void) blkcg_policy_unregister(&blkcg_policy_bfq); #endif bfq_slab_kill(); + bfq_disable(); } module_init(bfq_init); diff --git a/block/blk-iocost.c b/block/blk-iocost.c index 3b39deb8b9f8..1ef5b443c09a 100644 --- a/block/blk-iocost.c +++ b/block/blk-iocost.c @@ -605,8 +605,6 @@ static u32 vrate_adj_pct[] = 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 4, 4, 4, 4, 4, 4, 4, 4, 8, 8, 8, 8, 8, 8, 8, 8, 16 }; -static struct blkcg_policy blkcg_policy_iocost; - /* accessors and helpers */ static struct ioc *rqos_to_ioc(struct rq_qos *rqos) { @@ -2434,7 +2432,7 @@ static struct cftype ioc_files[] = { {} }; -static struct blkcg_policy blkcg_policy_iocost = { +struct blkcg_policy blkcg_policy_iocost = { .dfl_cftypes = ioc_files, .cpd_alloc_fn = ioc_cpd_alloc, .cpd_free_fn = ioc_cpd_free, @@ -2442,6 +2440,7 @@ static struct blkcg_policy blkcg_policy_iocost = { .pd_init_fn = ioc_pd_init, .pd_free_fn = ioc_pd_free, }; +EXPORT_SYMBOL_GPL(blkcg_policy_iocost); static int __init ioc_init(void) { diff --git a/include/linux/blk-cgroup.h b/include/linux/blk-cgroup.h index bed9e43f9426..5669e3cfa1bc 100644 --- a/include/linux/blk-cgroup.h +++ b/include/linux/blk-cgroup.h @@ -815,6 +815,11 @@ static inline void blkcg_clear_delay(struct blkcg_gq *blkg) void blkcg_add_delay(struct blkcg_gq *blkg, u64 now, u64 delta); void blkcg_schedule_throttle(struct request_queue *q, bool use_memdelay); void blkcg_maybe_throttle_current(void); + +#ifdef CONFIG_BLK_CGROUP_IOCOST +extern struct blkcg_policy blkcg_policy_iocost; +#endif + #else /* CONFIG_BLK_CGROUP */ struct blkcg { diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c index 8be1da1ebd9a..4d015328ebb0 100644 --- a/kernel/cgroup/cgroup.c +++ b/kernel/cgroup/cgroup.c @@ -4059,6 +4059,7 @@ int cgroup_rm_cftypes(struct cftype *cfts) mutex_unlock(&cgroup_mutex); return ret; } +EXPORT_SYMBOL_GPL(cgroup_rm_cftypes); /** * cgroup_add_cftypes - add an array of cftypes to a subsystem @@ -4115,6 +4116,7 @@ int cgroup_add_dfl_cftypes(struct cgroup_subsys *ss, struct cftype *cfts) cft->flags |= __CFTYPE_ONLY_ON_DFL; return cgroup_add_cftypes(ss, cfts); } +EXPORT_SYMBOL_GPL(cgroup_add_dfl_cftypes); /** * cgroup_add_legacy_cftypes - add an array of cftypes for legacy hierarchies