From nobody Tue Nov 26 13:27:12 2024 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.20]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A5DDB18CBEC; Fri, 18 Oct 2024 07:54:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.20 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729238074; cv=none; b=WFdjAPObL+FndS7FmLmrcBNfuf31yK9w113yxyBdMT9XgK0vjRmKjUcLRGEi0/d34oFRsRfUVtQcHJV30MMtFQUBy+92gyzc3QEpl6SvJzNqy3c6sR8js/hLgs0i0u+ixibqICbau458zUSXaPK7gCXe/nFaThPTBFtBKNdyqdI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729238074; c=relaxed/simple; bh=VYb4AXeRfDuSPexQUmqF2/JPGM2xgfoqbX7SzxfRB5g=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=pqAFbJf9FeJty9iwG7lIdNIr4YMJOU4gxx5Bm65MJ1S4Bqx0BHakhYIjuTspIuqgr6um4rhRtFFQ2NA6973HZuTgQ2suWl4ByzfEug7tviVu0qJE2FhctarsNY0L46lZv3j7kqMnjJZkMKmiARfQjHABiEaQOIUZDpADpJO1V5I= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=none smtp.mailfrom=linux.intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=K+qzlvoN; arc=none smtp.client-ip=198.175.65.20 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="K+qzlvoN" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1729238073; x=1760774073; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=VYb4AXeRfDuSPexQUmqF2/JPGM2xgfoqbX7SzxfRB5g=; b=K+qzlvoNWCRTFXp5eODqoCih4+AHIFc2LOeur3PVWAvFYuf1bAkgrSqW ZrHOWhyDlu4uM2wg1F8fSEtrlJa2E8OHMEC3o13HrsmCh0Fr7JDrFVO8H lZgombz3OV4rGBzbxkoYYhv9Lvc6DpP/WDCMdlF/Yh0uVGGqr5uH/NKau YRytlhMyBC+hyTweHapXB8rX1YSuqqV4i9joaP4ESlTdATGAyu39J4sZW U4hBw0o/iNZxiapLEAPM/ZrmmPszGbzPnJ94qrK9aP/m/3D41jhsJhPc/ 1hO/pYz1MH+M6af+oO/XPE3bqtHQimU9HSE62zxef7f4Zb5uVX4CoFWaW Q==; X-CSE-ConnectionGUID: beZaYOjEQDW1uktY6jFqOg== X-CSE-MsgGUID: 3QgOGX5/RcOgwCZhz6HWew== X-IronPort-AV: E=McAfee;i="6700,10204,11222"; a="28549560" X-IronPort-AV: E=Sophos;i="6.11,199,1725346800"; d="scan'208";a="28549560" Received: from orviesa008.jf.intel.com ([10.64.159.148]) by orvoesa112.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 18 Oct 2024 00:54:33 -0700 X-CSE-ConnectionGUID: C6HyQPG8RaaWj0C89faR3g== X-CSE-MsgGUID: f1pdlETeRN6DD9MxxgeLWQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.11,213,1725346800"; d="scan'208";a="79604071" Received: from klitkey1-mobl1.ger.corp.intel.com (HELO tkristo-desk.intel.com) ([10.245.246.169]) by orviesa008-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 18 Oct 2024 00:54:27 -0700 From: Tero Kristo To: axboe@kernel.dk Cc: hch@lst.de, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCHv2 2/2] blk-mq: add support for CPU latency limits Date: Fri, 18 Oct 2024 10:30:38 +0300 Message-ID: <20241018075416.436916-3-tero.kristo@linux.intel.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20241018075416.436916-1-tero.kristo@linux.intel.com> References: <20241018075416.436916-1-tero.kristo@linux.intel.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Add support for setting CPU latency limits when a request is dispatched to driver layer, and removing it once the device is idle. The latency limits use the dev PM QoS framework for setting per-cpu limits for active CPUs. The feature is user configurable via sysfs knobs under the block device. Signed-off-by: Tero Kristo --- block/blk-mq.c | 54 ++++++++++++++++++++++++++++++++++++++++++ include/linux/blk-mq.h | 12 ++++++++++ 2 files changed, 66 insertions(+) diff --git a/block/blk-mq.c b/block/blk-mq.c index 4b2c8e940f59..f8906e2aff6d 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -29,6 +29,7 @@ #include #include #include +#include =20 #include =20 @@ -2700,11 +2701,62 @@ static void blk_mq_plug_issue_direct(struct blk_plu= g *plug) static void __blk_mq_flush_plug_list(struct request_queue *q, struct blk_plug *plug) { + struct request *req, *next; + struct blk_mq_hw_ctx *hctx; + int cpu; + if (blk_queue_quiesced(q)) return; + + rq_list_for_each_safe(&plug->mq_list, req, next) { + hctx =3D req->mq_hctx; + + if (next && next->mq_hctx =3D=3D hctx) + continue; + + if (q->disk->cpu_lat_limit < 0) + continue; + + hctx->last_active =3D jiffies + msecs_to_jiffies(q->disk->cpu_lat_timeou= t); + + if (!hctx->cpu_lat_limit_active) { + hctx->cpu_lat_limit_active =3D true; + for_each_cpu(cpu, hctx->cpumask) { + struct dev_pm_qos_request *qos; + + qos =3D per_cpu_ptr(hctx->cpu_lat_qos, cpu); + dev_pm_qos_add_request(get_cpu_device(cpu), qos, + DEV_PM_QOS_RESUME_LATENCY, + q->disk->cpu_lat_limit); + } + schedule_delayed_work(&hctx->cpu_latency_work, + msecs_to_jiffies(q->disk->cpu_lat_timeout)); + } + } + q->mq_ops->queue_rqs(&plug->mq_list); } =20 +static void blk_mq_cpu_latency_work(struct work_struct *work) +{ + struct blk_mq_hw_ctx *hctx =3D container_of(work, struct blk_mq_hw_ctx, + cpu_latency_work.work); + int cpu; + + if (time_after(jiffies, hctx->last_active)) { + for_each_cpu(cpu, hctx->cpumask) { + struct dev_pm_qos_request *qos; + + qos =3D per_cpu_ptr(hctx->cpu_lat_qos, cpu); + dev_pm_qos_remove_request(qos); + } + hctx->cpu_lat_limit_active =3D false; + } else { + schedule_delayed_work(&hctx->cpu_latency_work, + msecs_to_jiffies(hctx->queue->disk->cpu_lat_timeout)); + } +} + static void blk_mq_dispatch_plug_list(struct blk_plug *plug, bool from_sch= ed) { struct blk_mq_hw_ctx *this_hctx =3D NULL; @@ -3729,6 +3778,11 @@ static int blk_mq_init_hctx(struct request_queue *q, if (xa_insert(&q->hctx_table, hctx_idx, hctx, GFP_KERNEL)) goto exit_flush_rq; =20 + hctx->cpu_lat_qos =3D alloc_percpu(struct dev_pm_qos_request); + if (!hctx->cpu_lat_qos) + goto exit_flush_rq; + INIT_DELAYED_WORK(&hctx->cpu_latency_work, blk_mq_cpu_latency_work); + return 0; =20 exit_flush_rq: diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h index b751cc92209b..2b61942490d6 100644 --- a/include/linux/blk-mq.h +++ b/include/linux/blk-mq.h @@ -435,6 +435,18 @@ struct blk_mq_hw_ctx { /** @kobj: Kernel object for sysfs. */ struct kobject kobj; =20 + /** @cpu_latency_work: Work to handle CPU latency PM limits. */ + struct delayed_work cpu_latency_work; + + /** @cpu_lat_limit_active: If CPU latency limits are active or not. */ + bool cpu_lat_limit_active; + + /** @last_active: Jiffies value when the queue was last active. */ + unsigned long last_active; + + /** @cpu_lat_qos: PM QoS latency limits for individual CPUs. */ + struct dev_pm_qos_request __percpu *cpu_lat_qos; + #ifdef CONFIG_BLK_DEBUG_FS /** * @debugfs_dir: debugfs directory for this hardware queue. Named --=20 2.43.1