From patchwork Tue Sep 3 09:34:57 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: =?utf-8?b?56ug6L6J?= X-Patchwork-Id: 13788409 Received: from outboundhk.mxmail.xiaomi.com (outboundhk.mxmail.xiaomi.com [207.226.244.122]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 0B31A1A0BC0; Tue, 3 Sep 2024 09:36:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=207.226.244.122 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725356173; cv=none; b=Fb4PoF5GiNF4uK+Bmk4/+eqRkcJdL8m/MyWpRFwDrozrxidjqveUxWLZUJtx52MGYZ4DXgeYRYcYKYdZvP2izdtj3jbZ9tSZqVU5hL2Mkum5mM72xueZT30cJouHnzvO+dz62TBNX8hGHfpebtCXW+Qie/MrkIXxsDQkF5dz3Ik= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725356173; c=relaxed/simple; bh=qyOBWzSA9PMTyI2ZdLp/3LZZLqjxeycKS2UtMNIUvdI=; h=From:To:CC:Subject:Date:Message-ID:MIME-Version:Content-Type; b=G7tBtTna2I+r49L9sLxwuahIGiMFToUFypZczhHFIiEnMrbmX5+5S0BFbKDOrV3yZzArMlETVZ3zPUpM66cLHTiK2BzaRc4DBVM6zAxFW3f4M85+V7prQ6Sp812ANi5/+P3sopV8Dir4IedCTPcLTsJD4F7vb2k1vPJFhKKMpSM= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=xiaomi.com; spf=pass smtp.mailfrom=xiaomi.com; arc=none smtp.client-ip=207.226.244.122 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=xiaomi.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=xiaomi.com X-CSE-ConnectionGUID: H0UdeGf+S2CthT+NhrvNXA== X-CSE-MsgGUID: oGc/Nm4wSimkmohUrdLHNA== X-IronPort-AV: E=Sophos;i="6.10,198,1719849600"; d="scan'208";a="121006317" From: ZhangHui To: , CC: , , Subject: [PATCH v2] block: move non sync requests complete flow to softirq Date: Tue, 3 Sep 2024 17:34:57 +0800 Message-ID: <20240903093457.35752-1-zhanghui31@xiaomi.com> X-Mailer: git-send-email 2.43.0 Precedence: bulk X-Mailing-List: linux-block@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-ClientProxiedBy: BJ-MBX05.mioffice.cn (10.237.8.125) To YZ-MBX07.mioffice.cn (10.237.88.127) From: zhanghui Currently, for a controller that supports multiple queues, like UFS4.0, the mq_ops->complete is executed in the interrupt top-half. Therefore, the file system's end io is executed during the request completion process, such as f2fs_write_end_io on smartphone. However, we found that the execution time of the file system end io is strongly related to the size of the bio and the processing speed of the CPU. Because the file system's end io will traverse every page in bio, this is a very time-consuming operation. We measured that the 80M bio write operation on the little CPU will cause the execution time of the top-half to be greater than 100ms. The CPU tick on a smartphone is only 4ms, which will undoubtedly affect scheduling efficiency. Let's fixed this issue by moved non sync request completion flow to softirq, and keep the sync request completion in the top-half. Signed-off-by: zhanghui --- block/blk-mq.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/block/blk-mq.c b/block/blk-mq.c index e3c3c0c21b55..06b232edff11 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -1193,6 +1193,8 @@ static void blk_mq_raise_softirq(struct request *rq) bool blk_mq_complete_request_remote(struct request *rq) { + blk_opf_t is_sync = op_is_sync(rq->cmd_flags); + WRITE_ONCE(rq->state, MQ_RQ_COMPLETE); /* @@ -1210,7 +1212,7 @@ bool blk_mq_complete_request_remote(struct request *rq) return true; } - if (rq->q->nr_hw_queues == 1) { + if ((rq->q->nr_hw_queues == 1) || !is_sync) { blk_mq_raise_softirq(rq); return true; }