From patchwork Fri Jun 14 08:01:35 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Anand Khoje X-Patchwork-Id: 13698147 Received: from mx0a-00069f02.pphosted.com (mx0a-00069f02.pphosted.com [205.220.165.32]) (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 0D4881474CB; Fri, 14 Jun 2024 08:01:53 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=205.220.165.32 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718352116; cv=none; b=XLJiiaDk1NSDhVbsMovnfphzr6giHfwMladFLMlbLPbHVPCWDwDhu9kAD9GjrfuDfCIaQnyaIfE193A62OJhbNUaTIheG4n3htfRJuGPyjw5Hj+covB4xfO4jhHtr7iPxl2l70P2KgWVKOs7Fe2UU1EbaLl2p+iBSfkFYCdx2oo= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718352116; c=relaxed/simple; bh=AiE3BsoHl6nbAyEPcQt6QjvUqcm6iPgk/BkHE4KsWHg=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version:Content-Type; b=G5CYJkuWsyxTrhTjhq29Ffq/pu6aTlp/NANXCJdNrLD0fYKfqfNnzj8kV5nhR++ryhLykn/20jLYYdwuqQHLpT6CAdW9Mmu9ZnKUgZfjuf4y1xvZ3yoh1kHlMzYXVRC39yT7iO+xjg0Rj7ZPppqPe9FXA87nMvAwNIvVFVHbqFU= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=oracle.com; spf=pass smtp.mailfrom=oracle.com; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b=RVptile8; arc=none smtp.client-ip=205.220.165.32 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=oracle.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=oracle.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="RVptile8" Received: from pps.filterd (m0246617.ppops.net [127.0.0.1]) by mx0b-00069f02.pphosted.com (8.18.1.2/8.18.1.2) with ESMTP id 45E1fRo7003155; Fri, 14 Jun 2024 08:01:46 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h= from:to:cc:subject:date:message-id:mime-version:content-type :content-transfer-encoding; s=corp-2023-11-20; bh=gGCJMnhO+L8oNf IArlpsLOLy5wZxlT0LIbb7sFe1hZY=; b=RVptile8zcftjCfyE9QkpluaOTDmmd e/XcXEDP1vatdHrlCFpjfbxxOrf/l0Jh9ujaeEoG73bU+PA6Si9GKBW249DkY5gL Wr4S7p2bjb9gHKmJJOh06aCZiTJ1hZS1h1NLhFGvIwUc3tKpvnxjnECQCMB644U6 BfFCv1e8YkjIfBX+WliquE9Yzaw+bTOmmH3QwZWRUmMjYl8fS9smekrpr7Moog1N a4UWzf61z6SoOd+Uuyai0wo1wduNnkkLmtRNcpj5ib4x+2GV7+j8jPZDkwYv9OYL lfE8Y7CH16ewV7ewBGnJpYdLdqYR/jhKJgJ6nVB2rL4jxBf5Yt6OdC9Q== Received: from iadpaimrmta03.imrmtpd1.prodappiadaev1.oraclevcn.com (iadpaimrmta03.appoci.oracle.com [130.35.103.27]) by mx0b-00069f02.pphosted.com (PPS) with ESMTPS id 3ymhajb6tx-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 14 Jun 2024 08:01:45 +0000 (GMT) Received: from pps.filterd (iadpaimrmta03.imrmtpd1.prodappiadaev1.oraclevcn.com [127.0.0.1]) by iadpaimrmta03.imrmtpd1.prodappiadaev1.oraclevcn.com (8.17.1.19/8.17.1.19) with ESMTP id 45E7FWfw020432; Fri, 14 Jun 2024 08:01:44 GMT Received: from aakhoje-ol.in.oracle.com (dhcp-10-76-34-154.vpn.oracle.com [10.76.34.154]) by iadpaimrmta03.imrmtpd1.prodappiadaev1.oraclevcn.com (PPS) with ESMTP id 3yncaymbrm-1; Fri, 14 Jun 2024 08:01:42 +0000 From: Anand Khoje To: linux-rdma@vger.kernel.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org Cc: saeedm@mellanox.com, leon@kernel.org, davem@davemloft.net Subject: [PATCH v3] net/mlx5 : Reclaim max 50K pages at once Date: Fri, 14 Jun 2024 13:31:35 +0530 Message-ID: <20240614080135.122656-1-anand.a.khoje@oracle.com> X-Mailer: git-send-email 2.43.0 Precedence: bulk X-Mailing-List: linux-rdma@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1039,Hydra:6.0.680,FMLib:17.12.28.16 definitions=2024-06-13_15,2024-06-13_02,2024-05-17_01 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 bulkscore=0 suspectscore=0 malwarescore=0 spamscore=0 mlxscore=0 phishscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2405010000 definitions=main-2406140054 X-Proofpoint-GUID: A8VZ0y80ZXnz0eB4BkEHfS2vhrAxgWIW X-Proofpoint-ORIG-GUID: A8VZ0y80ZXnz0eB4BkEHfS2vhrAxgWIW In non FLR context, at times CX-5 requests release of ~8 million FW pages. This needs humongous number of cmd mailboxes, which to be released once the pages are reclaimed. Release of humongous number of cmd mailboxes is consuming cpu time running into many seconds. Which with non preemptible kernels is leading to critical process starving on that cpu’s RQ. To alleviate this, this change restricts the total number of pages a worker will try to reclaim maximum 50K pages in one go. The limit 50K is aligned with the current firmware capacity/limit of releasing 50K pages at once per MLX5_CMD_OP_MANAGE_PAGES + MLX5_PAGES_TAKE device command. Our tests have shown significant benefit of this change in terms of time consumed by dma_pool_free(). During a test where an event was raised by HCA to release 1.3 Million pages, following observations were made: - Without this change: Number of mailbox messages allocated was around 20K, to accommodate the DMA addresses of 1.3 million pages. The average time spent by dma_pool_free() to free the DMA pool is between 16 usec to 32 usec. value ------------- Distribution ------------- count 256 | 0 512 |@ 287 1024 |@@@ 1332 2048 |@ 656 4096 |@@@@@ 2599 8192 |@@@@@@@@@@ 4755 16384 |@@@@@@@@@@@@@@@ 7545 32768 |@@@@@ 2501 65536 | 0 - With this change: Number of mailbox messages allocated was around 800; this was to accommodate DMA addresses of only 50K pages. The average time spent by dma_pool_free() to free the DMA pool in this case lies between 1 usec to 2 usec. value ------------- Distribution ------------- count 256 | 0 512 |@@@@@@@@@@@@@@@@@@ 346 1024 |@@@@@@@@@@@@@@@@@@@@@@ 435 2048 | 0 4096 | 0 8192 | 1 16384 | 0 Signed-off-by: Anand Khoje Reviewed-by: Leon Romanovsky --- Changes in v3: - Shifted the logic to function req_pages_handler() as per Leon's suggestion. --- drivers/net/ethernet/mellanox/mlx5/core/pagealloc.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/net/ethernet/mellanox/mlx5/core/pagealloc.c b/drivers/net/ethernet/mellanox/mlx5/core/pagealloc.c index 1b38397..e7c2d36 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/pagealloc.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/pagealloc.c @@ -508,6 +508,7 @@ enum { RELEASE_ALL_PAGES_MASK = 0x4000, }; +#define MAX_RECLAIM_NPAGES -50000 static int req_pages_handler(struct notifier_block *nb, unsigned long type, void *data) { @@ -539,9 +540,13 @@ static int req_pages_handler(struct notifier_block *nb, req->dev = dev; req->func_id = func_id; - req->npages = npages; req->ec_function = ec_function; req->release_all = release_all; + if (npages < MAX_RECLAIM_NPAGES) + req->npages = MAX_RECLAIM_NPAGES; + else + req->npages = npages; + INIT_WORK(&req->work, pages_work_handler); queue_work(dev->priv.pg_wq, &req->work); return NOTIFY_OK;