From patchwork Mon Jun 24 15:33:21 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Anand Khoje X-Patchwork-Id: 13709753 Received: from mx0b-00069f02.pphosted.com (mx0b-00069f02.pphosted.com [205.220.177.32]) (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 E01E819CD0B; Mon, 24 Jun 2024 15:33:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=205.220.177.32 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719243233; cv=none; b=Gqs5Dg9sQOEx2LJ0F9jJrI07JC03qvCtZ4/3Okv8ZlsFf7tpoHt0wpS8z5O5bMVHicVosFh489cywsqrWQRUntY8xDVmZ7CSG43GZ63EmaVWbu5zee2xrSdUDUNHXSO2YVbilSObhhrRLQSAKMIM8FNET0wME6bW7Pm8iWiuqfY= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719243233; c=relaxed/simple; bh=UTq25U8EovFIHY7zUXQYzBJ2OaikaCJHOw7txbFc8ak=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version:Content-Type; b=rFX3+PluhGh+dMARjz/g0O55j8QKSnZv7fYHkse9V4VgXWW+iHjTu4nfwC1mDOo7Vm4mwtYHn9C/tR5dwVSNd3RBjLqGS2zucSqYv80y0x2z/VRaU3fTYuJ3EXzWebjG9QtyrHoaLfysmnILGPlZi/6pEche2E2S0mhYt1BbRlE= 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=BSIL4hQE; arc=none smtp.client-ip=205.220.177.32 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="BSIL4hQE" Received: from pps.filterd (m0246632.ppops.net [127.0.0.1]) by mx0b-00069f02.pphosted.com (8.18.1.2/8.18.1.2) with ESMTP id 45OEtPKj014510; Mon, 24 Jun 2024 15:33:40 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=LjwTv1x14K+YU+ i4bv9l/35xuqtm0L02zqCA66eU4EE=; b=BSIL4hQE0BFqR1g9372u8H9iMKdxix /8gMrqJAC1Hjo7Mq+DaqP5UHUefb0Q+5ZkzLnrRODHu9es1YlzUmbZzMR5an9J0w jgPT9IlSBFcqwVeZKlQWTl9ubBv7eq2xlDpq1TMyry/I+oHAYDC1vCqsTuRlVnTh EVgB6sYiqN1gqYl4TQ5B6AeUEf4YJrp0w4SyWp7hsxI9b3Q4XOwaQNOICxFEM6/q uDlsFkPz/Dd94R+VkQgcQvFKKv8lOscjnrtuWwoUqF2IyJhVOkMQGeG31+M/U5i4 5oQn9DLIot5KSlBiN+ca2t/9Z8byx4CKTiZdo57l7sXhWg6Cs+9ZbKfg== Received: from iadpaimrmta03.imrmtpd1.prodappiadaev1.oraclevcn.com (iadpaimrmta03.appoci.oracle.com [130.35.103.27]) by mx0b-00069f02.pphosted.com (PPS) with ESMTPS id 3ywp7saw6p-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 24 Jun 2024 15:33:40 +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 45OF61wk010772; Mon, 24 Jun 2024 15:33:40 GMT Received: from aakhoje-ol.in.oracle.com (dhcp-10-76-47-230.vpn.oracle.com [10.76.47.230]) by iadpaimrmta03.imrmtpd1.prodappiadaev1.oraclevcn.com (PPS) with ESMTP id 3ywn2ckr8e-1; Mon, 24 Jun 2024 15:33:39 +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, tariqt@nvidia.com, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, davem@davemloft.net Subject: [PATCH v5] net/mlx5: Reclaim max 50K pages at once Date: Mon, 24 Jun 2024 21:03:21 +0530 Message-ID: <20240624153321.29834-1-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=2024-06-24_12,2024-06-24_01,2024-05-17_01 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 mlxlogscore=999 malwarescore=0 spamscore=0 suspectscore=0 adultscore=0 phishscore=0 bulkscore=0 mlxscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2406180000 definitions=main-2406240125 X-Proofpoint-GUID: iF7jeR9rpyYUWUuIT3ZtspPVrNHaJmbH X-Proofpoint-ORIG-GUID: iF7jeR9rpyYUWUuIT3ZtspPVrNHaJmbH 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 --- Changes in v5: - Made changes as per a suggestion from Leon. --- drivers/net/ethernet/mellanox/mlx5/core/pagealloc.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/net/ethernet/mellanox/mlx5/core/pagealloc.c b/drivers/net/ethernet/mellanox/mlx5/core/pagealloc.c index d894a88..1fc583b 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/pagealloc.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/pagealloc.c @@ -608,6 +608,7 @@ 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) { @@ -639,7 +640,7 @@ static int req_pages_handler(struct notifier_block *nb, req->dev = dev; req->func_id = func_id; - req->npages = npages; + req->npages = max_t(s32, npages, MAX_RECLAIM_NPAGES); req->ec_function = ec_function; req->release_all = release_all; INIT_WORK(&req->work, pages_work_handler);