From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752188AbeEQVOe (ORCPT ); Thu, 17 May 2018 17:14:34 -0400 Received: from mail-pg0-f65.google.com ([74.125.83.65]:34230 "EHLO mail-pg0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751017AbeEQVOc (ORCPT ); Thu, 17 May 2018 17:14:32 -0400 X-Google-Smtp-Source: AB8JxZq+QV+ZdqHf/IXQ54BB8ZOhR7vNw4lEX8h8EMdg1PMZdwwZ70QRQZz5lQDv6toN0c+v6x0UmA== Subject: Re: [PATCH v3] mlx4_core: allocate ICM memory in page size chunks To: Qing Huang , tariqt@mellanox.com, davem@davemloft.net, haakon.bugge@oracle.com, yanjun.zhu@oracle.com Cc: netdev@vger.kernel.org, linux-rdma@vger.kernel.org, linux-kernel@vger.kernel.org, gi-oh.kim@profitbricks.com References: <20180517205343.8401-1-qing.huang@oracle.com> From: Eric Dumazet Message-ID: Date: Thu, 17 May 2018 14:14:20 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.6.0 MIME-Version: 1.0 In-Reply-To: <20180517205343.8401-1-qing.huang@oracle.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 05/17/2018 01:53 PM, Qing Huang wrote: > When a system is under memory presure (high usage with fragments), > the original 256KB ICM chunk allocations will likely trigger kernel > memory management to enter slow path doing memory compact/migration > ops in order to complete high order memory allocations. > > When that happens, user processes calling uverb APIs may get stuck > for more than 120s easily even though there are a lot of free pages > in smaller chunks available in the system. > > Syslog: > ... > Dec 10 09:04:51 slcc03db02 kernel: [397078.572732] INFO: task > oracle_205573_e:205573 blocked for more than 120 seconds. > ... > NACK on this patch. You have been asked repeatedly to use kvmalloc() This is not a minor suggestion. Take a look at https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=d8c13f2271ec5178c52fbde072ec7b562651ed9d And you'll understand some people care about this. Strongly. Thanks.