From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1C0D3C6FD1D for ; Tue, 4 Apr 2023 07:03:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233128AbjDDHDc (ORCPT ); Tue, 4 Apr 2023 03:03:32 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39656 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231767AbjDDHDP (ORCPT ); Tue, 4 Apr 2023 03:03:15 -0400 X-Greylist: delayed 14194 seconds by postgrey-1.37 at lindbergh.monkeyblade.net; Tue, 04 Apr 2023 00:03:13 PDT Received: from m126.mail.126.com (m126.mail.126.com [220.181.12.37]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 25F922D72; Tue, 4 Apr 2023 00:03:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=126.com; s=s110527; h=Message-ID:Date:MIME-Version:Subject:From: Content-Type; bh=hLbeGhYUN7RnG6++2RqONKQkGZVwfn8OaLboDI884hQ=; b=ZjTO67EfPOZHIeqnL6m+MPONfHpZAHvRG9KZP6VJqIuAtJ3vi7Ez5DLs+Ly7HK suGBNPgX3xeE0/wMXGeV+I0ywRm1UhD89xE/lgvBn+KFDrGSH7A/GIiDb/J/N/5D rojzmrs8irpchHUbN7oPXure5hos7Pss2Hrg51E1pLZrg= Received: from [172.20.125.11] (unknown [116.128.244.169]) by zwqz-smtp-mta-g0-1 (Coremail) with SMTP id _____wBnX89myytkEaGrAw--.283S2; Tue, 04 Apr 2023 15:01:59 +0800 (CST) Message-ID: <940e1807-7e89-4de0-ee69-9346d231a59f@126.com> Date: Tue, 4 Apr 2023 15:01:58 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.2.2 Subject: Re: [PATCH] RDMA/hfi: add a judgment on the availability of cpumask To: Leon Romanovsky Cc: dennis.dalessandro@cornelisnetworks.com, jgg@ziepe.ca, linux-rdma@vger.kernel.org, linux-kernel@vger.kernel.org, Linkui Xiao References: <20230404030525.24020-1-xiaolinkui@126.com> <20230404060522.GH4514@unreal> Content-Language: en-US From: xiaolinkui In-Reply-To: <20230404060522.GH4514@unreal> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-CM-TRANSID: _____wBnX89myytkEaGrAw--.283S2 X-Coremail-Antispam: 1Uf129KBjvJXoW7Gw1fKFW8Wry5CrW8uF1xXwb_yoW8JF4rpF 4fWa1j9ay5Xay0ga1ktay3ArZ8tayfJ3yqyFyqyw18XF98X3ZrX345K3WF9r97Gr4ku3WS qF4DXFs0kF4xAaDanT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDUYxBIdaVFxhVjvjDU0xZFpf9x07j17KsUUUUU= X-Originating-IP: [116.128.244.169] X-CM-SenderInfo: p0ld0z5lqn3xa6rslhhfrp/1tbiig9H1lpEDPhFrQAAsW Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org Thanks for your reply. When CONFIG_CPUMASK_OFFSTACK=y, "ret" will be false if diff==NULL. However, when CONFIG_CPUMASK_OFFSTACK=n, these two are not necessarily equivalent. Thanks On 4/4/23 14:05, Leon Romanovsky wrote: > On Tue, Apr 04, 2023 at 11:05:25AM +0800, xiaolinkui wrote: >> From: Linkui Xiao >> >> When CONFIG_CPUMASK_OFFSTACK is n, cpumask may fail to allocate, cpumask may >> be NULL, and performing a bitmap operation on cpumask may cause problems at >> this time. >> >> Of course, this is a unlikely event. >> >> Signed-off-by: Linkui Xiao >> --- >> drivers/infiniband/hw/hfi1/affinity.c | 8 ++++---- >> 1 file changed, 4 insertions(+), 4 deletions(-) >> >> diff --git a/drivers/infiniband/hw/hfi1/affinity.c b/drivers/infiniband/hw/hfi1/affinity.c >> index 77ee77d4000f..3caa861f4d1d 100644 >> --- a/drivers/infiniband/hw/hfi1/affinity.c >> +++ b/drivers/infiniband/hw/hfi1/affinity.c >> @@ -1047,16 +1047,16 @@ int hfi1_get_proc_affinity(int node) >> */ >> >> ret = zalloc_cpumask_var(&diff, GFP_KERNEL); >> - if (!ret) >> + if (!ret || unlikely(!diff)) > Why do you think that check of "ret" is not enough? > "ret" will be false if diff == NULL. > > Thanks