From mboxrd@z Thu Jan  1 00:00:00 1970
From: "Burakov, Anatoly" <anatoly.burakov@intel.com>
Subject: Re: [PATCH] mempool: fix virt address mempool population
Date: Tue, 15 May 2018 08:58:06 +0100
Message-ID: <8ef0570b-6459-e0fb-b1a7-eed2aa5dd624@intel.com>
References: <014e66f8e34cb87fa126b7494ad644ef9ac68978.1526313945.git.anatoly.burakov@intel.com>
 <1848737.7LY3OboWmP@xps>
Mime-Version: 1.0
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Transfer-Encoding: 7bit
Cc: dev@dpdk.org, Olivier Matz <olivier.matz@6wind.com>,
 konstantin.ananyev@intel.com, arybchenko@solarflare.com,
 shreyansh.jain@nxp.com
To: Thomas Monjalon <thomas@monjalon.net>
Return-path: <dev-bounces@dpdk.org>
Received: from mga01.intel.com (mga01.intel.com [192.55.52.88])
 by dpdk.org (Postfix) with ESMTP id C1BD71B826
 for <dev@dpdk.org>; Tue, 15 May 2018 09:58:11 +0200 (CEST)
In-Reply-To: <1848737.7LY3OboWmP@xps>
Content-Language: en-US
List-Id: DPDK patches and discussions <dev.dpdk.org>
List-Unsubscribe: <https://dpdk.org/ml/options/dev>,
 <mailto:dev-request@dpdk.org?subject=unsubscribe>
List-Archive: <http://dpdk.org/ml/archives/dev/>
List-Post: <mailto:dev@dpdk.org>
List-Help: <mailto:dev-request@dpdk.org?subject=help>
List-Subscribe: <https://dpdk.org/ml/listinfo/dev>,
 <mailto:dev-request@dpdk.org?subject=subscribe>
Errors-To: dev-bounces@dpdk.org
Sender: "dev" <dev-bounces@dpdk.org>

On 14-May-18 7:48 PM, Thomas Monjalon wrote:
> 14/05/2018 18:06, Anatoly Burakov:
>> Currently, populate_virt will check if mempool is already populated.
>> This will cause inability to reserve multi-chunk mempools if
>> contiguous memory is not a hard requirement, because if allocating
>> all-contiguous memory fails, mempool will retry with virtual addresses
>> and will call populate_virt. It seems that the original code never
>> anticipated more than one non-physically contiguous area.
>>
>> Fix it by removing the check in populate virt. populate_anon() function
>> calls populate_virt() also, and it can be reasonably inferred that it is
>> expecting that virtual area is not already populated. Even though a
>> similar check is already in place there, also add the check that was
>> part of populate_virt() just in case.
>>
>> Fixes: aab4f62d6c1c ("mempool: support no hugepage mode")
> 
> If it is really the root cause, you need to add Cc: stable@dpdk.org.

Yes. It's not as pressing for previous DPDK versions because this 
codepath wasn't triggered unless --no-huge was used, but it's still a bug.

> 
>> Cc: olivier.matz@6wind.com
>>
>> Signed-off-by: Anatoly Burakov <anatoly.burakov@intel.com>
> 
> This patch looks sensible. It will wait some review,
> so it is a candidate for -rc4.
> 
> 
> 
> 
> 


-- 
Thanks,
Anatoly