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Message-ID: <fdf6ab76-cd2c-6596-41c1-369c176decad@wanadoo.fr>
Date:   Mon, 29 May 2023 16:25:09 +0200
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Subject: Re: [PATCH v3] hv_netvsc: Allocate rx indirection table size
 dynamically
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To:     Shradha Gupta <shradhagupta@linux.microsoft.com>
Cc:     linux-kernel@vger.kernel.org, linux-hyperv@vger.kernel.org,
        netdev@vger.kernel.org, Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>,
        "K. Y. Srinivasan" <kys@microsoft.com>,
        Haiyang Zhang <haiyangz@microsoft.com>,
        Wei Liu <wei.liu@kernel.org>, Dexuan Cui <decui@microsoft.com>,
        Long Li <longli@microsoft.com>,
        Michael Kelley <mikelley@microsoft.com>,
        "David S. Miller" <davem@davemloft.net>,
        Steen Hegelund <steen.hegelund@microchip.com>,
        Simon Horman <simon.horman@corigine.com>
References: <1685080949-18316-1-git-send-email-shradhagupta@linux.microsoft.com>
 <92bc6f3e-4463-e0fe-5cab-54c6c5eecd3f@wanadoo.fr>
 <20230529133019.GB21447@linuxonhyperv3.guj3yctzbm1etfxqx2vob5hsef.xx.internal.cloudapp.net>
From:   Christophe JAILLET <christophe.jaillet@wanadoo.fr>
In-Reply-To: <20230529133019.GB21447@linuxonhyperv3.guj3yctzbm1etfxqx2vob5hsef.xx.internal.cloudapp.net>
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Le 29/05/2023 à 15:30, Shradha Gupta a écrit :
> Thanks for the comment Christophe.
> On Mon, May 29, 2023 at 02:49:15PM +0200, Christophe JAILLET wrote:
>> Le 26/05/2023 ?? 08:02, Shradha Gupta a ??crit??:
>>> Allocate the size of rx indirection table dynamically in netvsc
>> >from the value of size provided by OID_GEN_RECEIVE_SCALE_CAPABILITIES
>>> query instead of using a constant value of ITAB_NUM.
>>>
>>> Signed-off-by: Shradha Gupta <shradhagupta@linux.microsoft.com>
>>> Tested-on: Ubuntu22 (azure VM, SKU size: Standard_F72s_v2)
>>> Testcases:
>>> 1. ethtool -x eth0 output
>>> 2. LISA testcase:PERF-NETWORK-TCP-THROUGHPUT-MULTICONNECTION-NTTTCP-Synthetic
>>> 3. LISA testcase:PERF-NETWORK-TCP-THROUGHPUT-MULTICONNECTION-NTTTCP-SRIOV
>>>
>>> ---
>>
>> [...]
>>
>>> @@ -1596,11 +1608,18 @@ void rndis_filter_device_remove(struct hv_device *dev,
>>>   				struct netvsc_device *net_dev)
>>>   {
>>>   	struct rndis_device *rndis_dev = net_dev->extension;
>>> +	struct net_device *net = hv_get_drvdata(dev);
>>> +	struct net_device_context *ndc = netdev_priv(net);
>>>   	/* Halt and release the rndis device */
>>>   	rndis_filter_halt_device(net_dev, rndis_dev);
>>>   	netvsc_device_remove(dev);
>>> +
>>> +	ndc->rx_table_sz = 0;
>>> +	kfree(ndc->rx_table);
>>> +	ndc->rx_table = NULL;
>>> +
>>
>> Nit: useless empty NL
> This is to prevent any potential double free, or accessing freed memory, etc.
> As requested by Haiyang in v2 patch

Setting ndc->rx_table to NULL is fine, but there is a useless *newline* 
(NL) just after.
If you have to send a v4, you can save a line of code.

CJ

>>
>>>   }
>>>   int rndis_filter_open(struct netvsc_device *nvdev)
>