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Message-ID: <857a2d22-5d0f-99d6-6686-98d50e4491d5@gmail.com>
Date:   Sat, 16 Apr 2022 15:18:13 +0200
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Subject: Re: [PATCH v3] intel: igb: igb_ethtool.c: Convert kmap() to
 kmap_local_page()
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To:     Julia Lawall <julia.lawall@inria.fr>
Cc:     outreachy@lists.linux.dev, jesse.brandeburg@intel.com,
        anthony.l.nguyen@intel.com, davem@davemloft.net, kuba@kernel.org,
        pabeni@redhat.com, intel-wired-lan@lists.osuosl.org,
        netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
        ira.weiny@intel.com
References: <20220416111457.5868-1-eng.alaamohamedsoliman.am@gmail.com>
 <alpine.DEB.2.22.394.2204161331080.3501@hadrien>
From:   Alaa Mohamed <eng.alaamohamedsoliman.am@gmail.com>
In-Reply-To: <alpine.DEB.2.22.394.2204161331080.3501@hadrien>
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On ١٦‏/٤‏/٢٠٢٢ ١٣:٣١, Julia Lawall wrote:
>
> On Sat, 16 Apr 2022, Alaa Mohamed wrote:
>
>> Convert kmap() to kmap_local_page()
>>
>> With kmap_local_page(), the mapping is per thread, CPU local and not
>> globally visible.
> It's not clearer.
I mean this " fix kunmap_local path value to take address of the mapped 
page" be more clearer
> This is a general statement about the function.  You
> need to explain why it is appropriate to use it here.  Unless it is the
> case that all calls to kmap should be converted to call kmap_local_page.
It's required to convert all calls kmap to kmap_local_page. So, I don't 
what should the commit message be?

Is this will be good :

"kmap_local_page() was recently developed as a replacement for kmap().  The
kmap_local_page() creates a mapping which is restricted to local use by a
single thread of execution. "
>
> julia
>
>> Signed-off-by: Alaa Mohamed <eng.alaamohamedsoliman.am@gmail.com>
>> ---
>> changes in V2:
>> 	fix kunmap_local path value to take address of the mapped page.
>> ---
>> changes in V3:
>> 	edit commit message to be clearer
>> ---
>>   drivers/net/ethernet/intel/igb/igb_ethtool.c | 4 ++--
>>   1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/net/ethernet/intel/igb/igb_ethtool.c b/drivers/net/ethernet/intel/igb/igb_ethtool.c
>> index 2a5782063f4c..c14fc871dd41 100644
>> --- a/drivers/net/ethernet/intel/igb/igb_ethtool.c
>> +++ b/drivers/net/ethernet/intel/igb/igb_ethtool.c
>> @@ -1798,14 +1798,14 @@ static int igb_check_lbtest_frame(struct igb_rx_buffer *rx_buffer,
>>
>>   	frame_size >>= 1;
>>
>> -	data = kmap(rx_buffer->page);
>> +	data = kmap_local_page(rx_buffer->page);
>>
>>   	if (data[3] != 0xFF ||
>>   	    data[frame_size + 10] != 0xBE ||
>>   	    data[frame_size + 12] != 0xAF)
>>   		match = false;
>>
>> -	kunmap(rx_buffer->page);
>> +	kunmap_local(data);
>>
>>   	return match;
>>   }
>> --
>> 2.35.2
>>
>>
>>