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Re: [PATCH 1/2] IB/hfi1: Fix a parameter of find_first_bit.

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Le 26/08/2016 à 15:35, Doug Ledford a écrit :
> On 8/26/2016 12:49 AM, Christophe JAILLET wrote:
>> The 2nd parameter of 'find_first_bit' is the number of bits to search.
>> In this case, we are passing 'sizeof(unsigned long)' which is likely to
>> be 4 or 8.
> If the size can be 4 or 8, then using 64 universally is not correct.
> Why not use sizeof() * 8 (or << 3)?
I agree with you...

BTW, the log message is wrong. 'port_mask' is a u64. (not an unsigned 
long). So the sizeof should always be 8.
(cut and paste error from another patch, sorry)

>
>> It is likely that the number of bits of 'port_mask' was expected 
>> here. This
>> variable is a 'u64', so use 64 instead.
>>
>> It has been spotted by the following coccinelle script:
>> @@
>> expression ret, x;
>>
>> @@
>> *  ret = \(find_first_bit \| find_first_zero_bit\) (x, sizeof(...));
>>
>> Signed-off-by: Christophe JAILLET 
>> <christophe.jaillet-39ZsbGIQGT5GWvitb5QawA@public.gmane.org>
>> ---
>> Not sure that using 64 directly is the best option.
>> Maybe '8 * sizeof(port_mask)' as used in the same file for
>> 'for_each_set_bit' would be better
>> ---
... as noted here

Would you like a v2 patch or, will you update it by yourself?

Best regards,
CJ

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[PATCH 1/2] IB/hfi1: Fix a parameter of find_first_bit. Christophe JAILLET <christophe.jaillet@wanadoo.fr> - 2016-08-26 07:00 +0200
  Re: [PATCH 1/2] IB/hfi1: Fix a parameter of find_first_bit. Doug Ledford <dledford@redhat.com> - 2016-08-26 15:40 +0200
    Re: [PATCH 1/2] IB/hfi1: Fix a parameter of find_first_bit. Doug Ledford <dledford@redhat.com> - 2016-08-26 20:10 +0200
      Re: [PATCH 1/2] IB/hfi1: Fix a parameter of find_first_bit. Doug Ledford <dledford@redhat.com> - 2016-08-26 21:40 +0200
        Re: [PATCH 1/2] IB/hfi1: Fix a parameter of find_first_bit. Leon Romanovsky <leon@kernel.org> - 2016-08-28 08:10 +0200
          Re: [PATCH 1/2] IB/hfi1: Fix a parameter of find_first_bit. Doug Ledford <dledford@redhat.com> - 2016-09-02 16:40 +0200
            Re: [PATCH 1/2] IB/hfi1: Fix a parameter of find_first_bit. Leon Romanovsky <leon@kernel.org> - 2016-09-04 11:10 +0200
      Re: [PATCH 1/2] IB/hfi1: Fix a parameter of find_first_bit. Leon Romanovsky <leon@kernel.org> - 2016-08-26 21:40 +0200
    Re: [PATCH 1/2] IB/hfi1: Fix a parameter of find_first_bit. Christophe JAILLET <christophe.jaillet@wanadoo.fr> - 2016-08-27 07:30 +0200
      Re: [PATCH 1/2] IB/hfi1: Fix a parameter of find_first_bit. Doug Ledford <dledford@redhat.com> - 2016-09-02 19:20 +0200

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