Re: MD-RAID: Use seq_putc() in three status functions?

From	Hannes Reinecke <hare@suse.de>
Newsgroups	linux.kernel
Subject	Re: MD-RAID: Use seq_putc() in three status functions?
Date	2016-10-17 17:40 +0200
Message-ID	<stib7-5fR-21@gated-at.bofh.it> (permalink)
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On 10/17/2016 04:30 PM, SF Markus Elfring wrote:
>>> Am I the only software developer so far who would dare to reconsider
>>> implementation details from three status functions?
>>>
>> No.
>
> Thanks for this kind of promising feedback.
>
>
>> But we're waiting for you showing is that it is an improvement.
>
> Can this aspect also be clarified to some degree from a logical point of view?
>
I sincerely doubt that.
We've discussed the logical implications already, and failed to come to 
a consensus. So we need some proof (as in: on this architecture I'm 
seeing this and that performance improvements).
Which you have to deliver.

> * Would you really like to know under which circumstances data processing
>   will be faster for a single character instead of using a string pointer
>   and corresponding two characters?
>
It's not a problem of the interface, it's a problem of the resulting 
code (ie assembler output). We can discuss all we like, if the compiler 
decides to throw in an optimisation none of the arguments even apply.

> * Do you care for a changed memory allocation characteristic?
>
> * Will it occasionally be useful to avoid the storage for another string literal?
>
Occasionally: yes.
In this particular case: hardly.

Cheers,

Hannes
-- 
Dr. Hannes Reinecke		      zSeries & Storage
hare@suse.de			      +49 911 74053 688
SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: J. Hawn, J. Guild, F. Imendörffer, HRB 16746 (AG Nürnberg)

Thread

[PATCH] MD-RAID: Use seq_putc() in three status functions SF Markus Elfring <elfring@users.sourceforge.net> - 2016-10-16 10:30 +0200
  Re: [PATCH] MD-RAID: Use seq_putc() in three status functions Hannes Reinecke <hare@suse.de> - 2016-10-16 19:00 +0200
    Re: MD-RAID: Use seq_putc() in three status functions? SF Markus Elfring <elfring@users.sourceforge.net> - 2016-10-16 19:20 +0200
      Re: MD-RAID: Use seq_putc() in three status functions? SF Markus Elfring <elfring@users.sourceforge.net> - 2016-10-16 19:20 +0200
      Re: MD-RAID: Use seq_putc() in three status functions? Hannes Reinecke <hare@suse.de> - 2016-10-17 08:00 +0200
        Re: MD-RAID: Use seq_putc() in three status functions? SF Markus Elfring <elfring@users.sourceforge.net> - 2016-10-17 09:50 +0200
          Re: MD-RAID: Use seq_putc() in three status functions? Hannes Reinecke <hare@suse.de> - 2016-10-17 10:20 +0200
            Re: MD-RAID: Use seq_putc() in three status functions? SF Markus Elfring <elfring@users.sourceforge.net> - 2016-10-17 11:10 +0200
              Re: MD-RAID: Use seq_putc() in three status functions? Hannes Reinecke <hare@suse.de> - 2016-10-17 12:00 +0200
                Re: MD-RAID: Use seq_putc() in three status functions? SF Markus Elfring <elfring@users.sourceforge.net> - 2016-10-17 13:20 +0200
                Re: MD-RAID: Use seq_putc() in three status functions? SF Markus Elfring <elfring@users.sourceforge.net> - 2016-10-17 13:50 +0200
                Re: MD-RAID: Use seq_putc() in three status functions? Hannes Reinecke <hare@suse.de> - 2016-10-17 16:10 +0200
                Re: MD-RAID: Use seq_putc() in three status functions? SF Markus Elfring <elfring@users.sourceforge.net> - 2016-10-17 16:40 +0200
                Re: MD-RAID: Use seq_putc() in three status functions? Hannes Reinecke <hare@suse.de> - 2016-10-17 17:40 +0200
                Re: MD-RAID: Use seq_putc() in three status functions? SF Markus Elfring <elfring@users.sourceforge.net> - 2016-10-17 18:10 +0200
                Re: MD-RAID: Use seq_putc() in three status functions? Hannes Reinecke <hare@suse.de> - 2016-10-17 19:20 +0200
                Re: MD-RAID: Use seq_putc() in three status functions? SF Markus Elfring <elfring@users.sourceforge.net> - 2016-10-18 20:30 +0200
                Re: MD-RAID: Use seq_putc() in three status functions? SF Markus Elfring <elfring@users.sourceforge.net> - 2016-10-20 14:30 +0200
                Re: MD-RAID: Use seq_putc() in three status functions? Bernd Petrovitsch <bernd@petrovitsch.priv.at> - 2016-10-17 14:20 +0200
                Re: MD-RAID: Use seq_putc() in three status functions? Hannes Reinecke <hare@suse.de> - 2016-10-17 16:10 +0200

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