Messages in this thread | | | From | Dmitry Voytik <> | Date | Wed, 10 Sep 2014 18:20:27 +0400 | Subject | Re: [PATCH] fs: seq_file: optimize seq_pad() |
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On Wed, Sep 10, 2014 at 5:21 PM, Al Viro <viro@zeniv.linux.org.uk> wrote: > On Wed, Sep 10, 2014 at 01:20:19PM +0400, Dmitry Voytik wrote: >> Use seq_putc() instead of seq_printf() in seq_pad() because the >> former is faster. > > _Solitary_ seq_putc() is certainly going to be faster, but that loop... > Do you have profiling results, or is it just an apriori "printf must > be sloooowwww"?
My fail, sorry. The commit message is little bit wrong. I meant that simple looping of seq_putc() is faster than seq_printf(). I haven't done profilings. I just realized that seq_printf() is more complex than simple loop with seq_putc() (no need to decode format string as in vsnprintf(), etc). If I resend the patch with the following commit message:
Use a simple loop with seq_putc() instead of seq_printf() in seq_pad() as this approach is faster due to less complexity in terms of machine cycles.
Would be it Okay? Thank you for reviewing.
-- Best Regards, Dmitry Voytik. voytikd@gmail.com
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