Re: [PATCH] direct-io: Deinline submit_page_section, save 5304 bytes

[Jeff Moyer]

Denys Vlasenko <dvlasenk@xxxxxxxxxx> writes:

> This function compiles to 2628 bytes, 2 callsites
>
>    text	   data	    bss	    dec	    hex	filename
>   15197	     16	      0	  15213	   3b6d	direct-io.o.before1
>    9655	     16	      0	   9671	   25c7	direct-io.o

And what is the consequence for performance?  If you look at the git
history for this file, you'll find the commit that introduced the
inline:

commit ba253fbf6d3502c54e1ac8792e7ac8290a1f5b8d
Author: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Date:   Mon Aug 1 21:38:08 2011 -0700

    direct-io: inline the complete submission path
    
    Add inlines to all the submission path functions. While this increases
    code size it also gives gcc a lot of optimization opportunities
    in this critical hotpath.

    ...

So you're essentially undoing that work.

NAK

Cheers,
Jeff