Messages in this thread | | | Date | Fri, 27 Dec 2013 15:30:17 -0800 | From | "H. Peter Anvin" <> | Subject | Re: [RFC] speeding up the stat() family of system calls... |
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On 12/26/2013 10:09 PM, H. Peter Anvin wrote: > On 12/26/2013 11:00 AM, Linus Torvalds wrote: >> >> Interestingly, looking at the cp_new_stat() profiles, the games we >> play to get efficient range checking seem to actually hurt us. Maybe >> it's the "sbb" that is just expensive, or maybe it's turning a (very >> predictable) conditional branch into a data dependency chain instead. >> Or maybe it's just random noise in my profiles that happened to make >> those sbb's look bad. >> > > Much to my surprise, this patch adds almost 10K of text to an > "allyesconfig" build. I wouldn't have expected it. I'll look at it > some more tomorrow. >
Mystery solved... it is all code added by gcov &c because a new (inline) function is added to the code base. So it is fluff, not real.
-hpa
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