On Tue, Oct 15, 2013 at 5:55 AM, Dhiru Kholia <dhiru.kholia@xxxxxxxxx> wrote: > On 10/15/13 at 05:30am, Josh Boyer wrote: >> On Tue, Oct 15, 2013 at 5:19 AM, Dhiru Kholia <dhiru.kholia@xxxxxxxxx> wrote: >> > During the development of "unSPEC" [1] benchmarking suite, I made some >> > interesting observations regarding prelink. >> > ... >> > - For building kernels (using the "kernel-bench" [3] component of unSPEC >> > suite), prelink saved <= 250 ms over the non-prelink environment >> > (which took 1m19.138s). hkario even reports worse performance numbers >> > for the prelink environment. Additionally, we have specialized >> > softwares like ccache and distcc to solve long-compilation-time >> > problems. >> >> I wouldn't expect building kernels to be a great thing to use to >> measure performance benefits of prelink. A kernel build is basically >> just calling gcc and ld over and over, and those two things themselves >> have relatively few libraries involved. So your numbers match what I >> would expect in this case, but I don't think it's really and accurate >> testcase. Prelink isn't intended to reduce compilation times. > > Hi Josh, > > Good points. > > Please see http://lwn.net/Articles/341244/ page. In particular, "Note, > also small but frequently used apps benefit. I run gcc etc a lot and > like every single saved cycle." > > I just wanted to quantify these kinds of use-cases too. Does this make > sense? Sure, if you take the "save every cycle I can approach". It's all relative to your point of view. I was just noting that a common Fedora user wouldn't necessarily expect prelink to help with compilation times. Even a crazy kernel developer like me doesn't expect that. I can be very impatient when it comes to dealing with machines, but even I can't notice 250ms ;). josh -- devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxxx https://admin.fedoraproject.org/mailman/listinfo/devel Fedora Code of Conduct: http://fedoraproject.org/code-of-conduct
