On 12/7/07, Giovanni Bajo <rasky@xxxxxxxxxxx> wrote: > On Fri, 2007-12-07 at 14:14 -0800, Jakub Narebski wrote: > > > > >> Is SHA a significant portion of the compute during these repacks? > > > >> I should run oprofile... > > > > SHA1 is almost totally insignificant on x86. It hardly shows up. But > > > > we have a good optimized version there. > > > > zlib tends to be a lot more noticeable (especially the > > > > *uncompression*: it may be faster than compression, but it's done _so_ > > > > much more that it totally dominates). > > > > > > Have you considered alternatives, like: > > > http://www.oberhumer.com/opensource/ucl/ > > > > <quote> > > As compared to LZO, the UCL algorithms achieve a better compression > > ratio but *decompression* is a little bit slower. See below for some > > rough timings. > > </quote> > > > > It is uncompression speed that is more important, because it is used > > much more often. > > I know, but the point is not what is the fastestest, but if it's fast > enough to get off the profiles. I think UCL is fast enough since it's > still times faster than zlib. Anyway, LZO is GPL too, so why not > considering it too. They are good libraries. At worst, you could also use fastlz (www.fastlz.org), which is faster than all of these by a factor of 4 (and compression wise, is actually sometimes better, sometimes worse, than LZO). - To unsubscribe from this list: send the line "unsubscribe git" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
