On 8 December 2017 at 01:35, Scott Bennett via ccache < ccache@lists.samba.org> wrote:
> Michael Fothergill via ccache <ccache@lists.samba.org> wrote: > > > I have an amd64 kaveri box with 8GB RAM and run Gentoo stable on it. > > > > I have just installed ccache with 2GB memory allocated to it. > > By that, I assume you have allocated some kind of memory-based device > for the cache. Is that a correct understanding? > Thanks for your reply and comments. I am assuming that by having the standard command CCACHE_SIZE="4G" (I have increased the allocation) then memory from the hard drive is being used by default here - I was not trying to use e.g. RAM memory. > > > I have tried some repeat compilations to see if there would be any speed > > increase. > > > > So far I have not seen much change but I am not skilled enough to improve > > things yet. > > Your statistics show that slightly more than 45% of your total > compiler invocations (hits/(hits+misses)) were avoided. Did that not > make a dent in your timings? > > > > I tried compiling gcc, glibc and imagemagick but did not see much > > improvement. > > If you run the full build process for gcc, I would not expect > to see much improvement because most of it involves the use of either > a) a temporarily built compiler in a temporary location or b) the > newly built compiler being used for testing, but not yet installed > into the production location on your system. > Would cachecc1 perform any better with gcc? > ImageMagick and GraphicsMagick both should provide useful timings > and ccache statistics. glibc probably would, too, though it's not > nearly as big. I don't know what sort of build procedures Gentoo uses, > but from the FreeBSD ports tree, here are some other good examples of > test cases: math/octave, www/webkit-gtk2, www/webkit-gtk3, > www/webkit2-gtk3, devel/llvm40. Be prepared to wait a long time for > the first compilation of each of the webkits. They are big and slow > to compile and, in the past, have shown instabilities in their build > procedures when parallel make runs were used. > I have now compiled qtwebengine, libreoffice and and dramatically reduced the compile time with ccache now I am using the 3.3.4 version of the program ( see here https://forums.gentoo.org/viewtopic-t-1073298.html ). I think the earlier version of ccache was not working properly. People on the thread have suggested that maybe cachecc1 might not work so well with gcc in practice and I should stick with ccache as is. But you may take a different view. > YMMV on another OS. > One big savings for me was in running "make buildworld" and "make > buildkernel". buildworld, on my last machine, was taking about six > hours elapsed time for a first run. When running it later after > updating the source tree, the elapsed time was reduced by 2/3 to 3/4, > depending upon the number and sizes of source modules affected by the > updates. > These sound like the emerge --ask --update --deep @world command used in Gentoo (and similar versions). It's not time to update the system again yet but I think that it could well speed things up as long as the cache size is big enough for a lot of packages (e.g. 200 plus) Thanks and comments appreciated. Michael Fothergill > Note that ccache and some other things need a slightly > different setup in order to build FreeBSD. Your OS may also need some > special provision, so be sure to read the ccache installation > instructions for Gentoo carefully. > > > Scott Bennett, Comm. ASMELG, CFIAG > ********************************************************************** > * Internet: bennett at sdf.org *xor* bennett at freeshell.org * > *--------------------------------------------------------------------* > * "A well regulated and disciplined militia, is at all times a good * > * objection to the introduction of that bane of all free governments * > * -- a standing army." * > * -- Gov. John Hancock, New York Journal, 28 January 1790 * > ********************************************************************** > > _______________________________________________ > ccache mailing list > ccache@lists.samba.org > https://lists.samba.org/mailman/listinfo/ccache > _______________________________________________ ccache mailing list ccache@lists.samba.org https://lists.samba.org/mailman/listinfo/ccache
