| 1 |
On Saturday 03 May 2008, David Relson wrote: |
| 2 |
> On Sat, 3 May 2008 14:17:39 +0100 |
| 3 |
> |
| 4 |
> Uwe Thiem wrote: |
| 5 |
> > On Saturday 03 May 2008, David Relson wrote: |
| 6 |
> > > On Fri, 2 May 2008 07:10:02 -0400 |
| 7 |
> > > David Relson wrote: |
| 8 |
> > > |
| 9 |
> > > ...[snip]... |
| 10 |
> > > |
| 11 |
> > > > As part of identifying the capabilities and files of your |
| 12 |
> > > > operating system (distro) ./configure creates a lot of small |
| 13 |
> > > > programs and compiles them. I can see how caching |
| 14 |
> > > > compilation info would help with this. |
| 15 |
> > > |
| 16 |
> > > I ran a quick test with ccache and ./configure. Using |
| 17 |
> > > bogofilter's configure script (because it was available): |
| 18 |
> > > |
| 19 |
> > > before installing ccache: |
| 20 |
> > > |
| 21 |
> > > 3 runs of ./configure averaged 6.07s |
| 22 |
> > > |
| 23 |
> > > ... installed ccache ... |
| 24 |
> > > |
| 25 |
> > > next run took 6.5 sec (slower than before) |
| 26 |
> > > next 3 runs averaged 4.96s (18.4% better than before) |
| 27 |
> > |
| 28 |
> > All your configure runs were for the same package, right? |
| 29 |
> |
| 30 |
> Correct. |
| 31 |
> |
| 32 |
> > > conclusion: ccache _does_ help ./configure |
| 33 |
> > |
| 34 |
> > It does not for different packages, AFAIK. And that was the |
| 35 |
> > question of the OP. |
| 36 |
> |
| 37 |
> There _should_ be some effect as there are many operations common |
| 38 |
> amongst configure scripts, for example determining the name of |
| 39 |
> the header file defining malloc or determining whether to use bzero |
| 40 |
> or memset, etc, etc. As with any form of caching the rate of cache |
| 41 |
> hits will vary depending on load and cache size. |
| 42 |
> k |
| 43 |
|
| 44 |
Disclaimer: I haven't tried this out. It's all speculation. ;-) |
| 45 |
|
| 46 |
There might be a way. If you don't set "ccache" as FEATURE |
| 47 |
in /etc/make.conf but mv /usr/bin/ccache to /usr/local/bin/ccache. |
| 48 |
Then make the following symlinks: |
| 49 |
ln -s /usr/local/bin/ccache /usr/local/bin/gcc |
| 50 |
ln -s /usr/local/bin/ccache /usr/local/bin/g++ |
| 51 |
ln -s /usr/local/bin/ccache /usr/local/bin/cc |
| 52 |
|
| 53 |
Next step: Make sure that /usr/local/bin comes before /usr/bin in your |
| 54 |
PATH. |
| 55 |
|
| 56 |
With this setup, every identical test program generated and compiled |
| 57 |
by configure may seem to be identical for ccache. As I have said, |
| 58 |
haven't tried it. |
| 59 |
|
| 60 |
Anyway, it seems to me that more and more projects switch from |
| 61 |
autotools to cmake which is *much* faster than autotools. |
| 62 |
|
| 63 |
Uwe |
| 64 |
|
| 65 |
-- |
| 66 |
Ignorance killed the cat, sir, curiosity was framed! |
| 67 |
-- |
| 68 |
gentoo-user@l.g.o mailing list |
Archives