Re: Build times of hurd and glibc for different versions of gnumach, hurd and glibc

[Richard Braun]

On Sun, Apr 17, 2016 at 10:24:32PM +0200, Samuel Thibault wrote:
> Thanks for the investigation.  I have added the attached patch to the
> gnumach running on the buildds. That'll revert to the old page cache
> policy, which seems to be reverting to the previous performance.
> 
> Looking at ps -feMj, it seems that it's ext2fs which consumes much more
> CPU time, thus increasing overall wallclock time. It'd probably be
> interesting to profile ext2fs, to see what takes longer. Perhaps it's
> the hash table which is less efficient since with the new page cache
> policy there are much more cached files?

There are undeniably more scalability issues to tackle, but I strongly
think we shouldn't revert the work that has been done. We'll keep
working on those, and we now have nice numbers to compare with. I
also think that, at some point, we should provide a 64-bits capable
kernel caching interface, and write an ext4fs server. I'll see if I
can spend some time on this after high memory.

-- 
Richard Braun