Rahul Sundaram wrote:
Ralf Corsepius wrote:
whether they want it or not now, they will learn when they need to.
Provide the results of the tests you exercised yourself. So far you haven't.
I gave you a reference. If you want more data, do the tests yourself.
OK, I ran my own test doing an rpmbuild of a custom kernel. My %_topdir and %_tmppath point to a filesystem that is normally mounted noatime (it's primarily used as a news spool and work area for backups), and my /usr is normally mounted read-only. I tried several combinations and found no meaningful difference.
Build tree mounted noatime, /usr mounted read-only: real 32m28.765s user 43m11.627s sys 4m36.532s
Build tree mounted atime, /usr mounted read-only: real 32m39.343s user 42m55.705s sys 4m41.920s
Build tree mounted atime, /usr mounted rw,atime: real 32m26.383s user 43m1.042s sys 4m42.099s
Repeating with build tree noatime, /usr read-only: real 32m13.625s user 42m59.867s sys 4m39.544s
The tiny differences are totally masked by differences in the amount of time GPG took for key generation. The builds were done on a 3.0 GHz Pentium 4 with Hyperthreading enabled and 1 GB of RAM. The system was essentially idle except for the builds.
As for enabling atime when I find I want it, that would likely be when I want to see what files haven't been used in the last 6 months and I realize I should have enabled atime 6 months ago. Oops, too late now.