On 13.01.17 14:15:00, Robert Richter wrote:

On 13.01.17 09:19:04, Will Deacon wrote:

quoted

On Thu, Jan 12, 2017 at 07:58:25PM +0100, Robert Richter wrote:

quoted

On 12.01.17 16:05:36, Will Deacon wrote:

quoted

On Mon, Jan 09, 2017 at 12:53:20PM +0100, Robert Richter wrote:

quoted

quoted

Kernel compile times (3 runs each):

pfn_valid_within():

real    6m4.088s
user    372m57.607s
sys     16m55.158s

real    6m1.532s
user    372m48.453s
sys     16m50.370s

real    6m4.061s
user    373m18.753s
sys     16m57.027s

Did you reboot the machine between each build here, or only when changing
kernel? If the latter, do you see variations in kernel build time by simply
rebooting the same Image?

I built it in a loop on the shell, so no reboots between builds. Note
that I was building the kernel in /dev/shm to not access harddisks. I
think build times should be comparable then since there is no fs
caching.

I guess I'm really asking what the standard deviation is if you *do* reboot
between builds, using the same kernel. It's hard to tell whether the numbers
are due to the patches, or just because of noise incurred by the way things
happen to initialise.

Ok, I am going to test this.

See below the data for a test with reboots between every 3 builds (9
builds per kernel). Though some deviation can be seen between reboots
there is a trend.

-Robert



pfn_valid_within(), boot #1:

real	6m0.007s
user	372m55.709s
sys	16m45.962s

real	5m58.718s
user	372m58.852s
sys	16m47.675s

real	5m58.481s
user	372m56.172s
sys	16m46.953s

pfn_valid_within(), Boot #2:

real	6m1.163s
user	372m57.282s
sys	16m52.025s

real	6m0.562s
user	373m4.957s
sys	16m52.847s

real	6m0.030s
user	372m54.710s
sys	16m54.516s

pfn_valid_within(), Boot #3:

real	6m1.784s
user	373m13.379s
sys	16m48.388s

real	5m58.579s
user	373m10.403s
sys	16m47.628s

real	5m59.151s
user	373m0.084s
sys	16m50.634s

early_pfn_valid(), Boot #1:

real	5m59.902s
user	372m57.201s
sys	16m42.157s

real	5m59.510s
user	372m59.762s
sys	16m47.331s

real	5m58.559s
user	372m46.530s
sys	16m49.010s

early_pfn_valid(), Boot #2:

real	6m0.652s
user	373m10.785s
sys	16m25.138s

real	5m58.663s
user	373m4.498s
sys	16m28.262s

real	5m57.675s
user	373m6.174s
sys	16m28.653s

early_pfn_valid(), Boot #3:

real	5m59.680s
user	373m4.007s
sys	16m26.781s

real	5m58.234s
user	372m58.895s
sys	16m26.957s

real	5m58.707s
user	372m40.546s
sys	16m29.345s