On Tue, Jan 17, 2017 at 11:00:15AM +0100, Robert Richter wrote: > On 13.01.17 14:15:00, Robert Richter wrote: > > On 13.01.17 09:19:04, Will Deacon wrote: > > > On Thu, Jan 12, 2017 at 07:58:25PM +0100, Robert Richter wrote: > > > > On 12.01.17 16:05:36, Will Deacon wrote: > > > > > On Mon, Jan 09, 2017 at 12:53:20PM +0100, Robert Richter wrote: > > > > > > > > > > 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. I can't really see the trend given that, for system time, your pfn_valid_within results have a variance of ~9 and the early_pfn_valid results have a variance of ~92. Given that the variance seems to come about due to the reboots, I think we need more numbers to establish whether the data sets end up largely overlapping or if they really are disjoint. Will -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>
