The performance at the low number of threads shows the same gap, but once the thread count hits the number of cores, the gap basically closes completely, so it appears that this kernel does not have the same issue with the sleep methods not behaving properly.
Also, the issue when running schedtool doesn't show the same degradation in performance but the sleep methods do take a hit at the higher thread counts which is probably to be expected and is still relatively minor, especially when compared to the performance of the standard kernel.
My general assessment would be that the kernel with the BFS scheduler and other CK modifications either reduces or eliminates the issue that is causing the unexpectedly high CPU usage of the sleep methods.
I installed the kernel with the BFS scheduler and other CK modifications from https:/ /launchpad. net/~chogydan/ +archive/ ppa and ran the test.
The performance at the low number of threads shows the same gap, but once the thread count hits the number of cores, the gap basically closes completely, so it appears that this kernel does not have the same issue with the sleep methods not behaving properly.
Also, the issue when running schedtool doesn't show the same degradation in performance but the sleep methods do take a hit at the higher thread counts which is probably to be expected and is still relatively minor, especially when compared to the performance of the standard kernel.
My general assessment would be that the kernel with the BFS scheduler and other CK modifications either reduces or eliminates the issue that is causing the unexpectedly high CPU usage of the sleep methods.