On Wed, Dec 02, 2015 at 04:36:50PM -0800, Greg KH wrote: > On Wed, Dec 02, 2015 at 05:50:30PM -0600, Victor Rodriguez wrote: > > On Tue, Dec 1, 2015 at 7:32 PM, Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> wrote: > > > On Tue, Dec 01, 2015 at 06:45:51PM -0600, Victor Rodriguez wrote: > > >> Hi > > >> > > >> Despite the fact that this is not a well formulated question. I wonder > > >> what tests could be a good subset to measure the performance of the > > >> kernel . I have some approaches like phoronix does here : > > >> > > >> http://www.phoronix.com/scan.php?page=article&item=linux-41-byt&num=1 > > >> > > >> I am sure postmark/ John the ripper/ Apache are good candidates but I > > >> want to ask the community if there is some specific test that you > > >> recommend > > > > > > It depends on what you want to test, specifically. The "kernel" isn't a > > > very specific thing, what most of those tests test is the speed of the > > > hardware, not specifically the kernel itself. > > > > > > good luck, > > > > > > greg k-h > > > > Thanks for the feedback . You are right they test the speed of the HW > > however I have seen that when there is a change in the kernel for > > network the performance of apache is changed, which make total sense . > > Maybe, maybe not, depending on if "apache" is cpu or hardware bound > (networking hardware has physical limits...) again, you have to be very > sure about exactly what you are wanting to test before using such a test > to try to "validate" anything other than just raw hardware speed. > > Take a look at the "old" lmbench set of benchmarks for valid things that > a kernel change can affect, it's much different from what you might be > thinking of as a test. > We also still use lmbench as the usual first level of assessment as it gives a lot of information about the change set impact on low-level functions (system-calls, IPC, allocation...) was. It is much more precise than trying to detect changes in complex applications that might only be making a handful of a affected system call and thus look like performance did not change while it actually did - just its in some hard to reach corner case. As with all testing - you need layers of testing to get a usable picture of what is going on and lmbench is a good candidate for the lowest level. Deducing system level changes from looking at complex application performance changes is alost impossible. Specifically lmbench has a simple make results; make rerun which can give a good overview of differences - but actually the tests default runs are only a small part of what the tests can uncover so looking at individual microbenchmarks to discover latency/bandwidth changes can be very helpful also to uncover odd hardware behavior. Some other low-level benchmarks we use are: rt-tests - scheduling, pi NetPIPE - network bandwidth bonnie++ - filesystem thx! hofrat _______________________________________________ Kernelnewbies mailing list Kernelnewbies@xxxxxxxxxxxxxxxxx http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
