On Mon, May 10, 2021 at 7:57 AM Shivank Garg <shivankgarg98@xxxxxxxxx> wrote: > > Hi Everyone! > > I want to profile the time taken to execute the __alloc_pages_nodemask > for different linux configurations/parameters. > To measure the execution time, I use the ktime_get() apis. I get the > ktime_get() on the top, and I want to do ktime_sub(ktime_get(),ktime) > and record it in a tracepoint. > However, the patch on implementation prevents the kernel from booting > up. I debugged the bug to find out that the issue recurs on adding > ktime_get() inside the __alloc_pages_nodemask path. So, that the > kernel fails to boot up ( and show the blank screen without any logs ) > I'm using the Linux kernel 5.6.13 (5821a5593fa9f28eb6fcc95c35d00454d9bb8624) Is there any reason that prevents you from using some advanced tools, i.e. perf, bcc/bpftrace, etc? They are much simpler than adding instrumentation in kernel. > > Is it an expected behavior? or a BUG? Has anyone else faced the same issue? > > Can you please suggest, what would be a good way to measure execution > time for page allocation (if not ktime_get) > > Stay Safe! > Best Regards, > Shivank Garg > Open-Source Enthusiast and Student, IIT Kanpur >
