On Mon, Jan 10, 2022 at 8:17 AM Joe Lawrence <joe.lawrence@xxxxxxxxxx> wrote: > > On 1/7/22 11:46 AM, Song Liu wrote: > > On Fri, Jan 7, 2022 at 6:13 AM Joe Lawrence <joe.lawrence@xxxxxxxxxx> wrote: > >> > >> On 12/29/21 4:56 PM, David Vernet wrote: > >>> For example, under certain workloads, enabling a KLP patch with > >>> many objects or functions may cause ksoftirqd to be starved, and thus for > >>> interrupts to be backlogged and delayed. > >> > >> Just curious, approximately how many objects/functions does it take to > >> hit this condition? While the livepatching kselftests are more about > >> API and kernel correctness, this sounds like an interesting test case > >> for some of the other (out of tree) test suites. > > > > Not many patched functions. We only do small fixes at the moment. In the recent > > example, we hit the issue with ~10 patched functions. Another version > > with 2 to 3 > > patched function seems fine. > > > > Yes, I think this is an important test case. > > > > Thanks, Song. If you can share any test setup details, I'll pass those > along to our internal QE group. And once merged, we'll be adding this > one to the list of backports for our distro. We get this on shadow production traffic of our web service, which we cannot recreate out of our data centers. I tried to use iperf to generate traffic (among a few hosts), but it doesn't work. At the moment, I am not sure what's the easiest way to repro this. Thanks, Song
