On Tue, Jul 11, 2017 at 2:03 AM, Ingo Molnar <[email protected]> wrote: > > * Kyle Huey <[email protected]> wrote: > >> On Wed, Jul 5, 2017 at 10:07 PM, Robert O'Callahan <[email protected]> >> wrote: >> > On Tue, Jul 4, 2017 at 3:21 AM, Mark Rutland <[email protected]> wrote: >> >> Should any of those be moved into the "should be dropped" pile? >> > >> > Why not be conservative and clear every sample you're not sure about? >> > >> > We'd appreciate a fix sooner rather than later here, since rr is >> > currently broken on every stable Linux kernel and our attempts to >> > implement a workaround have failed. >> > >> > (We have separate "interrupt" and "measure" counters, and I thought we >> > might work around this regression by programming the "interrupt" >> > counter to count kernel events as well as user events (interrupting >> > early is OK), but that caused our (completely separate) "measure" >> > counter to report off-by-one results (!), which seems to be a >> > different bug present on a range of older kernels.) >> >> This seems to have stalled out here unfortunately. >> >> Can we get a consensus (from ingo or peterz?) on Mark's question? Or, >> alternatively, can we move the patch at the top of this thread forward >> on the stable branches until we do reach an answer to that question? >> >> We've abandoned hope of working around this problem in rr and are >> currently broken for all of our users with an up-to-date kernel, so >> the situation for us is rather dire at the moment I'm afraid. > > Sorry about that - I've queued up a revert for the original commit and will > send > the fix to Linus later today. I've added a -stable tag as well so it can be > forwarded to Greg the moment it hits upstream.
Great, thank you. - Kyle
