On Tue, Jul 11, 2017 at 8:32 AM, Kyle Huey <me@xxxxxxxxxxxx> wrote: > On Tue, Jul 11, 2017 at 2:03 AM, Ingo Molnar <mingo@xxxxxxxxxx> wrote: >> >> * Kyle Huey <me@xxxxxxxxxxxx> wrote: >> >>> On Wed, Jul 5, 2017 at 10:07 PM, Robert O'Callahan <robert@xxxxxxxxxxxxx> wrote: >>> > On Tue, Jul 4, 2017 at 3:21 AM, Mark Rutland <mark.rutland@xxxxxxx> 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 Hi again, I saw that the revert landed on perf/urgent but it doesn't look like that got pulled by Linus in time for 4.13-rc1. Consider this a gentle poke to please get this merged :) - Kyle