On Wed, 30 Oct 2013, Will Deacon wrote: > On Wed, Oct 30, 2013 at 02:13:11PM +0000, Vince Weaver wrote: > > Uncompiled too I guess? > > > > kernel/events/core.c: In function ‘perf_event_period’: > > kernel/events/core.c:3531: error: invalid type argument of ‘->’ (have > > ‘local64_t’) > > make[3]: *** [kernel/events/core.o] Error 1 > > That's trivial to fix.
Probably, although Peter's been sending some "interesting" mostly untested perf patches to linux-kernel the past few days so before testing I'd rather have a patch that at least compiles cleanly. > > I also won't be able to test the ARM change, as my pandaboard won't boot > > with recent kernels (can't find the MMC root filesystem) and I haven't had > > time to track down why. Also even on a simple period changing test it > > often fails due to lost interrupts (the Cortex-A9 lost interrupt errata?). > > The omap guys like trying to blame the A9 erratum for that (which doesn't > even affect the cycle counter), but the reality is that the CTI never > worked reliably with mainline, and now there are no developers working > on that after the TI layoffs. I don't see the state of Pandaboard support > improving over time. So it might be OMAP4460/CTI specific and not related to the errata? That might be nice especially if things might work on other cortex-a9 boards. A shame about the TI people, they were often semi-responsive to my OMAP4460 questions even if it was usually just to say "ignore the documentation, that's broken, don't do that" > If you have a canned testcase for this stuff, I'm happy to run it on my > Chromebook. There's the tests/ioctl/ioctl_period test in my perf_event_tests.git tree but it's very simple. Currently it will likely just return success on current x86 Linux but fail on newish ARM and patched x86. I need to fix it to print old_behavior/new_behavior/fail I guess. I have a cortex-a15 chromebook too, but I haven't managed to get a recent kernel booting on it yet. Vince
