On 10/24/18 7:10 PM, Andrew Lunn wrote: > On Wed, Oct 24, 2018 at 05:09:05PM -0700, Florian Fainelli wrote: >> perf on ARM requires CONFIG_KUSER_HELPERS to be turned on to allow some >> independance with respect to the ARM CPU being used. Add a test which >> tries to locate the [vectors] page, created when CONFIG_KUSER_HELPERS is >> turned on to help asses the system's health. > > Hi Florian > > I've suffered the pain from missing CONFIG_KUSER_HELPERS. The > segfaults give little clue as to what is going wrong,and gdb is not > much use either.
If you have a working backtrace, you can typically see the virtual address being in 0xffff_xxxx which gives a bit of a clue, but yes, this is not particularly helpful. > > What i don't see here is any clue to CONFIG_KUSER_HELPERS. If the test > fails, could you print a message suggesting CONFIG_KUSER_HELPERS on > ARM? Sure, sounds reasonable, thanks for taking a look. -- Florian
