On Sat, May 04, 2019 at 07:06:19PM +0800, Hanjun Guo wrote: > Hi Jeremy, Mark, > > On 2019/5/4 7:24, Jeremy Linton wrote: > > This patch series enables the Arm Statistical Profiling > > Extension (SPE) on ACPI platforms. > > > > This is possible because ACPI 6.3 uses a previously > > reserved field in the MADT to store the SPE interrupt > > number, similarly to how the normal PMU is described. > > If a consistent valid interrupt exists across all the > > cores in the system, a platform device is registered. > > That then triggers the SPE module, which runs as normal. > > > > We also add the ability to parse the PPTT for IDENTICAL > > cores. We then use this to sanity check the single SPE > > device we create. This creates a bit of a problem with > > respect to the specification though. The specification > > says that its legal for multiple tree's to exist in the > > PPTT. We handle this fine, but what happens in the > > case of multiple tree's is that the lack of a common > > node with IDENTICAL set forces us to assume that there > > are multiple non-IDENTICAL cores in the machine. > > Adding this patch set on top of latest mainline kernel, > and tested on D06 which has the SPE feature, in boot message > shows it was probed successfully: > > arm_spe_pmu arm,spe-v1: probed for CPUs 0-95 [max_record_sz 128, align 4, features 0x7] > > but when I test it with spe events such as > > perf record -c 1024 -e arm_spe_0/branch_filter=0/ -o spe ls > > it fails with: > failed to mmap with 12 (Cannot allocate memory), > > Confirmed that patch [0] is merged and other perf events are working > fine. > > I narrowed this issue down that mmap() failed to alloc 4M memory > in perf tool but seems have no relationship with this SPE patch set, > then I'm lost, could you take look please? > Thanks for pointing this out. I had last tested SPE only with v5.0 and missed completely to check on v5.1. FWIW, I can reproduce this issue on v5.1 -- Regards, Sudeep
