Re: perf kmem --page stat and gpf_flags translation

[Steven Rostedt <rostedt@goodmis.org>]

On Thu, 21 Nov 2024 14:54:25 +0100 (CET)
Michael Petlan <mpetlan@redhat.com> wrote:

> Hello Steve and others,
> 
> We have found out that perf kmem --page stat sometimes fails like the
> following:
> 
> # perf kmem --page stat
> 0x2aa28 [0x8]: failed to process type: 68 [Operation not permitted]
> error during process events: -1
> 
> This seem to happen on s390x KVM machines.
> 
> When we tried to investigate for the reasons, it seems that the problem
> is caused by incorrect/unexpected translation of gpf_flags for event
> kmem:mm_page_alloc.
> 
> # perf script
> perf   96553 [003] 100299.663963: kmem:mm_page_alloc: page=0x1a8f9 pfn=0x1a8f9 order=0 migratetype=0 gfp_flags=0x500cc2
> perf   96553 [003] 100299.663995: kmem:mm_page_alloc: page=0x1bc3f pfn=0x1bc3f order=0 migratetype=0 gfp_flags=0x40cc0
> perf   96553 [003] 100299.664001: kmem:mm_page_alloc: page=0x1a9d9 pfn=0x1a9d9 order=0 migratetype=0 gfp_flags=0x40cc0
> perf   96553 [003] 100299.664011: kmem:mm_page_alloc: page=0x1788b pfn=0x1788b order=0 migratetype=0 gfp_flags=0x40cc0
> perf   96553 [003] 100299.664023: kmem:mm_page_alloc: page=0x17993 pfn=0x17993 order=0 migratetype=0 gfp_flags=0xcc0
> 

Does the same thing happen with trace-cmd record?

 # trace-cmd record -e mm_page_alloc
[ run tests, hit Ctrl^C ]

 # trace-cmd report

?

If so, could you send the trace.dat file to me.

Thanks,

-- Steve