[ltt-dev] LTTng 0.87 improved page fault tracing

[kosaki.motohiro@jp.fujitsu.com (KOSAKI Motohiro)]

Hi

interesting..

> I just combined the 4 page fault handler events that were in the tracing
> hot path of LTTng into 2 :
> 
> kernel page_fault_entry
> kernel page_fault_exit
> 
> They take as parameter the combination of what was available in the
> trap_entry/exit events and handle_mm_fault entry/exit events. This
> should lessen the performance impact of the tracer when it's active.
> I did the related modifications in LTTV 0.12.8.

Just question.

As far as I know, customer has two different requeremtn of the page fault.
  (1) collect number of all page fault
      -> if it is too large, too many interrupt decrease performance.
  (2) collect number of major page fault
      -> major page fault indicate to increase random access I/O,
         then, some customer want to collect major page fault
         (don't include minor page fault)

Is this patch fill (2) requirement?