Hi Peter,
On 8/11/2020 3:59 PM, Peter Zijlstra wrote:
On Tue, Aug 11, 2020 at 03:50:43PM +0800, Jin, Yao wrote:
Could I post v2 which basically refers to your patch but removes some
conditions since I see some issues in test if we use these conditions.
1. Remove '!event->attr.exclude_hv || !event->attr.exclude_host ||
!event->attr.exclude_guest' at the entry of sanitize_sample_regs().
2. Remove '!attr.exclude_hv || !attr.exclude_host || !attr.exclude_guest'
at the perf_event_open syscall entry.
exclude_host, maybe -- due to the dodgy semantics of it, but the others
should definitely be there.
exclude_guest and exclude_hv are tricky too.
If we do 'perf record -e cycles:u' in both host and guest, we can see:
event->attr.exclude_guest = 0
thus sanitize_sample_regs() returns regs directly even if exclude_kernel = 1.
And in guest, exclude_hv = 0, it's out of my expectation too.
Thanks
Jin Yao
