Re: [PATCH 1/2] perf: Add closing sibling events' file descriptors

[Alexander Shishkin]

Andi Kleen <ak@xxxxxxxxxxxxxxx> writes:

>> It didn't. I can't figure out what to charge on the locked memory, as
>> all that memory is in kernel-side objects. It also needs to make sense
>
> I don't see how that makes a difference for the count. It just account
> bytes. Can you elaborate?

Right, but which bytes? One byte per event? That's
arbitrary. sizeof(struct perf_event)? Then, probably also sizeof(struct
perf_event_context).

>> as iirc the default MLOCK_LIMIT is quite low, you'd hit it sooner than
>> the file descriptor limit.
>
> For a single process? 

The above two structs add up to 2288 bytes on my local build. Given the
default RLIMIT_MEMLOCK of 64k, that's 28 events. As opposed to ~1k
events if we keep using the RLIMIT_NOFILE. Unless I'm missing your
point.

Regards,
--
Alex