[lttng-dev] HugePages shared memory support in LLTng

Yiteng Guo guoyiteng at gmail.com
Wed Jul 24 11:54:38 EDT 2019


(Forgot to cc mailing list in the previous email)

Hi Jonathan,

On Tue, Jul 23, 2019 at 4:27 PM Jonathan Rajotte-Julien
<jonathan.rajotte-julien at efficios.com> wrote:
>
> CC'ing the mailing list back.
>
> On Tue, Jul 23, 2019 at 03:58:09PM -0400, Yiteng Guo wrote:
> > Hi Jonathan,
> >
> > Thank you for the patch! It is really helpful.
>
> Were you able to observe a positive impact?
>
> This is something we might be interested in upstreaming if we have good
> feedback.

Yes, page faults disappeared and I didn't get those periodic overheads anymore.

And I also solved the problem that hugepages are not closed correctly
in my patch. It is my fault that I forgot to close the mmap pointer. I
updated the patch here:
https://github.com/lttng/lttng-ust/compare/master...guoyiteng:hugepages
The current prefault solution works well for me and I will use that
for now. In my opinion, using hugepages could further reduce the TLB
misses, but that involved more changes in source codes than the
prefault solution.

Best,
Yiteng


More information about the lttng-dev mailing list