Re: MPS: User GC customizations

["Gerd Möllmann" <gerd.moellmann@gmail.com>]

Pip Cet <pipcet@protonmail.com> writes:

> On Thursday, July 4th, 2024 at 18:26, Ihor Radchenko <yantar92@posteo.net> wrote:
>> Gerd Möllmann gerd.moellmann@gmail.com writes:
>> 
>> > Pip mentioned scan functions, so let's say we set a flag in_scan while
>> > being in dflt_scan. MPS now calls dflt_scan, in the MPS thread, to do an
>> > increment of its work. While in dflt_scan we get SIGPROF and land in the
>> > signal handler in main thread, and the profiler sees in_scan == true.
>> > 
>> > Q: do we count that as part of GC work that the profiler should report,
>> > although it happened in the MPS thread? I understood Ihor as saying that
>> > he doesn't want that.
>> 
>> 
>> I think that we should ideally have multiple flags like this:
>> 1. when arena is locked
>> 2. when our dflt_scan code is running
>> 3. when we query MPS synchronously (e.g. memory allocation)
>> 4. when Emacs thread is paused by MPS
>
> 5. when our dflt_scan code is running on the main thread
>
> I think that's what Gerd meant to suggest, anyway?

I don't know. I only wanted to contribute something because I appeared
to be confused. Or maybe were confusing me. Whatever. I'm not thinking
about profiling otherwise.