Messages in this thread | | | Date | Tue, 4 Apr 2023 15:41:38 -0300 | From | Arnaldo Carvalho de Melo <> | Subject | Re: [PATCH v5 00/17] Reference count checker and related fixes |
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Em Tue, Apr 04, 2023 at 08:25:41PM +0300, Adrian Hunter escreveu: > On 4/04/23 18:58, Ian Rogers wrote: > > Ping. It would be nice to have this landed or at least the first 10 > > patches that refactor the map API and are the bulk of the > > lines-of-code changed. Having those landed would make it easier to > > rebase in the future, but I also think the whole series is ready to > > go. > > I was wondering if the handling of dynamic data like struct map makes > any sense at present. Perhaps someone can reassure me. > > A struct map can be updated when an MMAP event is processed. So it
Yes, it can, and the update is made via a new PERF_RECORD_MMAP, right?
So:
perf_event__process_mmap() machine__process_mmap2_event() map__new() + thread__insert_map(thread, map) maps__fixup_overlappings() maps__insert(thread->maps, map);
Ok, from this point on new samples on ] map->start .. map->end ] will grab a refcount to this new map in its hist_entry, right?
When we want to sort by dso we will look at hist_entry->map->dso, etc.
> seems like anything racing with event processing is already broken, and > reference counting / locking cannot help - unless there is also > copy-on-write (which there isn't at present)?
> For struct maps, referencing it while simultaneously processing > events seems to make even less sense?
Can you elaborate some more?
- Arnaldo
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