Anton Khirnov: > Quoting Andreas Rheinhardt (2024-04-17 11:29:18) >> Anton Khirnov: >>> It is more efficient and easier to manage. >>> --- >> >> Allocating structures used by slice contexts jointly has the potential >> downside of false sharing if the structures are not sufficiently >> aligned/padded. > > What do you suggest? Align first member to cacheline size? >
This is problematic, because av_malloc is not necessarily aligned to the chacheline size; for the same reason it is not possible to simply DECLARE_ALIGNED_64 for it (see e.g. 7945d30e91b96d2f4f5b612048169087d214d41e). Given that the structure we are talking about is already pretty big, the easiest way is to add explicit padding at the end. Use __GCC_DESTRUCTIVE_SIZE if that is defined or 64 if not (or maybe always use 128B? https://stackoverflow.com/questions/72126606/should-the-cache-padding-size-of-x86-64-be-128-bytes). - Andreas _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
