niyue commented on pull request #11588: URL: https://github.com/apache/arrow/pull/11588#issuecomment-961482283
> in MemoryMappedFile::ReadAt we call ::arrow::internal::MemoryAdviseWillNeed on the entire range accessed @westonpace I didn't realize this previously. Do you mean `MemoryMappedFile:WillNeed` is called internally by arrow during this process, which caused the OS prefetching issue? I will do more arrow coding reading to see how it works. Previously I briefly did some code searching on this part, and I thought the `WillNeed` API should be called explicitly by user program to indicate which part of the data is needed. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
