fsaintjacques commented on a change in pull request #7172: URL: https://github.com/apache/arrow/pull/7172#discussion_r425995665
########## File path: cpp/src/arrow/io/file.cc ########## @@ -636,6 +665,9 @@ Result<std::shared_ptr<Buffer>> MemoryMappedFile::ReadAt(int64_t position, ARROW_ASSIGN_OR_RAISE( nbytes, internal::ValidateReadRange(position, nbytes, memory_map_->size())); + // Arrange to page data in + RETURN_NOT_OK(::arrow::internal::MemoryAdviseWillNeed( Review comment: We have to change Parquet's reader PreBuffer to do so, and CSV/JSON reader. ---------------------------------------------------------------- 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. For queries about this service, please contact Infrastructure at: us...@infra.apache.org