forked from Imagelibrary/rtems
86ef0df976
The fat_file_datasync() read every cluster of the file into the cache and then synchronized it step-by-step. For unmodified buffers this is a non-operation. For modified buffers this will wake-up the swapout task which performs then a single buffer write operation. This is usually quite inefficient. Firstly we do single buffer writes, secondly we may perform a lot of unnecessary read operations (for huge files this is really bad), and thirdly this leads likely to cache evictions. The synchronization procedure is replaced by a simple rtems_bdbuf_sync_dev(). This has the side-effect that also buffers not related to the file are synchronized, but since the modified list is normally short this should be acceptable.