On Tue, Feb 20, 2018 at 03:06:10PM +0900, Damien Le Moal wrote: > For a zoned block device mount, an array of zone types for the device is > allocated and initialized in order to determine if a section is stored > on a sequential zone (zone reset needed) or a conventional zone (no zone > reset needed and regular discard applies). Considering this usage, the > zone types stored in memory can be replaced with a bitmap to indicate > equivalent information, that is, if a zone is sequential or not. This > reduces the memory usage for the device mount by roughly 8 (on a 14TB > disk with zones of 256 MB, the zone type array consumes 13x4KB pages > while the bitmap uses only 2x4KB pages. > > This patch changes the f2fs_dev_info structure blkz_type field to the > bitmap blkz_seq. Access to this bitmap is done using the function > f2fs_blkz_is_seq(), which is a rewrite of the function get_blkz_type(). Is there any way we could just provide a block layer helper to figure this out so that the file system code could be simplified even more?
