On 2025/12/2 03:16, Jaegeuk Kim via Linux-f2fs-devel wrote:
This patch fixes the broken readahead flow for POSIX_FADV_WILLNEED, where the problem is, in force_page_cache_ra(nr_to_read), nr_to_read is cut by the below code.max_pages = max_t(unsigned long, bdi->io_pages, ra->ra_pages); nr_to_read = min_t(unsigned long, nr_to_read, max_pages); IOWs, we are not able to read ahead larger than the above max_pages which is most likely the range of 2MB and 16MB. Note, it doesn't make sense to set ra->ra_pages to the entire file size. Instead, let's fix this logic. Before: f2fs_fadvise: dev = (252,16), ino = 14, i_size = 4294967296 offset:0, len:4294967296, advise:3 page_cache_ra_unbounded: dev=252:16 ino=e index=0 nr_to_read=512 lookahead_size=0 page_cache_ra_unbounded: dev=252:16 ino=e index=512 nr_to_read=512 lookahead_size=0 page_cache_ra_unbounded: dev=252:16 ino=e index=1024 nr_to_read=512 lookahead_size=0 page_cache_ra_unbounded: dev=252:16 ino=e index=1536 nr_to_read=512 lookahead_size=0 After: f2fs_fadvise: dev = (252,16), ino = 14, i_size = 4294967296 offset:0, len:4294967296, advise:3 page_cache_ra_unbounded: dev=252:16 ino=e index=0 nr_to_read=2048 lookahead_size=0 page_cache_ra_unbounded: dev=252:16 ino=e index=2048 nr_to_read=2048 lookahead_size=0 page_cache_ra_unbounded: dev=252:16 ino=e index=4096 nr_to_read=2048 lookahead_size=0 page_cache_ra_unbounded: dev=252:16 ino=e index=6144 nr_to_read=2048 lookahead_size=0 page_cache_ra_unbounded: dev=252:16 ino=e index=8192 nr_to_read=2048 lookahead_size=0 page_cache_ra_unbounded: dev=252:16 ino=e index=10240 nr_to_read=2048 lookahead_size=0 page_cache_ra_unbounded: dev=252:16 ino=e index=12288 nr_to_read=2048 lookahead_size=0 page_cache_ra_unbounded: dev=252:16 ino=e index=14336 nr_to_read=2048 lookahead_size=0 page_cache_ra_unbounded: dev=252:16 ino=e index=16384 nr_to_read=2048 lookahead_size=0 page_cache_ra_unbounded: dev=252:16 ino=e index=18432 nr_to_read=2048 lookahead_size=0 page_cache_ra_unbounded: dev=252:16 ino=e index=20480 nr_to_read=2048 lookahead_size=0 page_cache_ra_unbounded: dev=252:16 ino=e index=22528 nr_to_read=2048 lookahead_size=0 page_cache_ra_unbounded: dev=252:16 ino=e index=24576 nr_to_read=2048 lookahead_size=0 ... page_cache_ra_unbounded: dev=252:16 ino=e index=1042432 nr_to_read=2048 lookahead_size=0 page_cache_ra_unbounded: dev=252:16 ino=e index=1044480 nr_to_read=2048 lookahead_size=0 page_cache_ra_unbounded: dev=252:16 ino=e index=1046528 nr_to_read=2048 lookahead_size=0 Signed-off-by: Jaegeuk Kim <[email protected]>
Reviewed-by: Chao Yu <[email protected]> Thanks, _______________________________________________ Linux-f2fs-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
