This patch assigns the max folio order for readahead. After applying this patch, it starts with high-order page allocation successfully as shown in the below traces.
Before: f2fs_fadvise: dev = (252,16), ino = 14, i_size = 4294967296 offset:0, len:536870912, advise:3 page_cache_sync_ra: dev=252:16 ino=e index=0 req_count=2048 order=0 size=0 async_size=0 ra_pages=2048 mmap_miss=0 prev_pos=-1 page_cache_ra_order: dev=252:16 ino=e index=0 order=0 size=2048 async_size=1024 ra_pages=2048 page_cache_sync_ra: dev=252:16 ino=e index=2048 req_count=2048 order=0 size=2048 async_size=1024 ra_pages=2048 mmap_miss=0 prev_pos=-1 page_cache_ra_unbounded: dev=252:16 ino=e index=2048 nr_to_read=2048 lookahead_size=0 page_cache_sync_ra: dev=252:16 ino=e index=4096 req_count=2048 order=0 size=2048 async_size=1024 ra_pages=2048 mmap_miss=0 prev_pos=-1 page_cache_ra_unbounded: dev=252:16 ino=e index=4096 nr_to_read=2048 lookahead_size=0 page_cache_sync_ra: dev=252:16 ino=e index=6144 req_count=2048 order=0 size=2048 async_size=1024 ra_pages=2048 mmap_miss=0 prev_pos=-1 page_cache_ra_unbounded: dev=252:16 ino=e index=6144 nr_to_read=2048 lookahead_size=0 ... page_cache_sync_ra: dev=252:16 ino=e index=129024 req_count=2048 order=0 size=2048 async_size=1024 ra_pages=2048 mmap_miss=0 prev_pos=-1 page_cache_ra_unbounded: dev=252:16 ino=e index=129024 nr_to_read=2048 lookahead_size=0 After: f2fs_fadvise: dev = (252,16), ino = 14, i_size = 4294967296 offset:0, len:536870912, advise:3 page_cache_sync_ra: dev=252:16 ino=e index=0 req_count=2048 order=0 size=0 async_size=0 ra_pages=2048 mmap_miss=0 prev_pos=-1 page_cache_ra_order: dev=252:16 ino=e index=0 order=9 size=2048 async_size=1024 ra_pages=2048 page_cache_sync_ra: dev=252:16 ino=e index=2048 req_count=2048 order=9 size=2048 async_size=1024 ra_pages=2048 mmap_miss=0 prev_pos=-1 page_cache_ra_order: dev=252:16 ino=e index=2048 order=9 size=2048 async_size=1024 ra_pages=2048 page_cache_sync_ra: dev=252:16 ino=e index=4096 req_count=2048 order=9 size=2048 async_size=1024 ra_pages=2048 mmap_miss=0 prev_pos=-1 page_cache_ra_order: dev=252:16 ino=e index=4096 order=9 size=2048 async_size=1024 ra_pages=2048 page_cache_sync_ra: dev=252:16 ino=e index=6144 req_count=2048 order=9 size=2048 async_size=1024 ra_pages=2048 mmap_miss=0 prev_pos=-1 page_cache_ra_order: dev=252:16 ino=e index=6144 order=9 size=2048 async_size=1024 ra_pages=2048 page_cache_sync_ra: dev=252:16 ino=e index=8192 req_count=2048 order=9 size=2048 async_size=1024 ra_pages=2048 mmap_miss=0 prev_pos=-1 ... page_cache_sync_ra: dev=252:16 ino=e index=129024 req_count=2048 order=9 size=2048 async_size=1024 ra_pages=2048 mmap_miss=0 prev_pos=-1 page_cache_ra_order: dev=252:16 ino=e index=129024 order=9 size=2048 async_size=1024 ra_pages=2048 Cc: [email protected] Cc: Matthew Wilcox (Oracle) <[email protected]> Signed-off-by: Jaegeuk Kim <[email protected]> --- mm/readahead.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/mm/readahead.c b/mm/readahead.c index 54c78f8276fe..cfc63f7d5e81 100644 --- a/mm/readahead.c +++ b/mm/readahead.c @@ -593,7 +593,8 @@ void page_cache_sync_ra(struct readahead_control *ractl, * trivial case: (index - prev_index) == 1 * unaligned reads: (index - prev_index) == 0 */ - if (!index || req_count > max_pages || index - prev_index <= 1UL) { + if (!index || req_count > max_pages || index - prev_index <= 1UL || + mapping_large_folio_support(ractl->mapping)) { ra->start = index; ra->size = get_init_ra_size(req_count, max_pages); ra->async_size = ra->size > req_count ? ra->size - req_count : @@ -627,7 +628,7 @@ void page_cache_sync_ra(struct readahead_control *ractl, ra->size = min(contig_count + req_count, max_pages); ra->async_size = 1; readit: - ra->order = 0; + ra->order = mapping_max_folio_order(ractl->mapping); ractl->_index = ra->start; page_cache_ra_order(ractl, ra); } -- 2.52.0.107.ga0afd4fd5b-goog _______________________________________________ Linux-f2fs-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
