diff options
Diffstat (limited to 'mm/readahead.c')
| -rw-r--r-- | mm/readahead.c | 15 |
1 files changed, 8 insertions, 7 deletions
diff --git a/mm/readahead.c b/mm/readahead.c index d2504877b269..4a58befbde4a 100644 --- a/mm/readahead.c +++ b/mm/readahead.c @@ -46,7 +46,7 @@ void file_ra_state_init(struct file_ra_state *ra, struct address_space *mapping) { ra->ra_pages = mapping->backing_dev_info->ra_pages; - ra->prev_index = -1; + ra->prev_pos = -1; } EXPORT_SYMBOL_GPL(file_ra_state_init); @@ -327,7 +327,7 @@ static unsigned long get_next_ra_size(struct file_ra_state *ra, * indicator. The flag won't be set on already cached pages, to avoid the * readahead-for-nothing fuss, saving pointless page cache lookups. * - * prev_index tracks the last visited page in the _previous_ read request. + * prev_pos tracks the last visited byte in the _previous_ read request. * It should be maintained by the caller, and will be used for detecting * small random reads. Note that the readahead algorithm checks loosely * for sequential patterns. Hence interleaved reads might be served as @@ -351,11 +351,9 @@ ondemand_readahead(struct address_space *mapping, bool hit_readahead_marker, pgoff_t offset, unsigned long req_size) { - int max; /* max readahead pages */ - int sequential; - - max = ra->ra_pages; - sequential = (offset - ra->prev_index <= 1UL) || (req_size > max); + int max = ra->ra_pages; /* max readahead pages */ + pgoff_t prev_offset; + int sequential; /* * It's the expected callback offset, assume sequential access. @@ -369,6 +367,9 @@ ondemand_readahead(struct address_space *mapping, goto readit; } + prev_offset = ra->prev_pos >> PAGE_CACHE_SHIFT; + sequential = offset - prev_offset <= 1UL || req_size > max; + /* * Standalone, small read. * Read as is, and do not pollute the readahead state. |