diff options
Diffstat (limited to 'mm/readahead.c')
| -rw-r--r-- | mm/readahead.c | 19 |
1 files changed, 17 insertions, 2 deletions
diff --git a/mm/readahead.c b/mm/readahead.c index e273f0de3376..a59ea70527b9 100644 --- a/mm/readahead.c +++ b/mm/readahead.c @@ -19,6 +19,7 @@ #include <linux/syscalls.h> #include <linux/file.h> #include <linux/mm_inline.h> +#include <linux/blk-cgroup.h> #include "internal.h" @@ -385,6 +386,7 @@ ondemand_readahead(struct address_space *mapping, { struct backing_dev_info *bdi = inode_to_bdi(mapping->host); unsigned long max_pages = ra->ra_pages; + unsigned long add_pages; pgoff_t prev_offset; /* @@ -474,10 +476,17 @@ readit: * Will this read hit the readahead marker made by itself? * If so, trigger the readahead marker hit now, and merge * the resulted next readahead window into the current one. + * Take care of maximum IO pages as above. */ if (offset == ra->start && ra->size == ra->async_size) { - ra->async_size = get_next_ra_size(ra, max_pages); - ra->size += ra->async_size; + add_pages = get_next_ra_size(ra, max_pages); + if (ra->size + add_pages <= max_pages) { + ra->async_size = add_pages; + ra->size += add_pages; + } else { + ra->size = max_pages; + ra->async_size = max_pages >> 1; + } } return ra_submit(ra, mapping, filp); @@ -505,6 +514,9 @@ void page_cache_sync_readahead(struct address_space *mapping, if (!ra->ra_pages) return; + if (blk_cgroup_congested()) + return; + /* be dumb */ if (filp && (filp->f_mode & FMODE_RANDOM)) { force_page_cache_readahead(mapping, filp, offset, req_size); @@ -555,6 +567,9 @@ page_cache_async_readahead(struct address_space *mapping, if (inode_read_congested(mapping->host)) return; + if (blk_cgroup_congested()) + return; + /* do read-ahead */ ondemand_readahead(mapping, ra, filp, true, offset, req_size); } |