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Diffstat (limited to 'mm/readahead.c')
-rw-r--r--mm/readahead.c19
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);
}