VServer 1.9.2 (patch-2.6.8.1-vs1.9.2.diff)

[linux-2.6.git] / mm / readahead.c

diff --git a/mm/readahead.c b/mm/readahead.c
index 9723956..7073392 100644 (file)
--- a/mm/readahead.c
+++ b/mm/readahead.c
@@ -349,7 +349,6 @@ page_cache_readahead(struct address_space *mapping, struct file_ra_state *ra,
                        struct file *filp, unsigned long offset)
 {
        unsigned max;
-       unsigned min;
        unsigned orig_next_size;
        unsigned actual;
        int first_access=0;
@@ -374,7 +373,6 @@ page_cache_readahead(struct address_space *mapping, struct file_ra_state *ra,
        if (max == 0)
                goto out;       /* No readahead */
 
-       min = get_min_readahead(ra);
        orig_next_size = ra->next_size;
 
        if (ra->next_size == 0) {
@@ -470,7 +468,11 @@ do_io:
                          * pages shall be accessed in the next
                          * current window.
                          */
-                       ra->next_size = min(ra->average , (unsigned long)max);
+                       average = ra->average;
+                       if (ra->serial_cnt > average)
+                               average = (ra->serial_cnt + ra->average + 1) / 2;
+
+                       ra->next_size = min(average , (unsigned long)max);
                }
                ra->start = offset;
                ra->size = ra->next_size;
@@ -552,6 +554,7 @@ void handle_ra_miss(struct address_space *mapping,
                                ra->size = max;
                                ra->ahead_start = 0;
                                ra->ahead_size = 0;
+                               ra->average = max / 2;
                        }
                }
                ra->prev_page = offset;