The file_ra_state.age is node specific,
comparing ages between two nodes is a bug.
So add code to
- take down the node id in file_ra_state.flags;
- ensure that we are comparing the ages from the same node.
Signed-off-by: Fengguang Wu <[EMAIL PROTECTED]>
---
include/linux/fs.h | 2 +-
mm/readahead.c | 30 +++++++++++++++++++++++++-----
2 files changed, 26 insertions(+), 6 deletions(-)
--- linux-2.6.21-rc3-mm2.orig/include/linux/fs.h
+++ linux-2.6.21-rc3-mm2/include/linux/fs.h
@@ -738,7 +738,7 @@ struct file_ra_state {
unsigned long mmap_hit; /* Cache hit stat for mmap accesses */
unsigned long mmap_miss; /* Cache miss stat for mmap accesses */
- unsigned long flags; /* RA_FLAG_xxx | ra_class_old | ra_class_new */
+ unsigned long flags; /* RA_FLAG_xxx | node_id | class_old |
class_new */
unsigned long prev_page; /* Cache last read() position */
unsigned long ra_pages; /* Maximum readahead window */
};
--- linux-2.6.21-rc3-mm2.orig/mm/readahead.c
+++ linux-2.6.21-rc3-mm2/mm/readahead.c
@@ -52,11 +52,13 @@ EXPORT_SYMBOL_GPL(readahead_ratio);
int readahead_hit_rate = 1;
#endif /* CONFIG_ADAPTIVE_READAHEAD */
+#define RA_CLASS_SHIFT 4
+#define RA_CLASS_MASK ((1 << RA_CLASS_SHIFT) - 1)
+#define RA_NODE_SHIFT (2 * RA_CLASS_SHIFT)
+#define RA_NODE_MASK ((MAX_NUMNODES-1) << RA_NODE_SHIFT)
/*
* Detailed classification of read-ahead behaviors.
*/
-#define RA_CLASS_SHIFT 4
-#define RA_CLASS_MASK ((1 << RA_CLASS_SHIFT) - 1)
enum ra_class {
RA_CLASS_ALL,
RA_CLASS_INITIAL,
@@ -802,6 +804,11 @@ static inline enum ra_class ra_class_old
return (ra->flags >> RA_CLASS_SHIFT) & RA_CLASS_MASK;
}
+static inline int ra_node_id(struct file_ra_state *ra)
+{
+ return (ra->flags >> RA_NODE_SHIFT) & RA_NODE_MASK;
+}
+
static unsigned long ra_readahead_size(struct file_ra_state *ra)
{
return ra->readahead_index - ra->ra_index;
@@ -864,6 +871,18 @@ static void ra_set_size(struct file_ra_s
}
/*
+ * Save the current node id and age.
+ */
+static void ra_save_node_age(struct file_ra_state *ra)
+{
+ int nid = numa_node_id();
+
+ ra->flags &= ~RA_NODE_MASK;
+ ra->flags |= nid << RA_NODE_SHIFT;
+ ra->age = nr_scanned_pages_node(nid);
+}
+
+/*
* Submit IO for the read-ahead request in file_ra_state.
*/
static unsigned long ra_submit(struct file_ra_state *ra,
@@ -901,7 +920,7 @@ static unsigned long ra_submit(struct fi
}
/* Take down the current read-ahead aging value. */
- ra->age = nr_scanned_pages_node(numa_node_id());
+ ra_save_node_age(ra);
ra_size = ra_readahead_size(ra);
la_size = ra_lookahead_size(ra);
@@ -1025,9 +1044,10 @@ static unsigned long compute_thrashing_t
unsigned long stream_shift;
unsigned long ra_size;
uint64_t ll;
+ int nid = ra_node_id(ra);
- global_size = nr_free_inactive_pages_node(numa_node_id());
- global_shift = nr_scanned_pages_node(numa_node_id()) - ra->age;
+ global_size = nr_free_inactive_pages_node(nid);
+ global_shift = nr_scanned_pages_node(nid) - ra->age;
global_shift |= 1UL;
stream_shift = ra_invoke_interval(ra);
--
-
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