[svn-r8791] Purpose: Rewrote metadata cache (H5AC.c, etc.) to improve performance.

Description:

Replaced the old metadata cache with a cache with a modified LRU
replacement policy.  This should improve the hit rate.

Solution:

Since we want to flush cache entries in increasing address order, I
used the threaded binary B-tree code to store the cache entries.
There is a fair bit of overhead here, so we may want to consider
other options.

While the code is designed to allow the support of other replacement
algorithms, at present, only a modified version of LRU is supported.

The modified LRU algorithm requires that a user selectable portion
of the cache entries be clean.  The clean entries are evicted first
when writes are not permitted.  If the pool of clean entries is used
up, the cache grows beyond its user specified maximum size.  The
cache can also exceed its maximum size if the combined size of the
protected (or locked) entries exceeds the maximum size of the cache.


Platforms tested:

eirene (serial, parallel, fp), h5committested


Misc. update:

1 files changed, 52 insertions, 0 deletions

diff --git a/src/H5B.c b/src/H5B.c
index a6a4a32..d3aa046 100644
--- a/src/H5B.c
+++ b/src/H5B.c
@@ -156,6 +156,7 @@ static H5B_t *H5B_load(H5F_t *f, hid_t dxpl_id, haddr_t addr, const void *_type,
 static herr_t H5B_flush(H5F_t *f, hid_t dxpl_id, hbool_t destroy, haddr_t addr, H5B_t *b);
 static herr_t H5B_dest(H5F_t *f, H5B_t *b);
 static herr_t H5B_clear(H5F_t *f, H5B_t *b, hbool_t destroy);
+static herr_t H5B_compute_size(H5F_t *f, H5B_t *bt, size_t *size_ptr);
 
 /* H5B inherits cache-like properties from H5AC */
 static const H5AC_class_t H5AC_BT[1] = {{
@@ -164,6 +165,7 @@ static const H5AC_class_t H5AC_BT[1] = {{
     (H5AC_flush_func_t)H5B_flush,
     (H5AC_dest_func_t)H5B_dest,
     (H5AC_clear_func_t)H5B_clear,
+    (H5AC_size_func_t)H5B_compute_size,
 }};
 
 /* Declare a free list to manage the page information */
@@ -630,6 +632,56 @@ done:
 
 
 /*-------------------------------------------------------------------------
+ * Function:	H5B_compute_size
+ *
+ * Purpose:	Compute the size in bytes of the specified instance of 
+ *		H5B_t on disk, and return it in *len_ptr.  On failure, 
+ *		the value of *len_ptr is undefined.
+ *
+ * Return:	Non-negative on success/Negative on failure
+ *
+ * Programmer:	John Mainzer
+ *		5/13/04
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5B_compute_size(H5F_t *f, H5B_t *bt, size_t *size_ptr)
+{
+    herr_t      ret_value = SUCCEED;    /* Return value */
+    size_t	size;
+
+    FUNC_ENTER_NOAPI(H5B_compute_size, FAIL)
+
+    /* check arguments */
+    HDassert(f);
+    HDassert(bt);
+    HDassert(bt->type);
+    HDassert(size_ptr);
+
+    size = H5B_nodesize(f, bt->type, NULL, bt->sizeof_rkey);
+
+    if ( size == 0 ) {
+
+        HGOTO_ERROR(H5E_RESOURCE, H5E_CANTGETSIZE, FAIL, \
+                    "H5B_nodesize() failed");
+
+    } else {
+
+        *size_ptr = size;
+
+    }
+
+done:
+
+    FUNC_LEAVE_NOAPI(ret_value)
+
+} /* H5B_H5B_compute_size() */
+
+
+/*-------------------------------------------------------------------------
  * Function:	H5B_find
  *
  * Purpose:	Locate the specified information in a B-tree and return