The following changes since commit 4f5d1526bed98cde56829f9e5e040c6601c03236:
add link to new list archives (2010-04-14 10:13:57 +0200)
are available in the git repository at:
git://git.kernel.dk/fio.git master
Jens Axboe (2):
Add flist sorting
Fix typo in flist_sort.c
Makefile | 1 +
Makefile.FreeBSD | 1 +
Makefile.mac | 1 +
Makefile.solaris | 1 +
flist_sort.h | 9 ++++
lib/flist_sort.c | 140 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
6 files changed, 153 insertions(+), 0 deletions(-)
create mode 100644 flist_sort.h
create mode 100644 lib/flist_sort.c
---
Diff of recent changes:
diff --git a/Makefile b/Makefile
index 837f421..978f8b2 100644
--- a/Makefile
+++ b/Makefile
@@ -10,6 +10,7 @@ OBJS = gettime.o fio.o ioengines.o init.o stat.o log.o time.o filesetup.o \
cgroup.o profile.o debug.o
OBJS += lib/rand.o
+OBJS += lib/flist_sort.o
OBJS += crc/crc7.o
OBJS += crc/crc16.o
diff --git a/Makefile.FreeBSD b/Makefile.FreeBSD
index 3c59a99..5882961 100644
--- a/Makefile.FreeBSD
+++ b/Makefile.FreeBSD
@@ -9,6 +9,7 @@ OBJS = gettime.o fio.o ioengines.o init.o stat.o log.o time.o filesetup.o \
rbtree.o smalloc.o filehash.o helpers.o profile.o debug.o
OBJS += lib/rand.o
+OBJS += lib/flist_sort.o
OBJS += crc/crc7.o
OBJS += crc/crc16.o
diff --git a/Makefile.mac b/Makefile.mac
index fe84297..77e5f03 100644
--- a/Makefile.mac
+++ b/Makefile.mac
@@ -9,6 +9,7 @@ OBJS = gettime.o fio.o ioengines.o init.o stat.o log.o time.o filesetup.o \
rbtree.o smalloc.o filehash.o helpers.o profile.o debug.o
OBJS += lib/rand.o
+OBJS += lib/flist_sort.o
OBJS += crc/crc7.o
OBJS += crc/crc16.o
diff --git a/Makefile.solaris b/Makefile.solaris
index 49a4ef9..06020c2 100644
--- a/Makefile.solaris
+++ b/Makefile.solaris
@@ -8,6 +8,7 @@ OBJS = gettime.o fio.o ioengines.o init.o stat.o log.o time.o filesetup.o \
profile.o debug.o
OBJS += lib/rand.o
+OBJS += lib/flist_sort.o
OBJS += crc/crc7.o
OBJS += crc/crc16.o
diff --git a/flist_sort.h b/flist_sort.h
new file mode 100644
index 0000000..686b7a5
--- /dev/null
+++ b/flist_sort.h
@@ -0,0 +1,9 @@
+#ifndef FIO_FLIST_SORT_H
+#define FIO_FLIST_SORT_H
+
+struct flist_head;
+
+void flist_sort(void *priv, struct flist_head *head,
+ int (*cmp)(void *priv, struct flist_head *a,
+ struct flist_head *b));
+#endif
diff --git a/lib/flist_sort.c b/lib/flist_sort.c
new file mode 100644
index 0000000..9a2da84
--- /dev/null
+++ b/lib/flist_sort.c
@@ -0,0 +1,140 @@
+#include <string.h>
+#include <assert.h>
+
+#include "../flist.h"
+#include "../flist_sort.h"
+
+#ifndef ARRAY_SIZE
+#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]))
+#endif
+
+#define MAX_LIST_LENGTH_BITS 65
+
+/*
+ * Returns a list organized in an intermediate format suited
+ * to chaining of merge() calls: null-terminated, no reserved or
+ * sentinel head node, "prev" links not maintained.
+ */
+static struct flist_head *merge(void *priv,
+ int (*cmp)(void *priv, struct flist_head *a,
+ struct flist_head *b),
+ struct flist_head *a, struct flist_head *b)
+{
+ struct flist_head head, *tail = &head;
+
+ while (a && b) {
+ /* if equal, take 'a' -- important for sort stability */
+ if ((*cmp)(priv, a, b) <= 0) {
+ tail->next = a;
+ a = a->next;
+ } else {
+ tail->next = b;
+ b = b->next;
+ }
+ tail = tail->next;
+ }
+ tail->next = a?:b;
+ return head.next;
+}
+
+/*
+ * Combine final list merge with restoration of standard doubly-linked
+ * list structure. This approach duplicates code from merge(), but
+ * runs faster than the tidier alternatives of either a separate final
+ * prev-link restoration pass, or maintaining the prev links
+ * throughout.
+ */
+static void merge_and_restore_back_links(void *priv,
+ int (*cmp)(void *priv, struct flist_head *a,
+ struct flist_head *b),
+ struct flist_head *head,
+ struct flist_head *a, struct flist_head *b)
+{
+ struct flist_head *tail = head;
+
+ while (a && b) {
+ /* if equal, take 'a' -- important for sort stability */
+ if ((*cmp)(priv, a, b) <= 0) {
+ tail->next = a;
+ a->prev = tail;
+ a = a->next;
+ } else {
+ tail->next = b;
+ b->prev = tail;
+ b = b->next;
+ }
+ tail = tail->next;
+ }
+ tail->next = a ? : b;
+
+ do {
+ /*
+ * In worst cases this loop may run many iterations.
+ * Continue callbacks to the client even though no
+ * element comparison is needed, so the client's cmp()
+ * routine can invoke cond_resched() periodically.
+ */
+ cmp(priv, tail, tail);
+
+ tail->next->prev = tail;
+ tail = tail->next;
+ } while (tail->next);
+
+ tail->next = head;
+ head->prev = tail;
+}
+
+/**
+ * flist_sort - sort a list
+ * @priv: private data, opaque to flist_sort(), passed to @cmp
+ * @head: the list to sort
+ * @cmp: the elements comparison function
+ *
+ * This function implements "merge sort", which has O(nlog(n))
+ * complexity.
+ *
+ * The comparison function @cmp must return a negative value if @a
+ * should sort before @b, and a positive value if @a should sort after
+ * @b. If @a and @b are equivalent, and their original relative
+ * ordering is to be preserved, @cmp must return 0.
+ */
+void flist_sort(void *priv, struct flist_head *head,
+ int (*cmp)(void *priv, struct flist_head *a,
+ struct flist_head *b))
+{
+ struct flist_head *part[MAX_LIST_LENGTH_BITS+1]; /* sorted partial lists
+ -- last slot is a sentinel */
+ int lev; /* index into part[] */
+ int max_lev = 0;
+ struct flist_head *list;
+
+ if (flist_empty(head))
+ return;
+
+ memset(part, 0, sizeof(part));
+
+ head->prev->next = NULL;
+ list = head->next;
+
+ while (list) {
+ struct flist_head *cur = list;
+ list = list->next;
+ cur->next = NULL;
+
+ for (lev = 0; part[lev]; lev++) {
+ cur = merge(priv, cmp, part[lev], cur);
+ part[lev] = NULL;
+ }
+ if (lev > max_lev) {
+ assert(lev < ARRAY_SIZE(part) - 1);
+ max_lev = lev;
+ }
+ part[lev] = cur;
+ }
+
+ for (lev = 0; lev < max_lev; lev++)
+ if (part[lev])
+ list = merge(priv, cmp, part[lev], list);
+
+ merge_and_restore_back_links(priv, cmp, head, part[max_lev], list);
+}
--
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