Jan Beulich
2010-Dec-22 12:08 UTC
[Xen-devel] [PATCH, RFC 1/5] make sort() generally available
Rather having this general library function only on ia64, move it into
common code.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
--- a/xen/arch/ia64/linux-xen/Makefile
+++ b/xen/arch/ia64/linux-xen/Makefile
@@ -12,7 +12,6 @@ obj-y += sal.o
obj-y += setup.o
obj-y += smpboot.o
obj-y += smp.o
-obj-y += sort.o
obj-y += time.o
obj-y += tlb.o
obj-y += unaligned.o
--- a/xen/arch/ia64/linux-xen/README.origin
+++ b/xen/arch/ia64/linux-xen/README.origin
@@ -21,7 +21,6 @@ sal.c -> linux/arch/ia64/kernel/sal.c
setup.c -> linux/arch/ia64/kernel/setup.c
smp.c -> linux/arch/ia64/kernel/smp.c
smpboot.c -> linux/arch/ia64/kernel/smpboot.c
-sort.c -> linux/lib/sort.c
time.c -> linux/arch/ia64/kernel/time.c
tlb.c -> linux/arch/ia64/mm/tlb.c
unaligned.c -> linux/arch/ia64/kernel/unaligned.c
--- a/xen/arch/ia64/linux-xen/sort.c
+++ /dev/null
@@ -1,122 +0,0 @@
-/*
- * A fast, small, non-recursive O(nlog n) sort for the Linux kernel
- *
- * Jan 23 2005 Matt Mackall <mpm@selenic.com>
- */
-
-#include <linux/kernel.h>
-#include <linux/module.h>
-#ifdef XEN
-#include <linux/types.h>
-#endif
-
-void u32_swap(void *a, void *b, int size)
-{
- u32 t = *(u32 *)a;
- *(u32 *)a = *(u32 *)b;
- *(u32 *)b = t;
-}
-
-void generic_swap(void *a, void *b, int size)
-{
- char t;
-
- do {
- t = *(char *)a;
- *(char *)a++ = *(char *)b;
- *(char *)b++ = t;
- } while (--size > 0);
-}
-
-/*
- * sort - sort an array of elements
- * @base: pointer to data to sort
- * @num: number of elements
- * @size: size of each element
- * @cmp: pointer to comparison function
- * @swap: pointer to swap function or NULL
- *
- * This function does a heapsort on the given array. You may provide a
- * swap function optimized to your element type.
- *
- * Sorting time is O(n log n) both on average and worst-case. While
- * qsort is about 20% faster on average, it suffers from exploitable
- * O(n*n) worst-case behavior and extra memory requirements that make
- * it less suitable for kernel use.
- */
-
-void sort(void *base, size_t num, size_t size,
- int (*cmp)(const void *, const void *),
- void (*swap)(void *, void *, int size))
-{
- /* pre-scale counters for performance */
- int i = (num/2) * size, n = num * size, c, r;
-
- if (!swap)
- swap = (size == 4 ? u32_swap : generic_swap);
-
- /* heapify */
- for ( ; i >= 0; i -= size) {
- for (r = i; r * 2 < n; r = c) {
- c = r * 2;
- if (c < n - size && cmp(base + c, base + c + size) < 0)
- c += size;
- if (cmp(base + r, base + c) >= 0)
- break;
- swap(base + r, base + c, size);
- }
- }
-
- /* sort */
- for (i = n - size; i >= 0; i -= size) {
- swap(base, base + i, size);
- for (r = 0; r * 2 < i; r = c) {
- c = r * 2;
- if (c < i - size && cmp(base + c, base + c + size) < 0)
- c += size;
- if (cmp(base + r, base + c) >= 0)
- break;
- swap(base + r, base + c, size);
- }
- }
-}
-
-EXPORT_SYMBOL(sort);
-
-#if 0
-/* a simple boot-time regression test */
-
-int cmpint(const void *a, const void *b)
-{
- return *(int *)a - *(int *)b;
-}
-
-static int sort_test(void)
-{
- int *a, i, r = 1;
-
- a = kmalloc(1000 * sizeof(int), GFP_KERNEL);
- BUG_ON(!a);
-
- printk("testing sort()\n");
-
- for (i = 0; i < 1000; i++) {
- r = (r * 725861) % 6599;
- a[i] = r;
- }
-
- sort(a, 1000, sizeof(int), cmpint, NULL);
-
- for (i = 0; i < 999; i++)
- if (a[i] > a[i+1]) {
- printk("sort() failed!\n");
- break;
- }
-
- kfree(a);
-
- return 0;
-}
-
-module_init(sort_test);
-#endif
--- a/xen/common/Makefile
+++ b/xen/common/Makefile
@@ -20,6 +20,7 @@ obj-y += sched_sedf.o
obj-y += schedule.o
obj-y += shutdown.o
obj-y += softirq.o
+obj-y += sort.o
obj-y += spinlock.o
obj-y += stop_machine.o
obj-y += string.o
--- /dev/null
+++ b/xen/common/sort.c
@@ -0,0 +1,78 @@
+/*
+ * A fast, small, non-recursive O(nlog n) sort for the Linux kernel
+ *
+ * Jan 23 2005 Matt Mackall <mpm@selenic.com>
+ */
+
+#include <xen/types.h>
+
+static void u32_swap(void *a, void *b, int size)
+{
+ u32 t = *(u32 *)a;
+ *(u32 *)a = *(u32 *)b;
+ *(u32 *)b = t;
+}
+
+static void generic_swap(void *a, void *b, int size)
+{
+ char t;
+
+ do {
+ t = *(char *)a;
+ *(char *)a++ = *(char *)b;
+ *(char *)b++ = t;
+ } while (--size > 0);
+}
+
+/*
+ * sort - sort an array of elements
+ * @base: pointer to data to sort
+ * @num: number of elements
+ * @size: size of each element
+ * @cmp: pointer to comparison function
+ * @swap: pointer to swap function or NULL
+ *
+ * This function does a heapsort on the given array. You may provide a
+ * swap function optimized to your element type.
+ *
+ * Sorting time is O(n log n) both on average and worst-case. While
+ * qsort is about 20% faster on average, it suffers from exploitable
+ * O(n*n) worst-case behavior and extra memory requirements that make
+ * it less suitable for kernel use.
+ */
+
+void sort(void *base, size_t num, size_t size,
+ int (*cmp)(const void *, const void *),
+ void (*swap)(void *, void *, int size))
+{
+ /* pre-scale counters for performance */
+ int i = (num/2) * size, n = num * size, c, r;
+
+ if (!swap)
+ swap = (size == 4 ? u32_swap : generic_swap);
+
+ /* heapify */
+ for ( ; i >= 0; i -= size) {
+ for (r = i; r * 2 < n; r = c) {
+ c = r * 2;
+ if (c < n - size && cmp(base + c, base + c + size) < 0)
+ c += size;
+ if (cmp(base + r, base + c) >= 0)
+ break;
+ swap(base + r, base + c, size);
+ }
+ }
+
+ /* sort */
+ for (i = n - size; i >= 0; i -= size) {
+ swap(base, base + i, size);
+ for (r = 0; r * 2 < i; r = c) {
+ c = r * 2;
+ if (c < i - size && cmp(base + c, base + c + size) < 0)
+ c += size;
+ if (cmp(base + r, base + c) >= 0)
+ break;
+ swap(base + r, base + c, size);
+ }
+ }
+}
--- a/xen/include/asm-ia64/linux/README.origin
+++ b/xen/include/asm-ia64/linux/README.origin
@@ -16,7 +16,6 @@ notifier.h -> linux/include/linux/notif
percpu.h -> linux/include/linux/percpu.h
preempt.h -> linux/include/linux/preempt.h
seqlock.h -> linux/include/linux/seqlock.h
-sort.h -> linux/include/linux/sort.h
stddef.h -> linux/include/linux/stddef.h
thread_info.h -> linux/include/linux/thread_info.h
time.h -> linux/include/linux/time.h
--- a/xen/include/asm-ia64/linux/sort.h
+++ /dev/null
@@ -1,10 +0,0 @@
-#ifndef _LINUX_SORT_H
-#define _LINUX_SORT_H
-
-#include <linux/types.h>
-
-void sort(void *base, size_t num, size_t size,
- int (*cmp)(const void *, const void *),
- void (*swap)(void *, void *, int));
-
-#endif
--- /dev/null
+++ b/xen/include/xen/sort.h
@@ -0,0 +1,10 @@
+#ifndef __SORT_H__
+#define __SORT_H__
+
+#include <xen/types.h>
+
+void sort(void *base, size_t num, size_t size,
+ int (*cmp)(const void *, const void *),
+ void (*swap)(void *, void *, int));
+
+#endif /* __SORT_H__ */
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