diff -urNp --exclude CVS --exclude BitKeeper --exclude {arch} --exclude .arch-ids x-ref/include/linux/kernel.h x/include/linux/kernel.h
--- x-ref/include/linux/kernel.h 2003-10-04 10:52:28.000000000 +0200
+++ x/include/linux/kernel.h 2003-10-04 10:52:31.000000000 +0200
@@ -80,6 +80,8 @@ extern int sscanf(const char *, const ch
__attribute__ ((format (scanf,2,3)));
extern int vsscanf(const char *, const char *, va_list);
+extern void qsort(void *, size_t, size_t, int (*)(const void *,const void *));
+
extern int get_option(char **str, int *pint);
extern char *get_options(char *str, int nints, int *ints);
extern unsigned long long memparse(char *ptr, char **retptr);
diff -urNp --exclude CVS --exclude BitKeeper --exclude {arch} --exclude .arch-ids x-ref/kernel/ksyms.c x/kernel/ksyms.c
--- x-ref/kernel/ksyms.c 2003-10-04 10:52:29.000000000 +0200
+++ x/kernel/ksyms.c 2003-10-04 10:53:08.000000000 +0200
@@ -593,6 +593,9 @@ EXPORT_SYMBOL(get_write_access);
EXPORT_SYMBOL(strnicmp);
EXPORT_SYMBOL(strspn);
EXPORT_SYMBOL(strsep);
+#if defined(CONFIG_QSORT) && ! defined(CONFIG_QSORT_MODULE)
+EXPORT_SYMBOL(qsort);
+#endif
#ifdef CONFIG_CRC32
EXPORT_SYMBOL(crc32_le);
diff -urNp --exclude CVS --exclude BitKeeper --exclude {arch} --exclude .arch-ids x-ref/lib/Config.in x/lib/Config.in
--- x-ref/lib/Config.in 2003-10-02 00:09:47.000000000 +0200
+++ x/lib/Config.in 2003-10-04 10:52:31.000000000 +0200
@@ -46,4 +46,6 @@ if [ "$CONFIG_EXPERIMENTAL" = "y" -a \
tristate 'Hotplug firmware loading support (EXPERIMENTAL)' CONFIG_FW_LOADER
fi
+tristate 'Quick Sort' CONFIG_QSORT
+
endmenu
diff -urNp --exclude CVS --exclude BitKeeper --exclude {arch} --exclude .arch-ids x-ref/lib/Makefile x/lib/Makefile
--- x-ref/lib/Makefile 2003-10-04 10:52:24.000000000 +0200
+++ x/lib/Makefile 2003-10-04 10:53:43.000000000 +0200
@@ -9,13 +9,15 @@
L_TARGET := lib.a
export-objs := cmdline.o dec_and_lock.o rwsem.o rbtree.o crc32.o \
- firmware_class.o
+ firmware_class.o qsort.o
obj-y := errno.o ctype.o string.o vsprintf.o brlock.o cmdline.o \
bust_spinlocks.o rbtree.o dump_stack.o rwsem.o
obj-$(CONFIG_FW_LOADER) += firmware_class.o
+obj-$(CONFIG_QSORT) += qsort.o
+
ifneq ($(CONFIG_HAVE_DEC_LOCK),y)
obj-y += dec_and_lock.o
endif
diff -urNp --exclude CVS --exclude BitKeeper --exclude {arch} --exclude .arch-ids x-ref/lib/qsort.c x/lib/qsort.c
--- x-ref/lib/qsort.c 1970-01-01 01:00:00.000000000 +0100
+++ x/lib/qsort.c 2003-10-04 10:52:31.000000000 +0200
@@ -0,0 +1,254 @@
+/* Copyright (C) 1991, 1992, 1996, 1997, 1999 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+ Written by Douglas C. Schmidt (schmidt@ics.uci.edu).
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, write to the Free
+ Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+ 02111-1307 USA. */
+
+/* If you consider tuning this algorithm, you should consult first:
+ Engineering a sort function; Jon Bentley and M. Douglas McIlroy;
+ Software - Practice and Experience; Vol. 23 (11), 1249-1265, 1993. */
+
+# include <linux/module.h>
+# include <linux/slab.h>
+# include <linux/string.h>
+
+MODULE_LICENSE("GPL");
+
+/* Byte-wise swap two items of size SIZE. */
+#define SWAP(a, b, size) \
+ do \
+ { \
+ register size_t __size = (size); \
+ register char *__a = (a), *__b = (b); \
+ do \
+ { \
+ char __tmp = *__a; \
+ *__a++ = *__b; \
+ *__b++ = __tmp; \
+ } while (--__size > 0); \
+ } while (0)
+
+/* Discontinue quicksort algorithm when partition gets below this size.
+ This particular magic number was chosen to work best on a Sun 4/260. */
+#define MAX_THRESH 4
+
+/* Stack node declarations used to store unfulfilled partition obligations. */
+typedef struct
+ {
+ char *lo;
+ char *hi;
+ } stack_node;
+
+/* The next 5 #defines implement a very fast in-line stack abstraction. */
+/* The stack needs log (total_elements) entries (we could even subtract
+ log(MAX_THRESH)). Since total_elements has type size_t, we get as
+ upper bound for log (total_elements):
+ bits per byte (CHAR_BIT) * sizeof(size_t). */
+#define CHAR_BIT 8
+#define STACK_SIZE (CHAR_BIT * sizeof(size_t))
+#define PUSH(low, high) ((void) ((top->lo = (low)), (top->hi = (high)), ++top))
+#define POP(low, high) ((void) (--top, (low = top->lo), (high = top->hi)))
+#define STACK_NOT_EMPTY (stack < top)
+
+
+/* Order size using quicksort. This implementation incorporates
+ four optimizations discussed in Sedgewick:
+
+ 1. Non-recursive, using an explicit stack of pointer that store the
+ next array partition to sort. To save time, this maximum amount
+ of space required to store an array of SIZE_MAX is allocated on the
+ stack. Assuming a 32-bit (64 bit) integer for size_t, this needs
+ only 32 * sizeof(stack_node) == 256 bytes (for 64 bit: 1024 bytes).
+ Pretty cheap, actually.
+
+ 2. Chose the pivot element using a median-of-three decision tree.
+ This reduces the probability of selecting a bad pivot value and
+ eliminates certain extraneous comparisons.
+
+ 3. Only quicksorts TOTAL_ELEMS / MAX_THRESH partitions, leaving
+ insertion sort to order the MAX_THRESH items within each partition.
+ This is a big win, since insertion sort is faster for small, mostly
+ sorted array segments.
+
+ 4. The larger of the two sub-partitions is always pushed onto the
+ stack first, with the algorithm then concentrating on the
+ smaller partition. This *guarantees* no more than log (total_elems)
+ stack size is needed (actually O(1) in this case)! */
+
+void
+qsort(void *const pbase, size_t total_elems, size_t size,
+ int(*cmp)(const void *,const void *))
+{
+ register char *base_ptr = (char *) pbase;
+
+ const size_t max_thresh = MAX_THRESH * size;
+
+ if (total_elems == 0)
+ /* Avoid lossage with unsigned arithmetic below. */
+ return;
+
+ if (total_elems > MAX_THRESH)
+ {
+ char *lo = base_ptr;
+ char *hi = &lo[size * (total_elems - 1)];
+ stack_node stack[STACK_SIZE];
+ stack_node *top = stack + 1;
+
+ while (STACK_NOT_EMPTY)
+ {
+ char *left_ptr;
+ char *right_ptr;
+
+ /* Select median value from among LO, MID, and HI. Rearrange
+ LO and HI so the three values are sorted. This lowers the
+ probability of picking a pathological pivot value and
+ skips a comparison for both the LEFT_PTR and RIGHT_PTR in
+ the while loops. */
+
+ char *mid = lo + size * ((hi - lo) / size >> 1);
+
+ if ((*cmp) ((void *) mid, (void *) lo) < 0)
+ SWAP (mid, lo, size);
+ if ((*cmp) ((void *) hi, (void *) mid) < 0)
+ SWAP (mid, hi, size);
+ else
+ goto jump_over;
+ if ((*cmp) ((void *) mid, (void *) lo) < 0)
+ SWAP (mid, lo, size);
+ jump_over:;
+
+ left_ptr = lo + size;
+ right_ptr = hi - size;
+
+ /* Here's the famous ``collapse the walls'' section of quicksort.
+ Gotta like those tight inner loops! They are the main reason
+ that this algorithm runs much faster than others. */
+ do
+ {
+ while ((*cmp) ((void *) left_ptr, (void *) mid) < 0)
+ left_ptr += size;
+
+ while ((*cmp) ((void *) mid, (void *) right_ptr) < 0)
+ right_ptr -= size;
+
+ if (left_ptr < right_ptr)
+ {
+ SWAP (left_ptr, right_ptr, size);
+ if (mid == left_ptr)
+ mid = right_ptr;
+ else if (mid == right_ptr)
+ mid = left_ptr;
+ left_ptr += size;
+ right_ptr -= size;
+ }
+ else if (left_ptr == right_ptr)
+ {
+ left_ptr += size;
+ right_ptr -= size;
+ break;
+ }
+ }
+ while (left_ptr <= right_ptr);
+
+ /* Set up pointers for next iteration. First determine whether
+ left and right partitions are below the threshold size. If so,
+ ignore one or both. Otherwise, push the larger partition's
+ bounds on the stack and continue sorting the smaller one. */
+
+ if ((size_t) (right_ptr - lo) <= max_thresh)
+ {
+ if ((size_t) (hi - left_ptr) <= max_thresh)
+ /* Ignore both small partitions. */
+ POP (lo, hi);
+ else
+ /* Ignore small left partition. */
+ lo = left_ptr;
+ }
+ else if ((size_t) (hi - left_ptr) <= max_thresh)
+ /* Ignore small right partition. */
+ hi = right_ptr;
+ else if ((right_ptr - lo) > (hi - left_ptr))
+ {
+ /* Push larger left partition indices. */
+ PUSH (lo, right_ptr);
+ lo = left_ptr;
+ }
+ else
+ {
+ /* Push larger right partition indices. */
+ PUSH (left_ptr, hi);
+ hi = right_ptr;
+ }
+ }
+ }
+
+ /* Once the BASE_PTR array is partially sorted by quicksort the rest
+ is completely sorted using insertion sort, since this is efficient
+ for partitions below MAX_THRESH size. BASE_PTR points to the beginning
+ of the array to sort, and END_PTR points at the very last element in
+ the array (*not* one beyond it!). */
+
+ {
+ char *end_ptr = &base_ptr[size * (total_elems - 1)];
+ char *tmp_ptr = base_ptr;
+ char *thresh = min(end_ptr, base_ptr + max_thresh);
+ register char *run_ptr;
+
+ /* Find smallest element in first threshold and place it at the
+ array's beginning. This is the smallest array element,
+ and the operation speeds up insertion sort's inner loop. */
+
+ for (run_ptr = tmp_ptr + size; run_ptr <= thresh; run_ptr += size)
+ if ((*cmp) ((void *) run_ptr, (void *) tmp_ptr) < 0)
+ tmp_ptr = run_ptr;
+
+ if (tmp_ptr != base_ptr)
+ SWAP (tmp_ptr, base_ptr, size);
+
+ /* Insertion sort, running from left-hand-side up to right-hand-side. */
+
+ run_ptr = base_ptr + size;
+ while ((run_ptr += size) <= end_ptr)
+ {
+ tmp_ptr = run_ptr - size;
+ while ((*cmp) ((void *) run_ptr, (void *) tmp_ptr) < 0)
+ tmp_ptr -= size;
+
+ tmp_ptr += size;
+ if (tmp_ptr != run_ptr)
+ {
+ char *trav;
+
+ trav = run_ptr + size;
+ while (--trav >= run_ptr)
+ {
+ char c = *trav;
+ char *hi, *lo;
+
+ for (hi = lo = trav; (lo -= size) >= tmp_ptr; hi = lo)
+ *hi = *lo;
+ *hi = c;
+ }
+ }
+ }
+ }
+}
+/* If qsort is built into the kernel, we export the qsort symbol in
+ kernel/ksyms.c: The files in lib/ end up in lib.a, so qsort.o only
+ gets linked into the kernel image if it is used somewhere. */
+#if defined(CONFIG_QSORT_MODULE)
+EXPORT_SYMBOL(qsort);
+#endif