Revision cea20ca3f3181fc36788a15bc65d1062b96a0a6c authored by Linus Torvalds on 20 February 2012, 18:24:09 UTC, committed by Linus Torvalds on 20 February 2012, 18:24:09 UTC
This makes sure we clear the FPU usage counter for newly created tasks,
just so that we start off in a known state (for example, don't try to
preload the FPU state on the first task switch etc).

It also fixes a thinko in when we increment the fpu_counter at task
switch time, introduced by commit 34ddc81a230b ("i387: re-introduce FPU
state preloading at context switch time").  We should increment the
*new* task fpu_counter, not the old task, and only if we decide to use
that state (whether lazily or preloaded).

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 parent b01543d
Raw File
bsearch.c
/*
 * A generic implementation of binary search for the Linux kernel
 *
 * Copyright (C) 2008-2009 Ksplice, Inc.
 * Author: Tim Abbott <tabbott@ksplice.com>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; version 2.
 */

#include <linux/module.h>
#include <linux/bsearch.h>

/*
 * bsearch - binary search an array of elements
 * @key: pointer to item being searched for
 * @base: pointer to first element to search
 * @num: number of elements
 * @size: size of each element
 * @cmp: pointer to comparison function
 *
 * This function does a binary search on the given array.  The
 * contents of the array should already be in ascending sorted order
 * under the provided comparison function.
 *
 * Note that the key need not have the same type as the elements in
 * the array, e.g. key could be a string and the comparison function
 * could compare the string with the struct's name field.  However, if
 * the key and elements in the array are of the same type, you can use
 * the same comparison function for both sort() and bsearch().
 */
void *bsearch(const void *key, const void *base, size_t num, size_t size,
	      int (*cmp)(const void *key, const void *elt))
{
	size_t start = 0, end = num;
	int result;

	while (start < end) {
		size_t mid = start + (end - start) / 2;

		result = cmp(key, base + mid * size);
		if (result < 0)
			end = mid;
		else if (result > 0)
			start = mid + 1;
		else
			return (void *)base + mid * size;
	}

	return NULL;
}
EXPORT_SYMBOL(bsearch);
back to top