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Commit be5b4fbd authored by Jesper Juhl's avatar Jesper Juhl Committed by Linus Torvalds
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[PATCH] preempt_count is int - remove cast and don't assign to unsigned type 



In kernel/sched.c the return value from preempt_count() is cast to an int.
That made sense when preempt_count was defined as different types on is not
needed and should go away.  The patch removes the cast.

In kernel/timer.c the return value from preempt_count() is assigned to a
variable of type u32 and then that unsigned value is later compared to
preempt_count().  Since preempt_count() returns an int, an int is what
should be used to store its return value.  Storing the result in an
unsigned 32bit integer made a tiny bit of sense back when preempt_count was
different types on different archs, but no more - let's not play signed vs
unsigned comparison games when we don't have to.  The patch modifies the
code to use an int to hold the value.  While I was around that bit of code
I also made two changes to a nearby (related) printk() - I modified it to
specify the loglevel explicitly and also broke the line into a few pieces
to avoid it being longer than 80 chars and clarified the text a bit.

Signed-off-by: default avatarJesper Juhl <juhl-lkml@dif.dk>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent dcd497f9

kernel/sched.c

+1 −1
Original line number Diff line number Diff line
@@ -2576,7 +2576,7 @@ void fastcall add_preempt_count(int val) 
	/*

	 * Underflow?

	 */

	BUG_ON(((int)preempt_count() < 0));

	BUG_ON((preempt_count() < 0));

	preempt_count() += val;

	/*

	 * Spinlock count overflowing soon?

kernel/timer.c

+6 −2
Original line number Diff line number Diff line
@@ -489,10 +489,14 @@ static inline void __run_timers(tvec_base_t *base) 
			detach_timer(timer, 1);

			spin_unlock_irq(&base->t_base.lock);

			{

				u32 preempt_count = preempt_count();

				int preempt_count = preempt_count();

				fn(data);

				if (preempt_count != preempt_count()) {

					printk("huh, entered %p with %08x, exited with %08x?\n", fn, preempt_count, preempt_count());

					printk(KERN_WARNING "huh, entered %p "

					       "with preempt_count %08x, exited"

					       " with %08x?\n",

					       fn, preempt_count,

					       preempt_count());

					BUG();

				}

			}