MIPS still uses sleep_on*()

MIPS still uses sleep_on*()

[Nishanth Aravamudan]

Hi,

I am trying to clean up the remaning sleep_on*() calls in the kernel. These
functions have been deprecated for a *long* time, just never completely removed
:)

The only file I'm not comfortable with changing myself (since I am not a MIPS
user/expert) is arch/mips/kernel/process.c. This file references sleep_on(),
sleep_on_timeout(), interruptible_sleep_on() and
interruptible_sleep_on_timeout().

This file is (presuming my upcoming patches for sleep_on() go through
Kernel-Janitors ok) the final one before we can declare the kernel clean of
sleep_on() callers -- the other members of the family will take longer.

Any insight anyone could provide would be great, so that this milestone (for me,
at least) can be achieved.

Thanks,
Nish

Re: MIPS still uses sleep_on*()

[Atsushi Nemoto]

>>>>> On Tue, 25 Jan 2005 13:47:01 -0800, Nishanth Aravamudan <nacc@us.ibm.com> said:
nacc> The only file I'm not comfortable with changing myself (since I
nacc> am not a MIPS user/expert) is arch/mips/kernel/process.c. This
nacc> file references sleep_on(), sleep_on_timeout(),
nacc> interruptible_sleep_on() and interruptible_sleep_on_timeout().

Those references are just to implement get_wchan.  And anyway current
MIPS get_wchan is broken for a long time.

I suppose searching a caller of scheduling functions is not necessary.
Calling thread_saved_pc() will be enough for most usage.

Ralf, how about this patch?

diff -u linux-mips/arch/mips/kernel/process.c linux/arch/mips/kernel/process.c
--- linux-mips/arch/mips/kernel/process.c	2005-01-11 10:00:07.000000000 +0900
+++ linux/arch/mips/kernel/process.c	2005-01-26 10:23:21.000000000 +0900
@@ -186,11 +186,6 @@
 	int pc_offset;
 };
 static struct mips_frame_info schedule_frame;
-static struct mips_frame_info schedule_timeout_frame;
-static struct mips_frame_info sleep_on_frame;
-static struct mips_frame_info sleep_on_timeout_frame;
-static struct mips_frame_info wait_for_completion_frame;
-static int mips_frame_info_initialized;
 static int __init get_frame_info(struct mips_frame_info *info, void *func)
 {
 	int i;
@@ -242,14 +237,7 @@
 
 static int __init frame_info_init(void)
 {
-	mips_frame_info_initialized =
-		!get_frame_info(&schedule_frame, schedule) &&
-		!get_frame_info(&schedule_timeout_frame, schedule_timeout) &&
-		!get_frame_info(&sleep_on_frame, sleep_on) &&
-		!get_frame_info(&sleep_on_timeout_frame, sleep_on_timeout) &&
-		!get_frame_info(&wait_for_completion_frame, wait_for_completion);
-
-	return 0;
+	return get_frame_info(&schedule_frame, schedule);
 }
 
 arch_initcall(frame_info_init);
@@ -270,59 +258,14 @@
 	return ((unsigned long *)t->reg29)[schedule_frame.pc_offset];
 }
 
-/* get_wchan - a maintenance nightmare^W^Wpain in the ass ...  */
 unsigned long get_wchan(struct task_struct *p)
 {
-	unsigned long frame, pc;
+	unsigned long pc;
 
 	if (!p || p == current || p->state == TASK_RUNNING)
 		return 0;
 
-	if (!mips_frame_info_initialized)
-		return 0;
 	pc = thread_saved_pc(p);
-	if (!in_sched_functions(pc))
-		goto out;
-
-	if (pc >= (unsigned long) sleep_on_timeout)
-		goto schedule_timeout_caller;
-	if (pc >= (unsigned long) sleep_on)
-		goto schedule_caller;
-	if (pc >= (unsigned long) interruptible_sleep_on_timeout)
-		goto schedule_timeout_caller;
-	if (pc >= (unsigned long)interruptible_sleep_on)
-		goto schedule_caller;
-	if (pc >= (unsigned long)wait_for_completion)
-		goto schedule_caller;
-	goto schedule_timeout_caller;
-
-schedule_caller:
-	frame = ((unsigned long *)p->thread.reg30)[schedule_frame.frame_offset];
-	if (pc >= (unsigned long) sleep_on)
-		pc = ((unsigned long *)frame)[sleep_on_frame.pc_offset];
-	else
-		pc = ((unsigned long *)frame)[wait_for_completion_frame.pc_offset];
-	goto out;
-
-schedule_timeout_caller:
-	/*
-	 * The schedule_timeout frame
-	 */
-	frame = ((unsigned long *)p->thread.reg30)[schedule_frame.frame_offset];
-
-	/*
-	 * frame now points to sleep_on_timeout's frame
-	 */
-	pc    = ((unsigned long *)frame)[schedule_timeout_frame.pc_offset];
-
-	if (in_sched_functions(pc)) {
-		/* schedule_timeout called by [interruptible_]sleep_on_timeout */
-		frame = ((unsigned long *)frame)[schedule_timeout_frame.frame_offset];
-		pc    = ((unsigned long *)frame)[sleep_on_timeout_frame.pc_offset];
-	}
-
-out:
-
 #ifdef CONFIG_MIPS64
 	if (current->thread.mflags & MF_32BIT_REGS) /* Kludge for 32-bit ps  */
 		pc &= 0xffffffffUL;