2002-02-11 02:27:13

by Udo A. Steinberg

[permalink] [raw]
Subject: [PATCH] 2.5.4-pre6 apm compile fix


Hi Linus,

The attached patch fixes the following compiler warning in -pre6:

apm.c: In function `apm_mainloop':
apm.c:1376: warning: comparison between pointer and integer
apm.c:1384: warning: comparison between pointer and integer

nr_running is really a function and not an integer.

I believe this had already been applied in earlier 2.5 and then somehow
vanished, probably due to an update by whoever maintains apm.c

Regards,
-Udo.


--- linux-2.5.4-pre-vanilla/arch/i386/kernel/apm.c Mon Feb 11 03:04:25 2002
+++ linux-2.5.4-pre/arch/i386/kernel/apm.c Mon Feb 11 03:04:51 2002
@@ -1348,7 +1348,7 @@
* decide if we should just power down.
*
*/
-#define system_idle() (nr_running == 1)
+#define system_idle() (nr_running() == 1)

static void apm_mainloop(void)
{


2002-02-11 02:49:25

by Alan

[permalink] [raw]
Subject: Re: [PATCH] 2.5.4-pre6 apm compile fix

>
> I believe this had already been applied in earlier 2.5 and then somehow
> vanished, probably due to an update by whoever maintains apm.c

Doubt it - the 2.4.18pre tree uses a much more uptodate APM code set that
removes the rather broken system_idle check for a new algorithm (and
adds 20% to my typical battery lifetime!). Probably its another thing that
really wants porting forward.

I think its from scheduling changes.

> -#define system_idle() (nr_running == 1)
> +#define system_idle() (nr_running() == 1)

2002-02-12 01:23:45

by Stephen Rothwell

[permalink] [raw]
Subject: Re: [PATCH] 2.5.4-pre6 apm compile fix

On Mon, 11 Feb 2002 03:02:35 +0000 (GMT)
Alan Cox <[email protected]> wrote:

> >
> > I believe this had already been applied in earlier 2.5 and then
> > somehow vanished, probably due to an update by whoever maintains apm.c

It has been applied to the DJ series.

> Doubt it - the 2.4.18pre tree uses a much more uptodate APM code set
> that removes the rather broken system_idle check for a new algorithm
> (and adds 20% to my typical battery lifetime!). Probably its another
> thing that really wants porting forward.

Here is the patch against 2.5.4. I have compiled this patch under
2.5.3, so it should still be OK.

This patch just resyncs the driver with 2.4.18-pre (which is what is
being testd by others). The only outstanding known problem is some
very strange interaction with VMWARE. But otherwise people seem
happy with the changes.

Original announcement to Dave Jones and Marcelo:

Update a couple of email addresses
Fix the idle handling (this is an improved version of the fix
that Alan Cox has in his -ac tree)
Notify user mode of suspend events before drivers (fix)
Make the idling percentage boot time configurable
Rename kapm-idled to kapmd

Credit to Andreas Steinmetz, Russell King, Thomas Hood and me.

More small updates to come.
--
Cheers,
Stephen Rothwell [email protected]
http://www.canb.auug.org.au/~sfr/

diff -ruN 2.5.4/arch/i386/kernel/apm.c 2.5.4-APM.1/arch/i386/kernel/apm.c
--- 2.5.4/arch/i386/kernel/apm.c Thu Jan 31 09:59:34 2002
+++ 2.5.4-APM.1/arch/i386/kernel/apm.c Tue Feb 12 11:29:40 2002
@@ -39,6 +39,7 @@
* Feb 2000, Version 1.13
* Nov 2000, Version 1.14
* Oct 2001, Version 1.15
+ * Jan 2002, Version 1.16
*
* History:
* 0.6b: first version in official kernel, Linux 1.3.46
@@ -85,7 +86,7 @@
* change APM_NOINTS to CONFIG_APM_ALLOW_INTS
* remove dependency on CONFIG_PROC_FS
* Stephen Rothwell
- * 1.9: Fix small typo. <[email protected]>
+ * 1.9: Fix small typo. <[email protected]>
* Try to cope with BIOS's that need to have all display
* devices blanked and not just the first one.
* Ross Paterson <[email protected]>
@@ -164,8 +165,18 @@
* If an APM idle fails log it and idle sensibly
* 1.15: Don't queue events to clients who open the device O_WRONLY.
* Don't expect replies from clients who open the device O_RDONLY.
- * (Idea from Thomas Hood <jdthood at yahoo.co.uk>)
- * Minor waitqueue cleanups.(John Fremlin <[email protected]>)
+ * (Idea from Thomas Hood <[email protected]>)
+ * Minor waitqueue cleanups. (John Fremlin <[email protected]>)
+ * 1.16: Fix idle calling. (Andreas Steinmetz <[email protected]> et al.)
+ * Notify listeners of standby or suspend events before notifying
+ * drivers. Return EBUSY to ioctl() if suspend is rejected.
+ * (Russell King <[email protected]> and Thomas Hood)
+ * Ignore first resume after we generate our own resume event
+ * after a suspend (Thomas Hood <[email protected]>)
+ * Daemonize now gets rid of our controlling terminal (sfr).
+ * CONFIG_APM_CPU_IDLE now just affects the default value of
+ * idle_threshold (sfr).
+ * Change name of kernel apm daemon (as it no longer idles) (sfr).
*
* APM 1.1 Reference:
*
@@ -238,6 +249,12 @@
* [no-]power[-_]off power off on shutdown
* bounce[-_]interval=<n> number of ticks to ignore suspend
* bounces
+ * idle[-_]threshold=<n> System idle percentage above which to
+ * make APM BIOS idle calls. Set it to
+ * 100 to disable.
+ * idle[-_]period=<n> Period (in 1/100s of a second) over
+ * which the idle percentage is
+ * calculated.
*/

/* KNOWN PROBLEM MACHINES:
@@ -341,15 +358,26 @@
#define APM_BIOS_MAGIC 0x4101

/*
+ * idle percentage above which bios idle calls are done
+ */
+#ifdef CONFIG_APM_CPU_IDLE
+#define DEFAULT_IDLE_THRESHOLD 95
+#else
+#define DEFAULT_IDLE_THRESHOLD 100
+#endif
+#define DEFAULT_IDLE_PERIOD (100 / 3)
+
+/*
* Local variables
*/
static struct {
unsigned long offset;
unsigned short segment;
} apm_bios_entry;
-#ifdef CONFIG_APM_CPU_IDLE
static int clock_slowed;
-#endif
+static int idle_threshold = DEFAULT_IDLE_THRESHOLD;
+static int idle_period = DEFAULT_IDLE_PERIOD;
+static int set_pm_idle;
static int suspends_pending;
static int standbys_pending;
static int waiting_for_resume;
@@ -389,7 +417,7 @@
static struct apm_user * user_list;
static spinlock_t user_list_lock = SPIN_LOCK_UNLOCKED;

-static char driver_version[] = "1.15"; /* no spaces */
+static char driver_version[] = "1.16"; /* no spaces */

/*
* APM event names taken from the APM 1.2 specification. These are
@@ -685,8 +713,6 @@
return set_power_state(APM_DEVICE_ALL, state);
}

-#ifdef CONFIG_APM_CPU_IDLE
-
/**
* apm_do_idle - perform power saving
*
@@ -736,63 +762,89 @@
}
}

-#if 0
-extern int hlt_counter;
-
/*
- * If no process has been interested in this
- * CPU for some time, we want to wake up the
- * power management thread - we probably want
+ * If no process has really been interested in
+ * the CPU for some time, we want to call BIOS
+ * power management - we probably want
* to conserve power.
*/
-#define HARD_IDLE_TIMEOUT (HZ/3)
+#define IDLE_CALC_LIMIT (HZ * 100)
+#define IDLE_LEAKY_MAX 16

-/* This should wake up kapmd and ask it to slow the CPU */
-#define powermanagement_idle() do { } while (0)
+static void (*sys_idle)(void);
+
+extern void default_idle(void);

/**
* apm_cpu_idle - cpu idling for APM capable Linux
*
* This is the idling function the kernel executes when APM is available. It
- * tries to save processor time directly by using hlt instructions. A
- * separate apm thread tries to do the BIOS power management.
- *
- * N.B. This is curently not used for kernels 2.4.x.
+ * tries to do BIOS powermanagement based on the average system idle time.
+ * Furthermore it calls the system default idle routine.
*/

static void apm_cpu_idle(void)
{
- unsigned int start_idle;
+ static int use_apm_idle = 0;
+ static unsigned int last_jiffies = 0;
+ static unsigned int last_stime = 0;
+
+ int apm_is_idle = 0;
+ unsigned int jiffies_since_last_check = jiffies - last_jiffies;
+ unsigned int t1;
+
+
+recalc:
+ if (jiffies_since_last_check > IDLE_CALC_LIMIT) {
+ use_apm_idle = 0;
+ last_jiffies = jiffies;
+ last_stime = current->times.tms_stime;
+ } else if (jiffies_since_last_check > idle_period) {
+ unsigned int idle_percentage;
+
+ idle_percentage = current->times.tms_stime - last_stime;
+ idle_percentage *= 100;
+ idle_percentage /= jiffies_since_last_check;
+ use_apm_idle = (idle_percentage > idle_threshold);
+ last_jiffies = jiffies;
+ last_stime = current->times.tms_stime;
+ }
+
+ t1 = IDLE_LEAKY_MAX;
+
+ while (need_resched()) {
+ if (use_apm_idle) {
+ unsigned int t;

- start_idle = jiffies;
- while (1) {
- if (!need_resched()) {
- if (jiffies - start_idle < HARD_IDLE_TIMEOUT) {
- if (!current_cpu_data.hlt_works_ok)
- continue;
- if (hlt_counter)
+ t = jiffies;
+ switch (apm_do_idle()) {
+ case 0: apm_is_idle = 1;
+ if (t != jiffies) {
+ if (t1) {
+ t1 = IDLE_LEAKY_MAX;
+ continue;
+ }
+ } else if (t1) {
+ t1--;
continue;
- __cli();
- if (!need_resched())
- safe_halt();
- else
- __sti();
- continue;
+ }
+ break;
+ case 1: apm_is_idle = 1;
+ break;
}
-
- /*
- * Ok, do some power management - we've been idle for too long
- */
- powermanagement_idle();
}
-
- schedule();
- check_pgt_cache();
- start_idle = jiffies;
+ if (sys_idle)
+ sys_idle();
+ else
+ default_idle();
+ jiffies_since_last_check = jiffies - last_jiffies;
+ if (jiffies_since_last_check > idle_period)
+ goto recalc;
}
+
+ if (apm_is_idle)
+ apm_do_busy();
}
-#endif
-#endif

#ifdef CONFIG_SMP
static int apm_magic(void * unused)
@@ -1137,59 +1189,44 @@
#endif
}

-static int send_event(apm_event_t event)
+static int suspend(int vetoable)
{
- switch (event) {
- case APM_SYS_SUSPEND:
- case APM_CRITICAL_SUSPEND:
- case APM_USER_SUSPEND:
- /* map all suspends to ACPI D3 */
- if (pm_send_all(PM_SUSPEND, (void *)3)) {
- if (event == APM_CRITICAL_SUSPEND) {
- printk(KERN_CRIT
- "apm: Critical suspend was vetoed, "
- "expect armageddon\n" );
- return 0;
- }
+ int err;
+ struct apm_user *as;
+
+ if (pm_send_all(PM_SUSPEND, (void *)3)) {
+ /* Vetoed */
+ if (vetoable) {
if (apm_info.connection_version > 0x100)
apm_set_power_state(APM_STATE_REJECT);
- return 0;
+ err = -EBUSY;
+ waiting_for_resume = 0;
+ printk(KERN_WARNING "apm: suspend was vetoed.\n");
+ goto out;
}
- break;
- case APM_NORMAL_RESUME:
- case APM_CRITICAL_RESUME:
- /* map all resumes to ACPI D0 */
- (void) pm_send_all(PM_RESUME, (void *)0);
- break;
+ printk(KERN_CRIT "apm: suspend was vetoed, but suspending anyway.\n");
}
-
- return 1;
-}
-
-static int suspend(void)
-{
- int err;
- struct apm_user *as;
-
get_time_diff();
cli();
err = apm_set_power_state(APM_STATE_SUSPEND);
reinit_timer();
set_time();
+ sti();
if (err == APM_NO_ERROR)
err = APM_SUCCESS;
if (err != APM_SUCCESS)
apm_error("suspend", err);
- send_event(APM_NORMAL_RESUME);
- sti();
+ err = (err == APM_SUCCESS) ? 0 : -EIO;
+ pm_send_all(PM_RESUME, (void *)0);
queue_event(APM_NORMAL_RESUME, NULL);
+ ignore_normal_resume = 1;
+ out:
spin_lock(&user_list_lock);
for (as = user_list; as != NULL; as = as->next) {
as->suspend_wait = 0;
- as->suspend_result = ((err == APM_SUCCESS) ? 0 : -EIO);
+ as->suspend_result = err;
}
spin_unlock(&user_list_lock);
- ignore_normal_resume = 1;
wake_up_interruptible(&apm_suspend_waitqueue);
return err;
}
@@ -1198,6 +1235,7 @@
{
int err;

+ /* If needed, notify drivers here */
get_time_diff();
err = apm_set_power_state(APM_STATE_STANDBY);
if ((err != APM_SUCCESS) && (err != APM_NO_ERROR))
@@ -1241,17 +1279,13 @@
if (ignore_bounce
&& ((jiffies - last_resume) > bounce_interval))
ignore_bounce = 0;
- if (ignore_normal_resume && (event != APM_NORMAL_RESUME))
- ignore_normal_resume = 0;

switch (event) {
case APM_SYS_STANDBY:
case APM_USER_STANDBY:
- if (send_event(event)) {
- queue_event(event, NULL);
- if (standbys_pending <= 0)
- standby();
- }
+ queue_event(event, NULL);
+ if (standbys_pending <= 0)
+ standby();
break;

case APM_USER_SUSPEND:
@@ -1276,12 +1310,10 @@
*/
if (waiting_for_resume)
return;
- if (send_event(event)) {
- queue_event(event, NULL);
- waiting_for_resume = 1;
- if (suspends_pending <= 0)
- (void) suspend();
- }
+ waiting_for_resume = 1;
+ queue_event(event, NULL);
+ if (suspends_pending <= 0)
+ (void) suspend(1);
break;

case APM_NORMAL_RESUME:
@@ -1293,16 +1325,17 @@
if ((event != APM_NORMAL_RESUME)
|| (ignore_normal_resume == 0)) {
set_time();
- send_event(event);
+ pm_send_all(PM_RESUME, (void *)0);
queue_event(event, NULL);
}
+ ignore_normal_resume = 0;
break;

case APM_CAPABILITY_CHANGE:
case APM_LOW_BATTERY:
case APM_POWER_STATUS_CHANGE:
- send_event(event);
queue_event(event, NULL);
+ /* If needed, notify drivers here */
break;

case APM_UPDATE_TIME:
@@ -1310,12 +1343,10 @@
break;

case APM_CRITICAL_SUSPEND:
- send_event(event);
/*
- * We can only hope it worked - we are not allowed
- * to reject a critical suspend.
+ * We are not allowed to reject a critical suspend.
*/
- (void) suspend();
+ (void) suspend(0);
break;
}
}
@@ -1343,63 +1374,24 @@

/*
* This is the APM thread main loop.
- *
- * Check whether we're the only running process to
- * decide if we should just power down.
- *
*/
-#define system_idle() (nr_running == 1)

static void apm_mainloop(void)
{
- int timeout = HZ;
DECLARE_WAITQUEUE(wait, current);

add_wait_queue(&apm_waitqueue, &wait);
set_current_state(TASK_INTERRUPTIBLE);
for (;;) {
- /* Nothing to do, just sleep for the timeout */
- timeout = 2 * timeout;
- if (timeout > APM_CHECK_TIMEOUT)
- timeout = APM_CHECK_TIMEOUT;
- schedule_timeout(timeout);
+ schedule_timeout(APM_CHECK_TIMEOUT);
if (exit_kapmd)
break;
-
/*
* Ok, check all events, check for idle (and mark us sleeping
* so as not to count towards the load average)..
*/
set_current_state(TASK_INTERRUPTIBLE);
apm_event_handler();
-#ifdef CONFIG_APM_CPU_IDLE
- if (!system_idle())
- continue;
-
- /*
- * If we can idle...
- */
- if (apm_do_idle() != -1) {
- unsigned long start = jiffies;
- while ((!exit_kapmd) && system_idle()) {
- if (apm_do_idle()) {
- set_current_state(TASK_INTERRUPTIBLE);
- /* APM needs us to snooze .. either
- the BIOS call failed (-1) or it
- slowed the clock (1). We sleep
- until it talks to us again */
- schedule_timeout(1);
- }
- if ((jiffies - start) > APM_CHECK_TIMEOUT) {
- apm_event_handler();
- start = jiffies;
- }
- }
- apm_do_busy();
- apm_event_handler();
- timeout = 1;
- }
-#endif
}
remove_wait_queue(&apm_waitqueue, &wait);
}
@@ -1485,9 +1477,7 @@
as->standbys_read--;
as->standbys_pending--;
standbys_pending--;
- } else if (!send_event(APM_USER_STANDBY))
- return -EAGAIN;
- else
+ } else
queue_event(APM_USER_STANDBY, as);
if (standbys_pending <= 0)
standby();
@@ -1497,13 +1487,10 @@
as->suspends_read--;
as->suspends_pending--;
suspends_pending--;
- } else if (!send_event(APM_USER_SUSPEND))
- return -EAGAIN;
- else
+ } else
queue_event(APM_USER_SUSPEND, as);
if (suspends_pending <= 0) {
- if (suspend() != APM_SUCCESS)
- return -EIO;
+ return suspend(1);
} else {
as->suspend_wait = 1;
wait_event_interruptible(apm_suspend_waitqueue,
@@ -1533,7 +1520,7 @@
if (as->suspends_pending > 0) {
suspends_pending -= as->suspends_pending;
if (suspends_pending <= 0)
- (void) suspend();
+ (void) suspend(1);
}
spin_lock(&user_list_lock);
if (user_list == as)
@@ -1684,9 +1671,8 @@

daemonize();

- strcpy(current->comm, "kapm-idled");
+ strcpy(current->comm, "kapmd");
sigfillset(&current->blocked);
- current->tty = NULL; /* get rid of controlling tty */

if (apm_info.connection_version == 0) {
apm_info.connection_version = apm_info.bios.version;
@@ -1805,7 +1791,14 @@
if ((strncmp(str, "bounce-interval=", 16) == 0) ||
(strncmp(str, "bounce_interval=", 16) == 0))
bounce_interval = simple_strtol(str + 16, NULL, 0);
- invert = (strncmp(str, "no-", 3) == 0);
+ if ((strncmp(str, "idle-threshold=", 15) == 0) ||
+ (strncmp(str, "idle_threshold=", 15) == 0))
+ idle_threshold = simple_strtol(str + 15, NULL, 0);
+ if ((strncmp(str, "idle-period=", 12) == 0) ||
+ (strncmp(str, "idle_period=", 12) == 0))
+ idle_threshold = simple_strtol(str + 15, NULL, 0);
+ invert = (strncmp(str, "no-", 3) == 0) ||
+ (strncmp(str, "no_", 3) == 0);
if (invert)
str += 3;
if (strncmp(str, "debug", 5) == 0)
@@ -1976,6 +1969,14 @@

misc_register(&apm_device);

+ if (HZ != 100)
+ idle_period = (idle_period * HZ) / 100;
+ if (idle_threshold < 100) {
+ sys_idle = pm_idle;
+ pm_idle = apm_cpu_idle;
+ set_pm_idle = 1;
+ }
+
return 0;
}

@@ -1983,6 +1984,8 @@
{
int error;

+ if (set_pm_idle)
+ pm_idle = sys_idle;
if (((apm_info.bios.flags & APM_BIOS_DISENGAGED) == 0)
&& (apm_info.connection_version > 0x0100)) {
error = apm_engage_power_management(APM_DEVICE_ALL, 0);
@@ -2020,5 +2023,11 @@
MODULE_PARM(realmode_power_off, "i");
MODULE_PARM_DESC(realmode_power_off,
"Switch to real mode before powering off");
+MODULE_PARM(idle_threshold, "i");
+MODULE_PARM_DESC(idle_threshold,
+ "System idle percentage above which to make APM BIOS idle calls");
+MODULE_PARM(idle_period, "i");
+MODULE_PARM_DESC(idle_period,
+ "Period (in sec/100) over which to caculate the idle percentage");

EXPORT_NO_SYMBOLS;
diff -ruN 2.5.4/arch/i386/kernel/i386_ksyms.c 2.5.4-APM.1/arch/i386/kernel/i386_ksyms.c
--- 2.5.4/arch/i386/kernel/i386_ksyms.c Thu Nov 29 23:32:06 2001
+++ 2.5.4-APM.1/arch/i386/kernel/i386_ksyms.c Mon Feb 11 22:43:19 2002
@@ -32,9 +32,11 @@
extern void dump_thread(struct pt_regs *, struct user *);
extern spinlock_t rtc_lock;

-#if defined(CONFIG_APM) || defined(CONFIG_APM_MODULE)
+#if defined(CONFIG_APM_MODULE)
extern void machine_real_restart(unsigned char *, int);
EXPORT_SYMBOL(machine_real_restart);
+extern void default_idle(void);
+EXPORT_SYMBOL(default_idle);
#endif

#ifdef CONFIG_SMP
@@ -93,7 +95,6 @@

EXPORT_SYMBOL(strtok);
EXPORT_SYMBOL(strpbrk);
-EXPORT_SYMBOL(simple_strtol);
EXPORT_SYMBOL(strstr);

EXPORT_SYMBOL(strncpy_from_user);
diff -ruN 2.5.4/arch/i386/kernel/process.c 2.5.4-APM.1/arch/i386/kernel/process.c
--- 2.5.4/arch/i386/kernel/process.c Mon Feb 11 17:37:19 2002
+++ 2.5.4-APM.1/arch/i386/kernel/process.c Mon Feb 11 22:11:06 2002
@@ -78,7 +78,7 @@
* We use this if we don't have any better
* idle routine..
*/
-static void default_idle(void)
+void default_idle(void)
{
if (current_cpu_data.hlt_works_ok && !hlt_counter) {
__cli();

2002-02-12 21:15:22

by Pavel Machek

[permalink] [raw]
Subject: Re: [PATCH] 2.5.4-pre6 apm compile fix

Hi!

> This patch just resyncs the driver with 2.4.18-pre (which is what is
> being testd by others). The only outstanding known problem is some
> very strange interaction with VMWARE. But otherwise people seem
> happy with the changes.
>
> Original announcement to Dave Jones and Marcelo:
>
> Update a couple of email addresses
> Fix the idle handling (this is an improved version of the fix
> that Alan Cox has in his -ac tree)
> Notify user mode of suspend events before drivers (fix)
> Make the idling percentage boot time configurable

Maybe its time to kill CONFIG_APM_CPU_IDLE? No need for CONFIG_ option
when its configurable at boot time, right?
Pavel
--
(about SSSCA) "I don't say this lightly. However, I really think that the U.S.
no longer is classifiable as a democracy, but rather as a plutocracy." --hpa