Re: linux-next: build failure after merge of the final tree (pm tree related)
From: Pihet-XID, Jean
Date: Fri Aug 19 2011 - 04:14:27 EST
Hi Stephen, Rafael,
On Fri, Aug 19, 2011 at 5:03 AM, Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx> wrote:
> Hi all,
>
> After merging the final tree, today's linux-next build (powerpc
> allnoconfig) failed like this:
>
> In file included from include/linux/netdevice.h:34:0,
> from include/linux/icmpv6.h:173,
> from include/linux/ipv6.h:220,
> from include/net/ipv6.h:16,
> from include/linux/sunrpc/clnt.h:25,
> from include/linux/nfs_fs.h:50,
> from init/do_mounts.c:20:
> include/linux/pm_qos.h: In function 'dev_pm_qos_add_request':
> include/linux/pm_qos.h:123:6: warning: 'return' with no value, in function returning non-void
> include/linux/pm_qos.h: In function 'dev_pm_qos_update_request':
> include/linux/pm_qos.h:126:6: warning: 'return' with no value, in function returning non-void
> include/linux/pm_qos.h: In function 'dev_pm_qos_remove_request':
> include/linux/pm_qos.h:128:6: warning: 'return' with no value, in function returning non-void
>
> Caused by commit b6d5b88750dc ("PM QoS: Implement per-device PM QoS
> constraints").
I am really sorry about this. This build failure is indeed due to my
patch which has stubs for the !PM case.
Here is an updated patch (attached), the only change is in the stubs.
>
> Please, please compile test with CONFIG options that your patch depends
> on switched on and switched off - in this case CONFIG_PM.
Well, it is not as easy as it seems. As the patch set describes, I am
build testing for x86 and OMAP. At the moment due to config
dependencies it is _impossible_ to disable PM in the OMAP config.
Also I cannot build test every platform out there.
Do you have a procedure for build testing?
>
> I have reverted that commit (and the followinf commit 57afcf09649c ("PM
> QoS: Add global notification mechanism for device constraints")) for
> today.
Can we have the updated version merged in?
Meanwhile I am trying a build with a non PM config.
Kind regards,
Jean
>
> --
> Cheers,
> Stephen Rothwell sfr@xxxxxxxxxxxxxxxx
> http://www.canb.auug.org.au/~sfr/
>
From a75badc8e0126bc55a8b16510c7beb60fa313f89 Mon Sep 17 00:00:00 2001
From: Jean Pihet <j-pihet@xxxxxx>
Date: Mon, 8 Aug 2011 16:16:39 +0200
Subject: [PATCH 6/7] PM QoS: implement the per-device PM QoS constraints
Implement the per-device PM QoS constraints by creating a device
PM QoS API, which calls the PM QoS constraints management core code.
The per-device latency constraints data strctures are stored
in the device dev_pm_info struct.
The device PM code calls the init and destroy of the per-device constraints
data struct in order to support the dynamic insertion and removal of the
devices in the system.
To minimize the data usage by the per-device constraints, the data struct
is only allocated at the first call to dev_pm_qos_add_request.
The data is later free'd when the device is removed from the system.
A global mutex protects the constraints users from the data being
allocated and free'd.
Signed-off-by: Jean Pihet <j-pihet@xxxxxx>
---
drivers/base/power/Makefile | 4 +-
drivers/base/power/main.c | 3 +
drivers/base/power/qos.c | 339 +++++++++++++++++++++++++++++++++++++++++++
include/linux/pm.h | 9 +
include/linux/pm_qos.h | 42 ++++++
5 files changed, 395 insertions(+), 2 deletions(-)
create mode 100644 drivers/base/power/qos.c
diff --git a/drivers/base/power/Makefile b/drivers/base/power/Makefile
index 2639ae7..b707447 100644
--- a/drivers/base/power/Makefile
+++ b/drivers/base/power/Makefile
@@ -1,4 +1,4 @@
-obj-$(CONFIG_PM) += sysfs.o generic_ops.o
+obj-$(CONFIG_PM) += sysfs.o generic_ops.o qos.o
obj-$(CONFIG_PM_SLEEP) += main.o wakeup.o
obj-$(CONFIG_PM_RUNTIME) += runtime.o
obj-$(CONFIG_PM_TRACE_RTC) += trace.o
@@ -6,4 +6,4 @@ obj-$(CONFIG_PM_OPP) += opp.o
obj-$(CONFIG_PM_GENERIC_DOMAINS) += domain.o
obj-$(CONFIG_HAVE_CLK) += clock_ops.o
-ccflags-$(CONFIG_DEBUG_DRIVER) := -DDEBUG
\ No newline at end of file
+ccflags-$(CONFIG_DEBUG_DRIVER) := -DDEBUG
diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c
index a854591..956443f 100644
--- a/drivers/base/power/main.c
+++ b/drivers/base/power/main.c
@@ -22,6 +22,7 @@
#include <linux/mutex.h>
#include <linux/pm.h>
#include <linux/pm_runtime.h>
+#include <linux/pm_qos.h>
#include <linux/resume-trace.h>
#include <linux/interrupt.h>
#include <linux/sched.h>
@@ -97,6 +98,7 @@ void device_pm_add(struct device *dev)
dev_name(dev->parent));
list_add_tail(&dev->power.entry, &dpm_list);
mutex_unlock(&dpm_list_mtx);
+ dev_pm_qos_constraints_init(dev);
}
/**
@@ -107,6 +109,7 @@ void device_pm_remove(struct device *dev)
{
pr_debug("PM: Removing info for %s:%s\n",
dev->bus ? dev->bus->name : "No Bus", dev_name(dev));
+ dev_pm_qos_constraints_destroy(dev);
complete_all(&dev->power.completion);
mutex_lock(&dpm_list_mtx);
list_del_init(&dev->power.entry);
diff --git a/drivers/base/power/qos.c b/drivers/base/power/qos.c
new file mode 100644
index 0000000..9c0a00d
--- /dev/null
+++ b/drivers/base/power/qos.c
@@ -0,0 +1,339 @@
+/*
+ * Devices PM QoS constraints management
+ *
+ * Copyright (C) 2011 Texas Instruments, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ *
+ * This module exposes the interface to kernel space for specifying
+ * per-device PM QoS dependencies. It provides infrastructure for registration
+ * of:
+ *
+ * Dependents on a QoS value : register requests
+ * Watchers of QoS value : get notified when target QoS value changes
+ *
+ * This QoS design is best effort based. Dependents register their QoS needs.
+ * Watchers register to keep track of the current QoS needs of the system.
+ *
+ * Note about the per-device constraint data struct allocation:
+ * . The per-device constraints data struct ptr is tored into the device
+ * dev_pm_info.
+ * . To minimize the data usage by the per-device constraints, the data struct
+ * is only allocated at the first call to dev_pm_qos_add_request.
+ * . The data is later free'd when the device is removed from the system.
+ * . The constraints_state variable from dev_pm_info tracks the data struct
+ * allocation state:
+ * DEV_PM_QOS_NO_DEVICE: No device present or device removed, no data
+ * allocated,
+ * DEV_PM_QOS_DEVICE_PRESENT: Device present, data not allocated and will be
+ * allocated at the first call to dev_pm_qos_add_request,
+ * DEV_PM_QOS_ALLOCATED: Device present, data allocated. The per-device
+ * PM QoS constraints framework is operational and constraints can be
+ * added, updated or removed using the dev_pm_qos_* API.
+ * . A global mutex protects the constraints users from the data being
+ * allocated and free'd.
+ */
+
+#include <linux/pm_qos.h>
+#include <linux/spinlock.h>
+#include <linux/slab.h>
+#include <linux/device.h>
+#include <linux/mutex.h>
+
+
+static DEFINE_MUTEX(dev_pm_qos_mtx);
+
+/*
+ * dev_pm_qos_constraints_allocate
+ * @dev: device to allocate data for
+ *
+ * Called at the first call to add_request, for constraint data allocation
+ * Must be called with the dev_pm_qos_mtx mutex held
+ */
+static int dev_pm_qos_constraints_allocate(struct device *dev)
+{
+ struct pm_qos_constraints *c;
+ struct blocking_notifier_head *n;
+
+ c = kzalloc(sizeof(*c), GFP_KERNEL);
+ if (!c)
+ return -ENOMEM;
+
+ n = kzalloc(sizeof(*n), GFP_KERNEL);
+ if (!n) {
+ kfree(c);
+ return -ENOMEM;
+ }
+ BLOCKING_INIT_NOTIFIER_HEAD(n);
+
+ dev->power.constraints = c;
+ plist_head_init(&dev->power.constraints->list);
+ dev->power.constraints->target_value = PM_QOS_DEV_LAT_DEFAULT_VALUE;
+ dev->power.constraints->default_value = PM_QOS_DEV_LAT_DEFAULT_VALUE;
+ dev->power.constraints->type = PM_QOS_MIN;
+ dev->power.constraints->notifiers = n;
+ dev->power.constraints_state = DEV_PM_QOS_ALLOCATED;
+
+ return 0;
+}
+
+/**
+ * dev_pm_qos_constraints_init
+ * @dev: target device
+ *
+ * Called from the device PM subsystem at device insertion
+ */
+void dev_pm_qos_constraints_init(struct device *dev)
+{
+ mutex_lock(&dev_pm_qos_mtx);
+ dev->power.constraints_state = DEV_PM_QOS_DEVICE_PRESENT;
+ mutex_unlock(&dev_pm_qos_mtx);
+}
+
+/**
+ * dev_pm_qos_constraints_destroy
+ * @dev: target device
+ *
+ * Called from the device PM subsystem at device removal
+ */
+void dev_pm_qos_constraints_destroy(struct device *dev)
+{
+ struct dev_pm_qos_request *req, *tmp;
+
+ mutex_lock(&dev_pm_qos_mtx);
+
+ if (dev->power.constraints_state == DEV_PM_QOS_ALLOCATED) {
+ /* Flush the constraints list for the device */
+ plist_for_each_entry_safe(req, tmp,
+ &dev->power.constraints->list,
+ node) {
+ /*
+ * Update constraints list and call the per-device
+ * callbacks if needed
+ */
+ pm_qos_update_target(req->dev->power.constraints,
+ &req->node, PM_QOS_REMOVE_REQ,
+ PM_QOS_DEFAULT_VALUE);
+ memset(req, 0, sizeof(*req));
+ }
+
+ kfree(dev->power.constraints->notifiers);
+ kfree(dev->power.constraints);
+ dev->power.constraints = NULL;
+ }
+ dev->power.constraints_state = DEV_PM_QOS_NO_DEVICE;
+
+ mutex_unlock(&dev_pm_qos_mtx);
+}
+
+/**
+ * dev_pm_qos_add_request - inserts new qos request into the list
+ * @dev: target device for the constraint
+ * @req: pointer to a preallocated handle
+ * @value: defines the qos request
+ *
+ * This function inserts a new entry in the device constraints list of
+ * requested qos performance characteristics. It recomputes the aggregate
+ * QoS expectations of parameters and initializes the dev_pm_qos_request
+ * handle. Caller needs to save this handle for later use in updates and
+ * removal.
+ *
+ * Returns 1 if the aggregated constraint value has changed,
+ * 0 if the aggregated constraint value has not changed,
+ * -EINVAL in case of wrong parameters, -ENODEV if the device has been
+ * removed from the system
+ */
+int dev_pm_qos_add_request(struct device *dev, struct dev_pm_qos_request *req,
+ s32 value)
+{
+ int ret = 0;
+
+ if (!dev || !req) /*guard against callers passing in null */
+ return -EINVAL;
+
+ if (dev_pm_qos_request_active(req)) {
+ WARN(1, KERN_ERR "dev_pm_qos_add_request() called for already "
+ "added request\n");
+ return -EINVAL;
+ }
+
+ mutex_lock(&dev_pm_qos_mtx);
+ req->dev = dev;
+
+ /* Return if the device has been removed */
+ if (req->dev->power.constraints_state == DEV_PM_QOS_NO_DEVICE) {
+ ret = -ENODEV;
+ goto out;
+ }
+
+ /*
+ * Allocate the constraints data on the first call to add_request,
+ * i.e. only if the data is not already allocated and if the device has
+ * not been removed
+ */
+ if (dev->power.constraints_state == DEV_PM_QOS_DEVICE_PRESENT)
+ ret = dev_pm_qos_constraints_allocate(dev);
+
+ if (!ret)
+ ret = pm_qos_update_target(dev->power.constraints, &req->node,
+ PM_QOS_ADD_REQ, value);
+
+out:
+ mutex_unlock(&dev_pm_qos_mtx);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(dev_pm_qos_add_request);
+
+/**
+ * dev_pm_qos_update_request - modifies an existing qos request
+ * @req : handle to list element holding a dev_pm_qos request to use
+ * @new_value: defines the qos request
+ *
+ * Updates an existing dev PM qos request along with updating the
+ * target value.
+ *
+ * Attempts are made to make this code callable on hot code paths.
+ *
+ * Returns 1 if the aggregated constraint value has changed,
+ * 0 if the aggregated constraint value has not changed,
+ * -EINVAL in case of wrong parameters, -ENODEV if the device has been
+ * removed from the system
+ */
+int dev_pm_qos_update_request(struct dev_pm_qos_request *req,
+ s32 new_value)
+{
+ int ret = 0;
+
+ if (!req) /*guard against callers passing in null */
+ return -EINVAL;
+
+ if (!dev_pm_qos_request_active(req)) {
+ WARN(1, KERN_ERR "dev_pm_qos_update_request() called for "
+ "unknown object\n");
+ return -EINVAL;
+ }
+
+ mutex_lock(&dev_pm_qos_mtx);
+
+ if (req->dev->power.constraints_state == DEV_PM_QOS_ALLOCATED) {
+ if (new_value != req->node.prio)
+ ret = pm_qos_update_target(req->dev->power.constraints,
+ &req->node,
+ PM_QOS_UPDATE_REQ,
+ new_value);
+ } else {
+ /* Return if the device has been removed */
+ ret = -ENODEV;
+ }
+
+ mutex_unlock(&dev_pm_qos_mtx);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(dev_pm_qos_update_request);
+
+/**
+ * dev_pm_qos_remove_request - modifies an existing qos request
+ * @req: handle to request list element
+ *
+ * Will remove pm qos request from the list of constraints and
+ * recompute the current target value. Call this on slow code paths.
+ *
+ * Returns 1 if the aggregated constraint value has changed,
+ * 0 if the aggregated constraint value has not changed,
+ * -EINVAL in case of wrong parameters, -ENODEV if the device has been
+ * removed from the system
+ */
+int dev_pm_qos_remove_request(struct dev_pm_qos_request *req)
+{
+ int ret = 0;
+
+ if (!req) /*guard against callers passing in null */
+ return -EINVAL;
+
+ if (!dev_pm_qos_request_active(req)) {
+ WARN(1, KERN_ERR "dev_pm_qos_remove_request() called for "
+ "unknown object\n");
+ return -EINVAL;
+ }
+
+ mutex_lock(&dev_pm_qos_mtx);
+
+ if (req->dev->power.constraints_state == DEV_PM_QOS_ALLOCATED) {
+ ret = pm_qos_update_target(req->dev->power.constraints,
+ &req->node, PM_QOS_REMOVE_REQ,
+ PM_QOS_DEFAULT_VALUE);
+ memset(req, 0, sizeof(*req));
+ } else {
+ /* Return if the device has been removed */
+ ret = -ENODEV;
+ }
+
+ mutex_unlock(&dev_pm_qos_mtx);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(dev_pm_qos_remove_request);
+
+/**
+ * dev_pm_qos_add_notifier - sets notification entry for changes to target value
+ * of per-device PM QoS constraints
+ *
+ * @dev: target device for the constraint
+ * @notifier: notifier block managed by caller.
+ *
+ * Will register the notifier into a notification chain that gets called
+ * upon changes to the target value for the device.
+ */
+int dev_pm_qos_add_notifier(struct device *dev, struct notifier_block *notifier)
+{
+ int retval = 0;
+
+ mutex_lock(&dev_pm_qos_mtx);
+
+ /* Silently return if the device has been removed */
+ if (dev->power.constraints_state != DEV_PM_QOS_ALLOCATED)
+ goto out;
+
+ retval = blocking_notifier_chain_register(
+ dev->power.constraints->notifiers,
+ notifier);
+
+out:
+ mutex_unlock(&dev_pm_qos_mtx);
+ return retval;
+}
+EXPORT_SYMBOL_GPL(dev_pm_qos_add_notifier);
+
+/**
+ * dev_pm_qos_remove_notifier - deletes notification for changes to target value
+ * of per-device PM QoS constraints
+ *
+ * @dev: target device for the constraint
+ * @notifier: notifier block to be removed.
+ *
+ * Will remove the notifier from the notification chain that gets called
+ * upon changes to the target value.
+ */
+int dev_pm_qos_remove_notifier(struct device *dev,
+ struct notifier_block *notifier)
+{
+ int retval = 0;
+
+ mutex_lock(&dev_pm_qos_mtx);
+
+ /* Silently return if the device has been removed */
+ if (dev->power.constraints_state != DEV_PM_QOS_ALLOCATED)
+ goto out;
+
+ retval = blocking_notifier_chain_unregister(
+ dev->power.constraints->notifiers,
+ notifier);
+
+out:
+ mutex_unlock(&dev_pm_qos_mtx);
+ return retval;
+}
+EXPORT_SYMBOL_GPL(dev_pm_qos_remove_notifier);
+
diff --git a/include/linux/pm.h b/include/linux/pm.h
index f7c84c9..7a48951 100644
--- a/include/linux/pm.h
+++ b/include/linux/pm.h
@@ -421,6 +421,13 @@ enum rpm_request {
struct wakeup_source;
+/* Per-device PM QoS constraints data struct state */
+enum dev_pm_qos_state {
+ DEV_PM_QOS_NO_DEVICE, /* No device present */
+ DEV_PM_QOS_DEVICE_PRESENT, /* Device present, data not allocated */
+ DEV_PM_QOS_ALLOCATED, /* Device present, data allocated */
+};
+
struct dev_pm_info {
pm_message_t power_state;
unsigned int can_wakeup:1;
@@ -463,6 +470,8 @@ struct dev_pm_info {
unsigned long accounting_timestamp;
#endif
void *subsys_data; /* Owned by the subsystem. */
+ struct pm_qos_constraints *constraints;
+ enum dev_pm_qos_state constraints_state;
};
extern void update_pm_runtime_accounting(struct device *dev);
diff --git a/include/linux/pm_qos.h b/include/linux/pm_qos.h
index 84aa150..f75f74d 100644
--- a/include/linux/pm_qos.h
+++ b/include/linux/pm_qos.h
@@ -19,12 +19,18 @@
#define PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE (2000 * USEC_PER_SEC)
#define PM_QOS_NETWORK_LAT_DEFAULT_VALUE (2000 * USEC_PER_SEC)
#define PM_QOS_NETWORK_THROUGHPUT_DEFAULT_VALUE 0
+#define PM_QOS_DEV_LAT_DEFAULT_VALUE 0
struct pm_qos_request {
struct plist_node node;
int pm_qos_class;
};
+struct dev_pm_qos_request {
+ struct plist_node node;
+ struct device *dev;
+};
+
enum pm_qos_type {
PM_QOS_UNITIALIZED,
PM_QOS_MAX, /* return the largest value */
@@ -51,6 +57,11 @@ enum pm_qos_req_action {
PM_QOS_REMOVE_REQ /* Remove an existing request */
};
+static inline int dev_pm_qos_request_active(struct dev_pm_qos_request *req)
+{
+ return req->dev != 0;
+}
+
#ifdef CONFIG_PM
int pm_qos_update_target(struct pm_qos_constraints *c, struct plist_node *node,
enum pm_qos_req_action action, int value);
@@ -64,6 +75,17 @@ int pm_qos_request(int pm_qos_class);
int pm_qos_add_notifier(int pm_qos_class, struct notifier_block *notifier);
int pm_qos_remove_notifier(int pm_qos_class, struct notifier_block *notifier);
int pm_qos_request_active(struct pm_qos_request *req);
+
+int dev_pm_qos_add_request(struct device *dev, struct dev_pm_qos_request *req,
+ s32 value);
+int dev_pm_qos_update_request(struct dev_pm_qos_request *req, s32 new_value);
+int dev_pm_qos_remove_request(struct dev_pm_qos_request *req);
+int dev_pm_qos_add_notifier(struct device *dev,
+ struct notifier_block *notifier);
+int dev_pm_qos_remove_notifier(struct device *dev,
+ struct notifier_block *notifier);
+void dev_pm_qos_constraints_init(struct device *dev);
+void dev_pm_qos_constraints_destroy(struct device *dev);
#else
static inline int pm_qos_update_target(struct pm_qos_constraints *c,
struct plist_node *node,
@@ -89,6 +111,26 @@ static inline int pm_qos_remove_notifier(int pm_qos_class,
{ return 0; }
static inline int pm_qos_request_active(struct pm_qos_request *req)
{ return 0; }
+
+static inline int dev_pm_qos_add_request(struct device *dev,
+ struct dev_pm_qos_request *req,
+ s32 value)
+ { return 0; }
+static inline int dev_pm_qos_update_request(struct dev_pm_qos_request *req,
+ s32 new_value)
+ { return 0; }
+static inline int dev_pm_qos_remove_request(struct dev_pm_qos_request *req)
+ { return 0; }
+static inline int dev_pm_qos_add_notifier(struct device *dev,
+ struct notifier_block *notifier)
+ { return 0; }
+static inline int dev_pm_qos_remove_notifier(struct device *dev,
+ struct notifier_block *notifier)
+ { return 0; }
+static inline void dev_pm_qos_constraints_init(struct device *dev)
+ { return; }
+static inline void dev_pm_qos_constraints_destroy(struct device *dev)
+ { return; }
#endif
#endif
--
1.7.4.1