PM / Hibernate: Add sysfs knob to control size of memory for drivers

Martin reports that on his system hibernation occasionally fails due
to the lack of memory, because the radeon driver apparently allocates
too much of it during the device freeze stage.  It turns out that the
amount of memory allocated by radeon during hibernation (and
presumably during system suspend too) depends on the utilization of
the GPU (e.g. hibernating while there are two KDE 4 sessions with
compositing enabled causes radeon to allocate more memory than for
one KDE 4 session).

In principle it should be possible to use image_size to make the
memory preallocation mechanism free enough memory for the radeon
driver, but in practice it is not easy to guess the right value
because of the way the preallocation code uses image_size.  For this
reason, it seems reasonable to allow users to control the amount of
memory reserved for driver allocations made after the hibernate
preallocation, which currently is constant and amounts to 1 MB.

Introduce a new sysfs file, /sys/power/reserved_size, whose value
will be used as the amount of memory to reserve for the
post-preallocation reservations made by device drivers, in bytes.
For backwards compatibility, set its default (and initial) value to
the currently used number (1 MB).

References: https://bugzilla.kernel.org/show_bug.cgi?id=34102
Reported-and-tested-by: Martin Steigerwald <Martin@Lichtvoll.de>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
This commit is contained in:
Rafael J. Wysocki 2011-05-15 11:38:48 +02:00
parent 13e3813656
commit ddeb648708
5 changed files with 62 additions and 5 deletions

View File

@ -158,3 +158,17 @@ Description:
successful, will make the kernel abort a subsequent transition successful, will make the kernel abort a subsequent transition
to a sleep state if any wakeup events are reported after the to a sleep state if any wakeup events are reported after the
write has returned. write has returned.
What: /sys/power/reserved_size
Date: May 2011
Contact: Rafael J. Wysocki <rjw@sisk.pl>
Description:
The /sys/power/reserved_size file allows user space to control
the amount of memory reserved for allocations made by device
drivers during the "device freeze" stage of hibernation. It can
be written a string representing a non-negative integer that
will be used as the amount of memory to reserve for allocations
made by device drivers' "freeze" callbacks, in bytes.
Reading from this file will display the current value, which is
set to 1 MB by default.

View File

@ -982,10 +982,33 @@ static ssize_t image_size_store(struct kobject *kobj, struct kobj_attribute *att
power_attr(image_size); power_attr(image_size);
static ssize_t reserved_size_show(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
{
return sprintf(buf, "%lu\n", reserved_size);
}
static ssize_t reserved_size_store(struct kobject *kobj,
struct kobj_attribute *attr,
const char *buf, size_t n)
{
unsigned long size;
if (sscanf(buf, "%lu", &size) == 1) {
reserved_size = size;
return n;
}
return -EINVAL;
}
power_attr(reserved_size);
static struct attribute * g[] = { static struct attribute * g[] = {
&disk_attr.attr, &disk_attr.attr,
&resume_attr.attr, &resume_attr.attr,
&image_size_attr.attr, &image_size_attr.attr,
&reserved_size_attr.attr,
NULL, NULL,
}; };

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@ -337,6 +337,7 @@ static int __init pm_init(void)
if (error) if (error)
return error; return error;
hibernate_image_size_init(); hibernate_image_size_init();
hibernate_reserved_size_init();
power_kobj = kobject_create_and_add("power", NULL); power_kobj = kobject_create_and_add("power", NULL);
if (!power_kobj) if (!power_kobj)
return -ENOMEM; return -ENOMEM;

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@ -15,6 +15,7 @@ struct swsusp_info {
#ifdef CONFIG_HIBERNATION #ifdef CONFIG_HIBERNATION
/* kernel/power/snapshot.c */ /* kernel/power/snapshot.c */
extern void __init hibernate_reserved_size_init(void);
extern void __init hibernate_image_size_init(void); extern void __init hibernate_image_size_init(void);
#ifdef CONFIG_ARCH_HIBERNATION_HEADER #ifdef CONFIG_ARCH_HIBERNATION_HEADER
@ -55,6 +56,7 @@ extern int hibernation_platform_enter(void);
#else /* !CONFIG_HIBERNATION */ #else /* !CONFIG_HIBERNATION */
static inline void hibernate_reserved_size_init(void) {}
static inline void hibernate_image_size_init(void) {} static inline void hibernate_image_size_init(void) {}
#endif /* !CONFIG_HIBERNATION */ #endif /* !CONFIG_HIBERNATION */
@ -72,6 +74,8 @@ static struct kobj_attribute _name##_attr = { \
/* Preferred image size in bytes (default 500 MB) */ /* Preferred image size in bytes (default 500 MB) */
extern unsigned long image_size; extern unsigned long image_size;
/* Size of memory reserved for drivers (default SPARE_PAGES x PAGE_SIZE) */
extern unsigned long reserved_size;
extern int in_suspend; extern int in_suspend;
extern dev_t swsusp_resume_device; extern dev_t swsusp_resume_device;
extern sector_t swsusp_resume_block; extern sector_t swsusp_resume_block;

View File

@ -40,6 +40,18 @@ static int swsusp_page_is_free(struct page *);
static void swsusp_set_page_forbidden(struct page *); static void swsusp_set_page_forbidden(struct page *);
static void swsusp_unset_page_forbidden(struct page *); static void swsusp_unset_page_forbidden(struct page *);
/*
* Number of bytes to reserve for memory allocations made by device drivers
* from their ->freeze() and ->freeze_noirq() callbacks so that they don't
* cause image creation to fail (tunable via /sys/power/reserved_size).
*/
unsigned long reserved_size;
void __init hibernate_reserved_size_init(void)
{
reserved_size = SPARE_PAGES * PAGE_SIZE;
}
/* /*
* Preferred image size in bytes (tunable via /sys/power/image_size). * Preferred image size in bytes (tunable via /sys/power/image_size).
* When it is set to N, the image creating code will do its best to * When it is set to N, the image creating code will do its best to
@ -1263,11 +1275,13 @@ static unsigned long minimum_image_size(unsigned long saveable)
* frame in use. We also need a number of page frames to be free during * frame in use. We also need a number of page frames to be free during
* hibernation for allocations made while saving the image and for device * hibernation for allocations made while saving the image and for device
* drivers, in case they need to allocate memory from their hibernation * drivers, in case they need to allocate memory from their hibernation
* callbacks (these two numbers are given by PAGES_FOR_IO and SPARE_PAGES, * callbacks (these two numbers are given by PAGES_FOR_IO (which is a rough
* respectively, both of which are rough estimates). To make this happen, we * estimate) and reserverd_size divided by PAGE_SIZE (which is tunable through
* compute the total number of available page frames and allocate at least * /sys/power/reserved_size, respectively). To make this happen, we compute the
* total number of available page frames and allocate at least
* *
* ([page frames total] + PAGES_FOR_IO + [metadata pages]) / 2 + 2 * SPARE_PAGES * ([page frames total] + PAGES_FOR_IO + [metadata pages]) / 2
* + 2 * DIV_ROUND_UP(reserved_size, PAGE_SIZE)
* *
* of them, which corresponds to the maximum size of a hibernation image. * of them, which corresponds to the maximum size of a hibernation image.
* *
@ -1322,7 +1336,8 @@ int hibernate_preallocate_memory(void)
count -= totalreserve_pages; count -= totalreserve_pages;
/* Compute the maximum number of saveable pages to leave in memory. */ /* Compute the maximum number of saveable pages to leave in memory. */
max_size = (count - (size + PAGES_FOR_IO)) / 2 - 2 * SPARE_PAGES; max_size = (count - (size + PAGES_FOR_IO)) / 2
- 2 * DIV_ROUND_UP(reserved_size, PAGE_SIZE);
/* Compute the desired number of image pages specified by image_size. */ /* Compute the desired number of image pages specified by image_size. */
size = DIV_ROUND_UP(image_size, PAGE_SIZE); size = DIV_ROUND_UP(image_size, PAGE_SIZE);
if (size > max_size) if (size > max_size)