Commit db597605 authored by Tina Ruchandani's avatar Tina Ruchandani Committed by Rafael J. Wysocki
Browse files

PM / Hibernate: Migrate to ktime_t 



This patch migrates swsusp_show_speed and its callers to using ktime_t instead
of 'struct timeval' which suffers from the y2038 problem.

Changes to swsusp_show_speed:
        - use ktime_t for start and stop times
        - pass start and stop times by value
Calling functions affected:
        - load_image
        - load_image_lzo
        - save_image
        - save_image_lzo
        - hibernate_preallocate_memory
Design decisions:
        - use ktime_t to preserve same granularity of reporting as before
        - use centisecs logic as before to avoid 'div by zero' issues caused by
          using seconds and nanoseconds directly
        - use monotonic time (ktime_get()) since we only care about elapsed time.

Signed-off-by: default avatarTina Ruchandani <ruchandani.tina@gmail.com>
Suggested-by: default avatarArnd Bergmann <arnd@arndb.de>
Reviewed-by: default avatarArnd Bergmann <arnd@arndb.de>
Acked-by: default avatarPavel Machek <pavel@ucw.cz>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 0df1f248

kernel/power/hibernate.c

+6 −8
Original line number Diff line number Diff line
@@ -28,6 +28,7 @@ 
#include <linux/syscore_ops.h>

#include <linux/ctype.h>

#include <linux/genhd.h>

#include <linux/ktime.h>

#include <trace/events/power.h>



#include "power.h"
@@ -232,20 +233,17 @@ static void platform_recover(int platform_mode) 
 * @nr_pages: Number of memory pages processed between @start and @stop.

 * @msg: Additional diagnostic message to print.

 */

void swsusp_show_speed(struct timeval *start, struct timeval *stop,

void swsusp_show_speed(ktime_t start, ktime_t stop,

		      unsigned nr_pages, char *msg)

{

	ktime_t diff;

	u64 elapsed_centisecs64;

	unsigned int centisecs;

	unsigned int k;

	unsigned int kps;



	elapsed_centisecs64 = timeval_to_ns(stop) - timeval_to_ns(start);

	/*

	 * If "(s64)elapsed_centisecs64 < 0", it will print long elapsed time,

	 * it is obvious enough for what went wrong.

	 */

	do_div(elapsed_centisecs64, NSEC_PER_SEC / 100);

	diff = ktime_sub(stop, start);

	elapsed_centisecs64 = ktime_divns(diff, 10*NSEC_PER_MSEC);

	centisecs = elapsed_centisecs64;

	if (centisecs == 0)

		centisecs = 1;	/* avoid div-by-zero */

kernel/power/power.h

+1 −2
Original line number Diff line number Diff line
@@ -174,8 +174,7 @@ extern int hib_wait_on_bio_chain(struct bio **bio_chain); 


struct timeval;

/* kernel/power/swsusp.c */

extern void swsusp_show_speed(struct timeval *, struct timeval *,

				unsigned int, char *);

extern void swsusp_show_speed(ktime_t, ktime_t, unsigned int, char *);



#ifdef CONFIG_SUSPEND

/* kernel/power/suspend.c */

kernel/power/snapshot.c

+5 −4
Original line number Diff line number Diff line
@@ -28,6 +28,7 @@ 
#include <linux/list.h>

#include <linux/slab.h>

#include <linux/compiler.h>

#include <linux/ktime.h>



#include <asm/uaccess.h>

#include <asm/mmu_context.h>
@@ -1576,11 +1577,11 @@ int hibernate_preallocate_memory(void) 
	struct zone *zone;

	unsigned long saveable, size, max_size, count, highmem, pages = 0;

	unsigned long alloc, save_highmem, pages_highmem, avail_normal;

	struct timeval start, stop;

	ktime_t start, stop;

	int error;



	printk(KERN_INFO "PM: Preallocating image memory... ");

	do_gettimeofday(&start);

	start = ktime_get();



	error = memory_bm_create(&orig_bm, GFP_IMAGE, PG_ANY);

	if (error)
@@ -1709,9 +1710,9 @@ int hibernate_preallocate_memory(void) 
	free_unnecessary_pages();



 out:

	do_gettimeofday(&stop);

	stop = ktime_get();

	printk(KERN_CONT "done (allocated %lu pages)\n", pages);

	swsusp_show_speed(&start, &stop, pages, "Allocated");

	swsusp_show_speed(start, stop, pages, "Allocated");



	return 0;

kernel/power/swap.c

+21 −20
Original line number Diff line number Diff line
@@ -30,6 +30,7 @@ 
#include <linux/atomic.h>

#include <linux/kthread.h>

#include <linux/crc32.h>

#include <linux/ktime.h>



#include "power.h"
@@ -445,8 +446,8 @@ static int save_image(struct swap_map_handle *handle, 
	int nr_pages;

	int err2;

	struct bio *bio;

	struct timeval start;

	struct timeval stop;

	ktime_t start;

	ktime_t stop;



	printk(KERN_INFO "PM: Saving image data pages (%u pages)...\n",

		nr_to_write);
@@ -455,7 +456,7 @@ static int save_image(struct swap_map_handle *handle, 
		m = 1;

	nr_pages = 0;

	bio = NULL;

	do_gettimeofday(&start);

	start = ktime_get();

	while (1) {

		ret = snapshot_read_next(snapshot);

		if (ret <= 0)
@@ -469,12 +470,12 @@ static int save_image(struct swap_map_handle *handle, 
		nr_pages++;

	}

	err2 = hib_wait_on_bio_chain(&bio);

	do_gettimeofday(&stop);

	stop = ktime_get();

	if (!ret)

		ret = err2;

	if (!ret)

		printk(KERN_INFO "PM: Image saving done.\n");

	swsusp_show_speed(&start, &stop, nr_to_write, "Wrote");

	swsusp_show_speed(start, stop, nr_to_write, "Wrote");

	return ret;

}
@@ -580,8 +581,8 @@ static int save_image_lzo(struct swap_map_handle *handle, 
	int nr_pages;

	int err2;

	struct bio *bio;

	struct timeval start;

	struct timeval stop;

	ktime_t start;

	ktime_t stop;

	size_t off;

	unsigned thr, run_threads, nr_threads;

	unsigned char *page = NULL;
@@ -674,7 +675,7 @@ static int save_image_lzo(struct swap_map_handle *handle, 
		m = 1;

	nr_pages = 0;

	bio = NULL;

	do_gettimeofday(&start);

	start = ktime_get();

	for (;;) {

		for (thr = 0; thr < nr_threads; thr++) {

			for (off = 0; off < LZO_UNC_SIZE; off += PAGE_SIZE) {
@@ -759,12 +760,12 @@ static int save_image_lzo(struct swap_map_handle *handle, 


out_finish:

	err2 = hib_wait_on_bio_chain(&bio);

	do_gettimeofday(&stop);

	stop = ktime_get();

	if (!ret)

		ret = err2;

	if (!ret)

		printk(KERN_INFO "PM: Image saving done.\n");

	swsusp_show_speed(&start, &stop, nr_to_write, "Wrote");

	swsusp_show_speed(start, stop, nr_to_write, "Wrote");

out_clean:

	if (crc) {

		if (crc->thr)
@@ -965,8 +966,8 @@ static int load_image(struct swap_map_handle *handle, 
{

	unsigned int m;

	int ret = 0;

	struct timeval start;

	struct timeval stop;

	ktime_t start;

	ktime_t stop;

	struct bio *bio;

	int err2;

	unsigned nr_pages;
@@ -978,7 +979,7 @@ static int load_image(struct swap_map_handle *handle, 
		m = 1;

	nr_pages = 0;

	bio = NULL;

	do_gettimeofday(&start);

	start = ktime_get();

	for ( ; ; ) {

		ret = snapshot_write_next(snapshot);

		if (ret <= 0)
@@ -996,7 +997,7 @@ static int load_image(struct swap_map_handle *handle, 
		nr_pages++;

	}

	err2 = hib_wait_on_bio_chain(&bio);

	do_gettimeofday(&stop);

	stop = ktime_get();

	if (!ret)

		ret = err2;

	if (!ret) {
@@ -1005,7 +1006,7 @@ static int load_image(struct swap_map_handle *handle, 
		if (!snapshot_image_loaded(snapshot))

			ret = -ENODATA;

	}

	swsusp_show_speed(&start, &stop, nr_to_read, "Read");

	swsusp_show_speed(start, stop, nr_to_read, "Read");

	return ret;

}
@@ -1067,8 +1068,8 @@ static int load_image_lzo(struct swap_map_handle *handle, 
	int ret = 0;

	int eof = 0;

	struct bio *bio;

	struct timeval start;

	struct timeval stop;

	ktime_t start;

	ktime_t stop;

	unsigned nr_pages;

	size_t off;

	unsigned i, thr, run_threads, nr_threads;
@@ -1190,7 +1191,7 @@ static int load_image_lzo(struct swap_map_handle *handle, 
		m = 1;

	nr_pages = 0;

	bio = NULL;

	do_gettimeofday(&start);

	start = ktime_get();



	ret = snapshot_write_next(snapshot);

	if (ret <= 0)
@@ -1343,7 +1344,7 @@ out_finish: 
		wait_event(crc->done, atomic_read(&crc->stop));

		atomic_set(&crc->stop, 0);

	}

	do_gettimeofday(&stop);

	stop = ktime_get();

	if (!ret) {

		printk(KERN_INFO "PM: Image loading done.\n");

		snapshot_write_finalize(snapshot);
@@ -1359,7 +1360,7 @@ out_finish: 
			}

		}

	}

	swsusp_show_speed(&start, &stop, nr_to_read, "Read");

	swsusp_show_speed(start, stop, nr_to_read, "Read");

out_clean:

	for (i = 0; i < ring_size; i++)

		free_page((unsigned long)page[i]);

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