[PATCH] swsusp: add write-speed instrumentation
Add some instrumentation to the swsusp writeout code to show what bandwidth
we're achieving.
Cc: Pavel Machek <pavel@ucw.cz>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/kernel/power/swap.c b/kernel/power/swap.c
index f1dd146..79b66e7 100644
--- a/kernel/power/swap.c
+++ b/kernel/power/swap.c
@@ -146,6 +146,26 @@
handle->bitmap = NULL;
}
+static void show_speed(struct timeval *start, struct timeval *stop,
+ unsigned nr_pages, char *msg)
+{
+ s64 elapsed_centisecs64;
+ int centisecs;
+ int k;
+ int kps;
+
+ elapsed_centisecs64 = timeval_to_ns(stop) - timeval_to_ns(start);
+ do_div(elapsed_centisecs64, NSEC_PER_SEC / 100);
+ centisecs = elapsed_centisecs64;
+ if (centisecs == 0)
+ centisecs = 1; /* avoid div-by-zero */
+ k = nr_pages * (PAGE_SIZE / 1024);
+ kps = (k * 100) / centisecs;
+ printk("%s %d kbytes in %d.%02d seconds (%d.%02d MB/s)\n", msg, k,
+ centisecs / 100, centisecs % 100,
+ kps / 1000, (kps % 1000) / 10);
+}
+
static int get_swap_writer(struct swap_map_handle *handle)
{
handle->cur = (struct swap_map_page *)get_zeroed_page(GFP_KERNEL);
@@ -206,17 +226,21 @@
static int save_image(struct swap_map_handle *handle,
struct snapshot_handle *snapshot,
- unsigned int nr_pages)
+ unsigned int nr_to_write)
{
unsigned int m;
int ret;
int error = 0;
+ int nr_pages;
+ struct timeval start;
+ struct timeval stop;
- printk("Saving image data pages (%u pages) ... ", nr_pages);
- m = nr_pages / 100;
+ printk("Saving image data pages (%u pages) ... ", nr_to_write);
+ m = nr_to_write / 100;
if (!m)
m = 1;
nr_pages = 0;
+ do_gettimeofday(&start);
do {
ret = snapshot_read_next(snapshot, PAGE_SIZE);
if (ret > 0) {
@@ -228,8 +252,10 @@
nr_pages++;
}
} while (ret > 0);
+ do_gettimeofday(&stop);
if (!error)
printk("\b\b\b\bdone\n");
+ show_speed(&start, &stop, nr_to_write, "Wrote");
return error;
}