Re: [PATCH 02/23] Record & display i/o speed post resume.

From: Rafael J. Wysocki
Date: Mon Sep 27 2010 - 16:07:20 EST


On Monday, September 27, 2010, Nigel Cunningham wrote:
> Record the speed at which the image is written and read, and
> display it to the user post-resume.
>
> Signed-off-by: Nigel Cunningham <nigel@xxxxxxxxxxxx>
> ---
> kernel/power/hibernate.c | 11 ++++++++++-
> kernel/power/power.h | 3 ++-
> kernel/power/swap.c | 14 +++++++++++---
> 3 files changed, 23 insertions(+), 5 deletions(-)
>
> diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
> index 6c9c9dc..0cd1f05 100644
> --- a/kernel/power/hibernate.c
> +++ b/kernel/power/hibernate.c
> @@ -212,7 +212,7 @@ static void platform_recover(int platform_mode)
> * @msg - introductory message to print
> */
>
> -void swsusp_show_speed(struct timeval *start, struct timeval *stop,
> +int swsusp_show_speed(struct timeval *start, struct timeval *stop,
> unsigned nr_pages, char *msg)
> {
> s64 elapsed_centisecs64;
> @@ -231,6 +231,7 @@ void swsusp_show_speed(struct timeval *start, struct timeval *stop,
> msg, k,
> centisecs / 100, centisecs % 100,
> kps / 1000, (kps % 1000) / 10);
> + return kps / 1000;
> }
>
> /**
> @@ -648,6 +649,14 @@ int hibernate(void)
> power_down();
> } else {
> pr_debug("PM: Image restored successfully.\n");
> + if (write_speed)
> + pr_debug("PM: Image written at %u MB/s.\n",
> + (u8) write_speed);
> + write_speed = 0;
> + if (read_speed)
> + pr_debug("PM: Image read at %u MB/s.\n",
> + (u8) read_speed);
> + read_speed = 0;
> }
>
> Thaw:
> diff --git a/kernel/power/power.h b/kernel/power/power.h
> index 03634be..22f8607 100644
> --- a/kernel/power/power.h
> +++ b/kernel/power/power.h
> @@ -53,6 +53,7 @@ extern int hibernation_snapshot(int platform_mode);
> extern int hibernation_restore(int platform_mode);
> extern int hibernation_platform_enter(void);
>
> +extern char __nosavedata write_speed, read_speed;
> #else /* !CONFIG_HIBERNATION */
>
> static inline void hibernate_image_size_init(void) {}
> @@ -161,7 +162,7 @@ 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 *,
> +extern int swsusp_show_speed(struct timeval *, struct timeval *,
> unsigned int, char *);
>
> #ifdef CONFIG_SUSPEND
> diff --git a/kernel/power/swap.c b/kernel/power/swap.c
> index 3c01105..caf4db8 100644
> --- a/kernel/power/swap.c
> +++ b/kernel/power/swap.c
> @@ -45,7 +45,8 @@ struct swap_map_page {
> };
>
> struct swsusp_header {
> - char reserved[PAGE_SIZE - 20 - sizeof(sector_t) - sizeof(int)];
> + char reserved[PAGE_SIZE - 21 - sizeof(sector_t) - sizeof(int)];
> + char write_speed;
> sector_t image;
> unsigned int flags; /* Flags to pass to the "boot" kernel */
> char orig_sig[10];
> @@ -161,6 +162,7 @@ int swsusp_swap_in_use(void)
>
> static unsigned short root_swap = 0xffff;
> struct block_device *hib_resume_bdev;
> +char __nosavedata write_speed, read_speed;

I really should have noticed that earlier, but I don't really like __nosavedata
being used here. In fact, it shouldn't be used at all any more, because it's
meaningless on x86_64.

I'm not sure how to implement that without __nosavedata, but please don't
use it. Sorry aboiut that.

Rafael
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