Re: [RFC][PATCH -mm] PM: Do not sync from within the freezer during suspend to RAM

[Nigel Cunningham]

Hi.

On Thursday 05 July 2007 00:58:58 Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rjw@xxxxxxx>
> 
> The syncing of filesystems from within the freezer in not needed for suspend 
to
> RAM.  Change freeze_processes() so that it doesn't execute sys_sync() and
> introduce the "syncing" version of it to be called from the hibernation code
> paths.
> 
> Signed-off-by: Rafael J. Wysocki <rjw@xxxxxxx>
> ---
>  include/linux/freezer.h |   14 ++++++++++++--
>  kernel/power/disk.c     |    2 +-
>  kernel/power/main.c     |    6 ++++++
>  kernel/power/process.c  |    8 +++++---
>  kernel/power/user.c     |    2 +-
>  5 files changed, 25 insertions(+), 7 deletions(-)

Looks ok, except that I wonder if you want the following fragment. It looks to 
me (looking at rc6) like with this code, you'll currently call sys_sync twice 
when suspending to ram. Maybe I'm misreading it. Also, shouldn't it be done 
after taking the mutex?

Regards,

Nigel

> @@ -231,6 +232,11 @@ static int enter_state(suspend_state_t s
>  
>  	if (!valid_state(state))
>  		return -ENODEV;
> +
> +	printk("Syncing filesystems ... ");
> +	sys_sync();
> +	printk("done.\n");
> +
>  	if (!mutex_trylock(&pm_mutex))
>  		return -EBUSY;
>  


-- 
Nigel, Michelle and Alisdair Cunningham
5 Mitchell Street
Cobden 3266
Victoria, Australia

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