[linux-pm] [PATCH] PM: HIBERNATION: skip the swap size check if the snapshot image size is anticipative

[Barry Song]

2011/11/6 Pavel Machek <pavel at ucw.cz>:
> Hi!
>
>> From: Barry Song <Baohua.Song at csr.com>
>>
>> Current swsusp requires swap partitions even larger than real saved pages
>> due to the worst compress ratio:
>> but for an embedded system, which has limited storage space, then it might
>> can't give the big size partition to save snapshot.
>> In the another way, some embedded systems can definitely know the most size
>> needed for snapshot since they run some specific application lists.
>> So this patch provides the possibility for bootloader to tell kernel even
>> the system has a little snapshot partition, but it is still enough.
>> For example, if the system need to save 120MB memory, origin swsusp will require
>> a 130MB partition to save snapshot. but if users know 30MB is enough for them(
>> compressed image will be less than 30MB), they just make a 30MB
>> partition.
>
> Would it be better to have /sys/power/... entry which would allow
> configuring expected compression ratio at runtime?

i think it is better to have a sys node than add another kernel param.
but the point is i only care about the final image size but not
compression ratio. i don't care how well lzo will do for me since i
only have limited disk space and know how many pages want to be saved.
there has been a image_size node, will we have a expected_image_size node?
>                                                                Pavel
>
> --
Thanks
barry