Re: [PATCH] PM / Hibernate: Make default image size depend on totalRAM size

["M. Vefa Bicakci" <bicave@superonline.com>]

On 11/09/10 06:27 PM, Rafael J. Wysocki wrote:
> On Saturday, September 11, 2010, Rafael J. Wysocki wrote:
>> On Saturday, September 11, 2010, M. Vefa Bicakci wrote:
> ...
>>>
>>> I would be glad to test that patch as well, to see if it brings speed-ups.
>>> Actually, I might test hibernation with a larger value written to
>>> /sys/power/image_size when I have time.
>>
>> I think that would improve things, as it probably is impossible to reduce the
>> image size to 500 MB on your system.
>>
>> Anyway, I'll let you know when the patch is ready.
> 
> OK, please try the patch below on top of the previous one and see if it makes
> hibernation run faster on your system.

Dear Rafael Wysocki,

I think I have good news. I took a clean 2.6.35.4 tree, and first applied
the latest version of your larger snapshot.c patch, and then the patch you
appended to your final e-mail in this thread.

Here is a comparison of the timings from a kernel without your patch, and
one with it.

=== 8< ===
Sep 11 10:22:24 debian kernel: [  499.968989] PM: Allocated 2531300 kbytes in 52.66 seconds (48.06 MB/s)
Sep 11 10:44:08 debian kernel: [  764.379131] PM: Allocated 2531308 kbytes in 143.41 seconds (17.65 MB/s)
Sep 11 10:48:41 debian kernel: [  920.626386] PM: Allocated 2531300 kbytes in 66.44 seconds (38.09 MB/s)
Sep 11 10:53:37 debian kernel: [ 1092.919140] PM: Allocated 2531316 kbytes in 81.28 seconds (31.14 MB/s)
...
Sep 13 01:26:09 debian kernel: [   94.948054] PM: Allocated 1804008 kbytes in 28.72 seconds (62.81 MB/s)
Sep 13 01:29:58 debian kernel: [  176.678880] PM: Allocated 1803992 kbytes in 34.44 seconds (52.38 MB/s)
Sep 13 01:33:48 debian kernel: [  253.336405] PM: Allocated 1804000 kbytes in 27.35 seconds (65.95 MB/s)
=== >8 ===

I didn't have your latest patch applied on September 11, and it was applied
last night.

It looks like there is a good improvement. I think the data rates look
faster on Sept. 13 because the kernel spent less time "thinking" less
while compacting the memory image. (I don't think I have changed anything
in my configuration that could affect the data rates that much.)

Is it possible to have these patches applied to the 2.6.35 tree so that
the regression I reported is fixed? Should I e-mail Greg Kroah-Hartman
about this?

Once again, thank a lot to you, Kosaki Motohiro and Minchan Kim!

M. Vefa Bicakci

> [snip patch]