Re: slow resume from suspend to disk

[Pedro Ribeiro <pedrib@gmail.com>]

On 10 February 2010 23:40, Mihai Donțu <mihai.dontu@gmail.com> wrote:
> Hi,
>
> Is there any way to speed up the resume from suspend to disk? Currently, on my
> laptop it suspends in ~15s (wrote about 360MB) but resumes in ~120s and after
> that I'm still left with ~361MB in swap:
>
>             total       used       free     shared    buffers     cached
> Mem:       3333472    1139332    2194140          0      12808     473084
> -/+ buffers/cache:     653440    2680032
> Swap:      2104472     369428    1735044
>
> Right now I'm better off with a cold boot.
>
> Although I did not study the kernel code to see how things really work, I
> suspect on resume only necessary kernel data is loaded from swap and the
> userland tasks are left with the page fault mechanism to bring back their own
> data, which leads to an I/O storm on the swap device. Maybe changing the I/O
> scheduler from CFQ would help? or better yet, is there any way to tell the
> kernel to bring back all the pages from swap in one quick move? That would be
> something I want to put in my resume scripts.
>
> $ uname -a
> Linux mdontu-dell 2.6.32-gentoo-r3 #1 SMP PREEMPT Mon Feb 1 02:36:01 EET 2010
> x86_64 Intel(R) Core(TM)2 CPU T5500 @ 1.66GHz GenuineIntel GNU/Linux
>
> I've installed Windows XP just for a test, started a few apps (like visual
> studio, mplayer, etc.) and then suspended/hibernated (~15s). It took roughly
> 15s to come back.
>
> Thanks,
>
> PS: I'm editing this e-mail as I do tests and I just noticed that my /sbin
> directory is empty. rmmod is there and I needed it to reload the b43 driver
> which generally does not feel well after a suspend/resume. A reboot fixed it.
> Weird ...
>
> --
> Mihai Donțu
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If you know how to patch and compile a kernel, try http://www.tuxonice.net/
I find it way faster and more reliable than the in-kernel hibernation.

You also need to install at least the hibernate script, since it is
way better for hibernation that pm-utils which most distros use.

Ubuntu and some other distros have binary kernels already patched and
the hibernate script packaged.

Regards,
Pedro