TuxOnIce in Ubuntu kernel?
ncunningham at crca.org.au
Mon Oct 19 05:55:26 UTC 2009
Andy Whitcroft wrote:
> On Sun, Oct 18, 2009 at 04:59:03PM +0800, Chow Loong Jin wrote:
>> Hi Kernel Team,
>> I've recently been testing out TuxOnIce on my notebook, and was rather surprised
>> to note the performance improvements over the kernel method/swsusp. (Less than
>> half a minute to a functional desktop, with swap in dm-crypt/lvm).
>> On the same system, the kernel method and uswsusp both take 2-5 minutes to
>> resume, depending on how much memory/swap usage I had prior to hibernating.
>> While this might have been acceptable in the past, with Ubuntu's boot time
>> getting shorter and shorter (the target is 10s, IIRC), I think it's time our
>> hibernating/resuming time grew shorter.
>> Something I did notice in my tests is that for the same system, all three
>> methods resumed from cryptsetup's password prompt to userspace in pretty similar
>> time frames (<30s). However, for the kernel method and uswsusp, the system is
>> unusable while it continues to swap out for 2-5 minutes. A user on a bug report
>> once did some benchmarks by running `vmstat 1` and hibernating. The result was
>> that the swapout rate was approximately 1MB/s after resuming. IMO this is rather
>> suboptimal and could be improved much.
>> And hence my suggestions:
>> 1) Switch to tuxonice for hibernate/resume (tuxonice-userui can be improved, and
>> pm-utils already has support for tuxonice)
>> 2) Improve (u)swsusp to read out more from the swap instead of unfreezing tasks
>> prematurely and having the rest swapped out slowly.
> It seems that the plan is to pull the good bits of Tux-on-ice into the
> mainline kernel in an incremental manner over the next couple of releases.
> We will need to monitor this for Lucid.
It's going to take more than a couple of releases.
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