Re: -nice tree [was Re: [Swsusp-devel] Re: swsusp problems [was Re: Your opinion on the merge?]]

From: Pavel Machek
Date: Fri Mar 26 2004 - 05:24:01 EST


> >>upgraded my laptop's hard drive, and found I wasn't getting the
> >>performance improvements in suspending I expected. It turns out that the
> >>CPU is now the limiting factor. Because I had the /proc interface, I
> >>could easily adjust the debug settings to show me throughput and then
> >>try a couple of suspend cycles with compression enabled and with it
> >>disabled. Without the /proc interface, I would have had to have
> >>recompiled the kernel to switch settings. (I didn't try gzip because I
> >>knew it wasn't going to be a contender for me).
> >
> /proc is needed a lot
> - enable escape
> - select reboot mode
> which is essential for multibooting. We use it all the time to
> boot various installations of Linux

Perhaps reboot() can have parameter for that.

> - select compression none, lzw or gzip
> none is used when disk faster that cpu-limited lzf
> lzf is used when cpu is fast enough to compress to disk
> Fast CPU can do 100MB/s+ to 50MB/s drives
> gzip is used by some who care about image size eg flash users

If you are doing "resume=swap:<something>", why not "resume=lzw-swap:something"?

> - keep image mode (when compiled in)
> which is used for embedded kiosks for example
> Boeing requested and uses it

Boeing can keep external patch, this seems like pretty dangerous
feature for joe user. And it should not be selected at /proc, but as
command line parameter.

> - default console level
> Controls console messages or nice display
> - access debug info header
> This is needed to analyze swsusp2 performance
> - access resume parameters
> Saves a reboot when changing parameters
> - activate
> swsusp2 activation independent of apci, apm

Should not be needed. There's reboot() syscall to do that.

> - last result
> info on why swsusp2 did not suspend such as out of
> memory or swap or freezing failure

That should be return value of reboot() syscall.

When do you have a heart between your knees?
[Johanka's followup: and *two* hearts?]
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