Re: [PATCH 7/9] PM: Measure device suspend and resume times

From: Rafael J. Wysocki
Date: Fri Sep 11 2009 - 18:17:33 EST


On Friday 11 September 2009, Ben Gamari wrote:
> On Thu, Sep 10, 2009 at 01:39:21AM +0200, Rafael J. Wysocki wrote:
> > From: Rafael J. Wysocki <rjw@xxxxxxx>
> >
> > Measure and print the time of suspending and resuming all devices.
> >
> > Signed-off-by: Rafael J. Wysocki <rjw@xxxxxxx>
>
> Do you have any rough numbers describing actual suspend/resume times
> before and after this patch set? Of what order of magnitude is the
> improvement on standard x86 hardware? Just curious.

Depending on the system on which it's run, it gives up to 15% speedup,
but please note that only PCI and ACPI devices are now allowed to
suspend/resume asynchronously, while on my test systems the most significant
stalls are from USB, serio devices and (SATA) drives which are still
suspended/resumed synchronously.

Thanks,
Rafael
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