Thought about speeding up startup...
mdz at canonical.com
Thu Oct 21 18:11:27 CDT 2004
On Thu, Oct 21, 2004 at 11:49:41PM +0100, Matthew Garrett wrote:
> The actual scanning of hardware that occurs when hotplug runs is fairly
> fast - it's able to use information that the kernel already has. The
> delay is in loading the drivers, rather than anything else. The most
> significant problem with hotplug is the way it insists on trying to load
> drivers that aren't actually appropriate for the hardware - making
> hotplug more intelligent about what it tries would be a useful
In Oxford, I did some primitive profiling of this, and a huge part of the
delay is actually parsing out the (large) pcimap file using only the shell.
I believe it was about 300ms per PCI device, which adds up to a significant
amount of time. Most of the modules are actually fairly quick to load.
The whole pipeline is started up and stopped again for each device; I have
17 PCI devices in my laptop, and 11 in my desktop.
The trouble is that hotplug runs so early, that it can't rely on having much
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