Re: [PATCH] driver-core: devtmpfs - driver core maintained /devtmpfs

From: Lars Marowsky-Bree
Date: Mon May 04 2009 - 12:21:08 EST


On 2009-05-02T23:47:03, Kay Sievers <kay.sievers@xxxxxxxx> wrote:

> It is not about missing events, it is about the bootstrap step we
> would like to avoid. Buffering events, or reading all device
> information from sysfs at this stage introduces a hard checkpoint,
> where we need to bring a process up process these events and create
> nodes for them. Only after that we can start other things in userspace
> which depend on a working /dev, and with the kernel populated one, we
> can just go ahead.

So if udevd was present before the kernel started scanning devices this
would not be as much of a problem, would it?

(Couldn't udevd trigger the device scan? Could it be started so early as
for this not to matter?)

And isn't part of the problem that you have a choke point in the
dependency graph - namely "/dev working" as a predicate for running
certain services/scripts - instead of more fine-grained dependencies for
just the devices they need?


Regards,
Lars

--
SuSE Labs, OPS Engineering, Novell, Inc.
SUSE LINUX Products GmbH, GF: Markus Rex, HRB 16746 (AG Nürnberg)
"Experience is the name everyone gives to their mistakes." -- Oscar Wilde

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