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

From: Eric W. Biederman
Date: Sat May 09 2009 - 20:29:34 EST


Kay Sievers <kay.sievers@xxxxxxxx> writes:

> On Thu, May 7, 2009 at 10:17, Eric W. Biederman <ebiederm@xxxxxxxxxxxx> wrote:
>
>> sysfs is slow.
>> udev is slow.
>
> Everything is "slow" if you want to boot "fast". It's just numbers,
> and this is more about simplicity and reliability, with just the side
> effect that it's the fastest you can do, when you don't want to lose
> current functionality.

My primary concern is that you are inventing a new mechanism when
the existing mechanism has known issues that could explain the slowdowns.

My secondary concern is we have are adding a new mechanism when
the existing mechanism has some significant known issues, that are
not currently being addressed. Instead the next shiny bobble is
being tackled.

Finally I am stumped how creating a couple hundred device nodes can be
a significant slowdown in booting. It feels like we your patchset
adds a line of code for each device node it intends to create.

>> Let's bloat the kernel to solve that problem?
>
> You want to add namespaces for devices to it?

I think it is a logical conclusion, and it might potentially be needed.
But that is a long ways out.

Eric
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