[systemd-devel] udev took too long to start

[Kay Sievers]

On Mon, May 23, 2011 at 06:32, Chen Jie <chenj at lemote.com> wrote:
> 2011/5/20 Kay Sievers <kay.sievers at vrfy.org>:

>>  Why is blkid called 11 times? You have that many partitions?
> I guess, sda-sda4 plus loop0-7 and plus ram0-ram15.

What do you need 16 ramdisks for? Not sure if anything today should use them.

> I collect all block devices by "udevadm monitor --kernel" and then
> triggering devices' adding, see attachment for the block list of the
> test box .

Things like edd_id you can just not enable in udev 170.

> Some rules added by distro, e.g. 80-alsa.rules, does some thing like
> "/etc/init.d/alsa-utils start"

Should not be needed with recent alsa-utils which has native systemd
suspport. The old shell scripts used to do a lot of nonsense.

>> Is the speed of the disk really only 18MB/sec? That's expected?
> Yes. that's low.

I see.

> Thanks ALL, I removes some rules and saves ~200ms. I did a
> bootchart(see attachment "Loong-sid-20110523-1.png"). The boochart
> diagram shows it spends 1s between udevd starts and forks the first
> helper program. Seems udevd itself starts too slow on the test box.

I would expect it's mostly I/O that happens during that time, which
makes things look slow.

You might want to try udev version 170. We could try to run trigger
and udev.service in parallel.

Kay