[systemd-devel] Significant speedup of systemd boot time with CONFIG_HZ=1000

[Henrik Grindal Bakken]

"Kok, Auke-jan H" <auke-jan.h.kok at intel.com> writes:

> On Mon, Nov 5, 2012 at 7:19 AM, Henrik Grindal Bakken <hgb at ifi.uio.no> wrote:
>>
>> The kernel boot time seems pretty long there, but that's partly due to
>> a fairly long (intentional) delay in initramfs.
>
> You'll get a much fuller picture if you use github.com/sofar/bootchart and
> enable initcall_debug=1 at the kernel cmd line :^)

Okay, I'll look at it.

>> There is also a rather peculiar delay between the startup of several
>> services (dev-mqueue.mount, systemd-random-seed-load.service, etc)
>> which is very regular.  Not sure why this happens.
>>
>> Does anyone have any insights into why we have this huge difference?
>
> I know that systemd-random-seed-load.service is forced to load as part
> of basic.target and blocks it. During this window a lot of things are
> going on that can make this service take a long, long time.
>
> You can delay them and make non-critical services for your device
> part of multi-user.target and make them non-blocking to make the
> delay mostly go away.

With the 1000hz config, I'm getting pretty good boot times, so I'm not
sure I'll need to optimize that hard, but I'll see if it changes
anything.

Thanks, anyway.

-- 
Henrik Grindal Bakken <hgb at ifi.uio.no>
PGP ID: 8D436E52
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