Re: replace in-memory rules array with match/action token list

[Alan Jenkins <alan-jenkins@tuffmail.co.uk>]

Kay Sievers wrote:
> On Thu, Oct 23, 2008 at 13:34, Alan Jenkins <alan-jenkins@tuffmail.co.uk> wrote:
>   
>> Alan Jenkins wrote:
>>     
>>>> The in-memory rule array of a common desktop distro install took:
>>>>   1151088 bytes
>>>> with the token list:
>>>>   109232 bytes tokens (6827 * 16 bytes), 71302 bytes buffer
>>>>
>>>>         
>>> Sounds great from a performance point of view.
>>>
>>> It doesn't work for me though.  My simulation takes over 5 times as
>>> long, and doesn't finish cleanly; i.e. there's still lots in
>>> /dev/.udev/queue after the cpu usage has stopped.  I'll try to track it
>>> down.
>>>
>>>       
>> Sorry - the queue is cleaned up correctly.  I was just too impatient.
>>
>> It's not a perfect test; I'm comparing
>>
>> a391f49d7f5433e6204f35331b81391c2d110309 - good ..
>> b99028c96307e729303be8f6750418979a7488b9 - bad
>>
>> which includes a few more commits, though the match/action list is
>> obviously the biggest one.
>>
>> The bad version of udevd seems to be generating two extra uevents per
>> device, in addition to the ones generated by "udevadm trigger".  That
>> is, the output of "udevadm monitor --kernel" is three times as long!
>>
>> It's not a change in udevmonitor or udevtrigger; I'm still using the
>> Ubuntu installed version of udevadm for testing.  I really don't
>> understand how this could happen.  Do you have any idea?
>>     
>
> Hmm, I don't see that here. Any rules you have, which may trigger
> uevents, and which may behave differently now?
>   grep uevent /etc/udev/rules.d/* /lib/udev/rules.d/* /dev/.udev/rules.d/*
>
> Kay
>   

Nope.

Drat, I can't reproduce that any more.  It's still takes over five times
as long, but I can't see anything unexpected happening.

I tried using strace (piped through grep 'open.*uevent".*WR').  At that
point it seemed to stop happening, even when I rebooted and ran it
without strace.

All I can think is, I must have accidentally run "udevadm trigger" twice
before I started udevd.

Baaa

(sheepishly) Alan