[PATCH 0/8] Various large optimisations

[Rob Taylor]

Danny Kukawka wrote:
> On Montag, 19. November 2007, Richard Hughes wrote:
>> On Mon, 2007-11-19 at 11:55 -0500, Doug Klima wrote:
>>> Rob Taylor wrote:
>>>>  4) Allow hotplug events to process in parallel. This intruduces into
>>>> HAL a similar parallel event processing method as udev. Along with 2),
>>>> this removes the coldplug memory peak almost entirely (Cutting down to
>>>> 350K on my intel hardware and about 150K on an N800)
>> Be careful with this. I had big problems with this a few months ago with
>> coldplug ordering issues - I'm sure the list has all the juicy details.
> 
> I would also assume we get (many) regressions with this change.

Well, I didn't do this code blindly! I've tested on all the hardware I
own to check that there's no differences in the device database. Its
also uses pretty much the same logic as udev.

I agree that it needs testing on more systems, but just throwing up our
hands and going 'oooh! scary!' wont help that....

Any volunteers for testing?



>>>>  5) Add the ability in HalDeviceStore to index given properties by
>>>> value. Profiling showed that about 20% of coldplug time was spend in
>>>>  hal_device_store_match_key_value_string to look up devices by
>>>> sysfs_path. This generic patch cuts each lookup to a couple of hash
>>>> table lookups, versus n strcmps.
>> Can't we just hardcode sysfs path?
> 
> How this? IMO we don't speak about /sys, but about the indivdual path of the 
> devices.
> 

Yes, there's nothing to hardcode here. The lookup could have been made
specific to sysfs_path, but it seemed nicer to me to add a generic value
indexing facility, and very little extra overhead (a hash table lookup
in a hash table of one ;))

Thanks,
Rob

> Danny
> 
> _______________________________________________
> hal mailing list
> hal at lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/hal


-- 
Rob Taylor, Codethink Ltd. -  http://codethink.co.uk