[Dazuko-devel] Re: Performance enhancements

[John Ogness]

Hi Swade,

I would be very interested in seeing some of your performance 
enhancements. The easiest way to proceed would be to submit a patch. 
Then it is really easy for me to see exactly what you've implemented and 
integrate your code into the main tree.

Which version of Dazuko are your enhancements based on? The 
ON_CLOSE_MODIFIED event was removed in version 1.1.0 because it involved 
a lot of extra work for something that a client (registered) program 
could really implement. Like you said, lists needed to be searched and 
the sys_write also call had extra overhead.

The latest versions (1.1.0-1.1.2) only have ON_OPEN and ON_CLOSE events. 
This was to address stability and performance issues. However, I am 
still very interested in the work that you have done and would be more 
than happy to integrate any performance improvements. We could bring the 
ON_CLOSE_MODIFIED event back if the improvements are significant.

Regardless, I want to integrate your work. :)

You can upload a patch from the Dazuko developer site:

http://savannah.nongnu.org/patch/?func=addpatch&group=dazuko

or you could send me all the code and I'll do diff's myself (which also 
is no problem).

John Ogness


S Wade wrote:
> Hi All,
>
> I've recently done some work integrating dazuko with an anti-virus 
> scanner and I implemented some enhancements I'd like to submit for 
> consideration.
>
> I figured that searching the list of files to be scanned on 
> close-modified could affect performance, so I altered the search to move 
> files that have already been modified to the end of the list. So when 
> searching to see if a file needs to be indicated as modified, the search 
> can be terminated as soon as the first modified file entry is 
> encountered. I ran some tests and found that it enhanced performance 
> considerably; how much so is highly dependent on how many files are 
> simultaneously open and whether or not the scan on close-modified is used.
>
> I think that we could also enhance performance by offering an optional 
> kernel patch that would allow us to store a pointer to the dazuko file 
> information in the kernel's file table. That would eliminate searching 
> the list completely.
>
> I'm new to open source, so I'm not exactly sure how to procede or even 
> if there is interest in my ideas.
>
> Sincerely,
> Swade