Do you want to write something about KDE's memory usage? Simple, just follow these steps:
Really, it's as simple as that. So many people do it, you can too. See, for example, this review of KDE4.3. I have nothing against the review itself, since, I admit, I mostly skimmed over it, only two things caught my attention. First one was getting it backwards who copied from who the filtering feature in Present Windows compositing effect, which slightly amused me, and second one was the part talking about resources, which didn't.
The first item there is about kioslaves supposedly staying running for way too long, and it's not interesting here (although I like how it says "I suspect", like if checking it for real and then creating a bugreport is way too much work). The second item is about KWrited taking, imagine it, 18M of memory, and the last one is about the nVidia libraries wasting a good amount of memory, again.
Checking the KWrited item (I guess I was curious, or maybe bored) showed me several things. First of all, I don't have any KWrited daemon - openSUSE has libutempter, which allows building KWrited just as a KDED module. So instead I took KAccess, which should get similar treatment and not run on every system when it's mostly useless. Looking at numbers in top showed resident memory usage (RSS) 40M and shared memory usage (SHR) 25M. That was interesting for several reasons, like 40M being quite a lot, even for shared usage (since resident memory usage includes also all shared stuff, and so it doesn't really mean that much), or the fact that unshared memory usage for a small daemon being 40M-25M=15M is just plain rubbish.
The 40M is actually easy to explain - it is loaded using kdeinit, so it includes all memory from the basic libraries that are preloaded by kdeinit and shared by everything it launches. That includes the ~10M unshared bonus from nVidia libGL libraries that kdeinit helps to share.
The seeming 15M of unshared memory was more interesting and strange. Checking /proc/PID/status confirmed that data of the process is nowhere near that and that there must be something wrong going on. Checking /proc/PID/smaps in details showed similar results, again nothing anywhere near 15M. It is also not nVidia, since the memory is marked as dirty, but shared. And then it suddenly was obvious. The kernel (since that is whose numbers top blindly repeats) doesn't consider dirty shared memory to be really shared. A major portion of the 15M is the position-fixing of the non-PIC nVidia libraries, and some of it is also memory taken by symbol-binding to libraries. If a shared memory is dirty, then it may be dirty, but it is still shared. It got dirty before kdeinit started forking off new processes for launching, so it must be shared. Checking with Exmap, the only memory tool I trust so far, confirms. It is still some memory taken (and still big enough for those who don't know which year it is), but it's much smaller than what it seemed like.
Now, no wonder pretty much nobody can get KDE's resource usage right, when both people don't understand it and tools report nonsense. As it is said, two wrongs don't make a right. Here, they usually just make only a bigger wrong.
So, John, I think I might know what you could add to KSysGuard, after all. You could try to make KSysGuard a memory measuring tool that, unlike the rest, doesn't suck and make people write nonsense about KDE's resource usage. The magic line, in bash terms, is:
Where PID is pid and TYPE is:
I hope this can work out for KSysGuard. I am slightly worried that fetching all these numbers from kernel will take too much time, but that needs to be tried. But, if it will work, do we all now know what will be so special about KSysguard?