DPC Latency will destroy the AVAST'S reputation ?

Great; another thread that has been ruined by fanboys who don’t understand the concept of bug reporting.

If only fanboys could be moved to the virus vault, this forum might actually be useful again.

Sorry but you’re not right in this case, faust.

I spent a great deal of time trying to simulate the problem and/or find an issue in the avast driver sources that could lead to this scenario (e.g. holding spinlocks for too long etc). And I’m pretty confident that the problem is not related to avast in this case.

As you can easily check, cako is spending a lot of time complaining about this issue here (pretty much all of his ~100 posts so far are related to this). But the problem is, the measurements are inconsistent. Also, it simply doesn’t make sense that 5.0.462 would have this problem while the previous versions not have it as there were no meaningful changes that could make any difference. DPC Latencies are difficult to debug, and you usually need to understand what’s really going on under the hood to be able to understand the problem.

Now on a side note, we’ve just found that the paid version of Malwarebytes (namely its “IP Protection” component) is a real DPC Latency master though (we see huge latencies when doing e.g. speed tests with IP Protection enabled). And for some reason, it gets ever worse when avast is installed (I suppose that’s because with avast’s WebShield in place, the connections are doubles [as WebShield acts as a HTTP proxy]).

Vlk,so you suggest to run MBAM resident with out IP Protection with Avast 5 Free, to reduce DPC latency…is that correct?

Regards!

Well see for yourself, I wrote a bit more about it here: http://forum.avast.com/index.php?topic=56694.msg486878#msg486878
If this is happening even on your system (it will depend on your connection speed - here I have a ~60 mbit connection so pretty fast) you should get in touch with MBAM and report the issue to them.

It should be relatively easy to fix on their side, I assume they’re doing lookups to the banned IP list on DPC level (e.g. while holding a spinlock) while this is not really needed.

Two local proxy problem… if so, it is possible that this causes my sound chattering (only sometimes, indeed), because I use another local proxy (Proxomitron).
My sound chattering is always on my PC (long running worsens this), and avast! and Proxomitron is always together too… I thought chattering is because my PC’s power shortage, but it seems this is the reason.

Now DPC Latency Checker shows exactly same graph compared to before my post, and this time is only 1 hours after reboot (with no P2P application).
Cako, are you using other local proxy software? If so, it can cause your problem too.

Anyway, I like avast very much. Thanks Vlk for your great work!

vlk.
Sorry but you’re not right in this case, vlk.
faust its absolutely right, this is a site for support or not.
I’m proud of my 100 posts because I dont quit when someone says no, or i see a problem, or when someone say that is impossible, I try, I fight I win.
thought it would be like if everyone gave up the first problem …
if someone says “this is impossible”,just fight end make it “possible”,the persistence leads to success
why you dont say you did tests about the problem,I probably would not have written 100 posts.
I never said avast is a bad antivirus, he is the best, so I still use.
the sound problem on my PC is resolved by placing the emule (version 0.49c) on exceptions’s list of P2P shield.
i will update the emule soon end test again…
I insist on a permanent solution if it exists on my PC,and i dont understand how the 396 version its so perfect on my PC.
well,vlk I think you really dont like me, that’s why you did not write directly to me.
anyway,thanks for trying simulate the problem.

and guys, stop asking me to change antivirus I will not do that, and I will buy AIS5.
just change antivirus is a coward solution.

NON
I’m not using any proxy software.
i dont use Malwarebytes,i use Spybot - Search & Destroy (without real-time protection)
but probably have something on my PC and the sisterr’s PC who may be in conflict with avast (but why the 396 version dont have conflict ??? its a mystery.)
My modem is routed is a dslink 260e, my sister also.
the modem have a firewall, is there any chance of avast to be difficult to receive or scan the information packets of modem ???
avast probably conflicts with something on some PCs.
on my PC just happens when avast scan emule (utorrent) with the P2P shield,end i have the sound problems.
when I turn off P2P shield or place the emule (version 0.49c) on exceptions’s list of P2P shieldthe my sound and avast work perfectly.
you find the source of your problem ???
in your case is a proxy software. ???

I googled about DPC latency and P2P application… found some articles. If you have seen these before, then sorry for disturbing.

http://www.thefreewindows.com/?p=2497
This article says eMule has DPC Latency problem itself… and I can’t find any information about DPC latency in recent eMule changelog.
Perhaps this issue isn’t fixed yet, and appears in some situation (with avast 5.0.462 :frowning: ).

http://forum.utorrent.com/viewtopic.php?pid=468852
This forum users have DPC Latency problem with uTorrent and Microsoft Security Essentials… and they say shutting down one of these software resolves the problem immediately.

Please try to shut down P2P application or disable and re-enable avast!'s P2P shield when the problem happens. Does it show any change? After doing this, DPC Latency Checker still shows any peak?

I hope Cako’s problems will be solved soon. He really is suffering.

Chill down Zyndstoff, you seem to be learning fast from Logos… :wink:

Sorry, you are right.

I did what you said…the pictures (taked 4 hours after p2p scan emule) dont have quality,but is visible,and my modem has IP filter.
I just test the limewire right now end happened the same with him (high DPC latency).
I found this:
https://forums.comodo.com/bug-report-cis/cis-40x-still-causing-high-dpc-latency-issue-t54242.0.html
end this:
http://forum-en.msi.com/index.php?topic=132050.msg994534

if microsoft secure essential,avast end comodo internet security has the same problem, it must be very difficult of identify and fix,I think these programs conflict between one and more drivers or something in this computers, but what?.
I dont install beta programs on my PC, when emule is in the final version I’ll install end try make tests again, now emule is in 0.50a beta 2 i’am using version 0.49c final.
thanks for the links.

See, Cako, now you’re talking right stuff. ::slight_smile: That is exactly the way the problem goes. Drivers for hardware are written in a sloppy way, hardware has it’s problems. Sometimes is just the specific combination of hardware, drivers and software that just won’t fit together 100%. Every single part, taken on it’s on, is perfectly ok, but the unique combination just won’t go.
BTW: I think that in most of the cases it’s the driver side, that launches the problem - drivers are most often programmed in a hasty way and very, very often they don’t adhere 100% to agreed specifications.

Well, this Cako dont learns, even with VLK, the main developer, he dare tell VLK is wrong. Hey CAKO, you want to develops Avast, do you know to fix the problem? I dont think so…

Great software :o

From Comodo support forum:
https://forums.comodo.com/bug-report-cis/comodo-uses-to-much-system-resources-t34562.0.html;msg304996#msg304996

See image, you can identify which drivers causes high DPC Latency!
This app is contained Windows 7 SDK → Windows Development Tools

Edit: correct typo


I feel this is so-called “compatibility” problem… same program shows different result on different environment.

And one other thing, “latest” doesn’t mean “good”. One of my friends had a trouble with graphic driver, and version down to 2 before release solve the problem.

So I suggest this: I know you don’t like to do this, but return back to .396 for the time being, and wait for some ways appear… there are a good few people having similar problem, and if one of these problem successfully solved, it can be applied to yours.

P.S.
Did you already try to disable all resident software (from msconfig) except avast and run emule? If it works fine, the problem is caused by some of your resident software.

We use xperf as part of our routine testing. It’s one of the good tools in the Windows Driver Kit (WDK) that help developers debug these kind of issues.

Of course, if cako is willing to use the tool to find out what’s causing the peaks on his system, it would be welcome.

To be honnest : I would be surprised :-\

Greetz, Red.

I found this interesting:
Turn off indexing and speed up Windows XP
http://lifehacker.com/031440/turn-off-indexing-and-speed-up-windows-xp

I do not have indexing enabled on my XP system but I do on my Windows 7 system.

Thanks a lot for the link (and the link it links to) 8)

smudge

I found the download of RATTV3,my computer restart if I do the test now will not show anything
avast its scanner emule again,in a few hours the problem will appear end I will use the program.
NON, you can put the link of the program that you are using here.

YoKenny
I’ve tried it, cleaned the registry uninstall programs and no fix it.
thanks for the suggestion.

Sorry for late response.

You can download Windows7 SDK from here.
http://www.microsoft.com/downloads/details.aspx?FamilyID=c17ba869-9671-4330-a63e-1fd44e0e2505&displaylang=en

It’s a web based installer, so download and run it. Installer will start, and install Windows Development Tools.
After installation, you can see a short-cut in Start menu says “Install Windows Performance Analysis Tools” (or the like). Install.

Usage, here the quote from Comodo forum:

4. Open a command prompt (elevated if necessary) and navigate to the xperf folder the default is "C:\Program Files\Microsoft Windows Performance Toolkit"
  1. For the sake of simplicity type:

xperf -on DiagEasy and press return.

This will begin the trace. I suggest letting it run for several minutes to ensure you capture the details required.

  1. After a time has passed type :

xperf -d trace.etl and press return.

This will stop the trace.

  1. Type:

xperf trace.etl and press return.

This will display the results. We could have collected more specific data but using the DiagEasy switch is good enough for our purposes.

  1. Scroll down to the section headed DPC CPU Usage.

  2. Select a nice big spike, this corresponds to the spikes you will have observed in DPC latency checker. Select the spike and right click. From the menu select Summary Table. This will open a new window with details regarding drivers. The higher the value the more problematical the driver.

In fact, most of my DPC Latency is caused by “USBPORT.sys” and “ataport.sys” ???
Port controller driver? I should google for my problem again :frowning:

Good luck!