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-   -   120% CPU with OSX SecureCRT 8.1.4 ... how to fix? (https://forums.vandyke.com/showthread.php?t=12882)

SimonHF 10-31-2017 11:20 AM

120% CPU with OSX SecureCRT 8.1.4 ... how to fix?
 
I recently upgraded from SecureCRT 7.3.7 to 8.1.4 on OSX. I have 4 tabs open and SecureCRT is over 120% CPU. One tab is doing nothing and the two others are doing a light tail -f, and the last is running top. I noticed this because the laptop fan came on and was annoyingly loud.

If I ctrl-c the two tails and the top then the CPU usage stops.

If I start one of the tails then CPU usage hovers around 26% to 60%.

If I only start top then CPU usage hovers around 75% to 85%.

If I run only the following one-liner outputting 10 lines per second then CPU usage hovers around 90% to 120%:

$ perl -e 'use Time::HiRes; while(1){ printf qq[hello world!\n]; Time::HiRes::sleep(0.1); }'

If I leave the one-liner working and switch to another tab which is idle then CPU usage continues at the same rate.

If I modify the line for 10x more lines then the CPU usage stays the same.

If I modify the line for 10x less lines then the CPU usage hovers around 20% to 36%.

It doesn't seem to make any difference if the one-liner is run in a local shell tab or a remote shell tab.

FYI I'm running macOS Sierra Version 10.12.6 on a MacBook Pro (Retina, 15-inch, Mid 2014).

I tried running the same one-liner outputting 10 lines per second on SecureCRT 7.3.7 and CPU usage hovers around 60% if the tab is in focus and scrolling. If I switch to a different tab which isn't scrolling then CPU usage drops to about 6%.

I tried reducing the size of the tab to a quarter of the size on screen and CPU dropped to about 23% from 60%. Then I dragged the SecureCRT window from my external monitor onto the internal screen of the laptop and CPU dropped to about 16%. Dragging the same window onto the 2nd external monitor dropped the CPU usage to about 10%. This seems to match the order of display resolution with the first external monitor being biggest at 4K, internal display being second biggest retina resolution, and 2nd external monitor being the smallest.

Clearly the 8 version of SecureCRT is using up to double CPU than version 7 uses, and -- worse than that -- continues to chew on the CPU even if an idle tab is in focus.

Is this a known issue? Any ideas how to fix these new version 8 problems?

And any ideas how to lower the CPU usage for an active in focus tab on version 7?

Thanks,
Simon

bgagnon 10-31-2017 01:28 PM

Hi Simon,

I am sorry to hear about the issue you are experiencing. Sorry, no, I do not have any suggestions at this time as we have not yet collected any tangible data that can be analyzed and there is a need to clarify some of your statements.

When we attempted to replicate the issue based on our understanding of the info provided so far we were unable.

Quote:

I have 4 tabs open and SecureCRT is over 120% CPU.
How can it be > 100% CPU? Do you have multiple cores? What tool are you using to get these CPU measurements?

Quote:

FYI I'm running macOS Sierra Version 10.12.6 on a MacBook Pro (Retina, 15-inch, Mid 2014).
Your 2014 MacBook Pro did not come with Sierra installed, correct? When did you upgrade the OS? Does it coincide with these issues? Have you restarted the machine since upgrading SecureCRT? (As a note, SecureCRT version 7.3.x did not support Sierra OS.)

Please attach a screenshot of the About This Mac dialog so we will have further info about the hardware.

Quote:

I tried reducing the size of the tab to a quarter of the size on screen and CPU dropped to about 23% from 60%.
I do not understand the above statement. Please elaborate. You can't resize the tab itself. Do you mean the application window? If so, are you talking about resizing using a corner of the window?

SimonHF 10-31-2017 03:40 PM

2 Attachment(s)
Thanks for the quick response. Now to respond to your initial questions:

Brenda: How can it be > 100% CPU? Do you have multiple cores? What tool are you using to get these CPU measurements?

Simon: I believe the laptop has an Intel i7 which has 4 cores and another 4 hyper-threads. I used the OSX Activity Monitor app to view the CPU usage of SecureCRT. It's like the Mac equivalent of 'top' on Linux. It also shows how many threads an app is using. For SecureCRT is showed me 14 threads were being used at the time of the test. Please see uploaded screen shot. I'm guessing the threads are how to get above 100% CPU. AFAIK one thread on it's own could never use more than 100% CPU.

Brenda: Your 2014 MacBook Pro did not come with Sierra installed, correct? When did you upgrade the OS? Does it coincide with these issues? Have you restarted the machine since upgrading SecureCRT? (As a note, SecureCRT version 7.3.x did not support Sierra OS.)

Simon: Correct, OSX upgraded itself earlier in the year. I can't say when the SecureCRT 7.x.y issue started because I wasn't aware about it because the laptop fan did not draw it to my attention and selecting an idle tab 'fixed' the issue anyway. The worse SecureCRT 8.x.y issue started this morning after I used the newer 8 version for the first time. I noticed it straight away because the fan on the laptop was noisy. AFAICT SecureCRT 7 seems to work better with Sierra OS so far... at least regarding this CPU issue. The laptop was freshly booted. I attach a screen shot of the 'About this Mac' dialog FYI.

Simon: I tried reducing the size of the tab to a quarter of the size on screen and CPU dropped to about 23% from 60%.

Brenda: I do not understand the above statement. Please elaborate. You can't resize the tab itself. Do you mean the application window? If so, are you talking about resizing using a corner of the window?

Simon: Maybe I should have said that I tried reducing the size of the application window (the window where 'hello world' scrolls up the screen) belonging to the visible tab. And yes, I can use the diagonal stripy icon in the bottom right to resize... in my case to about a quarter of the size. Then I used Acitivity Monitor to report the CPU usage at the new size.

HTH,
Simon

bgagnon 11-01-2017 07:17 AM

Hi Simon,

Would you capture a process dump file when SecureCRT 8.x is in a state of high CPU usage?

Here is how to create it:
  • Open the Activity Monitor
  • In the Activity Monitor, click on SecureCRT
  • Select "Send Signal to Process" from the View menu
  • Send the "Abort (SIGABRT)" signal to SecureCRT
  • When you restart SecureCRT, information will be displayed about where to find the core dump
Please send an email to support@vandyke.com and include the email address associated with your VanDyke Software download account. I will then provide instructions for uploading the process dump file. Please use subject line of "Attn Brenda - Forum Thread #12882" in the email.

SimonHF 11-01-2017 11:04 AM

Thanks for sending me these steps which I carried out this morning. This results in a 273.6 MB .bz2 files which is probably too large to attach to an email. How else to upload that?

bgagnon 11-01-2017 11:08 AM

Hello Simon,

Please see prior post.

Quote:

Please send an email to support@vandyke.com and include the email address associated with your VanDyke Software download account. I will then provide instructions for uploading the process dump file. Please use subject line of "Attn Brenda - Forum Thread #12882" in the email.

SimonHF 11-01-2017 11:24 AM

Thanks, did that. Waiting for reply. Although my email is different from the email associated with the download account. That's because the license was bought on my behalf by our VP of Business Operations. -- Simon

SimonHF 11-01-2017 03:52 PM

Email arrived but having trouble locating the name and password used for the SecureCRT download section since the account is managed by somebody else in the company :-( In the meantime is there an alternative way to upload? -- Simon

SimonHF 11-01-2017 04:11 PM

Turns out that nobody at the company has an account for the SecureCRT download section... which is complicating things a lot. Trying to figure out how to best creating such an account. -- Simon

SimonHF 11-01-2017 04:28 PM

Managed to create the account and uploaded the large file. Looking forward to your comments! -- Simon

bgagnon 11-02-2017 07:29 AM

Hi Simon,

This seems to have all been sorted out now.

For others that may read this thread:

Please understand that purchasing our products (or possessing a valid license) *has nothing* to do with the eligibility/ability to have a download account. Since the current versions of our products are offered for evaluation, anyone (if they pass the online export restriction check) can register for a download account. The download account registration form is here.

The registration form helps ensure we are compliant with U.S. Homeland Security export restrictions for strong encryption software. It is a one-time only requirement (per email address).


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