system becomes unresponsive as soon as any process uses Disk I/O at about 300 MB/s speed or more

When any process uses Disk I/O at about 300 MB/s speed or more as seen in htop, the system becomes unresponsive (it often may take longer than a second to react to mouse movement or key presses) which IMO should never happen. Is this something unavoidable on Ubuntu, or are there any things to try which may solve this?

Also I use a SSD, a relatively fast one I think. No HDDs are even connected to the PC.

This is, for example, one of the issues that make it near impossible to use Android Emulator.

Magento 2.2.6 Catalog Search indexer process unknown error – Notice: Undefined offset: 53

I’m currently using Magento 2.2.6. I’ve recently encountered the following error while trying to reindex the catalogsearch_fulltext:

Notice: Undefined offset: 53 in vendor/magento/module-catalog-search/Model/Indexer/Fulltext/Action/Full.php on line 384

Does anyone know how to fix this error?

Any help would be much appreciated.

How to use sockets for inter process communication (between two different julia program) in julia?

I am trying to communicate between two different Julia program using sockets, but how to use Julia socket programming for Inter-Process Communication (IPC)? I can find the code for TPC sockets, but I guess it is used for communication between two different hosts rather than between two programs on the same computer. (I am a newbie)

HP laptop, Ubuntu 18.10, and runaway kacpid process !!PLS HELP!

So guys, I’ve been having trouble last couple of days trying to fix kworker/0:4+kacpid. All I know is that its consuming 90-100% of my CPU when no programs are running. So ill just list things I have tried and failed with so if you have any more suggestions or if you had same problems pls comment I’d rly like to fix this.

What have I tried and relevant informations:

  1. Laptop is HP ProBook 450 G3 with i3-6100, AMD R7 M340, 8GB ram, 2 SSD – 1. with Ubuntu 18.10, 2. with Windows 10
  2. I have updated BIOS and all the drivers HP offers on their site for my laptop, but only thing is that drivers are for Windows, they have no drivers for linux as you can see for yourself. https://support.hp.com/us-en/drivers/selfservice/hp-probook-450-g3-notebook-pc/7834555
  3. I have tried to download off official AMD site latest drivers for my R7 M340 but latest is for ubuntu 14.04, ubuntu update center offers no additional drivers and I get message my machine is up to date.
  4. I have tried setting in grub acpi=strict and pnpacpi=off non have worked.
  5. I have tried running live machines off usb to check if kacpid is still consuming 90% of CPU and IT IS on: Ubuntu 19.04, Ubuntu 18.10, Ubuntu 14.04, Fedora 29… yes all of them were 64 bit, so you can exclude GNOME and GNOME extensions as a problem…
  6. I have started a thread few days ago and if you would like to check out comments of people trying to help me resolve my problem here is the link: Ubuntu 18.10 CPU1 always around 100% despite no programs are running

I’d rly like to resolve this and if you even have suggestion what should i try pls leave a comment, I’m new to whole linux scene and I would rly like to stay. 🙂

Nested loop in lisp to process a 2d array – what’s good style (with and/or without loop macro)?

Code below is answer to an exercise in Paul Graham’s ANSI Common Lisp (ex. 4.1). The challenge is to rotate an array by 90 degrees. I found an example solution which I’ve commented below.

It seems ok’ish and I’m enjoying learning how to use do, but in this particular case it seems actually more verbose than the familir c-style nested for loops to process a 2d array. I’m wondering if the below is good style or if it can be improved upon?

Is the answer going to be the loop macro? I’m avoiding that at the moment while learning, waiting till I have better mastery of the basics. Yet would like to not pick up bad habits. Hence this question about style regarding the below.

(defun quarter-turn (arr)   (let* ((dim (array-dimensions arr))  ; let* sets sequentially, not in parallel.          (row (first dim))          (col (second dim))          (n row)  ; initialise n to row, just to organise          new-arr) ; shorthand for (new-arr nil)     (cond ((not (= row col))            (format t "The arg is not a square array.~%"))           (t (setf new-arr (make-array dim :initial-element nil))              (do ((i 0 (+ i 1)))  ; Q. surprisingly, lisp's 'do' here looks more                  ((= i n))        ; verbose than c-style 'for'. Is this good style?                  (do ((j 0 (+ j 1)))                      ((= j n))                      (setf (aref new-arr j i) (aref arr (- n i 1) j))))              new-arr)))) 

Source for the above code: http://www.cs.uml.edu/~lhao/ai/lisp/ansi-common-lisp/solution-ch04.htm

how you would move forward from completing the Planning, requirements modelling and analysis part of the development process?

I am following RUP/USDP practice. I have made Use case model, High level, Use case, Expanded, Interactions Diagrams, and Class Diagram.

Question: Explain how you would move forward from this part of the development process.

How exactly does a CPU do process scheduling?

I know in theory how various scheduling algorithms work, such as round robin, where each process is given small time slices to run a few instructions, before the operating system passes execution onto the next process, and so on.

What I don’t understand is how this is possible. The operating system is just some code, and so are all of the processes, so why doesn’t this happen?

  1. OS passes execution to the first process.
  2. Now that process is running, the OS can’t stop it, since the CPU can only run one instruction at a time, and that instruction is the process’.
  3. Now the operating system has no control over the process, and can’t stop it.

Now obviously this doesn’t happen, but why not? How would the operating system say something like “Okay, you can run 3 instructions now, but after that let the other process run”?

Process monitor script bash

I am using below script to monitor some processes on linux and restart if process is down and send email.

I want to add below improvements in this script, I need help in that case.

  • Seconds to wait between attempts to restart service
  • Number of attempts before giving up
  • Check interval in seconds
  • Generate logs in case of events.

Current script:

###edit the following export smtp=smtprelay.domainname.com:25 service=splunk email=mailID@xyz.com ###You can provide multiple mail ID's above in email variable separated by commas ###stop editing  host=`hostname -f` if (( $  (ps -ef | grep -v grep | grep $  service | wc -l) > 2 )) then echo "$  service is running" else /opt/splunk/bin/$  service restart if (( $  (ps -ef | grep -v grep | grep $  service | wc -l) > 2 )) then subject="$  service at $  host has been started" echo "$  service at $  host wasn't running and has been started" | mailx -s "$  subject" $  email else subject="$  service at $  host is not running" echo "$  service at $  host is stopped and cannot be started!!!" | mailx -s "$  subject" $  email fi fi