Occasionally my computer(Lubuntu 16.04 64 Bit) gets stuck at shutdown. It shows the message nmi watchdog bug soft lockup - cpu#1 stuck for 22s and never finishes shutdown.This message comes after the message Reached target shutdown.. What causes this error? How do I resolve this?
I get this error message   NMI watchdog: BUG: soft lockup - CPU#2 stuck for 23s! [plymouthd:305]    on the startup of my system (even with live-cd).  My PC is a dell inspiron 7559 with intel graphic and nvidia.  UPDATE - this issue also happens when attempting to install ubuntu 18.10 using LiveUSB
Theme Image Style for image located in module directory Probably coming at this from too much of a Drupal 6 view point but...  How do I theme an image in a given image style when that image lives in a module folder?  This is driving me batty and I know I'm just missing something simple.  Here is some example code showing what I'm trying to do:  $file_uri = 'public://sites/all/modules/my_module/logo.jpg'; $data['logo'] = theme('image_style', array('style_name' =&gt; 'medium', 'path' =&gt; $file_uri));   Even if I use file_build_uri(), I end up with a path to a file that doesn't exist. If I move the image to the files directory and change the $file_uri to 'public://logo.jpg', it works just fine.  Do I need to copy the image to the files directory as part of the module code?  If so, isn't this ridiculous?  What am I missing?  Is there documentation on how to do something like this?  I've spent over an hour mining the Drupal documentation and came up completely dry. I get the following error when i do sudo apt-get update  W: GPG error: http://ppa.launchpad.net precise Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 6AF0E940624A220   I tried following ways after reading various questions here and also by googling.  I tried  sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 6AF0E1940624A220   It did not help. I also tried  sudo gpg --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys   thinking port 11371(default) may be blocked due to firewall.  I also tried to reset everything as follows  sudo rm /var/lib/apt/lists/* -vf sudo apt-get update &amp;&amp; sudo apt-get upgrade   still i get the same error or get update. Any other possible solution I can try? How do I show that all continuous periodic functions are bounded and uniform continuous? A function $f:\mathbb{R}\to \mathbb{R}$ is periodic if there exits $p&gt;0$ such that $f(x+P)=f(x)$ for all $x\in \mathbb{R}$. Show that every continuous periodic function is bounded and uniformly continuous.   For boundedness, I first tried to show that since the a periodic function is continuous, it is continuous for the closed interval $[x_0,x_0+P]$. I know that there is a theorem saying that if it is continuous on a closed interval, then it is bounded. However, I'm not allowed to state that theorem directly. Should I just aim for a contradiction by supposing f is not bounded on the interval stated above? Reference - What does this regex mean? Can I travel within the Schengen area without a passport if I have my residency permit card? I am currently located in the Netherlands and have lived here for 4 years. I have a working visa for the Netherlands and would like to go on vacation to another country in Europe. I however do currently not have my passport as i sent it to an embassy for a visa application. Will I still be able to travel inside of Europe without a passport if I have my residency ID?  I have a resident permit, not a true Dutch ID. And I own a passport that is currently in transit.  I have called with the KLM and the service employee's conclusion was that I do need to carry my passport with me when i am going to fly, so it seems all I can do is wait and hope my passport is returned to me in the next few days as the amsterdam US consulate (who currently holds my passport) is incredibly difficult to contact for urgent matters. How do electromagnetic waves wave? Electromagnetic waves have a physical crest and trough as observed in microwaves and radio waves. I understand that is electromagnetic field vectors that wave, not the photon. But how do they wave? What does causes them to change direction? How to add a space between a string for every 5th letter? How to plot the first n rows of a table using pgfplots? Eclipse freeze accessing project -> properties -> android tab When going to any page of  with a new reputation gain, the achievements dropdown keeps showing a new badge green highlight:    And then trying to dismiss the notification by clicking on it gets rid of the green badge notification, but the +5 remains even after I've clicked away from the dropdown. Suppose $X_n$ is the fortune of a gambler after $n$ th game. Then the game is called fair (Breiman 1968) if   $$E[X_{n+1} \mid X_1, \dots, X_n] = X_n \forall n$$  My question is why a fair game is not defined as the following   $$E[X_{n+1}] = E[X_n] \forall n$$ i.e. $$E[X_{n+1}- X_n]=0$$. This should be the proper definition as a fair game is where avg. gain is zero. Nothing conditioning should be there. Why is Python 2.7 still the default Python version in Ubuntu? According to official documentation of Python, Python2.7 support will end near in future.     DEPRECATION: Python 2.7 will reach the end of its life on January 1st, 2020. Please upgrade your Python as Python 2.7 won't be maintained after that date. A future version of pip will drop support for Python 2.7. More details about Python 2 support in pip, can be found at    Why is Ubuntu not using Python3 as default in their upcoming version?  $ cat /etc/os-release  NAME="Ubuntu" VERSION="19.04 (Disco Dingo)" ID=ubuntu ID_LIKE=debian PRETTY_NAME="Ubuntu 19.04" VERSION_ID="19.04" HOME_URL="https://www.ubuntu.com/" SUPPORT_URL="https://help.ubuntu.com/" BUG_REPORT_URL="https://bugs.launchpad.net/ubuntu/" PRIVACY_POLICY_URL="https://www.ubuntu.com/legal/terms-and-policies/privacy-policy" VERSION_CODENAME=disco UBUNTU_CODENAME=disco     $ python Python 2.7.16 (default, Apr  6 2019, 01:42:57)  [GCC 8.3.0] on linux2 Type "help", "copyright", "credits" or "license" for more information. If $\cos x=\cos y$ and $\sin x=\sin y$ is $x=y$ or $x=2\pi,y=0$ or $x=0,y=2\pi$? $x,y\in[0,2\pi]$ I know that if $\sin x=\sin y$ then $x=n\pi+(-1)^ny$  and $\cos x=\cos y$ implies that $x=y+2k\pi$ or $x=-y+2l\pi$. Since the latter does not fit the form above $x=y+2k\pi$ which implies that $k=0,1,-1$. Hence, we have x=y or $x=2\pi,y=0$ or $x=0,y=2\pi$. Default currency symbol I'm looking for a way to get the Default currency symbol (in a none-multi-currency org) of the salesforce org locale (to have it displayed on a visualforce page in a field that can't be &lt;apex:inputField&gt; or &lt;apex:outputField&gt;) preferably query-able from apex (via the database, a describe or whatever) and then again the actual symbol, meaning € for Euro, $ for dollar, and so on...  There must surely be some sort of mapping hidden in the code somewhere salesforce does this via the input/outputfields if bound to an sobject of type currency  Can anyone point me in the right direction? Oversized \underbrace's label causes unwanted spacing Consider this:  \left( x-1 \right) \underbrace{ \left( ? \right) }_{ \text{what is this?} }   The label is longer than the braced portion, which causes unwanted space between the parentheses.  Is there a way around that, so that the parentheses "touch" as they would normally?  Please note that I just started on LaTeX, and I'm using TexMaths inside LibreOffice Writer. Django - specify which model manager Django admin should use What is the difference between \mathbin vs. \mathrel? These seem to be very similar as they both separate two operands. When would one be used over the other? Is there any difference in the math spacing surrounding them?  How would the spacing in these relate to to the spacing produced by \mathop? Consider following structure:  . |_s |_s  |_ss  |_ss+   |_sss  |_ss |_s |_s   How can I demote a subsection to subsubsection without changing markups ?  . |_s |_s  |_ss   |_sss+    |_p  |_ss |_s |_s   How can I promote a subsection to section without changing markups ?  . |_s |_s  |_ss |_s+  |_ss  |_ss |_s |_s   A wrapper command would be excellent  \begin[+1]{level} \section{} \end{level} How to format numbers as currency strings I would like to format a price in JavaScript. I'd like a function which takes a float as an argument and returns a string formatted like this: &quot;$ 2,500.00&quot;  What's the best way to do this? How to start itemize on same line as text? I've created a new environment called 'Example' like this:  \newenvironment{example}     {\textbf{Example:} \begin{itemize}}     {\end{itemize}}   The environment works fine, but the items are starting after the Example: text. Is it possible to start with the first item on the same line as the Example: text and vertically aline the rest of the items with the first item?