What is the theoretical impact of direct index access with “high” memory usage vs. “shifted” index access with “low” memory usage?
c++,performance,memory-management,cpu-usage
Accessing any array with an index involves adding an index multiplied by element size and adding it to the base-address of the array itself. Since we are already adding one number to another, making the adjustment for foo[N-A] could easily be done by adjusting the base-address down by N *...
Linux echo cpu (core) name/number for a given shell in PBS
It is up to the Linux scheduler to decide which process gets which core at any given moment. It makes those decisions many times a second frequently moving processes from core to core depending on the load. You can get a snapshot of the process to cpu allocation with the...
At what point do short sleeps increase CPU util rather than reduce it
java,c,multithreading,architecture,cpu-usage
Sleeping is an option of last resort. Instead, have a look at the tool in the concurrent API, especially the Queues which allow you to put a task to sleep until a message arrives on which it should act. Or look at Akka which allows you to easily build a...
CPU stuck between 95% to 100% for Standalone Jetty server
jetty,cpu-usage,java.util.concurrent
You state you do run the ExecutorService part on a different machine, but the URL is http://localhost:8080. That's a no-no in load testing. Some advice: Don't have the Client Load and the Server Load on the same machine (don't cheat and attempt to put the load on 2 different VMs...
How to get CPU usage of certain function in android app?
If by function you mean literally java function then why dont you measure CPU time of its execution (difference of end and start measurements)? You can use System.currentTimeMillis() but this will measure also time of other threads that got CPU quantum. So I believe you are after Debug.threadCpuTimeNanos() which will...
Number of threads to limit CPU usage
java,multithreading,performance,jvm,cpu-usage
To have a CPU usage of 50% does not necessarily mean that the number of threads needs to be N_Cores / 2. When dealing with I/O the CPU wastes many cycles in waiting for the data to arrive from devices. So you need a tool to measure real CPU usage...
How to wait for a child until it reaches CPU time timeout in c/c++?
You can change change the CPU limit of the child, and it will get killed if it exceeds that limit. if (pid == 0) { struct rlimit cpu_lim = {10,10}; //limit to 10 seconds if (setrlimit(RLIMIT_CPU , &cpu_lim) == -1) { perror("setrlimit"); return; } ... With this approach you don't...
CPU and memory usage of a file javascript
javascript,html5,canvas,cpu-usage,usage-statistics
You should take a look at this article from Paul Irish on his requestAnimationFrame cross-browser shim. It will firstly try to optimise frames based on browser capability, and also, have backwards compatibility for old, non-GPU enabled browsers. From the jQuery ticket: Benefits: let the browser choose the best 'animation tick'...
CPU usage is extremly high due to mysql process
Enable page support for the VPS instance: http://dev.mysql.com/doc/refman/5.5/en/large-page-support.html...
Python - Limit cpu usage for a script
Maybe try Python's "resource" package ? The resource package is basically a wraparound of "setrlimit" in UNIX. So you can set constrains for CPU/Memory usage, etc. More about "setrlimit" in UNIX Thanks @Stephane for pointing it out, this is actually my first answer ever....
PerformanceCounter reporting higher CPU usage than what's observed
c#,cpu-usage,performancecounter
new PerformanceCounter("Processor", ...); You are using the wrong counter if you insist on seeing an exact match with Task Manager or Perfmon. Use "Processor Information" instead of "Processor". The reason these counters show different values is addressed pretty well in this blog post. Which counter is "right" is a...
TaskManager android that will show current memory usage and cpu usage
java,android,cpu-usage,heap-memory,taskmanager
You will need to use Linux commands like top or ps using: Process process = Runtime.getRuntime().exec(...); http://m2catalyst.com/tutorial-finding-cpu-usage-for-individual-android-apps Get Memory Usage in Android...
How to limit the CPU usage of a dash loop that listens for a filesystem change?
On my Linux system, I can simply do $ sleep 0.1 and it sleeps for 0.1 seconds. The sleep here lives in /usr/bin/sleep. I don't know which other unix-like systems support that, though....
how to join 2 queries into 1
You could try a simple left join: select * from MapCountries mc left join CompanyDetails cd on mc.IndexName = cd.IndexName and mc.ModifiedDate = cd.ModifiedDate where mc.IndexName='SPX Index' and date(mc.ModifiedDate)='2015-04-24' and cd.CompanyTicker='A UN' ...
Accurate calculation of CPU usage given in percentage in Linux?
linux,linux-kernel,cpu,calculator,cpu-usage
According the htop source code at the time of writing, my assumptions looks like they are valid: https://github.com/hishamhm/htop/blob/master/ProcessList.c // Guest time is already accounted in usertime usertime = usertime - guest; # As you see here, it subtracts guest from user time nicetime = nicetime - guestnice; # and guest_nice...
Tomcat not using all cores in high load period
Sounds curious, but we set a tomcat start parameter to prefer IPv4, to solve this behaviour: -Djava.net.preferIPv4Stack=true Reference: http://www-01.ibm.com/support/docview.wss?uid=nas8N1011363 Additionally it should be helpful to configure another garbage collection: -XX:+UseParNewGC -XX:+UseConcMarkSweepGC ...
How to monitor and/or throttle rate limit cpu/bandwidth by client-side web pages?
javascript,html5,google-chrome-devtools,cpu-usage,bandwidth-throttling
You need a client side javascript manipulator.. they are known as User Scripts... For firefox, you want something like grease monkey.... its worth a google... This is not the simplest method, but most effective. Otherwise you will just want a ad-remover addon for firefox. Example For Chrome: https://chrome.google.com/webstore/detail/adblock/gighmmpiobklfepjocnamgkkbiglidom?hl=en They simply...
Websites use server or client hardware resources?
resources,cpu,hardware,cpu-usage,ram
It depends on whether the script is written in a server-side or client-side scripting language. For example, if the website uses an intensive php script it will run on the server as PHP is a server-side scripting language whereas Javascript is a client-side scripting language which will run on the...
Google App Engine : High CPU Utilization
google-app-engine,cpu-usage,google-cloud-platform
I replied for the above mail (added in the question) with the following Hi xxxx, Thanks for the details. All of the 5 projects that were suspended have just one single static page with Google Analytics using Google Tag Manager. And nothing else. My suspended projects are : xxx-xxxxxxx-xx, xxx-xxxxxxx-xx,...
How to Measure an App's Performance?
c#,performance,memory-management,cpu-usage
According to the way you've asked about analyzer tools, I'm pretty sure that you won't need any performance or management optimization. For that reason I'd like to start with a quote of Donald Knuth regarding optimization: We should forget about small efficiencies, say about 97% of the time: premature optimization...
New Relic cpu usage Heroku app
java,performance,heroku,cpu-usage,newrelic
New Relic can report on application server resource utilization through the application agent since the app is aware of those metrics. However, because of the unique infrastructure of the Heroku hosting platform, it is not currently possible to collect any further server metrics other than memory and load. Please consult...
Efficiency of running many more jobs than CPUs
performance,cpu-usage,processing-efficiency
Speed-wise, you're unlikely to get a performance boost spawning more threads than there are physical threads available unless your threads are spending a lot of time sleeping (in which case it gives your other threads an opportunity to execute). Note that thread sleeps can be implicit and hidden in I/O...
App Performance on Raspberry Pi vs multi Xeon core server [closed]
php,performance,raspberry-pi,cpu-usage,server
It depends upon what type of optimizations you are doing. Portability across different hardware all comes down to the architectural independences of the abstractions you are using (e.g. language, compiler, libraries). My understanding of PHP is that it works at a very high level as an interpreter intended to be...
Debugging Java application causes high cpu utilization
java,eclipse,performance,debugging,cpu-usage
in java debugging you can do something called method debugging, that type of method debugging severely impacts performance, make sure you didnt accidently added one of those eclipse method breakpoints...
mysql cpu usage is more than system cpu
Remeshx, The mysql load you see in "top" is total load of all mysql threads on all cores. If you have 24 core system, you can approximate the single core load by dividing 200%/24 which gives ~8% load, which is not bad at all. If you want to have detailed...
Using Cgroups to limit cpu usage
linux,performance,cpu-usage,cgroups
cpu cgroup is work conserving, ie. a task would not be stopped from using cpu if there is no competition. If you want to put a hard limit on amount of cpu a task can use, try setting cpu.cfs_quota_us and cpu.cfs_period_us. Look at the documentation here....
Linux(Ubuntu) load average higher than total-true-utilization?
Read this: Understanding load average vs. cpu usage If the load average is at 7, with 4 hyper-threaded processors, shouldn't that means that the CPU is working to about 7/8 capacity? No it just means that you have 7 running processes in the job queue on average. But I think...
Get Average CPU utilization for test execution in powershell
powershell,cpu-usage,powershell-v3.0,scriptblock
The underlying problem was that the test was running for anywhere between 2 and 60 seconds, and there where runs where the Get-WmiObject was taking longer than the test run, and thus the code for creating the file with the collected metrics wasn't executed for those runs. Adding a wait...
How to fully take advantage of multi-cores by python
python,multithreading,cpu,cpu-usage
Something like this will get you started. You'd need to tweak num_processes in order to match your hardware. import multiprocessing as mp import time def slow_func(): while True: for i in xrange(99999): j = i*i def main(): num_processes = 4 for _ in range(num_processes): process = mp.Process(target = slow_func) process.daemon...
How to show the CPU and disk usage in a JProgressBar?
java,cpu-usage,jprogressbar,diskusage
You can use javasysmon-0.3.4.jar file to get the system related informations as CPU Usage,memory usage etc. Some of the methods are listed below and if you want something else you can explore. JavaSysMon monitor=new JavaSysMon(); //System.out.println("Operating System name is "+monitor.osName()); long usersMillis = monitor.cpuTimes().getUserMillis(); /*System.out.println(String.format("User milli are %d days, %d...
How all the processors usage become 100% in multithreading
java,multithreading,process,cpu,cpu-usage
Yes, multiple threads of the same process can be split across multiple CPU. For many applications, that is the whole point of using multiple threads. Most current JVM implementations use native OS threads for this (one Java thread - one OS thread), so this is all done by the operating...
MySQL query runs ok in phpadmin but hangs in php
php,mysql,phpmyadmin,cpu-usage,hang
Use explicit join instead of implicit SELECT c.customers_id, c.customers_cid, c.customers_gender, c.customers_firstname, c.customers_lastname, c.customers_email_address, c.customers_telephone, c.customers_date_added, ab.entry_company, ab.entry_street_address, ab.entry_postcode, ab.entry_city, COUNT(o.customers_id) AS orders_number, SUM(ot.value) AS totalvalue, mb.bonus_points FROM orders o join orders_total ot on o.orders_id = ot.orders_id join customers c on c.customers_id = o.customers_id join address_book ab on...
mpi cpu usage doesn't make sense
Yes, this behaviour is expected. A general-purpose operating system such as (most versions of) Windows moves processes around cores. One reason for this is to ensure that no process is starved of execution time. Don't forget that on most Windows computers there will be all sorts of processes running at...
Retrieving CPU Load Percent total in Windows with C++
c++,windows,visual-studio-2013,cpu-usage
The reason it's popular to compute the load percentage over time is because CPUs don't really have variable speeds -- at any given instant, a CPU core is either processing instructions at its rated clock rate, or it's sitting idle, so an instantaneous measurement would only give you 0% or...
How can get memory and CPU usage of hadoop yarn application?
hadoop,memory,mapreduce,cpu-usage,yarn
Yes, you can very well check the total memory and cpu usage of the application. You may use the Job tracker UI, click on the counters link on the completed page, and might get a typical view as follows. The memory and cpu counters were highlighted. Clicking on the highlighted...
Easiest way to simulate the maximum CPU load?
c,multithreading,simulation,cpu-usage
Your code is serial. You have eight available threads (4 cores * 2 threads per core = 8 total threads), and your current code uses one of them for 1 thread / 8 available = 12.5% of your CPU. If you have to write your own code (and not use...
Low consuming loop in C [duplicate]
c,events,while-loop,cpu-usage,sdl-2
@artonge, I had the same problem. I wrote a Sleep(..) in the loop and the resource utilization did come down. Sleep(int milliSeconds); ...
force perl program to use all CPU capacity using threads
multithreading,perl,parallel-processing,cpu-usage
You need to make the threads actually do something. E.g. make them count from 0 to a large number. Sleeping doesn't take CPU time.
Calculating CPU Usage of a Process in Android
Explanation of error I suspect that you used the value in /sys/devices/system/cpu/cpu0/cpufreq/scaling_cur_freq as your hertz value. This is incorrect since that file gives you the CPU hardware clock frequency, but you must use the Linux kernel clock frequency as your hertz value. The CPU hardware clock and Linux kernel clock...
C linux regex performance issue
To begin, if something is using less than 100% cpu it means that the bottleneck is I/O or something else, not the cpu. That being said. You recompile the regular expression for every call to the check_regex function. That seems very inefficient. The reason why regex matching is split up...
Is there a way to measure the efficiency of a program regardless of CPU?
performance,cpu,cpu-usage,processing-efficiency
Environment: As I understand your problem, you want to measure the performance of a program written by a test taker, and then you want to be able to compare that performance against either a reference or against other test taker programs. These programs will run on possibly different web servers....
How to interpret CPU time vs CPU percentage
Some cloud monitoring tools give resource usage in standard time measures. (seconds, hours, days etc.) If you have usage in seconds like, min: 4.69s max: 2008.08 s avg : 207.63 s Then you can find out usage in % from above using definition of %. % utilization = (resource used...
Visual VM: how to interpret Self Time vs Self Time (CPU)
Can I interpret that Threads have been blocked in this method for some reason during 500-72=428s ? That is the most likely explanation. It is also conceivable that the thread was descheduled by the thread sheduler to let other threads run. Which would mean I can begin to search...
How to write an array to a file?
arrays,powershell-v2.0,cpu-usage
"FIFO" snippet : (get-content c:\temp\test.txt) |select -skip 1 | set-content c:\temp\test.txt ...
Why eclipse CPU usage increase when I run an application?
eclipse,jvm,cpu-usage,taskmanager
Eclipse has to read your program output to display it in the console, for example, which can take a bit of resources, especially if your program generates lots of output and/or long lines of output (in my experience, the Eclipse console is quite slow). I suppose you're not running in...
Calculate CPU per process
Under a normal invocation of top (no arguments), the %CPU column is the proportion of ticks used by the process against the total ticks provided by one CPU, over a period of time. From the top.c source, the %CPU field is calculated as: float u = (float)p->pcpu * Frame_tscale; where...
What is the cause of cpu high for given result in centos [closed]
The CPU Usage in top says: Cpu(s): 0.0%us, 0.0%sy, 0.0%ni,100.0%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st Your CPU is 100% idle. This is the explanation: us: user cpu time (or) % CPU time spent in user space sy: system cpu time (or) % CPU time spent in kernel space ni: user nice...
How to extract CPU Usage details from the log file in logstash
filter,cpu-usage,logstash,grok
As per the message from Magnus, you're using the grok match function incorrectly, @timestamp is the name of a system field that logstash uses as the timestamp the message was recieved at, not the name of a grok pattern. First I recommend you have a look at some of the...
Does Task Manager Slow down CPU usage
windows,multithreading,cpu-usage
It certainly does have an effect. The performance metrics may be gathered regardless of whether Task Manager is running. But when Task Manager is running, you are also using additional resources (RAM, processor timeslices, etc.) to display the Task Manager window, additional resources to update the graphics in the Task...
Is reading/writing to mysql database periodically CPU intensive? [closed]
mysql,database,delphi,table,cpu-usage
Databases are designed to handle many transactions frequently, but it really depends on what the queries you are using. A simple SELECT on a couple rows is unlikely to cause an issue, but large scale updates targeting many tables or multiple joins can slow performance. It all depends on what...