Search Results

Search found 10285 results on 412 pages for 'cpu architecture'.

Page 237/412 | < Previous Page | 233 234 235 236 237 238 239 240 241 242 243 244  | Next Page >

  • Understanding VS2010 C# parallel profiling results

    - by Haggai
    I have a program with many independent computations so I decided to parallelize it. I use Parallel.For/Each. The results were okay for a dual-core machine - CPU utilization of about 80%-90% most of the time. However, with a dual Xeon machine (i.e. 8 cores) I get only about 30%-40% CPU utilization, although the program spends quite a lot of time (sometimes more than 10 seconds) on the parallel sections, and I see it employs about 20-30 more threads in those sections compared to serial sections. Each thread takes more than 1 second to complete, so I see no reason for them to work in parallel - unless there is a synchronization problem. I used the built-in profiler of VS2010, and the results are strange. Even though I use locks only in one place, the profiler reports that about 85% of the program's time is spent on synchronization (also 5-7% sleep, 5-7% execution, under 1% IO). The locked code is only a cache (a dictionary) get/add: bool esn_found; lock (lock_load_esn) esn_found = cache.TryGetValue(st, out esn); if(!esn_found) { esn = pData.esa_inv_idx.esa[term_idx]; esn.populate(pData.esa_inv_idx.datafile); lock (lock_load_esn) { if (!cache.ContainsKey(st)) cache.Add(st, esn); } } lock_load_esn is a static member of the class of type Object. esn.populate reads from a file using a separate StreamReader for each thread. However, when I press the Synchronization button to see what causes the most delay, I see that the profiler reports lines which are function entrance lines, and doesn't report the locked sections themselves. It doesn't even report the function that contains the above code (reminder - the only lock in the program) as part of the blocking profile with noise level 2%. With noise level at 0% it reports all the functions of the program, which I don't understand why they count as blocking synchronizations. So my question is - what is going on here? How can it be that 85% of the time is spent on synchronization? How do I find out what really is the problem with the parallel sections of my program? Thanks.

    Read the article

  • How know when my mongoDB database overhead ?

    - by shingara
    I installed a MongoDB database on my server. My server is in 32Bit and I can't change it soon. When you use MongoDB in a 32Bit architecture you have a limit of 2,5Go of data, as mentionned in this MongoDB blog post. The thing is that I have several database. So how can I know if I am close or not to this limit ?

    Read the article

  • Is DxScene the "WPF for Delphi"? Anyone used it?

    - by André Mussche
    I am playing with DxScene and VxScene: http://www.ksdev.com/dxscene/index.html It looks very nice and powerful: 3d accelerated vector graphics, cross plaform, nice effects, many 2d GUI controls (vector based), good scaling, transparency, rotating (x, y, z), 3d models, etc. Even with many effects, the CPU stays very low (0%)! http://www.ksdev.com/dxscene/snapshot/screen0.jpeg But can it be seen as a good WPF alternative for Delphi? And does anyone use it instead of normal Delphi VCL?

    Read the article

  • Learning to write organized and modular programs

    - by Peter
    I'm a computer science student, and I'm just starting to write relatively larger programs for my coursework (between 750 - 1500 lines). Up until now, it's been possible to get by with any reasonable level of modularization and object oriented design. However, now that I'm writing more complex code for my assignments I'd like to learn to write better code. Can anyone point me in the direction of some resources for learning about what sort of things to look for when designing your program's architecture so that you can make it as modularized as possible?

    Read the article

  • Pause and resume thread drawing to SurfaceView

    - by fhucho
    I am developing a chess game for Android (http://androidchess.appspot.com), using SurfaceView for the chessboard. I have a drawing Thread, that draws the chessboard in a loop. The problem is that when there are no active animations (this is more that 90% of time), it makes no sense to waste CPU and battery for drawing. How should I solve this? Maybe somehow pausing and resuming the drawing Thread?

    Read the article

  • How can I get page faults statistics from kernel

    - by osgx
    Hello How can I get page faults statistics from kernel for my application while it is running? What about other events, like inter-cpu migrations count in SMP nodes, or number of context switches? I want to count such events for various small parts of the program. Thanks.

    Read the article

  • Controller inside MVC architechture

    - by Vinay
    Hi All, I want to know about the controller in struts MVC architecture. Does struts-conf.xml file is a controller. I know that it is a part of controller, but someone is saying that it is a controller and at what extend it is true. Please explain it. Thanks Vinay

    Read the article

  • What's holding up my PHP script?

    - by gAMBOOKa
    We've got a PHP crawler running on our web server. When the crawler is running, there are no cpu, memory or network bandwidth spikes. Everything is normal. But our website (also PHP), hosted on the same server, stops responding. Basically the crawler blocks any other php script from running. What could be the problem? EDIT: ** fsockopen is being used to download files to crawler! **

    Read the article

  • Local help not working in Visual Studio 2005

    The local help in Visual Studio 2005 never comes back with anything. Also, if I'm not connected to the Internet, of course I get nothing. When I run dexplore eventually it takes 100% of cpu. Also, the F1 help doesn't work (of course). I've repaired both VS 2005, MSDN in other orders. Any help will be appreciated! THanks -tim

    Read the article

  • How does volatile actually work?

    - by FredOverflow
    Marking a variable as volatile in Java ensures that every thread sees the value that was last written to it instead of some stale value. I was wondering how this is actually achieved. Does the JVM emit special instructions that flush the CPU cashes or something?

    Read the article

  • Numerical precision of double type in Visual C++ 2008 Express debugger

    - by damik
    I'm using Visual C++ 2008 Express Edition and when i debug code: double x = 0.2; I see in debugging tooltip on x 0.20000000000000001 but: typedef numeric_limits< double > double_limit; int a = double_limit::digits10 gives me: a = 15 Why results in debugger are longer than maybe ? What is this strange precision based on ? My CPU is Intel Core 2 Duo T7100

    Read the article

  • Single page Web App in Java framework or examples?

    - by Adam Gent
    Has anyone seen an example or done the following in Java: http://duganchen.ca/single-page-web-app-architecture-done-right/ That is a design a single page web app that will work with Google SEO with out massive violation of DRY using Java technologies? It doesn't seem terrible hard to do this on my own but I was curious (and lazy) to see if someone had already done it with either Spring or JAX-RS.

    Read the article

  • stock exchange software

    - by darko petreski
    Hi, Does anybody knows how several tens of display screens are refreshed each second in stock exchange buildings? Of course the server pushes the data to each screen, bud is this custom technology or some well known technology like example MSMQ ? Are there any study papers, books or something for the architecture of this kind of software ? Regards

    Read the article

  • Recommended textbook for machine-level programming?

    - by Norman Ramsey
    I'm looking at textbooks for an undergraduate course in machine-level programming. If the perfect book existed, this is what it would look like: Uses examples written in C or assembly language, or both. Covers machine-level operations such as two's-complement integer arithmetic, bitwise operations, and floating-point arithmetic. Explains how caches work and how they affect performance. Explains machine instructions or assembly instructions. Bonus if the example assembly language includes x86; triple bonus if it includes x86-64 (aka AMD64). Explains how C values and data structures are represented using hardware registers and memory. Explains how C control structures are translated into assembly language using conditional and unconditional branch instructions. Explains something about procedure calling conventions and how procedure calls are implemented at the machine level. Books I might be interested in would probably have the words "machine organization" or "computer architecture" in the title. Here are some books I'm considering but am not quite happy with: Computer Systems: A Programmer's Perspective by Randy Bryant and Dave O'Hallaron. This is quite a nice book, but it's a book for a broad, shallow course in systems programming, and it contains a great deal of material my students don't need. Also, it is just out in a second edition, which will make it expensive. Computer Organization and Design: The Hardware/Software Interface by Dave Patterson and John Hennessy. This is also a very nice book, but it contains way more information about how the hardware works than my students need. Also, the exercises look boring. Finally, it has a show-stopping bug: it is based very heavily on MIPS hardware and the use of a MIPS simulator. My students need to learn how to use DDD, and I can't see getting this to work on a simulator. Not to mention that I can't see them cross-compiling their code for the simulator, and so on and so forth. Another flaw is that the book mentions the x86 architecture only to sneer at it. I am entirely sympathetic to this point of view, but news flash! You guys lost! Write Great Code Vol I: Understanding the Machine by Randall Hyde. I haven't evaluated this book as thoroughly as the other two. It has a lot of what I need, but the translation from high-level language to assembler is deferred to Volume Two, which has mixed reviews. My students will be annoyed if I make them buy a two-volume series, even if the price of those two volumes is smaller than the price of other books. I would really welcome other suggestions of books that would help students in a class where they are to learn how C-language data structures and code are translated to machine-level data structures and code and where they learn how to think about performance, with an emphasis on the cache.

    Read the article

  • Why does Module::Build's testcover gives me "use of uninitialized value" warnings?

    - by Kurt W. Leucht
    I'm kinda new to Module::Build, so maybe I did something wrong. Am I the only one who gets warnings when I change my dispatch from "test" to "testcover"? Is there a bug in Devel::Cover? Is there a bug in Module::Build? I probably just did something wrong. I'm using ActiveState Perl v5.10.0 with Module::Build version 0.31012 and Devel::Cover 0.64 and Eclipse 3.4.1 with EPIC 0.6.34 for my IDE. UPDATE: I upgraded to Module::Build 0.34 and the warnings are still output. *UPDATE: Looks like a bug in B::Deparse. Hope it gets fixed someday.* Here's my unit test build file: use strict; use warnings; use Module::Build; my $build = Module::Build->resume ( properties => { config_dir => '_build', }, ); $build->dispatch('test'); When I run this unit test build file, I get the following output: t\MyLib1.......ok t\MyLib2.......ok t\MyLib3.......ok All tests successful. Files=3, Tests=24, 0 wallclock secs ( 0.00 cusr + 0.00 csys = 0.00 CPU) But when I change the dispatch line to 'testcover' I get the following output which always includes a bunch of "use of uninitialized value in bitwise and" warning messages: Deleting database D:/Documents and Settings/<username>/My Documents/<SNIP>/cover_db t\MyLib1.......ok Use of uninitialized value in bitwise and (&) at D:/Perl/lib/B/Deparse.pm line 4252. Use of uninitialized value in bitwise and (&) at D:/Perl/lib/B/Deparse.pm line 4252. t\MyLib2.......ok Use of uninitialized value in bitwise and (&) at D:/Perl/lib/B/Deparse.pm line 4252. Use of uninitialized value in bitwise and (&) at D:/Perl/lib/B/Deparse.pm line 4252. t\MyLib3.......ok Use of uninitialized value in bitwise and (&) at D:/Perl/lib/B/Deparse.pm line 4252. Use of uninitialized value in bitwise and (&) at D:/Perl/lib/B/Deparse.pm line 4252. All tests successful. Files=3, Tests=24, 0 wallclock secs ( 0.00 cusr + 0.00 csys = 0.00 CPU) Reading database from D:/Documents and Settings/<username>/My Documents/<SNIP>/cover_db ---------------------------- ------ ------ ------ ------ ------ ------ ------ File stmt bran cond sub pod time total ---------------------------- ------ ------ ------ ------ ------ ------ ------ .../lib/ActivePerl/Config.pm 0.0 0.0 0.0 0.0 0.0 n/a 0.0 ...l/lib/ActiveState/Path.pm 0.0 0.0 0.0 0.0 100.0 n/a 4.8 <SNIP> blib/lib/<SNIP>/MyLib2.pm 100.0 90.0 n/a 100.0 100.0 0.0 98.5 blib/lib/<SNIP>/MyLib3.pm 100.0 90.9 100.0 100.0 100.0 0.6 98.0 Total 14.4 6.7 3.8 18.3 20.0 100.0 11.6 ---------------------------- ------ ------ ------ ------ ------ ------ ------ Writing HTML output to D:/Documents and Settings/<username>/My Documents/<SNIP>/cover_db/coverage.html ... done.

    Read the article

  • Do Resource Adapters make RPC calls

    - by Subramanian
    The J2EE Conn Architecture deals with resource adapters to communicate with data stores - databases or EIS. From the adapter/driver perspective would it be right to say that they make a RPC call to the datastore? Or does RPC necessarily have to be a "discover and invoke" (lookup and call) type of call?

    Read the article

  • Which validation framework is better?

    - by Nick Yao
    Does anyone have any recommendations for either of these validation ASP.Net MVC Validation frameworks? xVal: http://xval.codeplex.com/ FluentValidation: http://fluentvalidation.codeplex.com/documentation NHibernate.Validator DataAnnotations by the way: my project use sharp-architecture

    Read the article

< Previous Page | 233 234 235 236 237 238 239 240 241 242 243 244  | Next Page >