Search Results

Search found 13403 results on 537 pages for 'epm performance tuning'.

Page 335/537 | < Previous Page | 331 332 333 334 335 336 337 338 339 340 341 342  | Next Page >

• 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

• Comparison of algorithmic approaches to the N queens problem

  - by iceman

  I wanted to evaluate performance comparisons for various approaches to solving the N queens problem. Mainly AI metaheuristics based algorithms like simulated annealing, tabu search and genetic algorithm etc compared to exact methods(like backtracking). Is there any code available for study? A lot of real-world optimization problems like it consider cooperative schemes between exact methods and metaheuristics.

  Read the article

• DNN 5.2.3 "GetPortalAliasByPortalID @PortalID=0" looping

  - by David Neale

  After tracing the DB activity from a DNN 5.2.3 site I noticed that there are 15 calls to the "dbo.GetPortalAliasByPortalID @PortalID=0" sproc, all one after the other. What is the reason for this? I am looking at performance problems and need to try and tie issues like these up.

  Read the article

• Please help with iPhone Memory & Images, memory usage crashing app

  - by Andrew Gray

  I have an issue with memory usage relating to images and I've searched the docs and watched the videos from cs193p and the iphone dev site on memory mgmt and performance. I've searched online and posted on forums, but I still can't figure it out. The app uses core data and simply lets the user associate text with a picture and stores the list of items in a table view that lets you add and delete items. Clicking on a row shows the image and related text. that's it. Everything runs fine on the simulator and on the device as well. I ran the analyzer and it looked good, so i then starting looking at performance. I ran leaks and everything looked good. My issue is when running Object Allocations as every time i select a row and the view with the image is shown, the live bytes jumps up a few MB and never goes down and my app eventually crashes due to memory usage. Sorting the live bytes column, i see 2 2.72MB mallocs (5.45Mb total), 14 CFDatas (3.58MB total), 1 2.74MB malloc and everything else is real small. the problem is all the related info in instruments is really technical and all the problem solving examples i've seen are just missing a release and nothing complicated. Instruments shows Core Data as the responsible library for all but one (libsqlite3.dylib the other) with [NSSQLCore _prepareResultsFromResultSet:usingFetchPlan:withMatchingRows:] as the caller for all but one (fetchResultSetReallocCurrentRow the other) and im just not sure how to track down what the problem is. i've looked at the stack traces and opened the last instance of my code and found 2 culprits (below). I havent been able to get any responses at all on this, so if anyone has any tips or pointers, I'd really appreciate it!!!! //this is from view controller that shows the title and image - (void)viewWillAppear:(BOOL)animated { [super viewWillAppear:animated]; self.title = item.title; self.itemTitleTextField.text = item.title; if ([item.notes length] == 0) { self.itemNotesTextView.hidden = YES; } else { self.itemNotesTextView.text = item.notes; } //this is the line instruments points to UIImage *image = item.photo.image; itemPhoto.image = image; } - (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath { if (editingStyle == UITableViewCellEditingStyleDelete) { // Delete the managed object for the given index path NSManagedObjectContext *context = [fetchedResultsController managedObjectContext]; [context deleteObject:[fetchedResultsController objectAtIndexPath:indexPath]]; // Save the context. NSError *error = nil; if (![context save:&error]) //this is the line instruments points to { NSLog(@"Unresolved error %@, %@", error, [error userInfo]); exit(-1); } } }

  Read the article

• Postgres: Convert varchar to text

  - by williamjones

  I screwed up and created a column as a varchar(255) where that is no longer sufficient. I've read that varchar has no performance benefits over text on Postgres, and so would like to convert the varchar to a text column in a safe way that preserves the data. What's the best way for me to do this?

  Read the article

• What is the need of collection framework in java?

  - by JavaUser

  Hi, What is the need of Collection framework in Java since all the data operations(sorting/adding/deleting) are possible with Arrays and moreover array is suitable for memory consumption and performance is also better compared with Collections. Can anyone point me a real time data oriented example which shows the difference in both(array/Collections) of these implementations. Thx

  Read the article

• Use '=' or LIKE to compare strings in SQL?

  - by furtelwart

  Hi! There's the (almost religious) discussion, if you should use LIKE or '=' to compare strings in SQL statements. Are there reasons to use LIKE? Are there reasons to use '='? Performance? Readability? Thanks in advance!

  Read the article

• Memory leak appears only when multiprocessing

  - by Sandro

  I am trying to use python's multiprocessing library to hopefully gain some performance. Specifically I am using its map function. Now, for some reason when I swap it out with its single threaded counterpart I don't get any memory leaks over time. But using the multiprocessing version of map causes my memory to go through the roof. For the record I am doing something which can easily hog up loads of memory, but what would the difference be between the two to cause such a stark difference?

  Read the article

• Exception handling best practices

  - by Costa

  Hi Is there any performance problem or something else about letting the exception to propagate, or it is better to write it like this try { } catch { throw; }

  Read the article

• springboard takes too much CPU

  - by tbarbe

  Is there a way to increase the application priority for the CPU on iPhone? I notice that SpringBoard takes up too much CPU at times causing some fluctuation in performance on the device.

  Read the article

• What is the best algorithm for an overridden System.Object.GetHashCode?

  - by bitbonk

  In .NET System.Object.GetHashCode method is use in a lot of places throughout the .NET base class libraries. Especially when finding items in a collection fast or to determine equality. Is there a standard algorithm/ best practise on how to implement the GetHashCode override for my custom classes so I don't degrate performance?

  Read the article

• Reasons for Parallel Extensions working slowly

  - by darja

  I am trying to make my calculating application faster by using Parallel Extensions. I am new in it, so I have just replaced the main foreach loop with Parallel.ForEach. But calculating became more slow. What can be common reasons for decreasing performance of parallel extensions? Thanks

  Read the article

• Do display objects outside of stage bounds still get rendered by Flash?

  - by Pup

  If an object exists outside of Flash's stage boundaries, is on the Display List, and is visible, is it causing a performance hit from Flash rendering it? In other words, does Flash render what isn't seen? This leads me to believe so: http://stackoverflow.com/questions/170203/how-do-you-make-flash-not-render-an-object-on-the-stage

  Read the article

• Using memcached as a session storage with CodeIgniter

  - by Alex N.

  I am researching possibilities of using memcached as a session storage for a system built on CodeIgniter. Has anybody done this before(that's probably a stupid question :) and if so what's your experience folks? Have you used any existing libraries/extensions? As far as performance improvement what have you seen? Any caveats?

  Read the article

• How can I figure out if an ASP.NET application contains 32bit code/component

  - by timeitquery

  We have an ASP.NET 3.5 application which we need to run on 64bit, but when we do the performance is worst than when we enable 32 bit on the App Pool. It seems like there is something we use in the project which requires 32 bit, but we cannot find what.

  Read the article

• Exploding by Array of Delimiters

  - by JoeC

  Is there any way to explode() using an array of delimiters? PHP Manual: array explode ( string $delimiter , string $string [, int $limit ] ) Instead of using string $delimiter is there any way to use array $delimiter without affecting performance too much?

  Read the article

• Linq to SQL Compact - Transaction or just SubmitChanges

  - by eWolf

  I'm using Linq to SQL on an SQL Compact database. I have a function where I insert multiple records into the database. I only call SubmitChanges at the end of the function. Would using a transaction (using the TransactionScope class) bring me any more performance or advantages?

  Read the article

• When and where do you put type annotations in Clojure code?

  - by Michiel Borkent

  When and where do you put type annotations in Clojure code? Obviously when performance counts. But are there rules by which you can live of when (only when doing Java Interop?) and where to add them (function definition arguments)?

  Read the article

• C# XPath id() not working?

  - by Iggyhopper

  I'm using C# and I'm stumped. Does it just not support id()? I have a large XML file, about 4-5 of them at ~400kb, so I need some speed and performance wherever I can get it. I use XmlDocument.SelectSingleNode("id('blahblahblah')") and it doesn't get the node by id. Am I going crazy or is it that C# XPath just doesn't support id()?

  Read the article

• Fastest way to read every 30th byte of large binary file?

  - by timmerk

  What is the fastest way to read every 30th byte of a large binary file (2-3 GB)? I've read there are performance problems with fseek because of I/O buffers, but I don't want to read 2-3 GB of data into memory before grabbing every 30th byte either.

  Read the article

• What is the right data type for calculations in Java

  - by Raju

  Should we use double or BigDecimal for calculations in Java? How much is the overhead in terms of performance for BigDecimal as compared to double?

  Read the article

• Concise way to getattr() and use it if not None in Python

  - by MTsoul

  I am finding myself doing the following a bit too often: attr = getattr(obj, 'attr', None) if attr is not None: attr() # Do something, either attr(), or func(attr), or whatever else: # Do something else Is there a more pythonic way of writing that? Is this better? (At least not in performance, IMO.) try: obj.attr() # or whatever except AttributeError: # Do something else

  Read the article

• Best approach to write huge xml data to file?

  - by Kayes

  Hi. I'm currently exporting a database table with huge data (100000+ records) into an xml file using XmlTextWriter class and I'm writing directly to a file on the physical drive. _XmlTextWriterObject = new XmlTextWriter(_xmlFilePath, null); While my code runs ok, my question is that is it the best approach? Or should I write the whole xml in memory stream first and then write the xml document in physical file from memory stream? And what are the effects on memory/ performance in both cases?

  Read the article

• WCF v.s. legacy ASP.Net Web Services

  - by George2

  Duplicate: although this is a good discussion, this is a duplicate of Web Services — WCF vs. Standard. Please consider adding any new information to the earlier question and closing this one. Could anyone recommend me some documents to describe why WCF is better than legacy ASP.Net web services? I am especially interested in performance and security. Thanks!

  Read the article

• Is 'epoll' the essential reason that Tornadoweb(or Nginx) is so fast?

  - by Mickey Shine

  Tornadoweb and Nginx are popular web servers for the moment and many benchmarkings show that they have a better performance than Apache under certain circumstances. So my question is: Is 'epoll' the most essential reason that make them so fast? And what can I learn from that if I want to write a good socket server?

  Read the article

< Previous Page | 331 332 333 334 335 336 337 338 339 340 341 342  | Next Page >