partitioning - Using Partitioner with PLINQ in F# -


i use following plinq-implemented parallel map function.

let parmap f (xs:list<_>) = xs.asparallel().select(fun x -> f x) |> seq.tolist

i want improve speedup on 4 cores i'm not able above 2. found 1 can custom partitioning improve parallel performance. have seen c# examples , not sure how work f#. following doesn't change think default partitioning used tpl? how can use different (static, dynamic,...) partitioning options here?

let pmap_plinqlst_parts f (xs:list<_>) =      let parts = partitioner.create(xs)     parts.asparallel().select(fun x -> f x) |> seq.tolist

typically custom partitioner used if work units extremely small. when faced problem may better off switching task rather async more suited smaller more numerous amounts of work, async being more suited io type operations latency typically longer.

for example batch calculations in sequences amongst parallel threads. yield vary depending on size of work units , number of total items.

there no limit scaling in of methods mentioned. parallelised black scholes calculation , managed around 6.8x on 8 core machine using async.parallel. although not perfect mechanism used simple division of work amongst initial sequences passed async.parallel.

are sure have true 4 core machine or 2 core machine hyper threading?


Comments

Post a Comment

Popular posts from this blog

java - Play! framework 2.0: How to display multiple image? -

i need display gallery of photos. here template: @(photos: list[photo]) @title = { <bold>gallery</bold> } @main(title,"photo"){ <ul class="thumbnails"> @for(photo <- photos) { <li class="span3"> <a href="#" class="thumbnail"> <img src="@photo.path" alt=""> </a> </li> } </ul> } and here controller method: public static result getphotos() { return ok(views.html.photo.gallery.render(photo.get())); } and here photo bean : @entity public class photo extends model { @id public long id; @required public string label; public string path; public photo(string path, string label) { this.path = path; this.label = label; } private static finder<long, photo> find = new finder<long, photo>( long.class, photo.class); public static list<phot...
Read more

gmail - Is there any documentation for read-only access to the Google Contacts API? -

i want read-only access user's google contacts. there stackoverflow member wanted this, , received following answer : yes, there is, use https://www.googleapis.com/auth/contacts.readonly scope , "view contacts". this exchange reference read-only access google contacts can find using google. simply using access token obtained attempt read usual google contacts api (i.e. https://www.google.com/m8/feeds ) fails insufficient permissions. similarly, using google contacts api on new target fails 404 errors (for example https://www.googleapis.com/auth/contacts.readonly/default/full ). is there documentation anywhere on how use api, or permissible way access google contacts api full read-write access?
Read more

php - Controller/JToolBar not working in Joomla 2.5 -

relevant code: jtoolbarhelper::custom('savecategories', 'save', '', 'save', false, false); ... <input type="hidden" name="controller" value="easyblogcontroller"> according can dig docs , own previous questions, should call savecategories() function in easyblogcontroller . i've tried setting value easyblog , easyblog.php (file name) current easyblogcontroller (class name). clicking on save button refreshes page. not redirect, echo or var_dump test code put in savecategories() function. var_dump ing jrequest::getvar('controller') , 'task' return correct values. creating controller object , using $controller->execute('task'); works. the values going depend on location of controller trying call, , have couple options here. typically there controller in base folder of component (likely components/com_easyblog) in file called controller.php , class name inside ...
Read more