FAQ Database Discussion Community


How to Calculate Effective Access Time

operating-system,paging,tlb,page-tables
Assume TLB hit ratio is 90%, physical memory access takes 100ns, TLB access takes 20 ns, compute the effective access time for a processor that uses two level page tables, and parallel TLB and page table indexing. This was my formula: (H)(TLB access time + mem access time) + (1-H)(TLB...

Multi-level page tables

memory-management,operating-system,paging,cpu-architecture
An x86 with 32 bit addressing and 4K pages would need a page table with 2ˆ20 entries to map an entire address space. Since each page table entry is usually four bytes, this would make the page tables an impractical 4 megabytes long. As a result, paged architectures page...

Paging data tables in jQuery

jquery,jquery-datatables,paging
I have a table with more the fifty records in it. I want to display them in pages of five records per page. My current approach uses jquery datatables, as shown below. $(document).ready(function () { var length = $('#data-datatable tbody tr').length; $('#data-datatable').dataTable({ "bFilter": false, "bLengthChange": false, "iTotalDisplayRecords" : 5, "iTotalRecords":...

Datatable show/hide sorting/paging

.net,sorting,datatable,jquery-datatables,paging
I have a problem with datatables.net I want to show sorting/paging based on when the screnn width is over 700px and hide it when its under 700px. It works when i go from over 700px to under 700px but when i increase the width again the sorting/paging isnt showing again....

What is the difference between demand paging and page replacement?

memory-management,operating-system,paging,page-replacement,demand-paging
From what I understand, demand paging is basically paging with swapping, so you can swap in a page when it is needed. But page replacement seems like more or less the same thing, where you bring in a page is needed and switching it with an existing page in physical...

Do multi-level page table store the entire page-table if only half is used?

memory,memory-management,paging,page-tables
Imagine I have a 2-level page table with 1024 entries. Consider that only 3 2-level page tables are used, of which one is half empty, so I have a top-level page-table with three entries. Now, how much memory does my page table system occupies in my RAM? Do I have...

Will physical addresses of all paging structures in Linux be mapped in the page tables

linux-kernel,paging,virtualization,kvm
In 64-bit Linux, IA-32E paging is used with 4 levels of paging structures (PML4/PDPT/PD/PT). The entries in the former three structures give the physical address of the corresponding next structure. My question is that will the physical addresses of all these paging structures be mapped in the paging table? If...

jqgrid paging on server side

jquery,jqgrid,server,paging
I'm trying to add server side paging to my grid. In adittion, I have a filter by 'license', 'number' and 'group'. When I press the next page button the controller is called and I obtain the data but my grid is reload on page 1 and I cant view the...

Access paging in iOS - previous and next : retrieved in JSON from facebook graph-api

json,facebook-graph-api,ios7,paging
Access paging in iOS Code from JSON previous and next link In JSON object retrieved from graph api, due to loads of information the information is paged, when I try to access the previous and next link it gives OAuth error. Can anyone help in how to access the link...

Paging in .NET Web API

c#,.net,asp.net-web-api,odata,paging
I have to do paging for an odata endpoint built using Entity Framework . I know I can do it using private ODataQuerySettings settings = new ODataQuerySettings(); settings.PageSize = myPageSize; // I keep this value in web.config of solution and options.ApplyTo(IQueryable, settings); But I am constrained not to use ApplyTo...

What does the User/Supervisor bit in the page table entry mean?

operating-system,paging
I am trying to understand whether: the User/Supervisor bit is used to distinguish pages of kernel memory, from those of the user process the User/Supervisor bit changes when execution moves to the kernel while executing a system call Or perhaps none of them. Can someone clarify?...

Hardware Support for Paging

operating-system,paging
"The address consists of 16 bits, and the page size is 8KB. The page table thus consists of eight entries that are kept in fast registers." How do we get the total entries in the page table as 8? According to the calculation it should be 1. Total Entries in...

Calculating the size of a 2-level page table

memory,operating-system,paging,page-tables
So I have page sizes of 4kb, 32 bit address CPU and an implemented 2-level page table. I want to store 1081 pages, so I need: 1024 entries in the 2-nd level page-table 57 entries in another 2-nd level page table A top level page table holding 2 entries. Now,...

Table paging in query results table

table,paging,jdeveloper,jqueryform
I have a query form with table in a page and I'm trying to use paging instead of using scrol to see all the data returned by the query. I have found a link that explains how can i do it site1 and it works, but when I try to...

PagedList.Mvc returns all records from the table

c#,asp.net-mvc,paging
I have following function in my Generic Repository. I have two issues with line var list = query.ToPagedList(pageNumber, pageSizeNumber); public IEnumerable<T> GetPagedListDbContext(string searchFieldName, string searchText, string searchOperator, string sortFieldName, int? page, int? pageSize) { int pageSizeNumber = (pageSize ?? 20); int pageNumber = (page ?? 1); string sql = string.Empty;...

How is the virtual adress of the page table is converted to its actual physical adress?

memory-management,linux-kernel,paging
If paging is enabled in OS, a page table is used to map the virtual address to the actual physical address. To be more specific, consider Linux 32 bit OS on X86, the cr3 register has the starting address of the page table directory. I guess this is a virtual...

ExtJS 5 - Paging toolbar for Grid not working with Memory Proxy

extjs,memory,proxy,paging,extjs5
I am loading inline data in my store with a memory proxy and enabling paging, but the problem is that my paging toolbar only shows the first page of data. The "Next" arrow button doesn't update the grid either. I have links to images at the bottom to show what...

Memory Management (Allocating Pages/Frames to Logical Addresses)

memory,memory-management,operating-system,paging,virtual-memory
I am new to Operating Systems and I was following this handbook which I am reading to get a better grasp on how computers really work. However having stumbled upon Memory Management I found it somewhat confusing when allocating Frames to Pages using Page tables. Say Page/Frame size is 4K...

Angular paging generates wrong number of pages

javascript,angularjs,bootstrap,paging
I am having a hard time getting the Angular paging to work correctly. The number of pages seems to be off. For example, for one of my searches, the number of returned results is 1005. Displaying 16 results per page, should have 63 pages total. Instead it generates 101. I...

Delete Gridview row when paging is enabled

c#,asp.net,gridview,datatable,paging
I have a Gridview with paging enabled and delete button enabled. With the below code the row above the one for which the delete button is pressed gets deleted. I have also tried doing "dt.Rows.Remove(dt.Rows[rowIndex-1]". The row values are in a DataTable only (not in Database). Stuck badly Need help...

When to do or not do INVLPG, MOV to CR3 to minimize TLB flushing

x86,paging,x86-64,virtual-memory,tlb
Prologue I am a operating system hobbyist, and my kernel runs on 80486+, and supports virtual memory already. Starting from 80386, the x86 processor family by Intel and various clones thereof has supported virtual memory with paging. It is well known that when the PG bit in CR0 is set,...

Why is the adressspace increased from 32 to 36 bits with PAE

paging,computer-architecture,ia-32,page-tables
The IA-32 architecture implements PAE to increase it's address space from 32 bits to 36 bits, this is done by dividing the page table in a three-level scheme. Page directory table -> page directory -> page table -> 4-kb page How is the increase from 32 to 36 bit address...

SQL - Paging comments

sql,sql-server,sql-server-2008,comments,paging
I have the Table Comment below: CREATE TABLE Comment ( CommentID int, Username nvarchar(50), Content nvarchar(255), ReplyID int, primary key (CommentID), ) ALTER TABLE dbo.Comment ADD FOREIGN KEY (CommentID) REFERENCES dbo.Comment (CommentID) ON DELETE NO ACTION ON UPDATE NO ACTION, And I want to query paging comment in detail product...