Stack Overflow
Stack Overflow

Questions tagged [fragmentation]

An unefficient usage of disk storage in memory or hard drive.

189 questions
4
votes
1 answer

Test for memory fragmentation

So as part of a course in OS that I'm taking, I've implemented a memory allocator (just like malloc in C). The free space is stored in a linked-list. My question in then following: How would I go about testing the various allocation strategies…
me_L_coding
  • 169
  • 10
4
votes
1 answer

Calculating memory fragmentation in Python

I have a long running process that allocates and releases objects constantly. Although objects are being freed, the RSS mem usage goes up over time. How can I calculate how much fragmentation is happening? One possibility is to calculate RSS /…
Ali
  • 1,503
  • 2
  • 15
  • 20
4
votes
1 answer

IP fragmentation and TCP ACK

I have a question on how TCP_ACK works when the original packet are fragmented. For example, original packet size is 1,500*N bytes and MTU is 1,500. Then, the packet will be frgmented into (approximately) N packets. In this case, how does the…
user1544411
  • 41
  • 2
4
votes
1 answer

How can I avoid file fragmentation while writing hundreds of multi-megabyte files?

My question is similar to How to avoid hard disc fragmentation?, but I will be generating several hundred files per day that can range in size from 2 MB to 100+ MB (that questioner implied his files were smaller as he was more worried about…
MrPhilTX
  • 113
  • 2
  • 9
3
votes
3 answers

Pre-allocate some memory in Large Object Heap memory

i am working on a C# application and this application is facing memory crunch, because many objects are getting memory allocation in the Large object Heap. My C# application has to work on many large file (as an string object) and therefore the…
Kunal
  • 151
  • 1
  • 2
  • 6
3
votes
1 answer

SQL Server rebuilding indexes - script

I'm using a script from @Namphibian, but I have some problems there. SET TRANSACTION ISOLATION LEVEL READ UNCOMMITTED CREATE TABLE #FragmentedIndexes ( DatabaseName SYSNAME, SchemaName SYSNAME, TableName SYSNAME, IndexName…
Roman Schmidt
  • 55
  • 1
  • 12
3
votes
1 answer

How to search Lucene.NET without indicating "top n" hits limit?

There are several overloads of IndexSearcher.Search method in Lucene. Some of them require "top n hits" argument, some don't (these are obsolete and will be removed in Lucene.NET 3.0). Those, which require "top n" argument actually cause memory…
Rezgar Cadro
  • 394
  • 4
  • 11
3
votes
6 answers

packet fragmentation for raw sockets

If I am using raw sockets to send a UDP packet of size 3000bytes, do I need to handle packet fragmentation myself in the code, or should the raw socket handle fragmentation similar to DGRAM socket?
SkypeMeSM
  • 3,197
  • 8
  • 43
  • 61
3
votes
1 answer

Effort due to Android fragmentation

With Android platform fragmentation, what changes in different OEM handset attributes force developers to port from one platform to another?
silkroader
  • 31
  • 3
3
votes
0 answers

Redis and memory

I am developing software in an embedded system (512 MB RAM). I'm using redis to take the place of a shared memory between processes inside a django application. We are talking about 150 values, stored every second, coming from a MODBUS device. They…
Luca Fallabrino
  • 31
  • 3
3
votes
2 answers

TCP/UDP and ethernet MTU Fragmentation

I've read various sites and tutorials online but I am still confused. If the message is bigger than IP MTU, then send() returns the byte sent. What happens to the rest of the message? Am I to call send() again and attempt to send rest of the…
Fantastic Fourier
  • 613
  • 7
  • 13
  • 20
3
votes
0 answers

Page fullness in SQL server: Is higher always better?

So I've got a very frequently-run query on my SQL server instance that's generating a lot of wait time. On examining the Plan, I was pointed in the direction of a clustered index seek that's accountable for 93% of the cost of the whole…
Biztalk Amateur
  • 53
  • 1
  • 1
  • 7
3
votes
2 answers

MS SQL query slow because of bad plan or fragmented indexes

I have a stored procedure which usually runs pretty quickly (hardly a few seconds), but then there are odd days where the same proc with the same parameters takes minutes to execute. But if I defrag the indexes at this point, it starts running…
Joseph.W
  • 45
  • 4
3
votes
3 answers

How does disk de-fragmenting work?

I'd like to have a go at writing something which shows the state of a hard drive in terms of how fragmented it is. Maybe even has a go at de-fragmenting it. But I've realised that I don't fully understand how this works. Can anyone explain this to…
Matt
  • 3,664
  • 3
  • 33
  • 39
3
votes
0 answers

Why does RAM fragmentation degrade performance if data can be accessed randomly?

From what I've read, fragmentation is a problem because only contiguous blocks of memory can be allocated. Why is this? Since data in RAM can be accessed in any order, can't non-contiguous blocks of memory be read just as fast? I've been thinking…
user3289912
  • 45
  • 3
1 2 3
…
12 13