Sponsored Content
Top Forums Programming Ways to preserve a memory cache Post 302701725 by goon12 on Monday 17th of September 2012 07:44:53 AM
Old 09-17-2012
Quote:
Originally Posted by Corona688
Can objects actually live inside the mapped file?

If not, you might as well use an ordinary file, there's no advantage.
I am not 100% sure. Just looking at the java doc:
Code:
A region of a file may be mapped directly into memory; for large files this is often much more efficient than invoking the usual read or write methods.

 

10 More Discussions You Might Find Interesting

1. Windows & DOS: Issues & Discussions

Clearing of cache memory

Pls! will someone help me on how to clear my cache memory of my Internet browser Thanks Kayode (3 Replies)
Discussion started by: kayode
3 Replies

2. Solaris

File cache portion of memory on Solaris

I'm looking to get the file cache portion of physical (real) memory on a Solaris workstation (Similar to the Cache: line in /proc/meminfo on some Linux systems): # swap -s; swap -l; vmstat 2 2; echo "::memstat" | mdb -k total: 309376k bytes allocated + 41428k reserved = 350804k used,... (5 Replies)
Discussion started by: Devyn
5 Replies

3. UNIX for Dummies Questions & Answers

High use of cache memory

Hi, I'm running a debian lenny 1GB ram, but with a high I/O. This server has 400IOPS and 3MB/s sustain. So, I noted cached memory use 800MB, buffered memory use 50MB, and no free memory is available. Questions: What does mean such a high cached memory? Who's using this cached memory? Is... (3 Replies)
Discussion started by: iga3725
3 Replies

4. UNIX for Advanced & Expert Users

linux memory buffers & cache usage

18:45:47 # free -m total used free shared buffers cached Mem: 96679 95909 770 0 1530 19550 -/+ buffers/cache: 74828 21851 Swap: 12287 652 11635 Hi all. The below output is from a RHEL 4.5... (0 Replies)
Discussion started by: drummerrob
0 Replies

5. Red Hat

Need to release Cache memory

Right now i am using Red Hat Enterprise Linux AS release 4 and cache memory occupying around 1.5GB mentioned below, total used free shared buffers cached Mem: 2026 2021 5 0 161 1477 -/+ buffers/cache: 382 1644 ... (4 Replies)
Discussion started by: thakshina
4 Replies

6. Solaris

clear cache memory

hi all, i have noticed that my server has 64 GB RAM and i have application in this server but the server has free memory only 15% and utilized 85% however it didn't eat from swap . does any parameter can be configured in kernel to make the system clear memory from cache like linux i found... (4 Replies)
Discussion started by: maxim42
4 Replies

7. UNIX for Dummies Questions & Answers

Clearing memory cache on Linux server

i wish to clear memory cache on a production box and i was wondering what is the worst that can happen if i do? i already tested this on a backup server and everything seemed fine. but i need to know from you experts what are the worst things that can happen when i run it on a real server: ... (5 Replies)
Discussion started by: SkySmart
5 Replies

8. AIX

AIX swap space, physical memory & cache

Hi, I am new to AIX, Can someone please help me how to know the swap space, total physical memory and system cache? We are using AIX 5.3. Thanks! (3 Replies)
Discussion started by: Phaneendra G
3 Replies

9. Programming

Memory and cache access time discrepancy

#include<stdio.h> #include<stdlib.h> #include<sys/time.h> #include<time.h> #include "rdtsc.h" #define SIZE 4*64*1024 int main() { unsigned long long a,b; int arr={0}; int i; register int r; a=rdtsc(); r=arr; b=rdtsc(); printf("1st element Access Cycles = %llu\n",b-a); (2 Replies)
Discussion started by: Vaibhavs1985
2 Replies

10. UNIX for Dummies Questions & Answers

Best ways to get clear info about CPU and Memory

Hello all i did search the web and found allot of answers but im confused what are the best ways to get this info via Linux default commands 1. current Cpu Usage in Percent 2. current Memory Usage In Bytes 3. current Memory Available In Bytes Thanks! (2 Replies)
Discussion started by: umen
2 Replies
munmap(2)							System Calls Manual							 munmap(2)

Name
       munmap - unmaps memory of a character device

Syntax
       #include <sys/types.h>
       #include <sys/mman.h>

       caddr_t munmap(addr, len)
       caddr_t addr;
       size_t len;

Arguments
       addr	 Specifies the address space of the calling process at which the unmapping begins.

       len	 Specifies the number of bytes to unmap.

Description
       The  system  call  unmaps  a  specified	number of bytes (len) starting at a specified address (addr) from the address space of the calling
       process.  You mapped this device in a previous call to Subsequent access to the unmapped region results in  a  signal.	You  cannot  unmap
       data, stack, and text segments using

       The system call rounds len to the nearest multiple of page size as returned by

       The range [addr, addr + len] may contain more than one mapped region created by In this case, unmaps all of the mapped regions.

Restrictions
       All  of	the  mapped  regions must be wholly contained in the range [addr, addr + len].	That is, addr must be the beginning of some mapped
       region and addr + len must be the end of some (possibly different) mapped region.

Return Value
       If successful, returns 0.  Otherwise, it returns -1 and sets the errno argument to one of the errors listed in the Diagnostics section.

Diagnostics
       The call to fails if one or more of the following is true:

       [EINVAL]  The address you specified in addr is not a multiple of the page size as returned by

       [EINVAL]  The addresses in the range [addr, addr + len] are not valid in the process address space.

       [EINVAL]  All of the segments being unmapped are not entirely contained in the range [addr, addr + len].

See Also
       getpagesize(2), getsysinfo(2), mmap(2)

																	 munmap(2)
All times are GMT -4. The time now is 10:37 PM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy