Let's analyse this While registering a Char deriver to kernel think that we had allocated memory using any of malloc/kmalloc/vmalloc.
If we forgot to Free that allocated memory while unregistering, will that memory be allocated aside or kernel clears it...?
clarrify the below points:1) Where does the Kmalloc/Vmalloc/get_free_pages/malloc Allocates memory in which space is it Kernel/User?2) Coming to Hardware Point of View is where Kernel/User Space Memory Allocates is it in RAM or any.?3) In Device Drivers, how Open Call get to know whether the hardware is connected/not?
View 6 Replies View RelatedI am new to C and linux. My code below does arbitary writes but I cant figure out where or how it does it.
I am calling the insertNode() function with seq = 'MISSISSPPI$' and alphabets = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ$'
Code:
Weird behaviour I should mention is that when I check for NULL pointer in node->child[index], the unassigned values are not null anymore, they point to arbitary memory.
I allocated a chunk of memory using kmalloc in a Device Driver. Kmalloc provides a pointer to the allocated memory. This is one of my first few drivers.
I assume that the address returned is a Virtual address. I need to find the physical address of the memory location. I am working on an Intel 64 bit Fedora machine. I used the virt_to_phys() routine present in <asm/io_64.h>. I found that this routine returns an unsigned long value (32 bit) instead of an unsigned long long value (64 bit). Moreover, it seems that it simply returns the address - OFFSET instead of extracting the value in the page tables.
So is there any function / system call in Linux which will allow me to see the actual physical address on the Intel 64 arch.
I'm afraid I have a huge issue with my newest Fedora 14 server. I recently migrated to Fedora 14 from Centos 5, which was very stable, but had ancient packages and libraries and my users were revolting...The machine is a HP ProLiant 360 G7, with 12G RAM and 6 SAS drives in RAID 5.After I migrated to Fedora 14, I noticed that for some reason, during the course of about 24 hours, all usable RAM "disappears" and applications are forced down to swap space. Needless to say I didn't have this issue on CentOS.
The server does heavy IO as per it's function (it's a heavily loaded file processing server and user simulation computing station among other things, which causes lots of random IO), so I thought it may be the cache, but then I realized it cannot be - because obviously Linux will use onyl "unused" RAM for caching and frees it up as soon as an app need it. Then, I thought to check the "slabtop" to see what's going on in Kernel memory. Unfortunately I don't have the screenshot from the time just before the latest crash, but there's a certain value displayed by slabtop, which slowly, byte-from-byte creeps over all available RAM, eventually forcing applications down to the swap. This is malloc-64, and as you can see from the bellow copy-paste, it's building up again even now...
Code:
Active / Total Objects (% used) : 9118075 / 9153600 (99.6%)
Active / Total Slabs (% used) : 152157 / 152157 (100.0%)
[code]...
I am developing a code where I need to store the planes of an object in a tree & also i need to store it in a list for further processing ... when I try to allocate using malloc the memory allocation when i checked this in internet , I came to know that it may because the memory that I am trying to allocate may be more than the size_t variable.
View 9 Replies View RelatedI am still confused about the memory issues. i have allocated JAVA_OPTS='-Djava.awt.headless=true -Xms512M -Xmx512M -XX:MaxPermSize=512M' think that it means that i have allocate java to use only 512mb of my memory. but when i run top here is my output.
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
15932 root 23 0 1495m 1.2g 3732 S 12.0 36.0 121:52.98 java
5070 postgres 15 0 55392 39m 35m R 11.6 1.2 0:51.61 postmaster
[code]....
When I am trying to run my application on RHEL 6 (Kernel 2.6*), I am getting the following error.*** glib detected *** ./corenms:malloc(); memory corruption : 0x086691d0 ***
View 4 Replies View RelatedIs there an easy way in C to get the total amount of allocated SHM memory on a machine?
View 7 Replies View RelatedI want to know if i can increase the memory space allocated for a process manually while the process is running ,,,, and if it is possible how i can do this .
View 2 Replies View RelatedI am trying to understand a large amount of allocated memory that seems not to be accounted for on my system.I'll say up front that I am discussing memory usage without cache and buffers, 'cause I know that misunderstanding comes up a lot.I am in a KDE 4.3 desktop (Kubuntu 9.10), using a number of java apps like Eclipse that tend to eat up a lot of memory.after a few days, even if I quit most apps, 1 gb of ram remains allocated (out of 2 gb).this appeared excessive, and I took the time to add up all values of the RES column in htop (for all users).the result was about 1/2 gb.am I trying to match the wrong values?or could some memory be allocated and not show up in the process list?this is the output of free
Code:
total used free shared buffers cached
Mem: 2055456 1940264 115192 0 123864 702900
[code]...
First off all, I'm booting from a large MEMDISK using PXE (900MB) . Due to our environment, I cannot decrease the size, nor move files to a nfs/iSCSI/... environment. Everything needs to be in that MEMDISK.
Now, when I try to run the OS, I get out of vmalloc space. How do I increase it to a number which allows such a large image to be mapped? I tried the parameter "vmalloc=1280M", but with that parameter, I don't get past the Booting the kernel screen.
Memory should not be an issue, since the machine(s) have at least 2GB RAM. (900MB MEMDISK + 256MB for other kernel stuff + 768MB for user stuff). The machine(s) have a Pentium 4 Extreme Edition processor, with hyperthreading and SSE2, but no EM64T.
How can I boot the system, and get past that message? Decreasing the MEMDISK size is not possible too. It is at the smallest we can get with our userland + kernel + modules.
#include<stdio.h>
#include<stdlib.h>
int main()
[code]...
I want to edit a grub file, but none of the online instructions exactly match my files. I'm trying to follow the instructions to add vmalloc=256M to a grub file, from here:
[Code]...
I want to use kmalloc() to allocate contiguous memory on ram. But I can not seem to find the required header file(s) like linux/slab.h. I suppose I do not have the required library and I certainly do not know what and where to look.
View 14 Replies View RelatedIf I copy text into the xterm clipboard from vim, it is cleared when I exit vim. How do I prevent this?
View 1 Replies View RelatedI am using Ubuntu 10.10 dual booted with windows vista. My boot is in a separate partition (sda5). My computer told me that there was limited space on that partition so I tried to clean things up using apt-get by removing old kernels. Turns out I didn't do it correctly because I consistently get an 'ERROR 15' when I shut down and rebooted my computer. I have a live-CD USB-stick so I tried reinstalling grub, (grub-install) updating the menu.lst (update-grub), and manually going through menu.lst and changing to root=(hd0,4) and groot=/dev/sda6. But I still get this ERROR 15 when I reboot.
when I do
sudo grub
find /boot/grub/stage1
find /boot/stage1
Both give me an ERROR 15 message and I'm not sure how to proceed with a diagnosis. When I ran update-grub, occasionally it used to tell me that /etc/fstab may be incorrect. Here is /boot/grub (note that stage 1 does exist!) ( this is /dev/sda5)
Code:
root@ubuntu:/# ls /boot/grub/
default fat_stage1_5 jfs_stage1_5 minix_stage1_5 stage2
device.map grubenv menu.lst reiserfs_stage1_5 xfs_stage1_5
e2fs_stage1_5 installed-version menu.lst~ stage1
Here is my problem
Code:
grub> find /boot/grub/stage1
Error 15: File not found
grub> find /boot/stage1
Error 15: File not found
I guess my main question is, if stage1 can't be found, what does that mean? What should I do next?
Found what takes space but not sure what to delete here is the output of df -h
Filesystem Size Used Avail Use% Mounted on
/dev/sda1 9.2G 157M 8.6G 2% /
/dev/sda5 9.4G 9.4G 20K 100% /usr
/dev/sda6 213G 213G 20K 100% /var
none 1.0G 12K 1.0G 1% /tmp
tmpfs 2.0G 0 2.0G 0% /usr/local/psa/handlers/before-local
How to identify what to delete to clear up space?
I am using malloc and frees a lot in my program. It shows its allocated but when i remove it doesnt show as the memory is removed(I am using the top command to view VIRT memory usage). If this continously grows what would happen to my program (Will it go out of memory?)
View 4 Replies View RelatedI have a computer with 16GB of ram. At the moment, top shows all the RAM is taken, (NOT by cache), but the RAM used by the various processes is very far from 16GB.I have seen this problem several times, but I don't understand what is happening.My only remedy so far has been to reboot the machine.
View 1 Replies View RelatedThis is my first post in these forums. I'm still quite new to Linux (using Mint 9) so please bear with my not-very-articulate question(s)When I boot up and open up a tty terminal I get a message saying "Memory corruption detected in low memory." I've done an extensive google search about the issue and it seems not uncommon. I ran a memtest with no errors returned, so I'm sure that there's nothing really wrong with the memory; apparently it's a bug in the kernel that's causing this.
View 2 Replies View RelatedI found from command 'top' that 8GB memory are used. However, using command 'ps' with some options to grep the running processes and then summing up the memory used by the running processes are less than 2 GB. Where has the used memory gone ?
View 7 Replies View RelatedHow do you malloc a struct in C? I have a structure of the form:
Code:
typedef struct child_req_to_parent
{
[code]...
So far I have this:
Code:
int mm_init (mm_t *MM, int hm, int sz) {
int i;
[code]...
Code:
#include <stdio.h>
#include <stdlib.h>
[code]...
So the place where I'm having a problem is here:
Code:
typedef struct {
void **Mem_Chunk;
[code]...
I have encountered this scenario wherein malloc does not return.
Code:
char * tmp;
rs = 100 to 40000 bytes
[code]...
I'm trying to compile ink but with no luck. Here are the terminal output,
Code:
[trumpet@Trumpet-PC ink-0.5.1]$ ./configure
checking for a BSD-compatible install... /usr/bin/install -c
[code]...
I am getting a weird compilation error with malloc.h/usr/include/malloc.h:86: error: expected ')' before '__size'This is what the code looks like inside malloc.hextern void *(*__morecore) __MALLOC_PMT ((ptrdiff_t __size))When I did some googling, it was stating that ptrdiff_t was not defined; but, it is.#define __malloc_ptrdiff_t ptrdiff_t
View 4 Replies View RelatedI have been trying to fix this problem for 3 days, any ideas before I jump through the window (not the bill gates one)?I am using ubuntu 9.10 and running a ./configure.
View 3 Replies View Related