From the following /proc/meminfo output only ~2GB is free out of total 250GB, but Cached is 194630300 kB. My customer is concerned over the very little memory showing as free. Kindly shed some light if the free memory available in this situation is some thing we need to worry or can we take it as expected behavior of Linux kernel - as most of them are cached.
Linux 2.6.39-400.277.1.el6uek.x86_64
hi,
we all know /proc is about the information of active process,
I have just read an artical which said you can use /proc/cpuinfo,
/proc/net./proc/meminfo etc. to know about some hardware
information .But I want to know how to use with command line? (1 Reply)
Hi,
What are the various way's to fix /proc folder in redhat linux 7.2 and how to verify /proc folder is proper or croupted?
Thank in advance
Bache Gowda (7 Replies)
:)
hi all !
Please help me
When I select data from oracle with proc * C prog.
I count the number of rows
For example the total rows is 1000000
but the number of result return is a limit number 5000 for ex
So How can I know this limit (5 Replies)
Hi,
I am trying to calculate the CPU Usage by getting the difference between the idle time reported by /proc/stat at 2 different intervals. Now the 4th entry in the first line of /proc/stat will give me the 'idle time'. But I also came across /proc/uptime that gives me 2 entries : 1st one as the... (0 Replies)
Hi,
I am trying to understand the role of buffer cache in block I/O.
I am monitoring /proc/meminfo, my question is does the value of 0 for 'buffers', mean that any subsequent disk read issued by a process, would get the data physically from the disk, and not an allocated buffer for the block?
... (1 Reply)
If you are adding the kernel module without any module parameter passing, it should print out following information to info1 file so that user can make read access to info1 file (via, for example, cat /proc/info1):
• Processor type
• Kernel version
• Total number of the processes currently... (1 Reply)
I'm in the process of adding various data to my rrdtool setup, and one of the things i want ot monitor is the meminfo stuff.
I have it running locally very well with the following:
/usr/bin/rrdupdate /etc/rrdtool/192.168.43.254.mem.rrd --template \
used:free:buff:cached:swap N:`awk ' \
... (2 Replies)
Discussion started by: Nunners
2 Replies
LEARN ABOUT DEBIAN
alloc_hugepages
ALLOC_HUGEPAGES(2) Linux Programmer's Manual ALLOC_HUGEPAGES(2)NAME
alloc_hugepages, free_hugepages - allocate or free huge pages
SYNOPSIS
void *alloc_hugepages(int key, void *addr, size_t len,
int prot, int flag);
int free_hugepages(void *addr);
DESCRIPTION
The system calls alloc_hugepages() and free_hugepages() were introduced in Linux 2.5.36 and removed again in 2.5.54. They existed only on
i386 and ia64 (when built with CONFIG_HUGETLB_PAGE). In Linux 2.4.20 the syscall numbers exist, but the calls fail with the error ENOSYS.
On i386 the memory management hardware knows about ordinary pages (4 KiB) and huge pages (2 or 4 MiB). Similarly ia64 knows about huge
pages of several sizes. These system calls serve to map huge pages into the process's memory or to free them again. Huge pages are locked
into memory, and are not swapped.
The key argument is an identifier. When zero the pages are private, and not inherited by children. When positive the pages are shared
with other applications using the same key, and inherited by child processes.
The addr argument of free_hugepages() tells which page is being freed: it was the return value of a call to alloc_hugepages(). (The memory
is first actually freed when all users have released it.) The addr argument of alloc_hugepages() is a hint, that the kernel may or may not
follow. Addresses must be properly aligned.
The len argument is the length of the required segment. It must be a multiple of the huge page size.
The prot argument specifies the memory protection of the segment. It is one of PROT_READ, PROT_WRITE, PROT_EXEC.
The flag argument is ignored, unless key is positive. In that case, if flag is IPC_CREAT, then a new huge page segment is created when
none with the given key existed. If this flag is not set, then ENOENT is returned when no segment with the given key exists.
RETURN VALUE
On success, alloc_hugepages() returns the allocated virtual address, and free_hugepages() returns zero. On error, -1 is returned, and
errno is set appropriately.
ERRORS
ENOSYS The system call is not supported on this kernel.
FILES
/proc/sys/vm/nr_hugepages Number of configured hugetlb pages. This can be read and written.
/proc/meminfo Gives info on the number of configured hugetlb pages and on their size in the three variables HugePages_Total,
HugePages_Free, Hugepagesize.
CONFORMING TO
These calls are specific to Linux on Intel processors, and should not be used in programs intended to be portable.
NOTES
These system calls are gone; they existed only in Linux 2.5.36 through to 2.5.54. Now the hugetlbfs file system can be used instead. Mem-
ory backed by huge pages (if the CPU supports them) is obtained by using mmap(2) to map files in this virtual file system.
The maximal number of huge pages can be specified using the hugepages= boot parameter.
COLOPHON
This page is part of release 3.44 of the Linux man-pages project. A description of the project, and information about reporting bugs, can
be found at http://www.kernel.org/doc/man-pages/.
Linux 2007-05-31 ALLOC_HUGEPAGES(2)