02-06-2014
Quote:
Originally Posted by
dzodzo
How can i tell what will be the maximum kernel memory? We measured this after reboot and starting the applications, kernel took only 2 GB but during 4 months it gradually grew to 13 GB. What would happen if i configured applications to take let's say 60 GB of memory. Will AIX handle that and live with 4 GB for kernel or will it start trashing until reboot is necessary?
I do not know a formula too calculate the minimum for kernel memory.
As you said the memory usage will grow with time and usage (mbufs, inode cache, jfs bufstructs, etc.) and the increase depends on the maximum installed memory. The Kernel used pinned memory (vmstat -v) and if your application with 60GB also used pinned memory, your server will crash/panic if there are no more memory which can be pinned. That happened to us after two weeks with a wrong Informix memory configuration. The other way the server starts to swap out (paging space) and the performance slows down.
Regards
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LEARN ABOUT DEBIAN
ns_calloc
Ns_Alloc(3aolserver) AOLserver Library Procedures Ns_Alloc(3aolserver)
__________________________________________________________________________________________________________________________________________________
NAME
ns_calloc, ns_free, ns_malloc, ns_realloc - Memory allocation functions
SYNOPSIS
#include "ns.h"
void *
ns_calloc(size_t num, size_t esize)
void
ns_free(void *ptr)
void *
ns_malloc(size_t size)
void *
ns_realloc(void *ptr, size_t size)
_________________________________________________________________
DESCRIPTION
The AOLserver memory storage allocation code was moved into Tcl core beginning with Tcl 8.4.0. Starting with AOLserver 3.5, these memory
allocation functions are wrappers that call Tcl_Alloc and Tcl_Free. Earlier versions of AOLserver used this fast memory storage allocator
internally, or the platform's memory allocator depending on how you configured it.
The actual amount of memory allocated or freed will be different from the requested amount. This is because the fast memory allocation
code pools memory into chunks and manages that memory internally. In addition, the Tcl distribution may be compiled to allocate even more
memory which is used internally for diagnostic reasons. Using ns_free to free memory created by routines other than ns_malloc, ns_realloc
and ns_calloc will almost certainly result in segmentation faults or undefined behavior.
The lowercase and mixed-case versions are identical; the lowercase versions are preferred.
ns_calloc(num, esize)
Allocates a block of memory that is num * esize large, zeros it, and returns a pointer to the beginning of the memory block or NULL
if the operation fails.
ns_free(ptr)
ns_free() frees the memory space pointed to by ptr. This pointer must have been created with a previous call to ns_malloc(), ns_cal-
loc() or ns_realloc(). If ptr is NULL, no operation is performed. ns_free() returns no value.
ns_malloc(size)
ns_malloc() allocates size bytes and returns a pointer to the allocated memory. The memory is not cleared. The value returned is a
pointer to the allocated memory or NULL if the request fails. The memory must be freed by ns_free.
ns_realloc(ptr, size)
ns_realloc changes the size of the memory block pointed to by ptr to size bytes. The contents will be unchanged to the minimum of
the old and new sizes. Newly allocated memory will be uninitialized. If ptr is NULL, the call is equivalent to ns_malloc(size); if
size is equal to zero, the call is equivalent to ns_free(ptr). Unless ptr is NULL, it must have been returned by an earlier call to
ns_malloc(), ns_calloc() or ns_realloc().
SEE ALSO
Tcl_Alloc(3), Tcl_Free(3)
KEYWORDS
memory, allocation
AOLserver 4.0 Ns_Alloc(3aolserver)