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Full Discussion: vm and buffer cache
Top Forums UNIX for Advanced & Expert Users vm and buffer cache Post 20424 by vish_shan on Friday 26th of April 2002 03:57:21 AM
Old 04-26-2002
vm and buffer cache

i have a serious doubht about the assignment of memory
in hp-ux system .
i read from somewhere that the page allocation in
hp-ux is not unified unlike compaq .
i wanted to know in hp-ux kernel ,once the pages are
assigned for the univarsal buffer cache ,can those pages
be used by the virtual memory system .
Are the total virtual memory pages noway related to
buff-cache pages . can their respective counts be treated as seperate assignmemt of pages .
anybody clarifies i will be thankfull .
vish shan

Smilie
 

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KMALLOC_ARRAY(9)					    Memory Management in Linux						  KMALLOC_ARRAY(9)

NAME
kmalloc_array - allocate memory for an array. SYNOPSIS
void * kmalloc_array(size_t n, size_t size, gfp_t flags); ARGUMENTS
n number of elements. size element size. flags the type of memory to allocate. DESCRIPTION
The flags argument may be one of: GFP_USER - Allocate memory on behalf of user. May sleep. GFP_KERNEL - Allocate normal kernel ram. May sleep. GFP_ATOMIC - Allocation will not sleep. May use emergency pools. For example, use this inside interrupt handlers. GFP_HIGHUSER - Allocate pages from high memory. GFP_NOIO - Do not do any I/O at all while trying to get memory. GFP_NOFS - Do not make any fs calls while trying to get memory. GFP_NOWAIT - Allocation will not sleep. __GFP_THISNODE - Allocate node-local memory only. GFP_DMA - Allocation suitable for DMA. Should only be used for kmalloc caches. Otherwise, use a slab created with SLAB_DMA. Also it is possible to set different flags by OR'ing in one or more of the following additional flags: __GFP_COLD - Request cache-cold pages instead of trying to return cache-warm pages. __GFP_HIGH - This allocation has high priority and may use emergency pools. __GFP_NOFAIL - Indicate that this allocation is in no way allowed to fail (think twice before using). __GFP_NORETRY - If memory is not immediately available, then give up at once. __GFP_NOWARN - If allocation fails, don't issue any warnings. __GFP_REPEAT - If allocation fails initially, try once more before failing. There are other flags available as well, but these are not intended for general use, and so are not documented here. For a full list of potential flags, always refer to linux/gfp.h. COPYRIGHT
Kernel Hackers Manual 3.10 June 2014 KMALLOC_ARRAY(9)
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