maximalni pridelena pamet procesu

Jarda Mikulík jarda.mikulik na jetedata.cz
Pondělí Květen 12 13:39:19 CEST 2003


vita na brtnik.isibrno.cz wrote:
> disponuji s:
> Mem:    773908K total,   371012K used,   402896K free,    31492K buffers
> Swap: 11711168K total,  2277740K used,  9433428K free,   171428K cached
> 
> potreboval bych poradit, jak umoznit procesu vyuzit vice jak 2GB pameti.
> 
> jadro jsem kompiloval s podporou highmem.

Vy máte fyzicky více než 960 MiB paměti (SWAP se do toho nepočítá), že 
tohle děláte? Pokud nemáte, tak nemáte ani důvod tohle dělat, viz. 
dokumentace ke kernelu:

High Memory support
CONFIG_NOHIGHMEM
   Linux can use up to 64 Gigabytes of physical memory on x86 systems.
   However, the address space of 32-bit x86 processors is only 4
   Gigabytes large. That means that, if you have a large amount of
   physical memory, not all of it can be "permanently mapped" by the
   kernel. The physical memory that's not permanently mapped is called
   "high memory".

   If you are compiling a kernel which will never run on a machine with
   more than 960 megabytes of total physical RAM, answer "off" here
   (default choice and suitable for most users). This will result in a
   "3GB/1GB" split: 3GB are mapped so that each process sees a 3GB
   virtual memory space and the remaining part of the 4GB virtual memory
   space is used by the kernel to permanently map as much physical memory
   as possible.

   If the machine has between 1 and 4 Gigabytes physical RAM, then
   answer "4GB" here.

   If more than 4 Gigabytes is used then answer "64GB" here. This
   selection turns Intel PAE (Physical Address Extension) mode on.
   PAE implements 3-level paging on IA32 processors. PAE is fully
   supported by Linux, PAE mode is implemented on all recent Intel
   processors (Pentium Pro and better). NOTE: If you say "64GB" here,
   then the kernel will not boot on CPUs that don't support PAE!

   The actual amount of total physical memory will either be auto
   detected or can be forced by using a kernel command line option such
   as "mem=256M". (Try "man bootparam" or see the documentation of your
   boot loader (grub, lilo or loadlin) about how to pass options to the
   kernel at boot time.)

   If unsure, say "off".

4GB
CONFIG_HIGHMEM4G
   Select this if you have a 32-bit processor and between 1 and 4
   gigabytes of physical RAM.

64GB
CONFIG_HIGHMEM64G
   Select this if you have a 32-bit processor and more than 4
   gigabytes of physical RAM.

HIGHMEM I/O support
CONFIG_HIGHIO
   If you want to be able to do I/O to high memory pages, say Y.
   Otherwise low memory pages are used as bounce buffers causing a
   degrade in performance.


     Jarda

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