Commit c673f1a9 authored by William Lee Irwin III's avatar William Lee Irwin III Committed by Linus Torvalds
Browse files

i386: divorce CONFIG_X86_PAE from CONFIG_HIGHMEM64G 



PAE is useful for more than supporting more than 4GB RAM.  It supports
expanded swapspace and NX executable protections.  Some users may want NX
or expanded swapspace support without the overhead or instability of
highmem.  For these reasons, the following patch divorces CONFIG_X86_PAE
from CONFIG_HIGHMEM64G.

Cc: Mark Lord <lkml@rtr.ca>
Signed-off-by: default avatarWilliam Irwin <wli@holomorphy.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarAndi Kleen <ak@suse.de>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 075bcd1f

arch/i386/Kconfig

+11 −5
Original line number Diff line number Diff line
@@ -548,6 +548,7 @@ config HIGHMEM4G 
config HIGHMEM64G

	bool "64GB"

	depends on !M386 && !M486

	select X86_PAE

	help

	  Select this if you have a 32-bit processor and more than 4

	  gigabytes of physical RAM.
@@ -577,12 +578,12 @@ choice 
	config VMSPLIT_3G

		bool "3G/1G user/kernel split"

	config VMSPLIT_3G_OPT

		depends on !HIGHMEM

		depends on !X86_PAE

		bool "3G/1G user/kernel split (for full 1G low memory)"

	config VMSPLIT_2G

		bool "2G/2G user/kernel split"

	config VMSPLIT_2G_OPT

		depends on !HIGHMEM

		depends on !X86_PAE

		bool "2G/2G user/kernel split (for full 2G low memory)"

	config VMSPLIT_1G

		bool "1G/3G user/kernel split"
@@ -602,10 +603,15 @@ config HIGHMEM 
	default y



config X86_PAE

	bool

	depends on HIGHMEM64G

	default y

	bool "PAE (Physical Address Extension) Support"

	default n

	depends on !HIGHMEM4G

	select RESOURCES_64BIT

	help

	  PAE is required for NX support, and furthermore enables

	  larger swapspace support for non-overcommit purposes. It

	  has the cost of more pagetable lookup overhead, and also

	  consumes more pagetable space per process.



# Common NUMA Features

config NUMA

arch/i386/kernel/setup.c

+4 −4
Original line number Diff line number Diff line
@@ -273,18 +273,18 @@ unsigned long __init find_max_low_pfn(void) 
		printk(KERN_WARNING "Warning only %ldMB will be used.\n",

					MAXMEM>>20);

		if (max_pfn > MAX_NONPAE_PFN)

			printk(KERN_WARNING "Use a PAE enabled kernel.\n");

			printk(KERN_WARNING "Use a HIGHMEM64G enabled kernel.\n");

		else

			printk(KERN_WARNING "Use a HIGHMEM enabled kernel.\n");

		max_pfn = MAXMEM_PFN;

#else /* !CONFIG_HIGHMEM */

#ifndef CONFIG_X86_PAE

#ifndef CONFIG_HIGHMEM64G

		if (max_pfn > MAX_NONPAE_PFN) {

			max_pfn = MAX_NONPAE_PFN;

			printk(KERN_WARNING "Warning only 4GB will be used.\n");

			printk(KERN_WARNING "Use a PAE enabled kernel.\n");

			printk(KERN_WARNING "Use a HIGHMEM64G enabled kernel.\n");

		}

#endif /* !CONFIG_X86_PAE */

#endif /* !CONFIG_HIGHMEM64G */

#endif /* !CONFIG_HIGHMEM */

	} else {

		if (highmem_pages == -1)

CRA Git | Maintained and supported by SUSTech CRA and CCSE