Commit-ID: 39bc5f36ea19403a1f0fa840e57fc3b929ad939e Gitweb: http://git.kernel.org/tip/39bc5f36ea19403a1f0fa840e57fc3b929ad939e Author: H. Peter Anvin <hpa@xxxxxxxxx> AuthorDate: Thu, 30 Apr 2009 18:14:16 -0700 Committer: H. Peter Anvin <hpa@xxxxxxxxx> CommitDate: Thu, 30 Apr 2009 20:27:05 -0700 x86, config: change defaults PHYSICAL_START and PHYSICAL_ALIGN Change the default for CONFIG_PHYSICAL_START to 16 MB; 4 MB if EMBEDDED. Change the default for CONFIG_PHYSICAL_ALIGN to match up with a large page alignment datum (4 MB for non-PAE, 2 MB for PAE.) The default of 16 MB is designed to avoid occupying ZONE_DMA, as well as avoiding a 15-16 MB memory hole, which some vendors inexplicably still have in their systems. [ Impact: minor performance improvement, leave ZONE_DMA free ] Signed-off-by: H. Peter Anvin <hpa@xxxxxxxxx> --- arch/x86/Kconfig | 19 +++++++++++-------- 1 files changed, 11 insertions(+), 8 deletions(-) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 039c3f0..13b3a5a 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -1455,17 +1455,20 @@ config KEXEC_JUMP config PHYSICAL_START hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP) - default "0x1000000" if X86_NUMAQ - default "0x200000" if X86_64 - default "0x100000" + default "0x400000" if EMBEDDED + default "0x1000000" ---help--- This gives the physical address where the kernel is loaded. If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then bzImage will decompress itself to above physical address and - run from there. Otherwise, bzImage will run from the address where - it has been loaded by the boot loader and will ignore above physical - address. + run from there. Otherwise, bzImage will run from the either + the above physical address or where it has been loaded by + the boot loader, whichever is higher. + + For embedded machines with very small memory (less than + about 24 MB) this may need to be adjusted downward from the + default value of 0x1000000 (16 MB). In normal kdump cases one does not have to set/change this option as now bzImage can be compiled as a completely relocatable image @@ -1516,8 +1519,8 @@ config RELOCATABLE config PHYSICAL_ALIGN hex prompt "Alignment value to which kernel should be aligned" if X86_32 - default "0x100000" if X86_32 - default "0x200000" if X86_64 + default "0x200000" if X86_64 || X86_PAE + default "0x400000" range 0x2000 0x400000 ---help--- This value puts the alignment restrictions on physical address -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
|