| commit | dc382fd5bcca7098a984705ed6ac880f539d068e | |
| author | David Rientjes <rientjes@google.com> | |
| Mon, 16 May 2011 20:54:10 +0000 (16 13:54 -0700) | ||
| committer | H. Peter Anvin <hpa@linux.intel.com> | |
| Mon, 16 May 2011 21:03:28 +0000 (16 14:03 -0700) | ||
| tree | c1e3cba89fcb91092061fecd5a2d688335e30216 | treesnapshot (tar.gz zip) |
| parent | e5a10c1bd12a5d71bbb6406c1b0dbbc9d8958397 | commitdiff |
x86, mm: Allow ZONE_DMA to be configurable
ZONE_DMA is unnecessary for a large number of machines that do not
require less than 32-bit DMA addressing, e.g. ISA legacy DMA or PCI
cards with a restricted DMA address mask.
This patch allows users to disable ZONE_DMA for x86 if they know they
will not be using such devices with their kernel.
This prevents the VM from unnecessarily reserving a ratio of memory
(defaulting to 1/256th of system capacity) with lowmem_reserve_ratio
for such allocations when it will never be used.
Signed-off-by: David Rientjes <rientjes@google.com>
Link: http://lkml.kernel.org/r/alpine.DEB.2.00.1105161353560.4353@chino.kir.corp.google.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
ZONE_DMA is unnecessary for a large number of machines that do not
require less than 32-bit DMA addressing, e.g. ISA legacy DMA or PCI
cards with a restricted DMA address mask.
This patch allows users to disable ZONE_DMA for x86 if they know they
will not be using such devices with their kernel.
This prevents the VM from unnecessarily reserving a ratio of memory
(defaulting to 1/256th of system capacity) with lowmem_reserve_ratio
for such allocations when it will never be used.
Signed-off-by: David Rientjes <rientjes@google.com>
Link: http://lkml.kernel.org/r/alpine.DEB.2.00.1105161353560.4353@chino.kir.corp.google.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
| arch/x86/Kconfig | diffblobblamehistory | |
| arch/x86/mm/init_32.c | diffblobblamehistory | |
| arch/x86/mm/init_64.c | diffblobblamehistory |