The bottom-up allocation style is introduced to cope with movable_node, where the limit inferior of allocation starts from kernel's end, due to lack of knowledge of memory hotplug info at this early time. Beside this original aim, 'kexec -c' prefers to reuse this style to alloc mem at lower address, since if the reserved region is beyond 4G, then it requires extra mem (default is 16M) for swiotlb. But at this time hotplug info has been got, the limit inferior can be extend to 0, which is done by this series
Cc: Tang Chen <[email protected]> Cc: "Rafael J. Wysocki" <[email protected]> Cc: Len Brown <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Mike Rapoport <[email protected]> Cc: Michal Hocko <[email protected]> Cc: Jonathan Corbet <[email protected]> Cc: Yaowei Bai <[email protected]> Cc: Pavel Tatashin <[email protected]> Cc: Nicholas Piggin <[email protected]> Cc: Naoya Horiguchi <[email protected]> Cc: Daniel Vacek <[email protected]> Cc: Mathieu Malaterre <[email protected]> Cc: Stefan Agner <[email protected]> Cc: Dave Young <[email protected]> Cc: Baoquan He <[email protected]> Cc: [email protected], Cc: [email protected] Cc: [email protected] Pingfan Liu (2): mm/memblock: extend the limit inferior of bottom-up after parsing hotplug attr x86/kdump: bugfix, make the behavior of crashkernel=X consistent with kaslr arch/x86/kernel/setup.c | 9 +++++--- drivers/acpi/numa.c | 4 ++++ include/linux/memblock.h | 1 + mm/memblock.c | 58 +++++++++++++++++++++++++++++------------------- 4 files changed, 46 insertions(+), 26 deletions(-) -- 2.7.4
