Commit 2d6bff31 authored by Mike Rapoport (Microsoft)'s avatar Mike Rapoport (Microsoft) Committed by Ingo Molnar
Browse files

x86/boot: Move setting of memblock parameters to e820__memblock_setup() 



Changing memblock parameters, namely bottom_up and allocation upper
limit does not have any effect before memblock initialization in
e820__memblock_setup().

Move the calls to memblock_set_bottom_up() and memblock_set_current_limit()
to e820__memblock_setup() to group all the memblock initial setup and make
setup_arch() more readable.

No functional changes.

Signed-off-by: default avatarMike Rapoport (Microsoft) <rppt@kernel.org>
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20250214090651.3331663-2-rppt@kernel.org
parent 0ad2507d

arch/x86/kernel/e820.c

+30 −0
Original line number Diff line number Diff line
@@ -1302,6 +1302,36 @@ void __init e820__memblock_setup(void) 
	int i;

	u64 end;



#ifdef CONFIG_MEMORY_HOTPLUG

	/*

	 * Memory used by the kernel cannot be hot-removed because Linux

	 * cannot migrate the kernel pages. When memory hotplug is

	 * enabled, we should prevent memblock from allocating memory

	 * for the kernel.

	 *

	 * ACPI SRAT records all hotpluggable memory ranges. But before

	 * SRAT is parsed, we don't know about it.

	 *

	 * The kernel image is loaded into memory at very early time. We

	 * cannot prevent this anyway. So on NUMA system, we set any

	 * node the kernel resides in as un-hotpluggable.

	 *

	 * Since on modern servers, one node could have double-digit

	 * gigabytes memory, we can assume the memory around the kernel

	 * image is also un-hotpluggable. So before SRAT is parsed, just

	 * allocate memory near the kernel image to try the best to keep

	 * the kernel away from hotpluggable memory.

	 */

	if (movable_node_is_enabled())

		memblock_set_bottom_up(true);

#endif



	/*

	 * At this point only the first megabyte is mapped for sure, the

	 * rest of the memory cannot be used for memblock resizing

	 */

	memblock_set_current_limit(ISA_END_ADDRESS);



	/*

	 * The bootstrap memblock region count maximum is 128 entries

	 * (INIT_MEMBLOCK_REGIONS), but EFI might pass us more E820 entries

arch/x86/kernel/setup.c

+0 −25
Original line number Diff line number Diff line
@@ -866,30 +866,6 @@ void __init setup_arch(char **cmdline_p) 
	if (efi_enabled(EFI_BOOT))

		efi_memblock_x86_reserve_range();



#ifdef CONFIG_MEMORY_HOTPLUG

	/*

	 * Memory used by the kernel cannot be hot-removed because Linux

	 * cannot migrate the kernel pages. When memory hotplug is

	 * enabled, we should prevent memblock from allocating memory

	 * for the kernel.

	 *

	 * ACPI SRAT records all hotpluggable memory ranges. But before

	 * SRAT is parsed, we don't know about it.

	 *

	 * The kernel image is loaded into memory at very early time. We

	 * cannot prevent this anyway. So on NUMA system, we set any

	 * node the kernel resides in as un-hotpluggable.

	 *

	 * Since on modern servers, one node could have double-digit

	 * gigabytes memory, we can assume the memory around the kernel

	 * image is also un-hotpluggable. So before SRAT is parsed, just

	 * allocate memory near the kernel image to try the best to keep

	 * the kernel away from hotpluggable memory.

	 */

	if (movable_node_is_enabled())

		memblock_set_bottom_up(true);

#endif



	x86_report_nx();



	apic_setup_apic_calls();
@@ -990,7 +966,6 @@ void __init setup_arch(char **cmdline_p) 


	cleanup_highmap();



	memblock_set_current_limit(ISA_END_ADDRESS);

	e820__memblock_setup();



	/*