[v2,3/5] x86: Kconfig: Remove CONFIG_NODES_SPAN_OTHER_NODES
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Message ID 1562887528-5896-4-git-send-email-Hoan@os.amperecomputing.com
State New
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Series
  • mm: Enable CONFIG_NODES_SPAN_OTHER_NODES by default for NUMA
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Commit Message

Hoan Tran OS July 11, 2019, 11:25 p.m. UTC
Remove CONFIG_NODES_SPAN_OTHER_NODES as it's enabled
by default with NUMA.

Signed-off-by: Hoan Tran <Hoan@os.amperecomputing.com>
---
 arch/x86/Kconfig | 9 ---------
 1 file changed, 9 deletions(-)

Comments

Thomas Gleixner July 15, 2019, 6:43 p.m. UTC | #1
On Thu, 11 Jul 2019, Hoan Tran OS wrote:

> Remove CONFIG_NODES_SPAN_OTHER_NODES as it's enabled
> by default with NUMA.

As I told you before this does not mention that the option is now enabled
even for x86(32bit) configurations which did not enable it before and does
not longer depend on X86_64_ACPI_NUMA.

And there is still no rationale why this makes sense.

Thanks,

	tglx
Hoan Tran OS Aug. 6, 2019, 4:47 p.m. UTC | #2
Hi Thomas,


On 7/15/19 11:43 AM, Thomas Gleixner wrote:
> On Thu, 11 Jul 2019, Hoan Tran OS wrote:
> 
>> Remove CONFIG_NODES_SPAN_OTHER_NODES as it's enabled
>> by default with NUMA.
> 
> As I told you before this does not mention that the option is now enabled
> even for x86(32bit) configurations which did not enable it before and does
> not longer depend on X86_64_ACPI_NUMA.

Agreed, let me add it into this patch description.

> 
> And there is still no rationale why this makes sense.
> 

As we know about the memmap_init_zone() function, it is used to 
initialize all pages. During initializing, early_pfn_in_nid() function 
makes sure the page is in the same node id. Otherwise, 
memmap_init_zone() only checks the page validity. It won't work with 
node memory spans across the others.

The option CONFIG_NODES_SPAN_OTHER_NODES is only used to enable 
early_pfn_in_nid() function.

It occurs during boot-time and won't affect the run-time performance.
And I saw the majority NUMA architectures enable this option by default 
with NUMA.

Thanks and Regards
Hoan


> Thanks,
> 
> 	tglx
>

Patch
diff mbox series

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 2bbbd4d..fa9318c 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -1567,15 +1567,6 @@  config X86_64_ACPI_NUMA
 	---help---
 	  Enable ACPI SRAT based node topology detection.
 
-# Some NUMA nodes have memory ranges that span
-# other nodes.  Even though a pfn is valid and
-# between a node's start and end pfns, it may not
-# reside on that node.  See memmap_init_zone()
-# for details.
-config NODES_SPAN_OTHER_NODES
-	def_bool y
-	depends on X86_64_ACPI_NUMA
-
 config NUMA_EMU
 	bool "NUMA emulation"
 	depends on NUMA