* [PATCH] arm64: mm: update max_pfn after memory hotplug
@ 2021-09-28 18:51 ` Chris Goldsworthy
0 siblings, 0 replies; 14+ messages in thread
From: Chris Goldsworthy @ 2021-09-28 18:51 UTC (permalink / raw)
To: Andrew Morton
Cc: David Hildenbrand, Catalin Marinas, Will Deacon,
Sudarshan Rajagopalan, Georgi Djakov, linux-arm-kernel,
linux-kernel, linux-mm, Chris Goldsworthy, Florian Fainelli
From: Sudarshan Rajagopalan <quic_sudaraja@quicinc.com>
After new memory blocks have been hotplugged, max_pfn and max_low_pfn
needs updating to reflect on new PFNs being hot added to system.
Without this patch, debug-related functions that use max_pfn such as
get_max_dump_pfn() or read_page_owner() will not work with any page in
memory that is hot-added after boot.
Fixes: 4ab215061554 ("arm64: Add memory hotplug support")
Signed-off-by: Sudarshan Rajagopalan <quic_sudaraja@quicinc.com>
Signed-off-by: Chris Goldsworthy <quic_cgoldswo@quicinc.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Georgi Djakov <quic_c_gdjako@quicinc.com>
---
arch/arm64/mm/mmu.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
index cfd9deb..fd85b51 100644
--- a/arch/arm64/mm/mmu.c
+++ b/arch/arm64/mm/mmu.c
@@ -1499,6 +1499,11 @@ int arch_add_memory(int nid, u64 start, u64 size,
if (ret)
__remove_pgd_mapping(swapper_pg_dir,
__phys_to_virt(start), size);
+ else {
+ max_pfn = PFN_UP(start + size);
+ max_low_pfn = max_pfn;
+ }
+
return ret;
}
--
2.7.4
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply related [flat|nested] 14+ messages in thread* Re: [PATCH] arm64: mm: update max_pfn after memory hotplug
2021-09-28 18:51 ` Chris Goldsworthy
@ 2021-09-28 19:34 ` Georgi Djakov
-1 siblings, 0 replies; 14+ messages in thread
From: Georgi Djakov @ 2021-09-28 19:34 UTC (permalink / raw)
To: Chris Goldsworthy, Andrew Morton
Cc: David Hildenbrand, Catalin Marinas, Will Deacon,
Sudarshan Rajagopalan, linux-arm-kernel, linux-kernel, linux-mm,
Florian Fainelli
On 9/28/2021 9:51 PM, Chris Goldsworthy wrote:
> From: Sudarshan Rajagopalan <quic_sudaraja@quicinc.com>
>
> After new memory blocks have been hotplugged, max_pfn and max_low_pfn
> needs updating to reflect on new PFNs being hot added to system.
> Without this patch, debug-related functions that use max_pfn such as
> get_max_dump_pfn() or read_page_owner() will not work with any page in
> memory that is hot-added after boot.
>
> Fixes: 4ab215061554 ("arm64: Add memory hotplug support")
> Signed-off-by: Sudarshan Rajagopalan <quic_sudaraja@quicinc.com>
> Signed-off-by: Chris Goldsworthy <quic_cgoldswo@quicinc.com>
> Acked-by: David Hildenbrand <david@redhat.com>
Tested-by: Georgi Djakov <quic_c_gdjako@quicinc.com>
> Cc: Florian Fainelli <f.fainelli@gmail.com>
> Cc: Georgi Djakov <quic_c_gdjako@quicinc.com>
> ---
> arch/arm64/mm/mmu.c | 5 +++++
> 1 file changed, 5 insertions(+)
>
> diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
> index cfd9deb..fd85b51 100644
> --- a/arch/arm64/mm/mmu.c
> +++ b/arch/arm64/mm/mmu.c
> @@ -1499,6 +1499,11 @@ int arch_add_memory(int nid, u64 start, u64 size,
> if (ret)
> __remove_pgd_mapping(swapper_pg_dir,
> __phys_to_virt(start), size);
> + else {
> + max_pfn = PFN_UP(start + size);
> + max_low_pfn = max_pfn;
> + }
> +
> return ret;
> }
>
>
^ permalink raw reply [flat|nested] 14+ messages in thread* Re: [PATCH] arm64: mm: update max_pfn after memory hotplug
@ 2021-09-28 19:34 ` Georgi Djakov
0 siblings, 0 replies; 14+ messages in thread
From: Georgi Djakov @ 2021-09-28 19:34 UTC (permalink / raw)
To: Chris Goldsworthy, Andrew Morton
Cc: David Hildenbrand, Catalin Marinas, Will Deacon,
Sudarshan Rajagopalan, linux-arm-kernel, linux-kernel, linux-mm,
Florian Fainelli
On 9/28/2021 9:51 PM, Chris Goldsworthy wrote:
> From: Sudarshan Rajagopalan <quic_sudaraja@quicinc.com>
>
> After new memory blocks have been hotplugged, max_pfn and max_low_pfn
> needs updating to reflect on new PFNs being hot added to system.
> Without this patch, debug-related functions that use max_pfn such as
> get_max_dump_pfn() or read_page_owner() will not work with any page in
> memory that is hot-added after boot.
>
> Fixes: 4ab215061554 ("arm64: Add memory hotplug support")
> Signed-off-by: Sudarshan Rajagopalan <quic_sudaraja@quicinc.com>
> Signed-off-by: Chris Goldsworthy <quic_cgoldswo@quicinc.com>
> Acked-by: David Hildenbrand <david@redhat.com>
Tested-by: Georgi Djakov <quic_c_gdjako@quicinc.com>
> Cc: Florian Fainelli <f.fainelli@gmail.com>
> Cc: Georgi Djakov <quic_c_gdjako@quicinc.com>
> ---
> arch/arm64/mm/mmu.c | 5 +++++
> 1 file changed, 5 insertions(+)
>
> diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
> index cfd9deb..fd85b51 100644
> --- a/arch/arm64/mm/mmu.c
> +++ b/arch/arm64/mm/mmu.c
> @@ -1499,6 +1499,11 @@ int arch_add_memory(int nid, u64 start, u64 size,
> if (ret)
> __remove_pgd_mapping(swapper_pg_dir,
> __phys_to_virt(start), size);
> + else {
> + max_pfn = PFN_UP(start + size);
> + max_low_pfn = max_pfn;
> + }
> +
> return ret;
> }
>
>
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: [PATCH] arm64: mm: update max_pfn after memory hotplug
2021-09-28 18:51 ` Chris Goldsworthy
@ 2021-10-01 6:38 ` Anshuman Khandual
-1 siblings, 0 replies; 14+ messages in thread
From: Anshuman Khandual @ 2021-10-01 6:38 UTC (permalink / raw)
To: Chris Goldsworthy, Andrew Morton
Cc: David Hildenbrand, Catalin Marinas, Will Deacon,
Sudarshan Rajagopalan, Georgi Djakov, linux-arm-kernel,
linux-kernel, linux-mm, Florian Fainelli
On 9/29/21 12:21 AM, Chris Goldsworthy wrote:
> From: Sudarshan Rajagopalan <quic_sudaraja@quicinc.com>
>
> After new memory blocks have been hotplugged, max_pfn and max_low_pfn
> needs updating to reflect on new PFNs being hot added to system.
> Without this patch, debug-related functions that use max_pfn such as
> get_max_dump_pfn() or read_page_owner() will not work with any page in
> memory that is hot-added after boot.
>
> Fixes: 4ab215061554 ("arm64: Add memory hotplug support")
> Signed-off-by: Sudarshan Rajagopalan <quic_sudaraja@quicinc.com>
> Signed-off-by: Chris Goldsworthy <quic_cgoldswo@quicinc.com>
> Acked-by: David Hildenbrand <david@redhat.com>
> Cc: Florian Fainelli <f.fainelli@gmail.com>
> Cc: Georgi Djakov <quic_c_gdjako@quicinc.com>
> ---
> arch/arm64/mm/mmu.c | 5 +++++
> 1 file changed, 5 insertions(+)
>
> diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
> index cfd9deb..fd85b51 100644
> --- a/arch/arm64/mm/mmu.c
> +++ b/arch/arm64/mm/mmu.c
> @@ -1499,6 +1499,11 @@ int arch_add_memory(int nid, u64 start, u64 size,
> if (ret)
> __remove_pgd_mapping(swapper_pg_dir,
> __phys_to_virt(start), size);
> + else {
> + max_pfn = PFN_UP(start + size);
> + max_low_pfn = max_pfn;
> + }
Do these variables get updated on *all* platforms that support memory
hotplug via an arch_add_memory() ? If not, dont they all face similar
issues as well ? Why not just update these in generic hotplug instead
, after looking into arch_add_memory() return code.
> +
> return ret;
> }
>
>
^ permalink raw reply [flat|nested] 14+ messages in thread* Re: [PATCH] arm64: mm: update max_pfn after memory hotplug
@ 2021-10-01 6:38 ` Anshuman Khandual
0 siblings, 0 replies; 14+ messages in thread
From: Anshuman Khandual @ 2021-10-01 6:38 UTC (permalink / raw)
To: Chris Goldsworthy, Andrew Morton
Cc: David Hildenbrand, Catalin Marinas, Will Deacon,
Sudarshan Rajagopalan, Georgi Djakov, linux-arm-kernel,
linux-kernel, linux-mm, Florian Fainelli
On 9/29/21 12:21 AM, Chris Goldsworthy wrote:
> From: Sudarshan Rajagopalan <quic_sudaraja@quicinc.com>
>
> After new memory blocks have been hotplugged, max_pfn and max_low_pfn
> needs updating to reflect on new PFNs being hot added to system.
> Without this patch, debug-related functions that use max_pfn such as
> get_max_dump_pfn() or read_page_owner() will not work with any page in
> memory that is hot-added after boot.
>
> Fixes: 4ab215061554 ("arm64: Add memory hotplug support")
> Signed-off-by: Sudarshan Rajagopalan <quic_sudaraja@quicinc.com>
> Signed-off-by: Chris Goldsworthy <quic_cgoldswo@quicinc.com>
> Acked-by: David Hildenbrand <david@redhat.com>
> Cc: Florian Fainelli <f.fainelli@gmail.com>
> Cc: Georgi Djakov <quic_c_gdjako@quicinc.com>
> ---
> arch/arm64/mm/mmu.c | 5 +++++
> 1 file changed, 5 insertions(+)
>
> diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
> index cfd9deb..fd85b51 100644
> --- a/arch/arm64/mm/mmu.c
> +++ b/arch/arm64/mm/mmu.c
> @@ -1499,6 +1499,11 @@ int arch_add_memory(int nid, u64 start, u64 size,
> if (ret)
> __remove_pgd_mapping(swapper_pg_dir,
> __phys_to_virt(start), size);
> + else {
> + max_pfn = PFN_UP(start + size);
> + max_low_pfn = max_pfn;
> + }
Do these variables get updated on *all* platforms that support memory
hotplug via an arch_add_memory() ? If not, dont they all face similar
issues as well ? Why not just update these in generic hotplug instead
, after looking into arch_add_memory() return code.
> +
> return ret;
> }
>
>
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 14+ messages in thread* Re: [PATCH] arm64: mm: update max_pfn after memory hotplug
2021-10-01 6:38 ` Anshuman Khandual
@ 2021-10-01 8:39 ` David Hildenbrand
-1 siblings, 0 replies; 14+ messages in thread
From: David Hildenbrand @ 2021-10-01 8:39 UTC (permalink / raw)
To: Anshuman Khandual, Chris Goldsworthy, Andrew Morton
Cc: Catalin Marinas, Will Deacon, Sudarshan Rajagopalan,
Georgi Djakov, linux-arm-kernel, linux-kernel, linux-mm,
Florian Fainelli
On 01.10.21 08:38, Anshuman Khandual wrote:
>
>
> On 9/29/21 12:21 AM, Chris Goldsworthy wrote:
>> From: Sudarshan Rajagopalan <quic_sudaraja@quicinc.com>
>>
>> After new memory blocks have been hotplugged, max_pfn and max_low_pfn
>> needs updating to reflect on new PFNs being hot added to system.
>> Without this patch, debug-related functions that use max_pfn such as
>> get_max_dump_pfn() or read_page_owner() will not work with any page in
>> memory that is hot-added after boot.
>>
>> Fixes: 4ab215061554 ("arm64: Add memory hotplug support")
>> Signed-off-by: Sudarshan Rajagopalan <quic_sudaraja@quicinc.com>
>> Signed-off-by: Chris Goldsworthy <quic_cgoldswo@quicinc.com>
>> Acked-by: David Hildenbrand <david@redhat.com>
>> Cc: Florian Fainelli <f.fainelli@gmail.com>
>> Cc: Georgi Djakov <quic_c_gdjako@quicinc.com>
>> ---
>> arch/arm64/mm/mmu.c | 5 +++++
>> 1 file changed, 5 insertions(+)
>>
>> diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
>> index cfd9deb..fd85b51 100644
>> --- a/arch/arm64/mm/mmu.c
>> +++ b/arch/arm64/mm/mmu.c
>> @@ -1499,6 +1499,11 @@ int arch_add_memory(int nid, u64 start, u64 size,
>> if (ret)
>> __remove_pgd_mapping(swapper_pg_dir,
>> __phys_to_virt(start), size);
>> + else {
>> + max_pfn = PFN_UP(start + size);
>> + max_low_pfn = max_pfn;
>> + }
>
> Do these variables get updated on *all* platforms that support memory
> hotplug via an arch_add_memory() ? If not, dont they all face similar
> issues as well ? Why not just update these in generic hotplug instead
> , after looking into arch_add_memory() return code.
s390x sets them to the possible maximum (based on the direct mapping
size) in init code.
Other archs like x86-64 have to update other parameters. So I guess it
just made sense to let the archs handle updating these 2 variables.
--
Thanks,
David / dhildenb
^ permalink raw reply [flat|nested] 14+ messages in thread* Re: [PATCH] arm64: mm: update max_pfn after memory hotplug
@ 2021-10-01 8:39 ` David Hildenbrand
0 siblings, 0 replies; 14+ messages in thread
From: David Hildenbrand @ 2021-10-01 8:39 UTC (permalink / raw)
To: Anshuman Khandual, Chris Goldsworthy, Andrew Morton
Cc: Catalin Marinas, Will Deacon, Sudarshan Rajagopalan,
Georgi Djakov, linux-arm-kernel, linux-kernel, linux-mm,
Florian Fainelli
On 01.10.21 08:38, Anshuman Khandual wrote:
>
>
> On 9/29/21 12:21 AM, Chris Goldsworthy wrote:
>> From: Sudarshan Rajagopalan <quic_sudaraja@quicinc.com>
>>
>> After new memory blocks have been hotplugged, max_pfn and max_low_pfn
>> needs updating to reflect on new PFNs being hot added to system.
>> Without this patch, debug-related functions that use max_pfn such as
>> get_max_dump_pfn() or read_page_owner() will not work with any page in
>> memory that is hot-added after boot.
>>
>> Fixes: 4ab215061554 ("arm64: Add memory hotplug support")
>> Signed-off-by: Sudarshan Rajagopalan <quic_sudaraja@quicinc.com>
>> Signed-off-by: Chris Goldsworthy <quic_cgoldswo@quicinc.com>
>> Acked-by: David Hildenbrand <david@redhat.com>
>> Cc: Florian Fainelli <f.fainelli@gmail.com>
>> Cc: Georgi Djakov <quic_c_gdjako@quicinc.com>
>> ---
>> arch/arm64/mm/mmu.c | 5 +++++
>> 1 file changed, 5 insertions(+)
>>
>> diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
>> index cfd9deb..fd85b51 100644
>> --- a/arch/arm64/mm/mmu.c
>> +++ b/arch/arm64/mm/mmu.c
>> @@ -1499,6 +1499,11 @@ int arch_add_memory(int nid, u64 start, u64 size,
>> if (ret)
>> __remove_pgd_mapping(swapper_pg_dir,
>> __phys_to_virt(start), size);
>> + else {
>> + max_pfn = PFN_UP(start + size);
>> + max_low_pfn = max_pfn;
>> + }
>
> Do these variables get updated on *all* platforms that support memory
> hotplug via an arch_add_memory() ? If not, dont they all face similar
> issues as well ? Why not just update these in generic hotplug instead
> , after looking into arch_add_memory() return code.
s390x sets them to the possible maximum (based on the direct mapping
size) in init code.
Other archs like x86-64 have to update other parameters. So I guess it
just made sense to let the archs handle updating these 2 variables.
--
Thanks,
David / dhildenb
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: [PATCH] arm64: mm: update max_pfn after memory hotplug
2021-09-28 18:51 ` Chris Goldsworthy
@ 2021-10-01 8:52 ` Anshuman Khandual
-1 siblings, 0 replies; 14+ messages in thread
From: Anshuman Khandual @ 2021-10-01 8:52 UTC (permalink / raw)
To: Chris Goldsworthy, Andrew Morton
Cc: David Hildenbrand, Catalin Marinas, Will Deacon,
Sudarshan Rajagopalan, Georgi Djakov, linux-arm-kernel,
linux-kernel, linux-mm, Florian Fainelli
On 9/29/21 12:21 AM, Chris Goldsworthy wrote:
> From: Sudarshan Rajagopalan <quic_sudaraja@quicinc.com>
>
> After new memory blocks have been hotplugged, max_pfn and max_low_pfn
> needs updating to reflect on new PFNs being hot added to system.
> Without this patch, debug-related functions that use max_pfn such as
> get_max_dump_pfn() or read_page_owner() will not work with any page in
> memory that is hot-added after boot.
>
> Fixes: 4ab215061554 ("arm64: Add memory hotplug support")
> Signed-off-by: Sudarshan Rajagopalan <quic_sudaraja@quicinc.com>
> Signed-off-by: Chris Goldsworthy <quic_cgoldswo@quicinc.com>
> Acked-by: David Hildenbrand <david@redhat.com>
> Cc: Florian Fainelli <f.fainelli@gmail.com>
> Cc: Georgi Djakov <quic_c_gdjako@quicinc.com>
As these variables need to be updated in the platform.
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
> ---
> arch/arm64/mm/mmu.c | 5 +++++
> 1 file changed, 5 insertions(+)
>
> diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
> index cfd9deb..fd85b51 100644
> --- a/arch/arm64/mm/mmu.c
> +++ b/arch/arm64/mm/mmu.c
> @@ -1499,6 +1499,11 @@ int arch_add_memory(int nid, u64 start, u64 size,
> if (ret)
> __remove_pgd_mapping(swapper_pg_dir,
> __phys_to_virt(start), size);
> + else {
> + max_pfn = PFN_UP(start + size);
> + max_low_pfn = max_pfn;
> + }
> +
> return ret;
> }
>
>
^ permalink raw reply [flat|nested] 14+ messages in thread* Re: [PATCH] arm64: mm: update max_pfn after memory hotplug
@ 2021-10-01 8:52 ` Anshuman Khandual
0 siblings, 0 replies; 14+ messages in thread
From: Anshuman Khandual @ 2021-10-01 8:52 UTC (permalink / raw)
To: Chris Goldsworthy, Andrew Morton
Cc: David Hildenbrand, Catalin Marinas, Will Deacon,
Sudarshan Rajagopalan, Georgi Djakov, linux-arm-kernel,
linux-kernel, linux-mm, Florian Fainelli
On 9/29/21 12:21 AM, Chris Goldsworthy wrote:
> From: Sudarshan Rajagopalan <quic_sudaraja@quicinc.com>
>
> After new memory blocks have been hotplugged, max_pfn and max_low_pfn
> needs updating to reflect on new PFNs being hot added to system.
> Without this patch, debug-related functions that use max_pfn such as
> get_max_dump_pfn() or read_page_owner() will not work with any page in
> memory that is hot-added after boot.
>
> Fixes: 4ab215061554 ("arm64: Add memory hotplug support")
> Signed-off-by: Sudarshan Rajagopalan <quic_sudaraja@quicinc.com>
> Signed-off-by: Chris Goldsworthy <quic_cgoldswo@quicinc.com>
> Acked-by: David Hildenbrand <david@redhat.com>
> Cc: Florian Fainelli <f.fainelli@gmail.com>
> Cc: Georgi Djakov <quic_c_gdjako@quicinc.com>
As these variables need to be updated in the platform.
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
> ---
> arch/arm64/mm/mmu.c | 5 +++++
> 1 file changed, 5 insertions(+)
>
> diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
> index cfd9deb..fd85b51 100644
> --- a/arch/arm64/mm/mmu.c
> +++ b/arch/arm64/mm/mmu.c
> @@ -1499,6 +1499,11 @@ int arch_add_memory(int nid, u64 start, u64 size,
> if (ret)
> __remove_pgd_mapping(swapper_pg_dir,
> __phys_to_virt(start), size);
> + else {
> + max_pfn = PFN_UP(start + size);
> + max_low_pfn = max_pfn;
> + }
> +
> return ret;
> }
>
>
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 14+ messages in thread