| Message ID | a51a27ee7be66024b5ce626310d673f24107bcb8.1632853776.git.quic_cgoldswo@quicinc.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | arm64: mm: update max_pfn after memory hotplug | expand |
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; > } > >
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; > } > >
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.
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; > } > >
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; }