Re: [Xen-devel] [PATCH v1 1/6] mm/memory_hotplug: make remove_memory() take the device_hotplug_lock
On Tue, Sep 18, 2018 at 1:48 PM David Hildenbrand wrote:
>
> remove_memory() is exported right now but requires the
> device_hotplug_lock, which is not exported. So let's provide a variant
> that takes the lock and only export that one.
>
> The lock is already held in
> arch/powerpc/platforms/pseries/hotplug-memory.c
> drivers/acpi/acpi_memhotplug.c
> So, let's use the locked variant.
>
> The lock is not held (but taken in)
> arch/powerpc/platforms/powernv/memtrace.c
> So let's keep using the (now) locked variant.
>
> Apart from that, there are not other users in the tree.
>
> Cc: Benjamin Herrenschmidt
> Cc: Paul Mackerras
> Cc: Michael Ellerman
> Cc: "Rafael J. Wysocki"
> Cc: Len Brown
> Cc: Rashmica Gupta
> Cc: Michael Neuling
> Cc: Balbir Singh
> Cc: Nathan Fontenot
> Cc: John Allen
> Cc: Andrew Morton
> Cc: Michal Hocko
> Cc: Dan Williams
> Cc: Joonsoo Kim
> Cc: Vlastimil Babka
> Cc: Pavel Tatashin
> Cc: Greg Kroah-Hartman
> Cc: Oscar Salvador
> Cc: YASUAKI ISHIMATSU
> Cc: Mathieu Malaterre
> Reviewed-by: Pavel Tatashin
> Signed-off-by: David Hildenbrand
> ---
> arch/powerpc/platforms/powernv/memtrace.c | 2 --
> arch/powerpc/platforms/pseries/hotplug-memory.c | 6 +++---
> drivers/acpi/acpi_memhotplug.c | 2 +-
> include/linux/memory_hotplug.h | 3 ++-
> mm/memory_hotplug.c | 9 -
> 5 files changed, 14 insertions(+), 8 deletions(-)
>
> diff --git a/arch/powerpc/platforms/powernv/memtrace.c
> b/arch/powerpc/platforms/powernv/memtrace.c
> index 51dc398ae3f7..8f1cd4f3bfd5 100644
> --- a/arch/powerpc/platforms/powernv/memtrace.c
> +++ b/arch/powerpc/platforms/powernv/memtrace.c
> @@ -90,9 +90,7 @@ static bool memtrace_offline_pages(u32 nid, u64 start_pfn,
> u64 nr_pages)
> walk_memory_range(start_pfn, end_pfn, (void *)MEM_OFFLINE,
> change_memblock_state);
>
> - lock_device_hotplug();
> remove_memory(nid, start_pfn << PAGE_SHIFT, nr_pages << PAGE_SHIFT);
> - unlock_device_hotplug();
>
> return true;
> }
> diff --git a/arch/powerpc/platforms/pseries/hotplug-memory.c
> b/arch/powerpc/platforms/pseries/hotplug-memory.c
> index c1578f54c626..b3f54466e25f 100644
> --- a/arch/powerpc/platforms/pseries/hotplug-memory.c
> +++ b/arch/powerpc/platforms/pseries/hotplug-memory.c
> @@ -334,7 +334,7 @@ static int pseries_remove_memblock(unsigned long base,
> unsigned int memblock_siz
> nid = memory_add_physaddr_to_nid(base);
>
> for (i = 0; i < sections_per_block; i++) {
> - remove_memory(nid, base, MIN_MEMORY_BLOCK_SIZE);
> + __remove_memory(nid, base, MIN_MEMORY_BLOCK_SIZE);
> base += MIN_MEMORY_BLOCK_SIZE;
> }
>
> @@ -423,7 +423,7 @@ static int dlpar_remove_lmb(struct drmem_lmb *lmb)
> block_sz = pseries_memory_block_size();
> nid = memory_add_physaddr_to_nid(lmb->base_addr);
>
> - remove_memory(nid, lmb->base_addr, block_sz);
> + __remove_memory(nid, lmb->base_addr, block_sz);
>
> /* Update memory regions for memory remove */
> memblock_remove(lmb->base_addr, block_sz);
> @@ -710,7 +710,7 @@ static int dlpar_add_lmb(struct drmem_lmb *lmb)
>
> rc = dlpar_online_lmb(lmb);
> if (rc) {
> - remove_memory(nid, lmb->base_addr, block_sz);
> + __remove_memory(nid, lmb->base_addr, block_sz);
> dlpar_remove_device_tree_lmb(lmb);
> } else {
> lmb->flags |= DRCONF_MEM_ASSIGNED;
> diff --git a/drivers/acpi/acpi_memhotplug.c b/drivers/acpi/acpi_memhotplug.c
> index 6b0d3ef7309c..811148415993 100644
> --- a/drivers/acpi/acpi_memhotplug.c
> +++ b/drivers/acpi/acpi_memhotplug.c
> @@ -282,7 +282,7 @@ static void acpi_memory_remove_memory(struct
> acpi_memory_device *mem_device)
> nid = memory_add_physaddr_to_nid(info->start_addr);
>
> acpi_unbind_memory_blocks(info);
> - remove_memory(nid, info->start_addr, info->length);
> + __remove_memory(nid, info->start_addr, info->length);
> list_del(>list);
> kfree(info);
> }
> diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h
> index 34a28227068d..1f096852f479 100644
> --- a/include/linux/memory_hotplug.h
> +++ b/include/linux/memory_hotplug.h
> @@ -301,6 +301,7 @@ extern bool is_mem_section_removable(unsigned long pfn,
> unsigned long nr_pages);
> extern void try_offline_node(int nid);
> extern int offline_pages(unsigned long start_pfn, unsigned long nr_pages);
> extern void remove_memory(int nid, u64 start, u64 size);
> +extern void __remove_memory(int nid, u64 start, u64 size);
>
> #else
> static inline bool is_mem_section_removable(unsigned long pfn,
> @@ -317,6 +318,7 @@ static inline int offline_pages(unsigned long start_pfn,
> unsigned long nr_pages)
> }
>
>
[Xen-devel] [PATCH v1 1/6] mm/memory_hotplug: make remove_memory() take the device_hotplug_lock
remove_memory() is exported right now but requires the
device_hotplug_lock, which is not exported. So let's provide a variant
that takes the lock and only export that one.
The lock is already held in
arch/powerpc/platforms/pseries/hotplug-memory.c
drivers/acpi/acpi_memhotplug.c
So, let's use the locked variant.
The lock is not held (but taken in)
arch/powerpc/platforms/powernv/memtrace.c
So let's keep using the (now) locked variant.
Apart from that, there are not other users in the tree.
Cc: Benjamin Herrenschmidt
Cc: Paul Mackerras
Cc: Michael Ellerman
Cc: "Rafael J. Wysocki"
Cc: Len Brown
Cc: Rashmica Gupta
Cc: Michael Neuling
Cc: Balbir Singh
Cc: Nathan Fontenot
Cc: John Allen
Cc: Andrew Morton
Cc: Michal Hocko
Cc: Dan Williams
Cc: Joonsoo Kim
Cc: Vlastimil Babka
Cc: Pavel Tatashin
Cc: Greg Kroah-Hartman
Cc: Oscar Salvador
Cc: YASUAKI ISHIMATSU
Cc: Mathieu Malaterre
Reviewed-by: Pavel Tatashin
Signed-off-by: David Hildenbrand
---
arch/powerpc/platforms/powernv/memtrace.c | 2 --
arch/powerpc/platforms/pseries/hotplug-memory.c | 6 +++---
drivers/acpi/acpi_memhotplug.c | 2 +-
include/linux/memory_hotplug.h | 3 ++-
mm/memory_hotplug.c | 9 -
5 files changed, 14 insertions(+), 8 deletions(-)
diff --git a/arch/powerpc/platforms/powernv/memtrace.c
b/arch/powerpc/platforms/powernv/memtrace.c
index 51dc398ae3f7..8f1cd4f3bfd5 100644
--- a/arch/powerpc/platforms/powernv/memtrace.c
+++ b/arch/powerpc/platforms/powernv/memtrace.c
@@ -90,9 +90,7 @@ static bool memtrace_offline_pages(u32 nid, u64 start_pfn,
u64 nr_pages)
walk_memory_range(start_pfn, end_pfn, (void *)MEM_OFFLINE,
change_memblock_state);
- lock_device_hotplug();
remove_memory(nid, start_pfn << PAGE_SHIFT, nr_pages << PAGE_SHIFT);
- unlock_device_hotplug();
return true;
}
diff --git a/arch/powerpc/platforms/pseries/hotplug-memory.c
b/arch/powerpc/platforms/pseries/hotplug-memory.c
index c1578f54c626..b3f54466e25f 100644
--- a/arch/powerpc/platforms/pseries/hotplug-memory.c
+++ b/arch/powerpc/platforms/pseries/hotplug-memory.c
@@ -334,7 +334,7 @@ static int pseries_remove_memblock(unsigned long base,
unsigned int memblock_siz
nid = memory_add_physaddr_to_nid(base);
for (i = 0; i < sections_per_block; i++) {
- remove_memory(nid, base, MIN_MEMORY_BLOCK_SIZE);
+ __remove_memory(nid, base, MIN_MEMORY_BLOCK_SIZE);
base += MIN_MEMORY_BLOCK_SIZE;
}
@@ -423,7 +423,7 @@ static int dlpar_remove_lmb(struct drmem_lmb *lmb)
block_sz = pseries_memory_block_size();
nid = memory_add_physaddr_to_nid(lmb->base_addr);
- remove_memory(nid, lmb->base_addr, block_sz);
+ __remove_memory(nid, lmb->base_addr, block_sz);
/* Update memory regions for memory remove */
memblock_remove(lmb->base_addr, block_sz);
@@ -710,7 +710,7 @@ static int dlpar_add_lmb(struct drmem_lmb *lmb)
rc = dlpar_online_lmb(lmb);
if (rc) {
- remove_memory(nid, lmb->base_addr, block_sz);
+ __remove_memory(nid, lmb->base_addr, block_sz);
dlpar_remove_device_tree_lmb(lmb);
} else {
lmb->flags |= DRCONF_MEM_ASSIGNED;
diff --git a/drivers/acpi/acpi_memhotplug.c b/drivers/acpi/acpi_memhotplug.c
index 6b0d3ef7309c..811148415993 100644
--- a/drivers/acpi/acpi_memhotplug.c
+++ b/drivers/acpi/acpi_memhotplug.c
@@ -282,7 +282,7 @@ static void acpi_memory_remove_memory(struct
acpi_memory_device *mem_device)
nid = memory_add_physaddr_to_nid(info->start_addr);
acpi_unbind_memory_blocks(info);
- remove_memory(nid, info->start_addr, info->length);
+ __remove_memory(nid, info->start_addr, info->length);
list_del(>list);
kfree(info);
}
diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h
index 34a28227068d..1f096852f479 100644
--- a/include/linux/memory_hotplug.h
+++ b/include/linux/memory_hotplug.h
@@ -301,6 +301,7 @@ extern bool is_mem_section_removable(unsigned long pfn,
unsigned long nr_pages);
extern void try_offline_node(int nid);
extern int offline_pages(unsigned long start_pfn, unsigned long nr_pages);
extern void remove_memory(int nid, u64 start, u64 size);
+extern void __remove_memory(int nid, u64 start, u64 size);
#else
static inline bool is_mem_section_removable(unsigned long pfn,
@@ -317,6 +318,7 @@ static inline int offline_pages(unsigned long start_pfn,
unsigned long nr_pages)
}
static inline void remove_memory(int nid, u64 start, u64 size) {}
+static inline void __remove_memory(int nid, u64 start, u64 size) {}
#endif /* CONFIG_MEMORY_HOTREMOVE */
extern void __ref free_area_init_core_hotplug(int nid);
@@ -330,7 +332,6 @@ extern void
