* [PATCH v10 0/3] mm: use memmap_on_memory semantics for dax/kmem
@ 2023-11-07 7:22 Vishal Verma
2023-11-07 7:22 ` [PATCH v10 1/3] mm/memory_hotplug: replace an open-coded kmemdup() in add_memory_resource() Vishal Verma
` (2 more replies)
0 siblings, 3 replies; 5+ messages in thread
From: Vishal Verma @ 2023-11-07 7:22 UTC (permalink / raw
To: Andrew Morton, David Hildenbrand, Oscar Salvador, Dan Williams,
Dave Jiang
Cc: linux-kernel, linux-mm, nvdimm, linux-cxl, Huang Ying,
Dave Hansen, Aneesh Kumar K.V, Michal Hocko, Jonathan Cameron,
Jeff Moyer, Vishal Verma, Fan Ni, Jonathan Cameron
The dax/kmem driver can potentially hot-add large amounts of memory
originating from CXL memory expanders, or NVDIMMs, or other 'device
memories'. There is a chance there isn't enough regular system memory
available to fit the memmap for this new memory. It's therefore
desirable, if all other conditions are met, for the kmem managed memory
to place its memmap on the newly added memory itself.
The main hurdle for accomplishing this for kmem is that memmap_on_memory
can only be done if the memory being added is equal to the size of one
memblock. To overcome this, allow the hotplug code to split an add_memory()
request into memblock-sized chunks, and try_remove_memory() to also
expect and handle such a scenario.
Patch 1 replaces an open-coded kmemdup()
Patch 2 teaches the memory_hotplug code to allow for splitting
add_memory() and remove_memory() requests over memblock sized chunks.
Patch 3 allows the dax region drivers to request memmap_on_memory
semantics. CXL dax regions default this to 'on', all others default to
off to keep existing behavior unchanged.
Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
---
Changes in v10:
- Rebase on current mainline (Andrew Morton)
- Pick up Reviewed-by (Fan Ni)
- Link to v9: https://lore.kernel.org/r/20231102-vv-kmem_memmap-v9-0-973d6b3a8f1a@intel.com
Changes in v9:
- Fix error unwinding for the ENOMEM case in
remove_memory_blocks_and_altmaps() (Ying, David)
- Misc readability and style cleanups (David)
- Link to v8: https://lore.kernel.org/r/20231101-vv-kmem_memmap-v8-0-5e4a83331388@intel.com
Changes in v8:
- Fix unwinding in create_altmaps_and_memory_blocks() to remove
partially added blocks and altmaps. (David, Ying)
- Simplify remove_memory_blocks_and_altmaps() since an altmap is
assured. (David)
- Since we remove per memory-block altmaps, the walk through memory
blocks for a larger range isn't needed. Instead we can lookup the
memory block directly from the pfn, allowing the test_has_altmap_cb()
callback to be dropped and removed. (David)
- Link to v7: https://lore.kernel.org/r/20231025-vv-kmem_memmap-v7-0-4a76d7652df5@intel.com
Changes in v7:
- Make the add_memory_resource() flow symmetrical w.r.t. try_remove_memory()
in terms of how the altmap path is taken (David Hildenbrand)
- Move a comment, clean up usage of 'memblock' vs. 'memory_block'
(David Hildenbrand)
- Don't use the altmap path for the mhp_supports_memmap_on_memory(memblock_size) == false
case (Huang Ying)
- Link to v6: https://lore.kernel.org/r/20231016-vv-kmem_memmap-v6-0-078f0d3c0371@intel.com
Changes in v6:
- Add a prep patch to replace an open coded kmemdup in
add_memory_resource() (Dan Williams)
- Fix ordering of firmware_map_remove w.r.t taking the hotplug lock
(David Hildenbrand)
- Remove unused 'nid' variable, and a stray whitespace (David Hildenbrand)
- Clean up and simplify the altmap vs non-altmap paths for
try_remove_memory (David Hildenbrand)
- Add a note to the changelog in patch 1 linking to the PUD mappings
proposal (David Hildenbrand)
- Remove the new sysfs ABI from the kmem/dax drivers until ABI
documentation for /sys/bus/dax can be established (will split this out
into a separate patchset) (Dan Williams)
- Link to v5: https://lore.kernel.org/r/20231005-vv-kmem_memmap-v5-0-a54d1981f0a3@intel.com
Changes in v5:
- Separate out per-memblock operations from per memory block operations
in try_remove_memory(), and rename the inner function appropriately.
This does expand the scope of the memory hotplug lock to include
remove_memory_block_devices(), but the alternative was to drop the
lock in the inner function separately for each iteration, and then
re-acquire it in try_remove_memory() creating a small window where
the lock isn't held. (David Hildenbrand)
- Remove unnecessary rc check from the memmap_on_memory_store sysfs
helper in patch 2 (Dan Carpenter)
- Link to v4: https://lore.kernel.org/r/20230928-vv-kmem_memmap-v4-0-6ff73fec519a@intel.com
Changes in v4:
- Rebase to Aneesh's PPC64 memmap_on_memory series v8 [2].
- Tweak a goto / error path in add_memory_create_devices() (Jonathan)
- Retain the old behavior for dax devices, only default to
memmap_on_memory for CXL (Jonathan)
- Link to v3: https://lore.kernel.org/r/20230801-vv-kmem_memmap-v3-0-406e9aaf5689@intel.com
[2]: https://lore.kernel.org/linux-mm/20230808091501.287660-1-aneesh.kumar@linux.ibm.com
Changes in v3:
- Rebase on Aneesh's patches [1]
- Drop Patch 1 - it is not needed since [1] allows for dynamic setting
of the memmap_on_memory param (David)
- Link to v2: https://lore.kernel.org/r/20230720-vv-kmem_memmap-v2-0-88bdaab34993@intel.com
[1]: https://lore.kernel.org/r/20230801044116.10674-1-aneesh.kumar@linux.ibm.com
Changes in v2:
- Drop the patch to create an override path for the memmap_on_memory
module param (David)
- Move the chunking into memory_hotplug.c so that any caller of
add_memory() can request this behavior. (David)
- Handle remove_memory() too. (David, Ying)
- Add a sysfs control in the kmem driver for memmap_on_memory semantics
(David, Jonathan)
- Add a #else case to define mhp_supports_memmap_on_memory() if
CONFIG_MEMORY_HOTPLUG is unset. (0day report)
- Link to v1: https://lore.kernel.org/r/20230613-vv-kmem_memmap-v1-0-f6de9c6af2c6@intel.com
---
Vishal Verma (3):
mm/memory_hotplug: replace an open-coded kmemdup() in add_memory_resource()
mm/memory_hotplug: split memmap_on_memory requests across memblocks
dax/kmem: allow kmem to add memory with memmap_on_memory
drivers/dax/bus.h | 1 +
drivers/dax/dax-private.h | 1 +
drivers/dax/bus.c | 3 +
drivers/dax/cxl.c | 1 +
drivers/dax/hmem/hmem.c | 1 +
drivers/dax/kmem.c | 8 +-
drivers/dax/pmem.c | 1 +
mm/memory_hotplug.c | 210 +++++++++++++++++++++++++++++-----------------
8 files changed, 150 insertions(+), 76 deletions(-)
---
base-commit: d2f51b3516dade79269ff45eae2a7668ae711b25
change-id: 20230613-vv-kmem_memmap-5483c8d04279
Best regards,
--
Vishal Verma <vishal.l.verma@intel.com>
^ permalink raw reply [flat|nested] 5+ messages in thread
* [PATCH v10 1/3] mm/memory_hotplug: replace an open-coded kmemdup() in add_memory_resource()
2023-11-07 7:22 [PATCH v10 0/3] mm: use memmap_on_memory semantics for dax/kmem Vishal Verma
@ 2023-11-07 7:22 ` Vishal Verma
2023-11-07 7:22 ` [PATCH v10 2/3] mm/memory_hotplug: split memmap_on_memory requests across memblocks Vishal Verma
2023-11-07 7:22 ` [PATCH v10 3/3] dax/kmem: allow kmem to add memory with memmap_on_memory Vishal Verma
2 siblings, 0 replies; 5+ messages in thread
From: Vishal Verma @ 2023-11-07 7:22 UTC (permalink / raw
To: Andrew Morton, David Hildenbrand, Oscar Salvador, Dan Williams,
Dave Jiang
Cc: linux-kernel, linux-mm, nvdimm, linux-cxl, Huang Ying,
Dave Hansen, Aneesh Kumar K.V, Michal Hocko, Jonathan Cameron,
Jeff Moyer, Vishal Verma, Fan Ni
A review of the memmap_on_memory modifications to add_memory_resource()
revealed an instance of an open-coded kmemdup(). Replace it with
kmemdup().
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Reported-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Fan Ni <fan.ni@samsung.com>
Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
---
mm/memory_hotplug.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index ab41a511e20a..3ed48059a780 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -1439,13 +1439,13 @@ int __ref add_memory_resource(int nid, struct resource *res, mhp_t mhp_flags)
if (mhp_flags & MHP_MEMMAP_ON_MEMORY) {
if (mhp_supports_memmap_on_memory(size)) {
mhp_altmap.free = memory_block_memmap_on_memory_pages();
- params.altmap = kmalloc(sizeof(struct vmem_altmap), GFP_KERNEL);
+ params.altmap = kmemdup(&mhp_altmap,
+ sizeof(struct vmem_altmap),
+ GFP_KERNEL);
if (!params.altmap) {
ret = -ENOMEM;
goto error;
}
-
- memcpy(params.altmap, &mhp_altmap, sizeof(mhp_altmap));
}
/* fallback to not using altmap */
}
--
2.41.0
^ permalink raw reply related [flat|nested] 5+ messages in thread
* [PATCH v10 2/3] mm/memory_hotplug: split memmap_on_memory requests across memblocks
2023-11-07 7:22 [PATCH v10 0/3] mm: use memmap_on_memory semantics for dax/kmem Vishal Verma
2023-11-07 7:22 ` [PATCH v10 1/3] mm/memory_hotplug: replace an open-coded kmemdup() in add_memory_resource() Vishal Verma
@ 2023-11-07 7:22 ` Vishal Verma
2023-11-07 7:22 ` [PATCH v10 3/3] dax/kmem: allow kmem to add memory with memmap_on_memory Vishal Verma
2 siblings, 0 replies; 5+ messages in thread
From: Vishal Verma @ 2023-11-07 7:22 UTC (permalink / raw
To: Andrew Morton, David Hildenbrand, Oscar Salvador, Dan Williams,
Dave Jiang
Cc: linux-kernel, linux-mm, nvdimm, linux-cxl, Huang Ying,
Dave Hansen, Aneesh Kumar K.V, Michal Hocko, Jonathan Cameron,
Jeff Moyer, Vishal Verma
The MHP_MEMMAP_ON_MEMORY flag for hotplugged memory is restricted to
'memblock_size' chunks of memory being added. Adding a larger span of
memory precludes memmap_on_memory semantics.
For users of hotplug such as kmem, large amounts of memory might get
added from the CXL subsystem. In some cases, this amount may exceed the
available 'main memory' to store the memmap for the memory being added.
In this case, it is useful to have a way to place the memmap on the
memory being added, even if it means splitting the addition into
memblock-sized chunks.
Change add_memory_resource() to loop over memblock-sized chunks of
memory if caller requested memmap_on_memory, and if other conditions for
it are met. Teach try_remove_memory() to also expect that a memory
range being removed might have been split up into memblock sized chunks,
and to loop through those as needed.
This does preclude being able to use PUD mappings in the direct map; a
proposal to how this could be optimized in the future is laid out
here[1].
[1]: https://lore.kernel.org/linux-mm/b6753402-2de9-25b2-36e9-eacd49752b19@redhat.com/
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Huang Ying <ying.huang@intel.com>
Suggested-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: "Huang, Ying" <ying.huang@intel.com>
Acked-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
---
mm/memory_hotplug.c | 212 +++++++++++++++++++++++++++++++++-------------------
1 file changed, 136 insertions(+), 76 deletions(-)
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 3ed48059a780..51d4895850ba 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -1380,6 +1380,85 @@ static bool mhp_supports_memmap_on_memory(unsigned long size)
return arch_supports_memmap_on_memory(vmemmap_size);
}
+static void __ref remove_memory_blocks_and_altmaps(u64 start, u64 size)
+{
+ unsigned long memblock_size = memory_block_size_bytes();
+ u64 cur_start;
+
+ /*
+ * For memmap_on_memory, the altmaps were added on a per-memblock
+ * basis; we have to process each individual memory block.
+ */
+ for (cur_start = start; cur_start < start + size;
+ cur_start += memblock_size) {
+ struct vmem_altmap *altmap = NULL;
+ struct memory_block *mem;
+
+ mem = find_memory_block(pfn_to_section_nr(PFN_DOWN(cur_start)));
+ if (WARN_ON_ONCE(!mem))
+ continue;
+
+ altmap = mem->altmap;
+ mem->altmap = NULL;
+
+ remove_memory_block_devices(cur_start, memblock_size);
+
+ arch_remove_memory(cur_start, memblock_size, altmap);
+
+ /* Verify that all vmemmap pages have actually been freed. */
+ WARN(altmap->alloc, "Altmap not fully unmapped");
+ kfree(altmap);
+ }
+}
+
+static int create_altmaps_and_memory_blocks(int nid, struct memory_group *group,
+ u64 start, u64 size)
+{
+ unsigned long memblock_size = memory_block_size_bytes();
+ u64 cur_start;
+ int ret;
+
+ for (cur_start = start; cur_start < start + size;
+ cur_start += memblock_size) {
+ struct mhp_params params = { .pgprot =
+ pgprot_mhp(PAGE_KERNEL) };
+ struct vmem_altmap mhp_altmap = {
+ .base_pfn = PHYS_PFN(cur_start),
+ .end_pfn = PHYS_PFN(cur_start + memblock_size - 1),
+ };
+
+ mhp_altmap.free = memory_block_memmap_on_memory_pages();
+ params.altmap = kmemdup(&mhp_altmap, sizeof(struct vmem_altmap),
+ GFP_KERNEL);
+ if (!params.altmap) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ /* call arch's memory hotadd */
+ ret = arch_add_memory(nid, cur_start, memblock_size, ¶ms);
+ if (ret < 0) {
+ kfree(params.altmap);
+ goto out;
+ }
+
+ /* create memory block devices after memory was added */
+ ret = create_memory_block_devices(cur_start, memblock_size,
+ params.altmap, group);
+ if (ret) {
+ arch_remove_memory(cur_start, memblock_size, NULL);
+ kfree(params.altmap);
+ goto out;
+ }
+ }
+
+ return 0;
+out:
+ if (ret && cur_start != start)
+ remove_memory_blocks_and_altmaps(start, cur_start - start);
+ return ret;
+}
+
/*
* NOTE: The caller must call lock_device_hotplug() to serialize hotplug
* and online/offline operations (triggered e.g. by sysfs).
@@ -1390,10 +1469,6 @@ int __ref add_memory_resource(int nid, struct resource *res, mhp_t mhp_flags)
{
struct mhp_params params = { .pgprot = pgprot_mhp(PAGE_KERNEL) };
enum memblock_flags memblock_flags = MEMBLOCK_NONE;
- struct vmem_altmap mhp_altmap = {
- .base_pfn = PHYS_PFN(res->start),
- .end_pfn = PHYS_PFN(res->end),
- };
struct memory_group *group = NULL;
u64 start, size;
bool new_node = false;
@@ -1436,30 +1511,22 @@ int __ref add_memory_resource(int nid, struct resource *res, mhp_t mhp_flags)
/*
* Self hosted memmap array
*/
- if (mhp_flags & MHP_MEMMAP_ON_MEMORY) {
- if (mhp_supports_memmap_on_memory(size)) {
- mhp_altmap.free = memory_block_memmap_on_memory_pages();
- params.altmap = kmemdup(&mhp_altmap,
- sizeof(struct vmem_altmap),
- GFP_KERNEL);
- if (!params.altmap) {
- ret = -ENOMEM;
- goto error;
- }
+ if ((mhp_flags & MHP_MEMMAP_ON_MEMORY) &&
+ mhp_supports_memmap_on_memory(memory_block_size_bytes())) {
+ ret = create_altmaps_and_memory_blocks(nid, group, start, size);
+ if (ret)
+ goto error;
+ } else {
+ ret = arch_add_memory(nid, start, size, ¶ms);
+ if (ret < 0)
+ goto error;
+
+ /* create memory block devices after memory was added */
+ ret = create_memory_block_devices(start, size, NULL, group);
+ if (ret) {
+ arch_remove_memory(start, size, NULL);
+ goto error;
}
- /* fallback to not using altmap */
- }
-
- /* call arch's memory hotadd */
- ret = arch_add_memory(nid, start, size, ¶ms);
- if (ret < 0)
- goto error_free;
-
- /* create memory block devices after memory was added */
- ret = create_memory_block_devices(start, size, params.altmap, group);
- if (ret) {
- arch_remove_memory(start, size, NULL);
- goto error_free;
}
if (new_node) {
@@ -1496,8 +1563,6 @@ int __ref add_memory_resource(int nid, struct resource *res, mhp_t mhp_flags)
walk_memory_blocks(start, size, NULL, online_memory_block);
return ret;
-error_free:
- kfree(params.altmap);
error:
if (IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK))
memblock_remove(start, size);
@@ -2068,17 +2133,13 @@ static int check_memblock_offlined_cb(struct memory_block *mem, void *arg)
return 0;
}
-static int test_has_altmap_cb(struct memory_block *mem, void *arg)
+static int count_memory_range_altmaps_cb(struct memory_block *mem, void *arg)
{
- struct memory_block **mem_ptr = (struct memory_block **)arg;
- /*
- * return the memblock if we have altmap
- * and break callback.
- */
- if (mem->altmap) {
- *mem_ptr = mem;
- return 1;
- }
+ u64 *num_altmaps = (u64 *)arg;
+
+ if (mem->altmap)
+ *num_altmaps += 1;
+
return 0;
}
@@ -2152,11 +2213,29 @@ void try_offline_node(int nid)
}
EXPORT_SYMBOL(try_offline_node);
+static int memory_blocks_have_altmaps(u64 start, u64 size)
+{
+ u64 num_memblocks = size / memory_block_size_bytes();
+ u64 num_altmaps = 0;
+
+ if (!mhp_memmap_on_memory())
+ return 0;
+
+ walk_memory_blocks(start, size, &num_altmaps,
+ count_memory_range_altmaps_cb);
+
+ if (num_altmaps == 0)
+ return 0;
+
+ if (WARN_ON_ONCE(num_memblocks != num_altmaps))
+ return -EINVAL;
+
+ return 1;
+}
+
static int __ref try_remove_memory(u64 start, u64 size)
{
- struct memory_block *mem;
- int rc = 0, nid = NUMA_NO_NODE;
- struct vmem_altmap *altmap = NULL;
+ int rc, nid = NUMA_NO_NODE;
BUG_ON(check_hotplug_memory_range(start, size));
@@ -2173,45 +2252,26 @@ static int __ref try_remove_memory(u64 start, u64 size)
if (rc)
return rc;
- /*
- * We only support removing memory added with MHP_MEMMAP_ON_MEMORY in
- * the same granularity it was added - a single memory block.
- */
- if (mhp_memmap_on_memory()) {
- rc = walk_memory_blocks(start, size, &mem, test_has_altmap_cb);
- if (rc) {
- if (size != memory_block_size_bytes()) {
- pr_warn("Refuse to remove %#llx - %#llx,"
- "wrong granularity\n",
- start, start + size);
- return -EINVAL;
- }
- altmap = mem->altmap;
- /*
- * Mark altmap NULL so that we can add a debug
- * check on memblock free.
- */
- mem->altmap = NULL;
- }
- }
-
/* remove memmap entry */
firmware_map_remove(start, start + size, "System RAM");
- /*
- * Memory block device removal under the device_hotplug_lock is
- * a barrier against racing online attempts.
- */
- remove_memory_block_devices(start, size);
-
mem_hotplug_begin();
- arch_remove_memory(start, size, altmap);
-
- /* Verify that all vmemmap pages have actually been freed. */
- if (altmap) {
- WARN(altmap->alloc, "Altmap not fully unmapped");
- kfree(altmap);
+ rc = memory_blocks_have_altmaps(start, size);
+ if (rc < 0) {
+ mem_hotplug_done();
+ return rc;
+ } else if (!rc) {
+ /*
+ * Memory block device removal under the device_hotplug_lock is
+ * a barrier against racing online attempts.
+ * No altmaps present, do the removal directly
+ */
+ remove_memory_block_devices(start, size);
+ arch_remove_memory(start, size, NULL);
+ } else {
+ /* all memblocks in the range have altmaps */
+ remove_memory_blocks_and_altmaps(start, size);
}
if (IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK)) {
--
2.41.0
^ permalink raw reply related [flat|nested] 5+ messages in thread
* [PATCH v10 3/3] dax/kmem: allow kmem to add memory with memmap_on_memory
2023-11-07 7:22 [PATCH v10 0/3] mm: use memmap_on_memory semantics for dax/kmem Vishal Verma
2023-11-07 7:22 ` [PATCH v10 1/3] mm/memory_hotplug: replace an open-coded kmemdup() in add_memory_resource() Vishal Verma
2023-11-07 7:22 ` [PATCH v10 2/3] mm/memory_hotplug: split memmap_on_memory requests across memblocks Vishal Verma
@ 2023-11-07 7:22 ` Vishal Verma
2023-12-08 9:11 ` Zhijian Li (Fujitsu)
2 siblings, 1 reply; 5+ messages in thread
From: Vishal Verma @ 2023-11-07 7:22 UTC (permalink / raw
To: Andrew Morton, David Hildenbrand, Oscar Salvador, Dan Williams,
Dave Jiang
Cc: linux-kernel, linux-mm, nvdimm, linux-cxl, Huang Ying,
Dave Hansen, Aneesh Kumar K.V, Michal Hocko, Jonathan Cameron,
Jeff Moyer, Vishal Verma, Jonathan Cameron
Large amounts of memory managed by the kmem driver may come in via CXL,
and it is often desirable to have the memmap for this memory on the new
memory itself.
Enroll kmem-managed memory for memmap_on_memory semantics if the dax
region originates via CXL. For non-CXL dax regions, retain the existing
default behavior of hot adding without memmap_on_memory semantics.
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Huang Ying <ying.huang@intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: "Huang, Ying" <ying.huang@intel.com>
Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
---
drivers/dax/bus.h | 1 +
drivers/dax/dax-private.h | 1 +
drivers/dax/bus.c | 3 +++
drivers/dax/cxl.c | 1 +
drivers/dax/hmem/hmem.c | 1 +
drivers/dax/kmem.c | 8 +++++++-
drivers/dax/pmem.c | 1 +
7 files changed, 15 insertions(+), 1 deletion(-)
diff --git a/drivers/dax/bus.h b/drivers/dax/bus.h
index 1ccd23360124..cbbf64443098 100644
--- a/drivers/dax/bus.h
+++ b/drivers/dax/bus.h
@@ -23,6 +23,7 @@ struct dev_dax_data {
struct dev_pagemap *pgmap;
resource_size_t size;
int id;
+ bool memmap_on_memory;
};
struct dev_dax *devm_create_dev_dax(struct dev_dax_data *data);
diff --git a/drivers/dax/dax-private.h b/drivers/dax/dax-private.h
index 27cf2daaaa79..446617b73aea 100644
--- a/drivers/dax/dax-private.h
+++ b/drivers/dax/dax-private.h
@@ -70,6 +70,7 @@ struct dev_dax {
struct ida ida;
struct device dev;
struct dev_pagemap *pgmap;
+ bool memmap_on_memory;
int nr_range;
struct dev_dax_range {
unsigned long pgoff;
diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c
index 1659b787b65f..1ff1ab5fa105 100644
--- a/drivers/dax/bus.c
+++ b/drivers/dax/bus.c
@@ -367,6 +367,7 @@ static ssize_t create_store(struct device *dev, struct device_attribute *attr,
.dax_region = dax_region,
.size = 0,
.id = -1,
+ .memmap_on_memory = false,
};
struct dev_dax *dev_dax = devm_create_dev_dax(&data);
@@ -1400,6 +1401,8 @@ struct dev_dax *devm_create_dev_dax(struct dev_dax_data *data)
dev_dax->align = dax_region->align;
ida_init(&dev_dax->ida);
+ dev_dax->memmap_on_memory = data->memmap_on_memory;
+
inode = dax_inode(dax_dev);
dev->devt = inode->i_rdev;
dev->bus = &dax_bus_type;
diff --git a/drivers/dax/cxl.c b/drivers/dax/cxl.c
index 8bc9d04034d6..c696837ab23c 100644
--- a/drivers/dax/cxl.c
+++ b/drivers/dax/cxl.c
@@ -26,6 +26,7 @@ static int cxl_dax_region_probe(struct device *dev)
.dax_region = dax_region,
.id = -1,
.size = range_len(&cxlr_dax->hpa_range),
+ .memmap_on_memory = true,
};
return PTR_ERR_OR_ZERO(devm_create_dev_dax(&data));
diff --git a/drivers/dax/hmem/hmem.c b/drivers/dax/hmem/hmem.c
index 5d2ddef0f8f5..b9da69f92697 100644
--- a/drivers/dax/hmem/hmem.c
+++ b/drivers/dax/hmem/hmem.c
@@ -36,6 +36,7 @@ static int dax_hmem_probe(struct platform_device *pdev)
.dax_region = dax_region,
.id = -1,
.size = region_idle ? 0 : range_len(&mri->range),
+ .memmap_on_memory = false,
};
return PTR_ERR_OR_ZERO(devm_create_dev_dax(&data));
diff --git a/drivers/dax/kmem.c b/drivers/dax/kmem.c
index 369c698b7706..42ee360cf4e3 100644
--- a/drivers/dax/kmem.c
+++ b/drivers/dax/kmem.c
@@ -12,6 +12,7 @@
#include <linux/mm.h>
#include <linux/mman.h>
#include <linux/memory-tiers.h>
+#include <linux/memory_hotplug.h>
#include "dax-private.h"
#include "bus.h"
@@ -93,6 +94,7 @@ static int dev_dax_kmem_probe(struct dev_dax *dev_dax)
struct dax_kmem_data *data;
struct memory_dev_type *mtype;
int i, rc, mapped = 0;
+ mhp_t mhp_flags;
int numa_node;
int adist = MEMTIER_DEFAULT_DAX_ADISTANCE;
@@ -179,12 +181,16 @@ static int dev_dax_kmem_probe(struct dev_dax *dev_dax)
*/
res->flags = IORESOURCE_SYSTEM_RAM;
+ mhp_flags = MHP_NID_IS_MGID;
+ if (dev_dax->memmap_on_memory)
+ mhp_flags |= MHP_MEMMAP_ON_MEMORY;
+
/*
* Ensure that future kexec'd kernels will not treat
* this as RAM automatically.
*/
rc = add_memory_driver_managed(data->mgid, range.start,
- range_len(&range), kmem_name, MHP_NID_IS_MGID);
+ range_len(&range), kmem_name, mhp_flags);
if (rc) {
dev_warn(dev, "mapping%d: %#llx-%#llx memory add failed\n",
diff --git a/drivers/dax/pmem.c b/drivers/dax/pmem.c
index ae0cb113a5d3..f3c6c67b8412 100644
--- a/drivers/dax/pmem.c
+++ b/drivers/dax/pmem.c
@@ -63,6 +63,7 @@ static struct dev_dax *__dax_pmem_probe(struct device *dev)
.id = id,
.pgmap = &pgmap,
.size = range_len(&range),
+ .memmap_on_memory = false,
};
return devm_create_dev_dax(&data);
--
2.41.0
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH v10 3/3] dax/kmem: allow kmem to add memory with memmap_on_memory
2023-11-07 7:22 ` [PATCH v10 3/3] dax/kmem: allow kmem to add memory with memmap_on_memory Vishal Verma
@ 2023-12-08 9:11 ` Zhijian Li (Fujitsu)
0 siblings, 0 replies; 5+ messages in thread
From: Zhijian Li (Fujitsu) @ 2023-12-08 9:11 UTC (permalink / raw
To: Vishal Verma, Andrew Morton, David Hildenbrand, Oscar Salvador,
Dan Williams, Dave Jiang
Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org,
nvdimm@lists.linux.dev, linux-cxl@vger.kernel.org, Huang Ying,
Dave Hansen, Aneesh Kumar K.V, Michal Hocko, Jonathan Cameron,
Jeff Moyer
On 07/11/2023 15:22, Vishal Verma wrote:
> Large amounts of memory managed by the kmem driver may come in via CXL,
> and it is often desirable to have the memmap for this memory on the new
> memory itself.
>
> Enroll kmem-managed memory for memmap_on_memory semantics if the dax
> region originates via CXL. For non-CXL dax regions, retain the existing
> default behavior of hot adding without memmap_on_memory semantics.
>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: David Hildenbrand <david@redhat.com>
> Cc: Michal Hocko <mhocko@suse.com>
> Cc: Oscar Salvador <osalvador@suse.de>
> Cc: Dan Williams <dan.j.williams@intel.com>
> Cc: Dave Jiang <dave.jiang@intel.com>
> Cc: Dave Hansen <dave.hansen@linux.intel.com>
> Cc: Huang Ying <ying.huang@intel.com>
> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> Reviewed-by: David Hildenbrand <david@redhat.com>
> Reviewed-by: "Huang, Ying" <ying.huang@intel.com>
> Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
Tested-by: Li Zhijian <lizhijian@fujitsu.com> # both cxl.kmem and nvdimm.kmem
> ---
> drivers/dax/bus.h | 1 +
> drivers/dax/dax-private.h | 1 +
> drivers/dax/bus.c | 3 +++
> drivers/dax/cxl.c | 1 +
> drivers/dax/hmem/hmem.c | 1 +
> drivers/dax/kmem.c | 8 +++++++-
> drivers/dax/pmem.c | 1 +
> 7 files changed, 15 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/dax/bus.h b/drivers/dax/bus.h
> index 1ccd23360124..cbbf64443098 100644
> --- a/drivers/dax/bus.h
> +++ b/drivers/dax/bus.h
> @@ -23,6 +23,7 @@ struct dev_dax_data {
> struct dev_pagemap *pgmap;
> resource_size_t size;
> int id;
> + bool memmap_on_memory;
> };
>
> struct dev_dax *devm_create_dev_dax(struct dev_dax_data *data);
> diff --git a/drivers/dax/dax-private.h b/drivers/dax/dax-private.h
> index 27cf2daaaa79..446617b73aea 100644
> --- a/drivers/dax/dax-private.h
> +++ b/drivers/dax/dax-private.h
> @@ -70,6 +70,7 @@ struct dev_dax {
> struct ida ida;
> struct device dev;
> struct dev_pagemap *pgmap;
> + bool memmap_on_memory;
> int nr_range;
> struct dev_dax_range {
> unsigned long pgoff;
> diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c
> index 1659b787b65f..1ff1ab5fa105 100644
> --- a/drivers/dax/bus.c
> +++ b/drivers/dax/bus.c
> @@ -367,6 +367,7 @@ static ssize_t create_store(struct device *dev, struct device_attribute *attr,
> .dax_region = dax_region,
> .size = 0,
> .id = -1,
> + .memmap_on_memory = false,
> };
> struct dev_dax *dev_dax = devm_create_dev_dax(&data);
>
> @@ -1400,6 +1401,8 @@ struct dev_dax *devm_create_dev_dax(struct dev_dax_data *data)
> dev_dax->align = dax_region->align;
> ida_init(&dev_dax->ida);
>
> + dev_dax->memmap_on_memory = data->memmap_on_memory;
> +
> inode = dax_inode(dax_dev);
> dev->devt = inode->i_rdev;
> dev->bus = &dax_bus_type;
> diff --git a/drivers/dax/cxl.c b/drivers/dax/cxl.c
> index 8bc9d04034d6..c696837ab23c 100644
> --- a/drivers/dax/cxl.c
> +++ b/drivers/dax/cxl.c
> @@ -26,6 +26,7 @@ static int cxl_dax_region_probe(struct device *dev)
> .dax_region = dax_region,
> .id = -1,
> .size = range_len(&cxlr_dax->hpa_range),
> + .memmap_on_memory = true,
> };
>
> return PTR_ERR_OR_ZERO(devm_create_dev_dax(&data));
> diff --git a/drivers/dax/hmem/hmem.c b/drivers/dax/hmem/hmem.c
> index 5d2ddef0f8f5..b9da69f92697 100644
> --- a/drivers/dax/hmem/hmem.c
> +++ b/drivers/dax/hmem/hmem.c
> @@ -36,6 +36,7 @@ static int dax_hmem_probe(struct platform_device *pdev)
> .dax_region = dax_region,
> .id = -1,
> .size = region_idle ? 0 : range_len(&mri->range),
> + .memmap_on_memory = false,
> };
>
> return PTR_ERR_OR_ZERO(devm_create_dev_dax(&data));
> diff --git a/drivers/dax/kmem.c b/drivers/dax/kmem.c
> index 369c698b7706..42ee360cf4e3 100644
> --- a/drivers/dax/kmem.c
> +++ b/drivers/dax/kmem.c
> @@ -12,6 +12,7 @@
> #include <linux/mm.h>
> #include <linux/mman.h>
> #include <linux/memory-tiers.h>
> +#include <linux/memory_hotplug.h>
> #include "dax-private.h"
> #include "bus.h"
>
> @@ -93,6 +94,7 @@ static int dev_dax_kmem_probe(struct dev_dax *dev_dax)
> struct dax_kmem_data *data;
> struct memory_dev_type *mtype;
> int i, rc, mapped = 0;
> + mhp_t mhp_flags;
> int numa_node;
> int adist = MEMTIER_DEFAULT_DAX_ADISTANCE;
>
> @@ -179,12 +181,16 @@ static int dev_dax_kmem_probe(struct dev_dax *dev_dax)
> */
> res->flags = IORESOURCE_SYSTEM_RAM;
>
> + mhp_flags = MHP_NID_IS_MGID;
> + if (dev_dax->memmap_on_memory)
> + mhp_flags |= MHP_MEMMAP_ON_MEMORY;
> +
> /*
> * Ensure that future kexec'd kernels will not treat
> * this as RAM automatically.
> */
> rc = add_memory_driver_managed(data->mgid, range.start,
> - range_len(&range), kmem_name, MHP_NID_IS_MGID);
> + range_len(&range), kmem_name, mhp_flags);
>
> if (rc) {
> dev_warn(dev, "mapping%d: %#llx-%#llx memory add failed\n",
> diff --git a/drivers/dax/pmem.c b/drivers/dax/pmem.c
> index ae0cb113a5d3..f3c6c67b8412 100644
> --- a/drivers/dax/pmem.c
> +++ b/drivers/dax/pmem.c
> @@ -63,6 +63,7 @@ static struct dev_dax *__dax_pmem_probe(struct device *dev)
> .id = id,
> .pgmap = &pgmap,
> .size = range_len(&range),
> + .memmap_on_memory = false,
> };
>
> return devm_create_dev_dax(&data);
>
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2023-12-08 9:12 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2023-11-07 7:22 [PATCH v10 0/3] mm: use memmap_on_memory semantics for dax/kmem Vishal Verma
2023-11-07 7:22 ` [PATCH v10 1/3] mm/memory_hotplug: replace an open-coded kmemdup() in add_memory_resource() Vishal Verma
2023-11-07 7:22 ` [PATCH v10 2/3] mm/memory_hotplug: split memmap_on_memory requests across memblocks Vishal Verma
2023-11-07 7:22 ` [PATCH v10 3/3] dax/kmem: allow kmem to add memory with memmap_on_memory Vishal Verma
2023-12-08 9:11 ` Zhijian Li (Fujitsu)
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