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Patch series "drivers/base/memory: Two cleanups", v3.
Two cleanups to drivers/base/memory.
This patch (of 2)L
It's unnecessary to count the present sections for the specified block
since the block will be added if any section in the block is present.
Besides, for_each_present_section_nr() can be reused as Andrew Morton
suggested.
Improve by using for_each_present_section_nr() and dropping the
unnecessary @section_count.
No functional changes intended.
Link: https://lkml.kernel.org/r/20250311233045.148943-1-gshan@redhat.com
Link: https://lkml.kernel.org/r/20250311233045.148943-2-gshan@redhat.com
Signed-off-by: Gavin Shan <gshan@redhat.com>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Oscar Salvador <osalvador@suse.de>
Cc: Danilo Krummrich <dakr@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Add functions that are called just before the per-section memmap is
initialized and just before the memmap page structures are initialized.
They are called sparse_vmemmap_init_nid_early and
sparse_vmemmap_init_nid_late, respectively.
This allows for mm subsystems to add calls to initialize memmap and page
structures in a specific way, if using SPARSEMEM_VMEMMAP. Specifically,
hugetlb can pre-HVO bootmem allocated pages that way, so that no time and
resources are wasted on allocating vmemmap pages, only to free them later
(and possibly unnecessarily running the system out of memory in the
process).
Refactor some code and export a few convenience functions for external
use.
In sparse_init_nid, skip any sections that are already initialized, e.g.
they have been initialized by sparse_vmemmap_init_nid_early already.
The hugetlb code to use these functions will be added in a later commit.
Export section_map_size, as any alternate memmap init code will want to
use it.
The internal config option to enable this is SPARSEMEM_VMEMMAP_PREINIT,
which is selected if an architecture-specific option,
ARCH_WANT_HUGETLB_VMEMMAP_PREINIT, is set. In the future, if other
subsystems want to do preinit too, they can do it in a similar fashion.
The internal config option is there because a section flag is used, and
the number of flags available is architecture-dependent (see mmzone.h).
Architecures can decide if there is room for the flag when enabling
options that select SPARSEMEM_VMEMMAP_PREINIT.
Fortunately, as of right now, all sparse vmemmap using architectures do
have room.
Link: https://lkml.kernel.org/r/20250228182928.2645936-11-fvdl@google.com
Signed-off-by: Frank van der Linden <fvdl@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Dan Carpenter <dan.carpenter@linaro.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Joao Martins <joao.m.martins@oracle.com>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Roman Gushchin (Cruise) <roman.gushchin@linux.dev>
Cc: Usama Arif <usamaarif642@gmail.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Yu Zhao <yuzhao@google.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Before SLUB initialization, various subsystems used memblock_alloc to
allocate memory. In most cases, when memory allocation fails, an
immediate panic is required. To simplify this behavior and reduce
repetitive checks, introduce `memblock_alloc_or_panic`. This function
ensures that memory allocation failures result in a panic automatically,
improving code readability and consistency across subsystems that require
this behavior.
[guoweikang.kernel@gmail.com: arch/s390: save_area_alloc default failure behavior changed to panic]
Link: https://lkml.kernel.org/r/20250109033136.2845676-1-guoweikang.kernel@gmail.com
Link: https://lore.kernel.org/lkml/Z2fknmnNtiZbCc7x@kernel.org/
Link: https://lkml.kernel.org/r/20250102072528.650926-1-guoweikang.kernel@gmail.com
Signed-off-by: Guo Weikang <guoweikang.kernel@gmail.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> [m68k]
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> [s390]
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Encode the type into the bottom four bits of page->private and the info
into the remaining bits. Also turn the bootmem type into a named enum.
[arnd@arndb.de: bootmem: add bootmem_type stub function]
Link: https://lkml.kernel.org/r/20241015143802.577613-1-arnd@kernel.org
[akpm@linux-foundation.org: fix build with !CONFIG_HAVE_BOOTMEM_INFO_NODE]
Link: https://lore.kernel.org/oe-kbuild-all/202410090311.eaqcL7IZ-lkp@intel.com/
Link: https://lkml.kernel.org/r/20241005200121.3231142-6-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: kernel test robot <lkp@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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For clarity. It's increasingly hard to reason about the code, when KASLR
is moving around the boundaries. In this case where KASLR is randomizing
the location of the kernel image within physical memory, the maximum
number of address bits for physical memory has not changed.
What has changed is the ending address of memory that is allowed to be
directly mapped by the kernel.
Let's name the variable, and the associated macro accordingly.
Also, enhance the comment above the direct_map_physmem_end definition,
to further clarify how this all works.
Link: https://lkml.kernel.org/r/20241009025024.89813-1-jhubbard@nvidia.com
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: Pankaj Gupta <pankaj.gupta@amd.com>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Will Deacon <will@kernel.org>
Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Jordan Niethe <jniethe@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Thomas Gleixner:
- x2apic_disable() clears x2apic_state and x2apic_mode unconditionally,
even when the state is X2APIC_ON_LOCKED, which prevents the kernel to
disable it thereby creating inconsistent state.
Reorder the logic so it actually works correctly
- The XSTATE logic for handling LBR is incorrect as it assumes that
XSAVES supports LBR when the CPU supports LBR. In fact both
conditions need to be true. Otherwise the enablement of LBR in the
IA32_XSS MSR fails and subsequently the machine crashes on the next
XRSTORS operation because IA32_XSS is not initialized.
Cache the XSTATE support bit during init and make the related
functions use this cached information and the LBR CPU feature bit to
cure this.
- Cure a long standing bug in KASLR
KASLR uses the full address space between PAGE_OFFSET and vaddr_end
to randomize the starting points of the direct map, vmalloc and
vmemmap regions. It thereby limits the size of the direct map by
using the installed memory size plus an extra configurable margin for
hot-plug memory. This limitation is done to gain more randomization
space because otherwise only the holes between the direct map,
vmalloc, vmemmap and vaddr_end would be usable for randomizing.
The limited direct map size is not exposed to the rest of the kernel,
so the memory hot-plug and resource management related code paths
still operate under the assumption that the available address space
can be determined with MAX_PHYSMEM_BITS.
request_free_mem_region() allocates from (1 << MAX_PHYSMEM_BITS) - 1
downwards. That means the first allocation happens past the end of
the direct map and if unlucky this address is in the vmalloc space,
which causes high_memory to become greater than VMALLOC_START and
consequently causes iounmap() to fail for valid ioremap addresses.
Cure this by exposing the end of the direct map via PHYSMEM_END and
use that for the memory hot-plug and resource management related
places instead of relying on MAX_PHYSMEM_BITS. In the KASLR case
PHYSMEM_END maps to a variable which is initialized by the KASLR
initialization and otherwise it is based on MAX_PHYSMEM_BITS as
before.
- Prevent a data leak in mmio_read(). The TDVMCALL exposes the value of
an initialized variabled on the stack to the VMM. The variable is
only required as output value, so it does not have to exposed to the
VMM in the first place.
- Prevent an array overrun in the resource control code on systems with
Sub-NUMA Clustering enabled because the code failed to adjust the
index by the number of SNC nodes per L3 cache.
* tag 'x86-urgent-2024-09-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/resctrl: Fix arch_mbm_* array overrun on SNC
x86/tdx: Fix data leak in mmio_read()
x86/kaslr: Expose and use the end of the physical memory address space
x86/fpu: Avoid writing LBR bit to IA32_XSS unless supported
x86/apic: Make x2apic_disable() work correctly
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iounmap() on x86 occasionally fails to unmap because the provided valid
ioremap address is not below high_memory. It turned out that this
happens due to KASLR.
KASLR uses the full address space between PAGE_OFFSET and vaddr_end to
randomize the starting points of the direct map, vmalloc and vmemmap
regions. It thereby limits the size of the direct map by using the
installed memory size plus an extra configurable margin for hot-plug
memory. This limitation is done to gain more randomization space
because otherwise only the holes between the direct map, vmalloc,
vmemmap and vaddr_end would be usable for randomizing.
The limited direct map size is not exposed to the rest of the kernel, so
the memory hot-plug and resource management related code paths still
operate under the assumption that the available address space can be
determined with MAX_PHYSMEM_BITS.
request_free_mem_region() allocates from (1 << MAX_PHYSMEM_BITS) - 1
downwards. That means the first allocation happens past the end of the
direct map and if unlucky this address is in the vmalloc space, which
causes high_memory to become greater than VMALLOC_START and consequently
causes iounmap() to fail for valid ioremap addresses.
MAX_PHYSMEM_BITS cannot be changed for that because the randomization
does not align with address bit boundaries and there are other places
which actually require to know the maximum number of address bits. All
remaining usage sites of MAX_PHYSMEM_BITS have been analyzed and found
to be correct.
Cure this by exposing the end of the direct map via PHYSMEM_END and use
that for the memory hot-plug and resource management related places
instead of relying on MAX_PHYSMEM_BITS. In the KASLR case PHYSMEM_END
maps to a variable which is initialized by the KASLR initialization and
otherwise it is based on MAX_PHYSMEM_BITS as before.
To prevent future hickups add a check into add_pages() to catch callers
trying to add memory above PHYSMEM_END.
Fixes: 0483e1fa6e09 ("x86/mm: Implement ASLR for kernel memory regions")
Reported-by: Max Ramanouski <max8rr8@gmail.com>
Reported-by: Alistair Popple <apopple@nvidia.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-By: Max Ramanouski <max8rr8@gmail.com>
Tested-by: Alistair Popple <apopple@nvidia.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Alistair Popple <apopple@nvidia.com>
Reviewed-by: Kees Cook <kees@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/all/87ed6soy3z.ffs@tglx
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Fix invalid access to pgdat during hot-remove operation:
ndctl users reported a GPF when trying to destroy a namespace:
$ ndctl destroy-namespace all -r all -f
Segmentation fault
dmesg:
Oops: general protection fault, probably for
non-canonical address 0xdffffc0000005650: 0000 [#1] PREEMPT SMP KASAN
PTI
KASAN: probably user-memory-access in range
[0x000000000002b280-0x000000000002b287]
CPU: 26 UID: 0 PID: 1868 Comm: ndctl Not tainted 6.11.0-rc1 #1
Hardware name: Dell Inc. PowerEdge R640/08HT8T, BIOS
2.20.1 09/13/2023
RIP: 0010:mod_node_page_state+0x2a/0x110
cxl-test users report a GPF when trying to unload the test module:
$ modrpobe -r cxl-test
dmesg
BUG: unable to handle page fault for address: 0000000000004200
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 0 P4D 0
Oops: Oops: 0000 [#1] PREEMPT SMP PTI
CPU: 0 UID: 0 PID: 1076 Comm: modprobe Tainted: G O N 6.11.0-rc1 #197
Tainted: [O]=OOT_MODULE, [N]=TEST
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/15
RIP: 0010:mod_node_page_state+0x6/0x90
Currently, when memory is hot-plugged or hot-removed the accounting is
done based on the assumption that memmap is allocated from the same node
as the hot-plugged/hot-removed memory, which is not always the case.
In addition, there are challenges with keeping the node id of the memory
that is being remove to the time when memmap accounting is actually
performed: since this is done after remove_pfn_range_from_zone(), and
also after remove_memory_block_devices(). Meaning that we cannot use
pgdat nor walking though memblocks to get the nid.
Given all of that, account the memmap overhead system wide instead.
For this we are going to be using global atomic counters, but given that
memmap size is rarely modified, and normally is only modified either
during early boot when there is only one CPU, or under a hotplug global
mutex lock, therefore there is no need for per-cpu optimizations.
Also, while we are here rename nr_memmap to nr_memmap_pages, and
nr_memmap_boot to nr_memmap_boot_pages to be self explanatory that the
units are in page count.
[pasha.tatashin@soleen.com: address a few nits from David Hildenbrand]
Link: https://lkml.kernel.org/r/20240809191020.1142142-4-pasha.tatashin@soleen.com
Link: https://lkml.kernel.org/r/20240809191020.1142142-4-pasha.tatashin@soleen.com
Link: https://lkml.kernel.org/r/20240808213437.682006-4-pasha.tatashin@soleen.com
Fixes: 15995a352474 ("mm: report per-page metadata information")
Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Reported-by: Yi Zhang <yi.zhang@redhat.com>
Closes: https://lore.kernel.org/linux-cxl/CAHj4cs9Ax1=CoJkgBGP_+sNu6-6=6v=_L-ZBZY0bVLD3wUWZQg@mail.gmail.com
Reported-by: Alison Schofield <alison.schofield@intel.com>
Closes: https://lore.kernel.org/linux-mm/Zq0tPd2h6alFz8XF@aschofie-mobl2/#t
Tested-by: Dan Williams <dan.j.williams@intel.com>
Tested-by: Alison Schofield <alison.schofield@intel.com>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: David Rientjes <rientjes@google.com>
Tested-by: Yi Zhang <yi.zhang@redhat.com>
Cc: Domenico Cerasuolo <cerasuolodomenico@gmail.com>
Cc: Fan Ni <fan.ni@samsung.com>
Cc: Joel Granados <j.granados@samsung.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Li Zhijian <lizhijian@fujitsu.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Sourav Panda <souravpanda@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Yosry Ahmed <yosryahmed@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Function subsection_map_init() is only used in free_area_init() in the
loop of for_each_mem_pfn_range(). And we are sure in each iteration of
for_each_mem_pfn_range(), start_pfn < end_pfn.
So nr_pages is not possible to be 0 and we can remove the check.
Link: https://lkml.kernel.org/r/20240619010612.20740-1-richard.weiyang@gmail.com
Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Today, we do not have any observability of per-page metadata and how much
it takes away from the machine capacity. Thus, we want to describe the
amount of memory that is going towards per-page metadata, which can vary
depending on build configuration, machine architecture, and system use.
This patch adds 2 fields to /proc/vmstat that can used as shown below:
Accounting per-page metadata allocated by boot-allocator:
/proc/vmstat:nr_memmap_boot * PAGE_SIZE
Accounting per-page metadata allocated by buddy-allocator:
/proc/vmstat:nr_memmap * PAGE_SIZE
Accounting total Perpage metadata allocated on the machine:
(/proc/vmstat:nr_memmap_boot +
/proc/vmstat:nr_memmap) * PAGE_SIZE
Utility for userspace:
Observability: Describe the amount of memory overhead that is going to
per-page metadata on the system at any given time since this overhead is
not currently observable.
Debugging: Tracking the changes or absolute value in struct pages can help
detect anomalies as they can be correlated with other metrics in the
machine (e.g., memtotal, number of huge pages, etc).
page_ext overheads: Some kernel features such as page_owner
page_table_check that use page_ext can be optionally enabled via kernel
parameters. Having the total per-page metadata information helps users
precisely measure impact. Furthermore, page-metadata metrics will reflect
the amount of struct pages reliquished (or overhead reduced) when
hugetlbfs pages are reserved which will vary depending on whether hugetlb
vmemmap optimization is enabled or not.
For background and results see:
lore.kernel.org/all/20240220214558.3377482-1-souravpanda@google.com
Link: https://lkml.kernel.org/r/20240605222751.1406125-1-souravpanda@google.com
Signed-off-by: Sourav Panda <souravpanda@google.com>
Acked-by: David Rientjes <rientjes@google.com>
Reviewed-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Chen Linxuan <chenlinxuan@uniontech.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Ivan Babrou <ivan@cloudflare.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Tomas Mudrunka <tomas.mudrunka@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Wei Xu <weixugc@google.com>
Cc: Yang Yang <yang.yang29@zte.com.cn>
Cc: Yosry Ahmed <yosryahmed@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Setting 'limit' variable to 0 might seem like it means "no limit". But in
the memblock API, 0 actually means the 'MEMBLOCK_ALLOC_ACCESSIBLE' enum,
which limits the physical address range end based on
'memblock.current_limit'. This could be confusing.
Use the enum instead of 0 to make it clear.
Link: https://lkml.kernel.org/r/20240610151528.943680-1-lsahn@wewakecorp.com
Signed-off-by: Leesoo Ahn <lsahn@ooseel.net>
Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>
Reviewed-by: Wei Yang <richard.weiyang@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Consistently name the return variable with an _nr suffix, whenever calling
pfn_to_section_nr(), to avoid confusion with a (struct mem_section *).
Link: https://lkml.kernel.org/r/20240531124144.240399-1-dev.jain@arm.com
Signed-off-by: Dev Jain <dev.jain@arm.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Acked-by: Oscar Salvador <osalvador@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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We usually have this check, while commit 2a3cb8baef71 ("mm/sparse: delete
old sparse_init and enable new one") missed to take it.
Link: https://lkml.kernel.org/r/20240416012559.4536-1-richard.weiyang@gmail.com
Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Acked-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: "Mike Rapoport (IBM)" <rppt@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Patch series "mm/init: minor clean up and improvement".
These are all observed when going through code flow during mm init.
This patch (of 7):
When CONFIG_SPARSEMEM_EXTREME is enabled, mem_section need be initialized
to point at a two-dimensional array, and its 1st dimension of length
NR_SECTION_ROOTS will be dynamically allocated. Once the allocation is
done, it's available for all nodes.
So take the 1st dimension of mem_section initialization out of
memory_present()(), and put it into memblocks_present() which is a more
appripriate place.
Link: https://lkml.kernel.org/r/20240326061134.1055295-1-bhe@redhat.com
Link: https://lkml.kernel.org/r/20240326061134.1055295-2-bhe@redhat.com
Signed-off-by: Baoquan He <bhe@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: "Mike Rapoport (IBM)" <rppt@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Patch series "implement "memmap on memory" feature on s390".
This series provides "memmap on memory" support on s390 platform. "memmap
on memory" allows struct pages array to be allocated from the hotplugged
memory range instead of allocating it from main system memory.
s390 currently preallocates struct pages array for all potentially
possible memory, which ensures memory onlining always succeeds, but with
the cost of significant memory consumption from the available system
memory during boottime. In certain extreme configuration, this could lead
to ipl failure.
"memmap on memory" ensures struct pages array are populated from self
contained hotplugged memory range instead of depleting the available
system memory and this could eliminate ipl failure on s390 platform.
On other platforms, system might go OOM when the physically hotplugged
memory depletes the available memory before it is onlined. Hence, "memmap
on memory" feature was introduced as described in commit a08a2ae34613
("mm,memory_hotplug: allocate memmap from the added memory range").
Unlike other architectures, s390 memory blocks are not physically
accessible until it is online. To make it physically accessible two new
memory notifiers MEM_PREPARE_ONLINE / MEM_FINISH_OFFLINE are added and
this notifier lets the hypervisor inform that the memory should be made
physically accessible. This allows for "memmap on memory" initialization
during memory hotplug onlining phase, which is performed before calling
MEM_GOING_ONLINE notifier.
Patch 1 introduces MEM_PREPARE_ONLINE/MEM_FINISH_OFFLINE memory notifiers
to prepare the transition of memory to and from a physically accessible
state. New mhp_flag MHP_OFFLINE_INACCESSIBLE is introduced to ensure
altmap cannot be written when adding memory - before it is set online.
This enhancement is crucial for implementing the "memmap on memory"
feature for s390 in a subsequent patch.
Patches 2 allocates vmemmap pages from self-contained memory range for
s390. It allocates memory map (struct pages array) from the hotplugged
memory range, rather than using system memory by passing altmap to vmemmap
functions.
Patch 3 removes unhandled memory notifier types on s390.
Patch 4 implements MEM_PREPARE_ONLINE/MEM_FINISH_OFFLINE memory notifiers
on s390. MEM_PREPARE_ONLINE memory notifier makes memory block physical
accessible via sclp assign command. The notifier ensures self-contained
memory maps are accessible and hence enabling the "memmap on memory" on
s390. MEM_FINISH_OFFLINE memory notifier shifts the memory block to an
inaccessible state via sclp unassign command.
Patch 5 finally enables MHP_MEMMAP_ON_MEMORY on s390.
This patch (of 5):
Introduce MEM_PREPARE_ONLINE/MEM_FINISH_OFFLINE memory notifiers to
prepare the transition of memory to and from a physically accessible
state. This enhancement is crucial for implementing the "memmap on
memory" feature for s390 in a subsequent patch.
Platforms such as x86 can support physical memory hotplug via ACPI. When
there is physical memory hotplug, ACPI event leads to the memory addition
with the following callchain:
acpi_memory_device_add()
-> acpi_memory_enable_device()
-> __add_memory()
After this, the hotplugged memory is physically accessible, and altmap
support prepared, before the "memmap on memory" initialization in
memory_block_online() is called.
On s390, memory hotplug works in a different way. The available hotplug
memory has to be defined upfront in the hypervisor, but it is made
physically accessible only when the user sets it online via sysfs,
currently in the MEM_GOING_ONLINE notifier. This is too late and "memmap
on memory" initialization is performed before calling MEM_GOING_ONLINE
notifier.
During the memory hotplug addition phase, altmap support is prepared and
during the memory onlining phase s390 requires memory to be physically
accessible and then subsequently initiate the "memmap on memory"
initialization process.
The memory provider will handle new MEM_PREPARE_ONLINE /
MEM_FINISH_OFFLINE notifications and make the memory accessible.
The mhp_flag MHP_OFFLINE_INACCESSIBLE is introduced and is relevant when
used along with MHP_MEMMAP_ON_MEMORY, because the altmap cannot be written
(e.g., poisoned) when adding memory -- before it is set online. This
allows for adding memory with an altmap that is not currently made
available by a hypervisor. When onlining that memory, the hypervisor can
be instructed to make that memory accessible via the new notifiers and the
onlining phase will not require any memory allocations, which is helpful
in low-memory situations.
All architectures ignore unknown memory notifiers. Therefore, the
introduction of these new notifiers does not result in any functional
modifications across architectures.
Link: https://lkml.kernel.org/r/20240108132747.3238763-1-sumanthk@linux.ibm.com
Link: https://lkml.kernel.org/r/20240108132747.3238763-2-sumanthk@linux.ibm.com
Signed-off-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Suggested-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Suggested-by: David Hildenbrand <david@redhat.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
The below race is observed on a PFN which falls into the device memory
region with the system memory configuration where PFN's are such that
[ZONE_NORMAL ZONE_DEVICE ZONE_NORMAL]. Since normal zone start and end
pfn contains the device memory PFN's as well, the compaction triggered
will try on the device memory PFN's too though they end up in NOP(because
pfn_to_online_page() returns NULL for ZONE_DEVICE memory sections). When
from other core, the section mappings are being removed for the
ZONE_DEVICE region, that the PFN in question belongs to, on which
compaction is currently being operated is resulting into the kernel crash
with CONFIG_SPASEMEM_VMEMAP enabled. The crash logs can be seen at [1].
compact_zone() memunmap_pages
------------- ---------------
__pageblock_pfn_to_page
......
(a)pfn_valid():
valid_section()//return true
(b)__remove_pages()->
sparse_remove_section()->
section_deactivate():
[Free the array ms->usage and set
ms->usage = NULL]
pfn_section_valid()
[Access ms->usage which
is NULL]
NOTE: From the above it can be said that the race is reduced to between
the pfn_valid()/pfn_section_valid() and the section deactivate with
SPASEMEM_VMEMAP enabled.
The commit b943f045a9af("mm/sparse: fix kernel crash with
pfn_section_valid check") tried to address the same problem by clearing
the SECTION_HAS_MEM_MAP with the expectation of valid_section() returns
false thus ms->usage is not accessed.
Fix this issue by the below steps:
a) Clear SECTION_HAS_MEM_MAP before freeing the ->usage.
b) RCU protected read side critical section will either return NULL
when SECTION_HAS_MEM_MAP is cleared or can successfully access ->usage.
c) Free the ->usage with kfree_rcu() and set ms->usage = NULL. No
attempt will be made to access ->usage after this as the
SECTION_HAS_MEM_MAP is cleared thus valid_section() return false.
Thanks to David/Pavan for their inputs on this patch.
[1] https://lore.kernel.org/linux-mm/994410bb-89aa-d987-1f50-f514903c55aa@quicinc.com/
On Snapdragon SoC, with the mentioned memory configuration of PFN's as
[ZONE_NORMAL ZONE_DEVICE ZONE_NORMAL], we are able to see bunch of
issues daily while testing on a device farm.
For this particular issue below is the log. Though the below log is
not directly pointing to the pfn_section_valid(){ ms->usage;}, when we
loaded this dump on T32 lauterbach tool, it is pointing.
[ 540.578056] Unable to handle kernel NULL pointer dereference at
virtual address 0000000000000000
[ 540.578068] Mem abort info:
[ 540.578070] ESR = 0x0000000096000005
[ 540.578073] EC = 0x25: DABT (current EL), IL = 32 bits
[ 540.578077] SET = 0, FnV = 0
[ 540.578080] EA = 0, S1PTW = 0
[ 540.578082] FSC = 0x05: level 1 translation fault
[ 540.578085] Data abort info:
[ 540.578086] ISV = 0, ISS = 0x00000005
[ 540.578088] CM = 0, WnR = 0
[ 540.579431] pstate: 82400005 (Nzcv daif +PAN -UAO +TCO -DIT -SSBSBTYPE=--)
[ 540.579436] pc : __pageblock_pfn_to_page+0x6c/0x14c
[ 540.579454] lr : compact_zone+0x994/0x1058
[ 540.579460] sp : ffffffc03579b510
[ 540.579463] x29: ffffffc03579b510 x28: 0000000000235800 x27:000000000000000c
[ 540.579470] x26: 0000000000235c00 x25: 0000000000000068 x24:ffffffc03579b640
[ 540.579477] x23: 0000000000000001 x22: ffffffc03579b660 x21:0000000000000000
[ 540.579483] x20: 0000000000235bff x19: ffffffdebf7e3940 x18:ffffffdebf66d140
[ 540.579489] x17: 00000000739ba063 x16: 00000000739ba063 x15:00000000009f4bff
[ 540.579495] x14: 0000008000000000 x13: 0000000000000000 x12:0000000000000001
[ 540.579501] x11: 0000000000000000 x10: 0000000000000000 x9 :ffffff897d2cd440
[ 540.579507] x8 : 0000000000000000 x7 : 0000000000000000 x6 :ffffffc03579b5b4
[ 540.579512] x5 : 0000000000027f25 x4 : ffffffc03579b5b8 x3 :0000000000000001
[ 540.579518] x2 : ffffffdebf7e3940 x1 : 0000000000235c00 x0 :0000000000235800
[ 540.579524] Call trace:
[ 540.579527] __pageblock_pfn_to_page+0x6c/0x14c
[ 540.579533] compact_zone+0x994/0x1058
[ 540.579536] try_to_compact_pages+0x128/0x378
[ 540.579540] __alloc_pages_direct_compact+0x80/0x2b0
[ 540.579544] __alloc_pages_slowpath+0x5c0/0xe10
[ 540.579547] __alloc_pages+0x250/0x2d0
[ 540.579550] __iommu_dma_alloc_noncontiguous+0x13c/0x3fc
[ 540.579561] iommu_dma_alloc+0xa0/0x320
[ 540.579565] dma_alloc_attrs+0xd4/0x108
[quic_charante@quicinc.com: use kfree_rcu() in place of synchronize_rcu(), per David]
Link: https://lkml.kernel.org/r/1698403778-20938-1-git-send-email-quic_charante@quicinc.com
Link: https://lkml.kernel.org/r/1697202267-23600-1-git-send-email-quic_charante@quicinc.com
Fixes: f46edbd1b151 ("mm/sparsemem: add helpers track active portions of a section at boot")
Signed-off-by: Charan Teja Kalla <quic_charante@quicinc.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
next_present_section_nr() has already ensured that
'section_nr<=__highest_present_section_nr', so this check is removed.
Link: https://lkml.kernel.org/r/20230707060501.29184-1-liuq131@chinatelecom.cn
Signed-off-by: liuq <liuq131@chinatelecom.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull non-mm updates from Andrew Morton:
- Arnd Bergmann has fixed a bunch of -Wmissing-prototypes in top-level
directories
- Douglas Anderson has added a new "buddy" mode to the hardlockup
detector. It permits the detector to work on architectures which
cannot provide the required interrupts, by having CPUs periodically
perform checks on other CPUs
- Zhen Lei has enhanced kexec's ability to support two crash regions
- Petr Mladek has done a lot of cleanup on the hard lockup detector's
Kconfig entries
- And the usual bunch of singleton patches in various places
* tag 'mm-nonmm-stable-2023-06-24-19-23' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (72 commits)
kernel/time/posix-stubs.c: remove duplicated include
ocfs2: remove redundant assignment to variable bit_off
watchdog/hardlockup: fix typo in config HARDLOCKUP_DETECTOR_PREFER_BUDDY
powerpc: move arch_trigger_cpumask_backtrace from nmi.h to irq.h
devres: show which resource was invalid in __devm_ioremap_resource()
watchdog/hardlockup: define HARDLOCKUP_DETECTOR_ARCH
watchdog/sparc64: define HARDLOCKUP_DETECTOR_SPARC64
watchdog/hardlockup: make HAVE_NMI_WATCHDOG sparc64-specific
watchdog/hardlockup: declare arch_touch_nmi_watchdog() only in linux/nmi.h
watchdog/hardlockup: make the config checks more straightforward
watchdog/hardlockup: sort hardlockup detector related config values a logical way
watchdog/hardlockup: move SMP barriers from common code to buddy code
watchdog/buddy: simplify the dependency for HARDLOCKUP_DETECTOR_PREFER_BUDDY
watchdog/buddy: don't copy the cpumask in watchdog_next_cpu()
watchdog/buddy: cleanup how watchdog_buddy_check_hardlockup() is called
watchdog/hardlockup: remove softlockup comment in touch_nmi_watchdog()
watchdog/hardlockup: in watchdog_hardlockup_check() use cpumask_copy()
watchdog/hardlockup: don't use raw_cpu_ptr() in watchdog_hardlockup_kick()
watchdog/hardlockup: HAVE_NMI_WATCHDOG must implement watchdog_hardlockup_probe()
watchdog/hardlockup: keep kernel.nmi_watchdog sysctl as 0444 if probe fails
...
|
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These parameters ms and map_offset are not used in
sparse_remove_section(), so remove them.
The __remove_section() is only called by __remove_pages(), remove it. And
put the WARN_ON_ONCE() in sparse_remove_section().
Link: https://lkml.kernel.org/r/20230607023952.2247489-1-yajun.deng@linux.dev
Signed-off-by: Yajun Deng <yajun.deng@linux.dev>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Oscar Salvador <osalvador@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
There are two definitions of this function, but the second one lacks the
'static' annotation:
mm/sparse.c:704:25: error: no previous prototype for 'populate_section_memmap' [-Werror=missing-prototypes]
Link: https://lkml.kernel.org/r/20230517131102.934196-4-arnd@kernel.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Eric Paris <eparis@redhat.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J. Wysocki <rafael@kernel.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman Long <longman@redhat.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
rc is assigned first, so it does not need to initialize the
assignment.
Link: https://lkml.kernel.org/r/20230421214733.2909-1-zeming@nfschina.com
Signed-off-by: Li zeming <zeming@nfschina.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
W=1 build with clangs complains:
mm/sparse.c:347:27: warning: unused function 'pgdat_to_phys' [-Wunused-function]
static inline phys_addr_t pgdat_to_phys(struct pglist_data *pgdat)
^
1 warning generated.
pgdat_to_phys() is only used by functions defined when
CONFIG_MEMORY_HOTREMOVE=y.
Move pgdat_to_phys() under #ifdef CONFIG_MEMORY_HOTREMOVE
to make clang happy.
Link: https://lkml.kernel.org/r/20230121101151.1703292-1-rppt@kernel.org
Signed-off-by: Mike Rapoport <rppt@kernel.org>
Reported-by: kernel test robot <lkp@intel.com>
Link: https://lore.kernel.org/all/202301210155.1E5zABb5-lkp@intel.com
Cc: Miles Chen <miles.chen@mediatek.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Currently PageHWPoison flag does not behave well when experiencing memory
hotremove/hotplug. Any data field in struct page is unreliable when the
associated memory is offlined, and the current mechanism can't tell
whether a memory block is onlined because a new memory devices is
installed or because previous failed offline operations are undone.
Especially if there's a hwpoisoned memory, it's unclear what the best
option is.
So introduce a new mechanism to make struct memory_block remember that a
memory block has hwpoisoned memory inside it. And make any online event
fail if the onlining memory block contains hwpoison. struct memory_block
is freed and reallocated over ACPI-based hotremove/hotplug, but not over
sysfs-based hotremove/hotplug. So the new counter can distinguish these
cases.
Link: https://lkml.kernel.org/r/20221024062012.1520887-5-naoya.horiguchi@linux.dev
Signed-off-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Reported-by: kernel test robot <lkp@intel.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jane Chu <jane.chu@oracle.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Patch series "make hugetlb_optimize_vmemmap compatible with
memmap_on_memory", v3.
This series makes hugetlb_optimize_vmemmap compatible with
memmap_on_memory.
This patch (of 2):
We are almost running out of section flags, only one bit is available in
the worst case (powerpc with 256k pages). However, there are still some
free bits (in ->section_mem_map) on other architectures (e.g. x86_64 has
10 bits available, arm64 has 8 bits available with worst case of 64K
pages). We have hard coded those numbers in code, it is inconvenient to
use those bits on other architectures except powerpc. So transfer those
section flags to enumeration to make it easy to add new section flags in
the future. Also, move SECTION_TAINT_ZONE_DEVICE into the scope of
CONFIG_ZONE_DEVICE to save a bit on non-zone-device case.
[songmuchun@bytedance.com: replace enum with defines per David]
Link: https://lkml.kernel.org/r/20220620110616.12056-2-songmuchun@bytedance.com
Link: https://lkml.kernel.org/r/20220617135650.74901-1-songmuchun@bytedance.com
Link: https://lkml.kernel.org/r/20220617135650.74901-2-songmuchun@bytedance.com
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Xiongchun Duan <duanxiongchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Patch series "memory-failure: fix hwpoison_filter", v2.
As well known, the memory failure mechanism handles memory corrupted
event, and try to send SIGBUS to the user process which uses this
corrupted page.
For the virtualization case, QEMU catches SIGBUS and tries to inject MCE
into the guest, and the guest handles memory failure again. Thus the
guest gets the minimal effect from hardware memory corruption.
The further step I'm working on:
1, try to modify code to decrease poisoned pages in a single place
(mm/memofy-failure.c: simplify num_poisoned_pages_dec in this series).
2, try to use page_handle_poison() to handle SetPageHWPoison() and
num_poisoned_pages_inc() together. It would be best to call
num_poisoned_pages_inc() in a single place too.
3, introduce memory failure notifier list in memory-failure.c: notify
the corrupted PFN to someone who registers this list. If I can
complete [1] and [2] part, [3] will be quite easy(just call notifier
list after increasing poisoned page).
4, introduce memory recover VQ for memory balloon device, and registers
memory failure notifier list. During the guest kernel handles memory
failure, balloon device gets notified by memory failure notifier list,
and tells the host to recover the corrupted PFN(GPA) by the new VQ.
5, host side remaps the corrupted page(HVA), and tells the guest side
to unpoison the PFN(GPA). Then the guest fixes the corrupted page(GPA)
dynamically.
This patch (of 5):
clear_hwpoisoned_pages() clears HWPoison flag and decreases the number of
poisoned pages, this actually works as part of memory failure.
Move this function from sparse.c to memory-failure.c, finally there is no
CONFIG_MEMORY_FAILURE in sparse.c.
Link: https://lkml.kernel.org/r/20220509105641.491313-1-pizhenwei@bytedance.com
Link: https://lkml.kernel.org/r/20220509105641.491313-2-pizhenwei@bytedance.com
Signed-off-by: zhenwei pi <pizhenwei@bytedance.com>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Patch series "sparse-vmemmap: memory savings for compound devmaps (device-dax)", v9.
This series minimizes 'struct page' overhead by pursuing a similar
approach as Muchun Song series "Free some vmemmap pages of hugetlb page"
(now merged since v5.14), but applied to devmap with @vmemmap_shift
(device-dax).
The vmemmap dedpulication original idea (already used in HugeTLB) is to
reuse/deduplicate tail page vmemmap areas, particular the area which only
describes tail pages. So a vmemmap page describes 64 struct pages, and
the first page for a given ZONE_DEVICE vmemmap would contain the head page
and 63 tail pages. The second vmemmap page would contain only tail pages,
and that's what gets reused across the rest of the subsection/section.
The bigger the page size, the bigger the savings (2M hpage -> save 6
vmemmap pages; 1G hpage -> save 4094 vmemmap pages).
This is done for PMEM /specifically only/ on device-dax configured
namespaces, not fsdax. In other words, a devmap with a @vmemmap_shift.
In terms of savings, per 1Tb of memory, the struct page cost would go down
with compound devmap:
* with 2M pages we lose 4G instead of 16G (0.39% instead of 1.5% of
total memory)
* with 1G pages we lose 40MB instead of 16G (0.0014% instead of 1.5% of
total memory)
The series is mostly summed up by patch 4, and to summarize what the
series does:
Patches 1 - 3: Minor cleanups in preparation for patch 4. Move the very
nice docs of hugetlb_vmemmap.c into a Documentation/vm/ entry.
Patch 4: Patch 4 is the one that takes care of the struct page savings
(also referred to here as tail-page/vmemmap deduplication). Much like
Muchun series, we reuse the second PTE tail page vmemmap areas across a
given @vmemmap_shift On important difference though, is that contrary to
the hugetlbfs series, there's no vmemmap for the area because we are
late-populating it as opposed to remapping a system-ram range. IOW no
freeing of pages of already initialized vmemmap like the case for
hugetlbfs, which greatly simplifies the logic (besides not being
arch-specific). altmap case unchanged and still goes via the
vmemmap_populate(). Also adjust the newly added docs to the device-dax
case.
[Note that device-dax is still a little behind HugeTLB in terms of
savings. I have an additional simple patch that reuses the head vmemmap
page too, as a follow-up. That will double the savings and namespaces
initialization.]
Patch 5: Initialize fewer struct pages depending on the page size with
DRAM backed struct pages -- because fewer pages are unique and most tail
pages (with bigger vmemmap_shift).
NVDIMM namespace bootstrap improves from ~268-358 ms to
~80-110/<1ms on 128G NVDIMMs with 2M and 1G respectivally. And struct
page needed capacity will be 3.8x / 1071x smaller for 2M and 1G
respectivelly. Tested on x86 with 1.5Tb of pmem (including pinning,
and RDMA registration/deregistration scalability with 2M MRs)
This patch (of 5):
In support of using compound pages for devmap mappings, plumb the pgmap
down to the vmemmap_populate implementation. Note that while altmap is
retrievable from pgmap the memory hotplug code passes altmap without
pgmap[*], so both need to be independently plumbed.
So in addition to @altmap, pass @pgmap to sparse section populate
functions namely:
sparse_add_section
section_activate
populate_section_memmap
__populate_section_memmap
Passing @pgmap allows __populate_section_memmap() to both fetch the
vmemmap_shift in which memmap metadata is created for and also to let
sparse-vmemmap fetch pgmap ranges to co-relate to a given section and pick
whether to just reuse tail pages from past onlined sections.
While at it, fix the kdoc for @altmap for sparse_add_section().
[*] https://lore.kernel.org/linux-mm/20210319092635.6214-1-osalvador@suse.de/
Link: https://lkml.kernel.org/r/20220420155310.9712-1-joao.m.martins@oracle.com
Link: https://lkml.kernel.org/r/20220420155310.9712-2-joao.m.martins@oracle.com
Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jane Chu <jane.chu@oracle.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
It's only used in the sparse.c now. So we can make it static and further
clean up the relevant code.
Link: https://lkml.kernel.org/r/20220127093221.63524-1-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
page->freelist is for the use of slab. Using page->index is the same
set of bits as page->freelist, and by u |
