Pull more liveupdate updates from Mike Rapoport:
"Make boot time huge page allocation work nicely with kexec handover.
Today allocation of gigantic pages in HugeTLB cannot work reliably
with kexec handover (KHO):
- HugeTLB allocates gigantic pages using memblock and autoscaling of
KHO scratch accounts for these allocations. When gigantic pages
occupy half of the memory of more, KHO fails to allocate its
scratch memory.
- After kexec handover, memblock allocations exclusively use KHO
scratch that is not supposed to contain preserved memory. This
essentially blocks preservation of HugeTLB with gigantic pages.
Extend early memory pools available for KHO kernel with areas that are
guaranteed not to contain preserved memory"
* tag 'liveupdate-v7.3-rc1-20260823' of git://git.kernel.org/pub/scm/linux/kernel/git/liveupdate/linux: (21 commits)
kho: exclude hugetlb memory from scratch size calculation
memblock: add memblock_reserved_hugetlb_size()
memblock: make HugeTLB bootmem allocation work with KHO
memblock: always include KHO headers
kho: extend scratch
mm/mm_init: don't rely on memblock to get KHO scratch migratetype
kho: initialize preserved memory map radix tree earlier
kho: initialize kho_scratch pointer earlier in boot
kho: expose kho_scratch_overlap() to kexec_handover.h
kho: add kho_radix_init_tree()
kho: allow destroying KHO radix tree
kho: allow early-boot usage of the KHO radix tree
kho: add data argument to radix walk callback
kho: add callback for table pages
kho: add a struct for radix callbacks
kho: move all memory retrieval logic to kho_mem_retrieve()
kho: store incoming radix tree in kho_in
kho: disallow wide keys in radix tree
kho: make radix max key width more obvious
kho: generalize radix tree APIs
...
In a coming commit, memblock will start using kho_scratch_overlap()
without a compile guard. The compile guard for the function is in
kexec_handover.h and provides a stub when CONFIG_KEXEC_HANDOVER is
disabled.
Since in memblock the call will exist unconditionally, always include
the KHO headers.
Including these headers unconditionally breaks memblock test
compilation. Add stubs to fix that.
Signed-off-by: Pratyush Yadav (Google) <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Mike Rapoport (Microsoft) <[email protected]>
Support for discovering memory blocks with no preserved memory will be
added in coming patches. These areas will also be marked as scratch to
allow allocations from them. Memblock will switch to looking through the
scratch array to decide the right migratetype.
Expose kho_scratch_overlap() to KHO users. Since it is now used by
non-debug code, move it out of kexec_handover_debug.c and into
kexec_handover.c. Gate the overlap checks in kho_preserve_folio() and
kho_preserve_pages() by IS_ENABLED(CONFIG_KEXEC_HANDOVER_DEBUG) instead.
Since kexec_handover_debug.c is now empty, delete it.
Add a stub for kho_scratch_overlap() to memblock tests to make sure it
compiles. It will be used in memblock by a coming commit.
No functional changes.
Signed-off-by: Pratyush Yadav (Google) <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Mike Rapoport (Microsoft) <[email protected]>
Pull liveupdate updates from Mike Rapoport:
"Kexec Handover (KHO):
- make memory preservation compatible with deferred initialization
of the memory map
Live Update Orchestrator (LUO):
- add LIVEUPDATE_SESSION_GET_NAME ioctl and parameter verification
for LIVEUPDATE_IOCTL_CREATE_SESSION ioctl
- documentation updates for liveupdate=on command line option,
systemd support and the current compatibility status
- remove the fixed limits on the number of files that can be
preserved within a single session, and the total number of
sessions managed by the LUO
Misc fixes:
- reference count incoming File-Lifecycle-Bound (FLB) data so
it cannot be freed while a subsystem is still using it
- fixes for a TOCTOU race in luo_session_retrieve(), a use-
after-free in the file finish and unpreserve paths, concurrent
session mutations during reboot and serialization on
preserve_context kexec
- make sure ioctls for incoming LUO sessions are blocked for
outgoing sessions and vice versa
- make sure KHO scratch size is always aligned by
CMA_MIN_ALIGNMENT_BYTES
- fix memblock tests build issue introduced by KHO changes"
* tag 'liveupdate-v7.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/liveupdate/linux: (36 commits)
liveupdate: Document that retrieve failure is permanent
docs: memfd_preservation: fix rendering of ABI documentation
selftests/liveupdate: Add stress-files kexec test
selftests/liveupdate: Add stress-sessions kexec test
selftests/liveupdate: Test session and file limit removal
liveupdate: Remove limit on the number of files per session
liveupdate: Remove limit on the number of sessions
liveupdate: defer session block allocation and physical address setting
kho: add support for linked-block serialization
liveupdate: Extract luo_session_deserialize_one helper
liveupdate: Extract luo_file_deserialize_one helper
liveupdate: register luo_ser as KHO subtree
liveupdate: centralize state management into struct luo_ser
liveupdate: avoid mixing cleanup guards with goto in luo_session_retrieve_fd
liveupdate: change file_set->count type to u64 for type safety
liveupdate: Remove unused ser field from struct luo_session
liveupdate: fix u-a-f in luo_file_unpreserve_files() and luo_file_finish()
liveupdate: block session mutations during reboot
liveupdate: fix TOCTOU race in luo_session_retrieve()
liveupdate: skip serialization for context-preserving kexec
...
memblock allocations now reserve memory with MEMBLOCK_RSRV_KERN and,
on NUMA configurations, record the requested node on the reserved
region. Several memblock simulator NUMA tests still expected merges
that only worked before those reservation semantics changed, so the
suite aborted even though the allocator behavior was correct.
Update the NUMA merge expectations in the memblock_alloc_try_nid()
and memblock_alloc_exact_nid_raw() tests to match the current reserved
region metadata rules. For cases that should still merge, create the
pre-existing reservation with matching nid and MEMBLOCK_RSRV_KERN
metadata. Also strengthen the memblock_alloc_node() coverage by
checking the newly created reserved region directly instead of
re-reading the source memory node descriptor.
Finally, drop the stale README/TODO notes that still claimed
memblock_alloc_node() could not be tested.
The memblock simulator passes again with NUMA enabled after these
updates.
Signed-off-by: Priyanshu Kumar <[email protected]>
Link: https://patch.msgid.link/[email protected]
[rppt: dropped unrelated changes]
Signed-off-by: Mike Rapoport (Microsoft) <[email protected]>
kho_scratch_migratetype(), defined in include/linux/memblock.h uses enum
migratetype. This breaks build for memblock tests with:
./linux/memblock.h:634:73: error: parameter 2 (‘mt’) has incomplete type
634 | enum migratetype mt)
Fix it by defining enum migratetype and MIGRATE_CMA. As is the case with
the other headers in tools/testing/memblock, do not bring in the whole
thing, only what is needed.
Reported-by: Mike Rapoport <[email protected]>
Closes: https://lore.kernel.org/linux-mm/[email protected]/
Signed-off-by: Pratyush Yadav (Google) <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Mike Rapoport (Microsoft) <[email protected]>
free_reserved_area() is related to memblock as it frees reserved memory
back to the buddy allocator, similar to what memblock_free_late() does.
Move free_reserved_area() to mm/memblock.c to prepare for further
consolidation of the functions that free reserved memory.
No functional changes.
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Mike Rapoport (Microsoft) <[email protected]>
Acked-by: Vlastimil Babka (SUSE) <[email protected]>
reserve_bootmem_region() is only called from
memmap_init_reserved_pages() and it was in mm/mm_init.c because of its
dependecies on static init_deferred_page().
Since init_deferred_page() is not static anymore, move
reserve_bootmem_region(), rename it to memmap_init_reserved_range() and
make it static.
Update the comment describing it to better reflect what the function
does and drop bogus comment about reserved pages in free_bootmem_page().
Update memblock test stubs to reflect the core changes.
Reviewed-by: Lorenzo Stoakes (Oracle) <[email protected]>
Reviewed-by: David Hildenbrand (Arm) <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Mike Rapoport (Microsoft) <[email protected]>
When using the "reserve_mem" parameter, users aim at having an
area that (hopefully) persists across boots, so pstore infrastructure
(like ramoops module) can make use of that to save oops/ftrace logs,
for example.
There is no easy way to determine if this kernel parameter is properly
set though; the kernel doesn't show information about this memory in
memblock debugfs, neither in /proc/iomem nor dmesg. This is a relevant
information for tools like kdumpst[0], to determine if it's reliable
to use the reserved area as ramoops persistent storage; checking only
/proc/cmdline is not sufficient as it doesn't tell if the reservation
effectively succeeded or not.
Add here a new file under memblock debugfs showing properly set memory
reservations, with name and size as passed to "reserve_mem". Notice that
if no "reserve_mem=" is passed on command-line or if the reservation
attempts fail, the file is not created.
[0] https://aur.archlinux.org/packages/kdumpst
Reviewed-by: SeongJae Park <[email protected]>
Signed-off-by: Guilherme G. Piccoli <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Mike Rapoport (Microsoft) <[email protected]>
memblock_free_pages() currently takes both a struct page * and the
corresponding PFN. The page pointer is always derived from the PFN at
call sites (pfn_to_page(pfn)), making the parameter redundant and also
allowing accidental mismatches between the two arguments.
Simplify the interface by removing the struct page * argument and
deriving the page locally from the PFN, after the deferred struct page
initialization check. This keeps the behavior unchanged while making
the helper harder to misuse.
Signed-off-by: Shengming Hu <[email protected]>
Reviewed-by: David Hildenbrand (Red Hat) <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Mike Rapoport (Microsoft) <[email protected]>
Patch series "kexec: introduce Kexec HandOver (KHO)", v8.
Kexec today considers itself purely a boot loader: When we enter the new
kernel, any state the previous kernel left behind is irrelevant and the
new kernel reinitializes the system.
However, there are use cases where this mode of operation is not what we
actually want. In virtualization hosts for example, we want to use kexec
to update the host kernel while virtual machine memory stays untouched.
When we add device assignment to the mix, we also need to ensure that
IOMMU and VFIO states are untouched. If we add PCIe peer to peer DMA, we
need to do the same for the PCI subsystem. If we want to kexec while an
SEV-SNP enabled virtual machine is running, we need to preserve the VM
context pages and physical memory. See "pkernfs: Persisting guest memory
and kernel/device state safely across kexec" Linux Plumbers Conference
2023 presentation for details:
https://lpc.events/event/17/contributions/1485/
To start us on the journey to support all the use cases above, this patch
implements basic infrastructure to allow hand over of kernel state across
kexec (Kexec HandOver, aka KHO). As a really simple example target, we
use memblock's reserve_mem.
With this patchset applied, memory that was reserved using "reserve_mem"
command line options remains intact after kexec and it is guaranteed to
reside at the same physical address.
== Alternatives ==
There are alternative approaches to (parts of) the problems above:
* Memory Pools [1] - preallocated persistent memory region + allocator
* PRMEM [2] - resizable persistent memory regions with fixed metadata
pointer on the kernel command line + allocator
* Pkernfs [3] - preallocated file system for in-kernel data with fixed
address location on the kernel command line
* PKRAM [4] - handover of user space pages using a fixed metadata page
specified via command line
All of the approaches above fundamentally have the same problem: They
require the administrator to explicitly carve out a physical memory
location because they have no mechanism outside of the kernel command line
to pass data (including memory reservations) between kexec'ing kernels.
KHO provides that base foundation. We will determine later whether we
still need any of the approaches above for fast bulk memory handover of
for example IOMMU page tables. But IMHO they would all be users of KHO,
with KHO providing the foundational primitive to pass metadata and bulk
memory reservations as well as provide easy versioning for data.
== Overview ==
We introduce a metadata file that the kernels pass between each other.
How they pass it is architecture specific. The file's format is a
Flattened Device Tree (fdt) which has a generator and parser already
included in Linux. KHO is enabled in the kernel command line by `kho=on`.
When the root user enables KHO through
/sys/kernel/debug/kho/out/finalize, the kernel invokes callbacks to every
KHO users to register preserved memory regions, which contain drivers'
states.
When the actual kexec happens, the fdt is part of the image set that we
boot into. In addition, we keep "scratch regions" available for kexec:
physically contiguous memory regions that are guaranteed to not have any
memory that KHO would preserve. The new kernel bootstraps itself using
the scratch regions and sets all handed over memory as in use. When
drivers initialize that support KHO, they introspect the fdt, restore
preserved memory regions, and retrieve their states stored in the
preserved memory.
== Limitations ==
Currently KHO is only implemented for file based kexec. The kernel
interfaces in the patch set are already in place to support user space
kexec as well, but it is still not implemented it yet inside kexec tools.
== How to Use ==
To use the code, please boot the kernel with the "kho=on" command line
parameter. KHO will automatically create scratch regions. If you want to
set the scratch size explicitly you can use "kho_scratch=" command line
parameter. For instance, "kho_scratch=16M,512M,256M" will reserve a 16
MiB low memory scratch area, a 512 MiB global scratch region, and 256 MiB
per NUMA node scratch regions on boot.
Make sure to have a reserved memory range requested with reserv_mem
command line option, for example, "reserve_mem=64m:4k:n1".
Then before you invoke file based "kexec -l", finalize KHO FDT:
# echo 1 > /sys/kernel/debug/kho/out/finalize
You can preview the generated FDT using `dtc`,
# dtc /sys/kernel/debug/kho/out/fdt
# dtc /sys/kernel/debug/kho/out/sub_fdts/memblock
`dtc` is available on ubuntu by `sudo apt-get install device-tree-compiler`.
Now kexec into the new kernel,
# kexec -l Image --initrd=initrd -s
# kexec -e
(The order of KHO finalization and "kexec -l" does not matter.)
The new kernel will boot up and contain the previous kernel's reserve_mem
contents at the same physical address as the first kernel.
You can also review the FDT passed from the old kernel,
# dtc /sys/kernel/debug/kho/in/fdt
# dtc /sys/kernel/debug/kho/in/sub_fdts/memblock
This patch (of 17):
To denote areas that were reserved for kernel use either directly with
memblock_reserve_kern() or via memblock allocations.
Link: https://lore.kernel.org/lkml/[email protected]/
Link: https://lore.kernel.org/lkml/[email protected]/
Link: https://lore.kernel.org/lkml/[email protected]/
Link: https://lore.kernel.org/lkml/[email protected]/
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Mike Rapoport (Microsoft) <[email protected]>
Co-developed-by: Changyuan Lyu <[email protected]>
Signed-off-by: Changyuan Lyu <[email protected]>
Cc: Alexander Graf <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Anthony Yznaga <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Cc: Ashish Kalra <[email protected]>
Cc: Ben Herrenschmidt <[email protected]>
Cc: Borislav Betkov <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: David Woodhouse <[email protected]>
Cc: Eric Biederman <[email protected]>
Cc: "H. Peter Anvin" <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: James Gowans <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Cc: Krzysztof Kozlowski <[email protected]>
Cc: Marc Rutland <[email protected]>
Cc: Paolo Bonzini <[email protected]>
Cc: Pasha Tatashin <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Pratyush Yadav <[email protected]>
Cc: Rob Herring <[email protected]>
Cc: Saravana Kannan <[email protected]>
Cc: Stanislav Kinsburskii <[email protected]>
Cc: Steven Rostedt <[email protected]>
Cc: Thomas Gleinxer <[email protected]>
Cc: Thomas Lendacky <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: Jason Gunthorpe <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Add a test to check memblock_set_node() behavior.
And create a corner case in which the memblock.reserved array is doubled
during memblock_set_node(). And finally make sure all regions in
memblock.reserved are with valid node id.
Signed-off-by: Wei Yang <[email protected]>
CC: Mike Rapoport <[email protected]>
CC: Yajun Deng <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Mike Rapoport (Microsoft) <[email protected]>
Pull memblock updates from Mike Rapoport:
- new memblock_estimated_nr_free_pages() helper to replace
totalram_pages() which is less accurate when
CONFIG_DEFERRED_STRUCT_PAGE_INIT is set
- fixes for memblock tests
* tag 'memblock-v6.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock:
s390/mm: get estimated free pages by memblock api
kernel/fork.c: get estimated free pages by memblock api
mm/memblock: introduce a new helper memblock_estimated_nr_free_pages()
memblock test: fix implicit declaration of function 'strscpy'
memblock test: fix implicit declaration of function 'isspace'
memblock test: fix implicit declaration of function 'memparse'
memblock test: add the definition of __setup()
memblock test: fix implicit declaration of function 'virt_to_phys'
tools/testing: abstract two init.h into common include directory
memblock tests: include export.h in linkage.h as kernel dose
memblock tests: include memory_hotplug.h in mmzone.h as kernel dose
Commit 1e4c64b71c ("mm/memblock: Add "reserve_mem" to reserved named
memory at boot up") introduce the usage of memparse(), which is not
defined in memblock test.
Add the definition and link it to fix the build.
Signed-off-by: Wei Yang <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Mike Rapoport (Microsoft) <[email protected]>
This may trigger the case fixed by commit 48c3b583bb ("mm/memblock:
fix overlapping allocation when doubling reserved array").
This is done by adding the 129th reserve region into memblock.memory. If
memblock_double_array() use this reserve region as new array, it fails.
Signed-off-by: Wei Yang <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Mike Rapoport (IBM) <[email protected]>
The dummy entry is introduced in the initial implementation of lmb in
commit 7c8c6b9776 ("powerpc: Merge lmb.c and make MM initialization
use it.").
As the comment says the empty dummy entry is to simplify the code.
/* Create a dummy zero size LMB which will get coalesced away later.
* This simplifies the lmb_add() code below...
*/
While current code is reimplemented by Tejun in commit 784656f9c6
("memblock: Reimplement memblock_add_region()"). This empty dummy entry
seems not benefit the code any more.
Let's remove it.
Signed-off-by: Wei Yang <[email protected]>
CC: Paul Mackerras <[email protected]>
CC: Tejun Heo <[email protected]>
CC: Mike Rapoport <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Mike Rapoport (IBM) <[email protected]>
commit 23baf831a3 ("mm, treewide: redefine MAX_ORDER sanely") has
changed the definition of MAX_ORDER to be inclusive. This has caused
issues with code that was not yet upstream and depended on the previous
definition.
To draw attention to the altered meaning of the define, rename MAX_ORDER
to MAX_PAGE_ORDER.
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Kirill A. Shutemov <[email protected]>
Cc: Linus Torvalds <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Building memblock tests produces the following warning:
cc -I. -I../../include -Wall -O2 -fsanitize=address -fsanitize=undefined -D CONFIG_PHYS_ADDR_T_64BIT -c -o main.o main.c
In file included from tests/common.h:9,
from tests/basic_api.h:5,
from main.c:2:
./linux/memblock.h:601:50: warning: ‘struct seq_file’ declared inside parameter list will not be visible outside of this definition or declaration
601 | static inline void memtest_report_meminfo(struct seq_file *m) { }
| ^~~~~~~~
Add declaration of 'struct seq_file' to tools/include/linux/seq_file.h
to fix it.
Signed-off-by: Mike Rapoport (IBM) <[email protected]>
This patch fix the follow errors.
commit 61167ad5fe ("mm: pass nid to reserve_bootmem_region()") pass nid
parameter to reserve_bootmem_region(),
$ make -C tools/testing/memblock/
...
memblock.c: In function ‘memmap_init_reserved_pages’:
memblock.c:2111:25: error: too many arguments to function ‘reserve_bootmem_region’
2111 | reserve_bootmem_region(start, end, nid);
| ^~~~~~~~~~~~~~~~~~~~~~
../../include/linux/mm.h:32:6: note: declared here
32 | void reserve_bootmem_region(phys_addr_t start, phys_addr_t end);
| ^~~~~~~~~~~~~~~~~~~~~~
memblock.c:2122:17: error: too many arguments to function ‘reserve_bootmem_region’
2122 | reserve_bootmem_region(start, end, nid);
| ^~~~~~~~~~~~~~~~~~~~~~
commit dcdfdd40fa ("mm: Add support for unaccepted memory") call
accept_memory() in memblock.c
$ make -C tools/testing/memblock/
...
cc -fsanitize=address -fsanitize=undefined main.o memblock.o \
lib/slab.o mmzone.o slab.o tests/alloc_nid_api.o \
tests/alloc_helpers_api.o tests/alloc_api.o tests/basic_api.o \
tests/common.o tests/alloc_exact_nid_api.o -o main
/usr/bin/ld: memblock.o: in function `memblock_alloc_range_nid':
memblock.c:(.text+0x7ae4): undefined reference to `accept_memory'
Signed-off-by: Rong Tao <[email protected]>
Fixes: dcdfdd40fa ("mm: Add support for unaccepted memory")
Fixes: 61167ad5fe ("mm: pass nid to reserve_bootmem_region()")
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Mike Rapoport (IBM) <[email protected]>
This test is aimed at verifying the memblock_alloc_node() to work as
expected, so setting the correct NUMA node for the new allocated
region. The memblock_alloc_node() is called directly without using any
stub. The core check is between the requested NUMA node and the `nid`
field inside the memblock_region structure. These two are supposed to
be equal for the test to succeed.
Signed-off-by: Claudio Migliorelli <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Mike Rapoport (IBM) <[email protected]>
This reverts commit 115d9d77bb.
The pages being freed by memblock_free_late() have already been
initialized, but if they are in the deferred init range,
__free_one_page() might access nearby uninitialized pages when trying to
coalesce buddies. This can, for example, trigger this BUG:
BUG: unable to handle page fault for address: ffffe964c02580c8
RIP: 0010:__list_del_entry_valid+0x3f/0x70
<TASK>
__free_one_page+0x139/0x410
__free_pages_ok+0x21d/0x450
memblock_free_late+0x8c/0xb9
efi_free_boot_services+0x16b/0x25c
efi_enter_virtual_mode+0x403/0x446
start_kernel+0x678/0x714
secondary_startup_64_no_verify+0xd2/0xdb
</TASK>
A proper fix will be more involved so revert this change for the time
being.
Fixes: 115d9d77bb ("mm: Always release pages to the buddy allocator in memblock_free_late().")
Signed-off-by: Aaron Thompson <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Mike Rapoport (IBM) <[email protected]>
If CONFIG_DEFERRED_STRUCT_PAGE_INIT is enabled, memblock_free_pages()
only releases pages to the buddy allocator if they are not in the
deferred range. This is correct for free pages (as defined by
for_each_free_mem_pfn_range_in_zone()) because free pages in the
deferred range will be initialized and released as part of the deferred
init process. memblock_free_pages() is called by memblock_free_late(),
which is used to free reserved ranges after memblock_free_all() has
run. All pages in reserved ranges have been initialized at that point,
and accordingly, those pages are not touched by the deferred init
process. This means that currently, if the pages that
memblock_free_late() intends to release are in the deferred range, they
will never be released to the buddy allocator. They will forever be
reserved.
In addition, memblock_free_pages() calls kmsan_memblock_free_pages(),
which is also correct for free pages but is not correct for reserved
pages. KMSAN metadata for reserved pages is initialized by
kmsan_init_shadow(), which runs shortly before memblock_free_all().
For both of these reasons, memblock_free_pages() should only be called
for free pages, and memblock_free_late() should call __free_pages_core()
directly instead.
One case where this issue can occur in the wild is EFI boot on
x86_64. The x86 EFI code reserves all EFI boot services memory ranges
via memblock_reserve() and frees them later via memblock_free_late()
(efi_reserve_boot_services() and efi_free_boot_services(),
respectively). If any of those ranges happens to fall within the
deferred init range, the pages will not be released and that memory will
be unavailable.
For example, on an Amazon EC2 t3.micro VM (1 GB) booting via EFI:
v6.2-rc2:
# grep -E 'Node|spanned|present|managed' /proc/zoneinfo
Node 0, zone DMA
spanned 4095
present 3999
managed 3840
Node 0, zone DMA32
spanned 246652
present 245868
managed 178867
v6.2-rc2 + patch:
# grep -E 'Node|spanned|present|managed' /proc/zoneinfo
Node 0, zone DMA
spanned 4095
present 3999
managed 3840
Node 0, zone DMA32
spanned 246652
present 245868
managed 222816 # +43,949 pages
Fixes: 3a80a7fa79 ("mm: meminit: initialise a subset of struct pages if CONFIG_DEFERRED_STRUCT_PAGE_INIT is set")
Signed-off-by: Aaron Thompson <[email protected]>
Link: https://lore.kernel.org/r/01010185892de53e-e379acfb-7044-4b24-b30a-e2657c1ba989-000000@us-west-2.amazonses.com
Signed-off-by: Mike Rapoport (IBM) <[email protected]>
Commit cf4694be2b ("tools: Add atomic_test_and_set_bit()") changed
tools/arch/x86/include/asm/atomic.h to include <asm/asm.h>, which causes
'make -C tools/testing/memblock' to fail with:
In file included from ../../include/asm/atomic.h:6,
from ../../include/linux/atomic.h:5,
from ./linux/mmzone.h:5,
from ../../include/linux/mm.h:5,
from ../../include/linux/pfn.h:5,
from ./linux/memory_hotplug.h:6,
from ./linux/init.h:7,
from ./linux/memblock.h:11,
from tests/common.h:8,
from tests/basic_api.h:5,
from main.c:2:
../../include/asm/../../arch/x86/include/asm/atomic.h:11:10: fatal error: asm/asm.h: No such file or directory
11 | #include <asm/asm.h>
| ^~~~~~~~~~~
Create a symlink to asm/asm.h in the same manner as the existing one to
asm/cmpxchg.h.
Signed-off-by: Aaron Thompson <[email protected]>
Link: https://lore.kernel.org/r/010101857c402765-96e2dbc6-b82b-47e2-a437-4834dbe0b96b-000000@us-west-2.amazonses.com
Signed-off-by: Mike Rapoport (IBM) <[email protected]>
Add tests for memblock_alloc_exact_nid_raw() where the simulated physical
memory is set up with multiple NUMA nodes. Additionally, all but one of
these tests set nid != NUMA_NO_NODE. All tests are run for both top-down
and bottom-up allocation directions.
The tested scenarios are:
Range unrestricted:
- region cannot be allocated:
+ there are no previously reserved regions, but requested node is
too small
+ the requested node is fully reserved
+ the requested node is partially reserved and does not have
enough space
+ none of the nodes have enough memory to allocate the region
Range restricted:
- region can be allocated in the specific node requested without
dropping min_addr:
+ the range fully overlaps with the node, and there are adjacent
reserved regions
- region cannot be allocated:
+ range partially overlaps with two different nodes, where the
second node is the requested node
+ range overlaps with multiple nodes along node boundaries, and
the requested node starts after max_addr
+ nid is set to NUMA_NO_NODE and the total range can fit the
region, but the range is split between two nodes and everything
else is reserved
Acked-by: David Hildenbrand <[email protected]>
Signed-off-by: Rebecca Mckeever <[email protected]>
Signed-off-by: Mike Rapoport <[email protected]>
Link: https://lore.kernel.org/r/51b14da46e6591428df3aefc5acc7dca9341a541.1667802195.git.remckee0@gmail.com
Add tests for memblock_alloc_exact_nid_raw() where the simulated physical
memory is set up with multiple NUMA nodes. Additionally, all of these
tests set nid != NUMA_NO_NODE. These tests are run with a bottom-up
allocation direction.
The tested scenarios are:
Range unrestricted:
- region can be allocated in the specific node requested:
+ there are no previously reserved regions
+ the requested node is partially reserved but has enough space
Range restricted:
- region can be allocated in the specific node requested after dropping
min_addr:
+ range partially overlaps with two different nodes, where the
first node is the requested node
+ range partially overlaps with two different nodes, where the
requested node ends before min_addr
+ range overlaps with multiple nodes along node boundaries, and
the requested node ends before min_addr
Acked-by: David Hildenbrand <[email protected]>
Signed-off-by: Rebecca Mckeever <[email protected]>
Signed-off-by: Mike Rapoport <[email protected]>
Link: https://lore.kernel.org/r/935f0eed5e06fd44dc67d9f49b277923d7896bd3.1667802195.git.remckee0@gmail.com
Add tests for memblock_alloc_exact_nid_raw() where the simulated physical
memory is set up with multiple NUMA nodes. Additionally, all of these
tests set nid != NUMA_NO_NODE. These tests are run with a top-down
allocation direction.
The tested scenarios are:
Range unrestricted:
- region can be allocated in the specific node requested:
+ there are no previously reserved regions
+ the requested node is partially reserved but has enough space
Range restricted:
- region can be allocated in the specific node requested after dropping
min_addr:
+ range partially overlaps with two different nodes, where the
first node is the requested node
+ range partially overlaps with two different nodes, where the
requested node ends before min_addr
+ range overlaps with multiple nodes along node boundaries, and
the requested node ends before min_addr
Acked-by: David Hildenbrand <[email protected]>
Signed-off-by: Rebecca Mckeever <[email protected]>
Signed-off-by: Mike Rapoport <[email protected]>
Link: https://lore.kernel.org/r/2cc0883243d68ddc3faf833d2d9e86f48534c1d7.1667802195.git.remckee0@gmail.com
Add TEST_F_EXACT flag, which specifies that tests should run
memblock_alloc_exact_nid_raw(). Introduce range tests for
memblock_alloc_exact_nid_raw() by using the TEST_F_EXACT flag to run the
range tests in alloc_nid_api.c, since memblock_alloc_exact_nid_raw() and
memblock_alloc_try_nid_raw() behave the same way when nid = NUMA_NO_NODE.
Rename tests and other functions in alloc_nid_api.c by removing "_try".
Since the test names will be displayed in verbose output, they need to
be general enough to refer to any of the memblock functions that the
tests may run.
Acked-by: David Hildenbrand <[email protected]>
Signed-off-by: Rebecca Mckeever <[email protected]>
Signed-off-by: Mike Rapoport <[email protected]>
Link: https://lore.kernel.org/r/5a4b6d1b6130ab7375314e1c45a6d5813dfdabbd.1667802195.git.remckee0@gmail.com
Reserve 129th region in the memblock, and this will trigger the
memblock_double_array() function, this needs valid memory regions. So
using dummy_physical_memory_init() to allocate a valid memory region.
At the same time, reserve 128 faked memory region, and make sure these
reserved region not intersect with the valid memory region. So
memblock_double_array() will choose the valid memory region, and it will
success.
Also need to restore the reserved.regions after memblock_double_array(),
to make sure the subsequent tests can run as normal.
Signed-off-by: Shaoqin Huang <[email protected]>
Signed-off-by: Mike Rapoport <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Add 129th region into the memblock, and this will trigger the
memblock_double_array() function, this needs valid memory regions. So
using dummy_physical_memory_init() to allocate a large enough memory
region, and split it into a large enough memory which can be choosed by
memblock_double_array(), and the left memory will be split into small
memory region, and add them into the memblock. It make sure the
memblock_double_array() will always choose the valid memory region that
is allocated by the dummy_physical_memory_init().
So memblock_double_array() must success.
Another thing should be done is to restore the memory.regions after
memblock_double_array(), due to now the memory.regions is pointing to a
memory region allocated by dummy_physical_memory_init(). And it will
affect the subsequent tests if we don't restore the memory region. So
simply record the origin region, and restore it after the test.
Signed-off-by: Shaoqin Huang <[email protected]>
Signed-off-by: Mike Rapoport <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Pull memblock updates from Mike Rapoport:
"Test suite improvements:
- Added verification that memblock allocations zero the allocated
memory
- Added more test cases for memblock_add(), memblock_remove(),
memblock_reserve() and memblock_free()
- Added tests for memblock_*_raw() family
- Added tests for NUMA-aware allocations in memblock_alloc_try_nid()
and memblock_alloc_try_nid_raw()"
* tag 'memblock-v6.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock:
memblock tests: add generic NUMA tests for memblock_alloc_try_nid*
memblock tests: add bottom-up NUMA tests for memblock_alloc_try_nid*
memblock tests: add top-down NUMA tests for memblock_alloc_try_nid*
memblock tests: add simulation of physical memory with multiple NUMA nodes
memblock_tests: move variable declarations to single block
memblock tests: remove 'cleared' from comment blocks
memblock tests: add tests for memblock_trim_memory
memblock tests: add tests for memblock_*bottom_up functions
memblock tests: update alloc_nid_api to test memblock_alloc_try_nid_raw
memblock tests: update alloc_api to test memblock_alloc_raw
memblock tests: add additional tests for basic api and memblock_alloc
memblock tests: add labels to verbose output for generic alloc tests
memblock tests: update zeroed memory check for memblock_alloc_* tests
memblock tests: update tests to check if memblock_alloc zeroed memory
memblock tests: update reference to obsolete build option in comments
memblock tests: add command line help option
Add tests for memblock_alloc_try_nid() and memblock_alloc_try_nid_raw()
where the simulated physical memory is set up with multiple NUMA nodes.
Additionally, two of these tests set nid != NUMA_NO_NODE. All tests are
run for both top-down and bottom-up allocation directions.
The tested scenarios are:
Range unrestricted:
- region cannot be allocated:
+ none of the nodes have enough memory to allocate the region
Range restricted:
- region can be allocated in the specific node requested without dropping
min_addr:
+ the range fully overlaps with the node, and there are adjacent
reserved regions
- region cannot be allocated:
+ nid is set to NUMA_NO_NODE and the total range can fit the region,
but the range is split between two nodes and everything else is
reserved
Acked-by: David Hildenbrand <[email protected]>
Signed-off-by: Rebecca Mckeever <[email protected]>
Signed-off-by: Mike Rapoport <[email protected]>
Link: https://lore.kernel.org/r/4b2c7e6e5f3a9837939e99293c77e0e6fc3ae4f9.1663046060.git.remckee0@gmail.com
Add tests for memblock_alloc_try_nid() and memblock_alloc_try_nid_raw()
where the simulated physical memory is set up with multiple NUMA nodes.
Additionally, all of these tests set nid != NUMA_NO_NODE. These tests are
run with a bottom-up allocation direction.
The tested scenarios are:
Range unrestricted:
- region can be allocated in the specific node requested:
+ there are no previously reserved regions
+ the requested node is partially reserved but has enough space
- the specific node requested cannot accommodate the request, but the
region can be allocated in a different node:
+ there are no previously reserved regions, but node is too small
+ the requested node is fully reserved
+ the requested node is partially reserved and does not have
enough space
Range restricted:
- region can be allocated in the specific node requested after dropping
min_addr:
+ range partially overlaps with two different nodes, where the first
node is the requested node
+ range partially overlaps with two different nodes, where the
requested node ends before min_addr
- region cannot be allocated in the specific node requested, but it can be
allocated in the requested range:
+ range overlaps with multiple nodes along node boundaries, and the
requested node ends before min_addr
+ range overlaps with multiple nodes along node boundaries, and the
requested node starts after max_addr
- region cannot be allocated in the specific node requested, but it can be
allocated after dropping min_addr:
+ range partially overlaps with two different nodes, where the
second node is the requested node
Acked-by: David Hildenbrand <[email protected]>
Signed-off-by: Rebecca Mckeever <[email protected]>
Signed-off-by: Mike Rapoport <[email protected]>
Link: https://lore.kernel.org/r/00c4810daaf5d050abc71915b24ed7419bb16b51.1663046060.git.remckee0@gmail.com
Add tests for memblock_alloc_try_nid() and memblock_alloc_try_nid_raw()
where the simulated physical memory is set up with multiple NUMA nodes.
Additionally, all of these tests set nid != NUMA_NO_NODE. These tests are
run with a top-down allocation direction.
The tested scenarios are:
Range unrestricted:
- region can be allocated in the specific node requested:
+ there are no previously reserved regions
+ the requested node is partially reserved but has enough space
- the specific node requested cannot accommodate the request, but the
region can be allocated in a different node:
+ there are no previously reserved regions, but node is too small
+ the requested node is fully reserved
+ the requested node is partially reserved and does not have
enough space
Range restricted:
- region can be allocated in the specific node requested after dropping
min_addr:
+ range partially overlaps with two different nodes, where the first
node is the requested node
+ range partially overlaps with two different nodes, where the
requested node ends before min_addr
- region cannot be allocated in the specific node requested, but it can be
allocated in the requested range:
+ range overlaps with multiple nodes along node boundaries, and the
requested node ends before min_addr
+ range overlaps with multiple nodes along node boundaries, and the
requested node starts after max_addr
- region cannot be allocated in the specific node requested, but it can be
allocated after dropping min_addr:
+ range partially overlaps with two different nodes, where the
second node is the requested node
Acked-by: David Hildenbrand <[email protected]>
Signed-off-by: Rebecca Mckeever <[email protected]>
Signed-off-by: Mike Rapoport <[email protected]>
Link: https://lore.kernel.org/r/84009c5b3969337ccf89df850db56d364f8c228b.1663046060.git.remckee0@gmail.com
Add function setup_numa_memblock() for setting up a memory layout with
multiple NUMA nodes in a previously allocated dummy physical memory.
This function can be used in place of setup_memblock() in tests that need
to simulate a NUMA system.
setup_numa_memblock():
- allows for setting up a memory layout by specifying the fraction of
MEM_SIZE in each node
Set CONFIG_NODES_SHIFT to 4 when building with NUMA=1 to allow for up to
16 NUMA nodes.
Reviewed-by: David Hildenbrand <[email protected]>
Signed-off-by: Rebecca Mckeever <[email protected]>
Signed-off-by: Mike Rapoport <[email protected]>
Link: https://lore.kernel.org/r/4566d816a85f009268d4858d1ef06c7571a960f9.1663046060.git.remckee0@gmail.com
The tests in alloc_nid_api can now run either memblock_alloc_try_nid()
or memblock_alloc_try_nid_raw(). The comment blocks for these tests
should not refer to a 'cleared' region since that only applies to
memblock_alloc_try_nid(). Remove 'cleared' from the comment blocks so
that the comments are accurate for either memblock function.
Signed-off-by: Rebecca Mckeever <[email protected]>
Signed-off-by: Mike Rapoport <[email protected]>
Link: https://lore.kernel.org/r/e8be24137e54e9f81a06af969ded82b319114d7a.1662264347.git.remckee0@gmail.com
Linus Torvalds