205 Commits
Author SHA1 Message Date
Dave Airlie 2232ba9c79 mm: add gpu active/reclaim per-node stat counters (v2)
While discussing memcg intergration with gpu memory allocations,
it was pointed out that there was no numa/system counters for
GPU memory allocations.

With more integrated memory GPU server systems turning up, and
more requirements for memory tracking it seems we should start
closing the gap.

Add two counters to track GPU per-node system memory allocations.

The first is currently allocated to GPU objects, and the second
is for memory that is stored in GPU page pools that can be reclaimed,
by the shrinker.

Cc: Christian Koenig <christian.koenig@amd.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: linux-mm@kvack.org
Cc: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Zi Yan <ziy@nvidia.com>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2026-04-08 06:52:47 +10:00
Linus Torvalds bf4afc53b7 Convert 'alloc_obj' family to use the new default GFP_KERNEL argument
This was done entirely with mindless brute force, using

    git grep -l '\<k[vmz]*alloc_objs*(.*, GFP_KERNEL)' |
        xargs sed -i 's/\(alloc_objs*(.*\), GFP_KERNEL)/\1)/'

to convert the new alloc_obj() users that had a simple GFP_KERNEL
argument to just drop that argument.

Note that due to the extreme simplicity of the scripting, any slightly
more complex cases spread over multiple lines would not be triggered:
they definitely exist, but this covers the vast bulk of the cases, and
the resulting diff is also then easier to check automatically.

For the same reason the 'flex' versions will be done as a separate
conversion.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2026-02-21 17:09:51 -08:00
Kees Cook 69050f8d6d treewide: Replace kmalloc with kmalloc_obj for non-scalar types
This is the result of running the Coccinelle script from
scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to
avoid scalar types (which need careful case-by-case checking), and
instead replace kmalloc-family calls that allocate struct or union
object instances:

Single allocations:	kmalloc(sizeof(TYPE), ...)
are replaced with:	kmalloc_obj(TYPE, ...)

Array allocations:	kmalloc_array(COUNT, sizeof(TYPE), ...)
are replaced with:	kmalloc_objs(TYPE, COUNT, ...)

Flex array allocations:	kmalloc(struct_size(PTR, FAM, COUNT), ...)
are replaced with:	kmalloc_flex(*PTR, FAM, COUNT, ...)

(where TYPE may also be *VAR)

The resulting allocations no longer return "void *", instead returning
"TYPE *".

Signed-off-by: Kees Cook <kees@kernel.org>
2026-02-21 01:02:28 -08:00
Donet TomandAndrew Morton d945667dcb drivers/base/node: fold unregister_node() into unregister_one_node()
unregister_node() is only called from unregister_one_node().  This patch
folds unregister_node() into its only caller and renames
unregister_one_node() to unregister_node().

This reduces unnecessary indirection and simplifies the code structure. 
No functional changes are introduced.

[donettom@linux.ibm.com: remove extra spaces before @nid and "All"]
  Link: https://lkml.kernel.org/r/cff01514-9074-4c97-bcf1-d4e3594e48b0@linux.ibm.com
Link: https://lkml.kernel.org/r/32b7d5d8f0f30d313c3e1d8798f591459c8746f9.1760097208.git.donettom@linux.ibm.com
Signed-off-by: Donet Tom <donettom@linux.ibm.com>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Acked-by: SeongJae Park <sj@kernel.org>
Cc: Aboorva Devarajan <aboorvad@linux.ibm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Danilo Krummrich <dakr@kernel.org>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "Ritesh Harjani (IBM)" <ritesh.list@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16 17:28:03 -08:00
Donet TomandAndrew Morton eb8762dc22 drivers/base/node: fold register_node() into register_one_node()
Patch series "drivers/base/node: fold node register and unregister
functions", v2.

The first patch merges register_one_node() and register_node(), leaving a
single register_node() function.

The second patch merges unregister_one_node() and unregister_node(),
leaving a single unregister_node() function.

There are no functional changes in these patches.


This patch (of 2):

register_node() is only called from register_one_node().  This patch folds
register_node() into its only caller and renames register_one_node() to
register_node().

This reduces unnecessary indirection and simplifies the code structure. 
No functional changes are introduced.

[akpm@linux-foundation.org: fix kerneldoc, per David]
Link: https://lkml.kernel.org/r/cover.1760097207.git.donettom@linux.ibm.com
Link: https://lkml.kernel.org/r/910853c9dd61f7a2190a56cba101e73e9c6859be.1760097207.git.donettom@linux.ibm.com
Signed-off-by: Donet Tom <donettom@linux.ibm.com>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Acked-by: SeongJae Park <sj@kernel.org>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Aboorva Devarajan <aboorvad@linux.ibm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Danilo Krummrich <dakr@kernel.org>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "Ritesh Harjani (IBM)" <ritesh.list@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16 17:28:02 -08:00
Linus Torvalds 7a405dbb0f Merge tag 'mm-stable-2025-10-03-16-49' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull more MM updates from Andrew Morton:
"Only two patch series in this pull request:

   - "mm/memory_hotplug: fixup crash during uevent handling" from Hannes
     Reinecke fixes a race that was causing udev to trigger a crash in
     the memory hotplug code

   - "mm_slot: following fixup for usage of mm_slot_entry()" from Wei
     Yang adds some touchups to the just-merged mm_slot changes"

* tag 'mm-stable-2025-10-03-16-49' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
  mm/khugepaged: use KMEM_CACHE()
  mm/ksm: cleanup mm_slot_entry() invocation
  Documentation/mm: drop pxx_mkdevmap() descriptions from page table helpers
  mm: clean up is_guard_pte_marker()
  drivers/base: move memory_block_add_nid() into the caller
  mm/memory_hotplug: activate node before adding new memory blocks
  drivers/base/memory: add node id parameter to add_memory_block()
2025-10-05 12:11:07 -07:00
Linus Torvalds d104e3d17f Merge tag 'cxl-for-6.18' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl
Pull CXL updates from Dave Jiang:
 "The changes include adding poison injection support, fixing CXL access
  coordinates when onlining CXL memory, and delaing the enumeration of
  downstream switch ports for CXL hierarchy to ensure that the CXL link
  is established at the time of enumeration to address a few issues
  observed on AMD and Intel platforms.

  Misc changes:
   - Use str_plural() instead of open code for emitting strings.
   - Use str_enabled_disabled() instead of ternary operator
   - Fix emit of type resource_size_t argument for
     validate_region_offset()
   - Typo fixup in CXL driver-api documentation
   - Rename CFMWS coherency restriction defines
   - Add convention doc describe dealing with x86 low memory hole
     and CXL

  Poison Inject support:
   - Move hpa_to_spa callback to new reoot decoder ops structure
   - Define a SPA to HPA callback for interleave calculation with
     XOR math
   - Add support for SPA to DPA address translation with XOR
   - Add locked variants of poison inject and clear functions
   - Add inject and clear poison support by region offset

  CXL access coordinates update fix:
   - A comment update for hotplug memory callback prority defines
   - Add node_update_perf_attrs() for updating perf attrs on a node
   - Update cxl_access_coordinates() to use the new node update function
   - Remove hmat_update_target_coordinates() and related code

  CXL delayed downstream port enumeration and initialization:
   - Add helper to detect top of CXL device topology and remove
     open coding
   - Add helper to delete single dport
   - Add a cached copy of target_map to cxl_decoder
   - Refactor decoder setup to reduce cxl_test burden
   - Defer dport allocation for switch ports
   - Add mock version of devm_cxl_add_dport_by_dev() for cxl_test
   - Adjust the mock version of devm_cxl_switch_port_decoders_setup()
     due to cxl core usage
   - Setup target_map for cxl_test decoder initialization
   - Change SSLBIS handler to handle single dport
   - Move port register setup to when first dport appears"

* tag 'cxl-for-6.18' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl: (25 commits)
  cxl: Move port register setup to when first dport appear
  cxl: Change sslbis handler to only handle single dport
  cxl/test: Setup target_map for cxl_test decoder initialization
  cxl/test: Adjust the mock version of devm_cxl_switch_port_decoders_setup()
  cxl/test: Add mock version of devm_cxl_add_dport_by_dev()
  cxl: Defer dport allocation for switch ports
  cxl/test: Refactor decoder setup to reduce cxl_test burden
  cxl: Add a cached copy of target_map to cxl_decoder
  cxl: Add helper to delete dport
  cxl: Add helper to detect top of CXL device topology
  cxl: Documentation/driver-api/cxl: Describe the x86 Low Memory Hole solution
  cxl/acpi: Rename CFMW coherency restrictions
  Documentation/driver-api: Fix typo error in cxl
  acpi/hmat: Remove now unused hmat_update_target_coordinates()
  cxl, acpi/hmat: Update CXL access coordinates directly instead of through HMAT
  drivers/base/node: Add a helper function node_update_perf_attrs()
  mm/memory_hotplug: Update comment for hotplug memory callback priorities
  cxl: Fix emit of type resource_size_t argument for validate_region_offset()
  cxl/region: Add inject and clear poison by region offset
  cxl/core: Add locked variants of the poison inject and clear funcs
  ...
2025-10-04 12:02:50 -07:00
Hannes ReineckeandAndrew Morton 0a947c14e4 drivers/base: move memory_block_add_nid() into the caller
Now the node id only needs to be set for early memory, so move
memory_block_add_nid() into the caller and rename it into
memory_block_add_nid_early().  This allows us to further simplify the code
by dropping the 'context' argument to
do_register_memory_block_under_node().

Link: https://lkml.kernel.org/r/20250729064637.51662-4-hare@kernel.org
Suggested-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Hannes Reinecke <hare@kernel.org>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: Donet Tom <donettom@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-10-03 16:42:43 -07:00
Donet TomandAndrew Morton 0efdedfa53 drivers/base/node: fix double free in register_one_node()
When device_register() fails in register_node(), it calls
put_device(&node->dev).  This triggers node_device_release(), which calls
kfree(to_node(dev)), thereby freeing the entire node structure.

As a result, when register_node() returns an error, the node memory has
already been freed.  Calling kfree(node) again in register_one_node()
leads to a double free.

This patch removes the redundant kfree(node) from register_one_node() to
prevent the double free.

Link: https://lkml.kernel.org/r/20250918054144.58980-1-donettom@linux.ibm.com
Fixes: 786eb990cf ("drivers/base/node: handle error properly in register_one_node()")
Signed-off-by: Donet Tom <donettom@linux.ibm.com>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Oscar Salvador <osalvador@suse.de>
Cc: Alison Schofield <alison.schofield@intel.com>
Cc: Chris Mason <clm@meta.com>
Cc: Danilo Krummrich <dakr@kernel.org>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Hiroyouki Kamezawa <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Joanthan Cameron <Jonathan.Cameron@huawei.com>
Cc: "Ritesh Harjani (IBM)" <ritesh.list@gmail.com>
Cc: Yury Norov (NVIDIA) <yury.norov@gmail.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-09-28 11:51:31 -07:00
Donet TomandAndrew Morton 786eb990cf drivers/base/node: handle error properly in register_one_node()
If register_node() returns an error, it is not handled correctly.
The function will proceed further and try to register CPUs under the
node, which is not correct.

So, in this patch, if register_node() returns an error, we return
immediately from the function.

Link: https://lkml.kernel.org/r/20250822084845.19219-1-donettom@linux.ibm.com
Fixes: 76b67ed9dc ("[PATCH] node hotplug: register cpu: remove node struct")
Signed-off-by: Donet Tom <donettom@linux.ibm.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Alison Schofield <alison.schofield@intel.com>
Cc: Danilo Krummrich <dakr@kernel.org>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Donet Tom <donettom@linux.ibm.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Hiroyouki Kamezawa <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Joanthan Cameron <Jonathan.Cameron@huawei.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: "Ritesh Harjani (IBM)" <ritesh.list@gmail.com>
Cc: Yury Norov (NVIDIA) <yury.norov@gmail.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-09-13 16:55:17 -07:00
Dave Jiang b57fc652ca drivers/base/node: Add a helper function node_update_perf_attrs()
Add helper function node_update_perf_attrs() to allow update of node access
coordinates computed by an external agent such as CXL. The helper allows
updating of coordinates after the attribute being created by HMAT.

Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Link: https://patch.msgid.link/20250829222907.1290912-3-dave.jiang@intel.com
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
2025-09-02 14:46:47 -07:00
Linus Torvalds beace86e61 Merge tag 'mm-stable-2025-07-30-15-25' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:
 "As usual, many cleanups. The below blurbiage describes 42 patchsets.
  21 of those are partially or fully cleanup work. "cleans up",
  "cleanup", "maintainability", "rationalizes", etc.

  I never knew the MM code was so dirty.

  "mm: ksm: prevent KSM from breaking merging of new VMAs" (Lorenzo Stoakes)
     addresses an issue with KSM's PR_SET_MEMORY_MERGE mode: newly
     mapped VMAs were not eligible for merging with existing adjacent
     VMAs.

  "mm/damon: introduce DAMON_STAT for simple and practical access monitoring" (SeongJae Park)
     adds a new kernel module which simplifies the setup and usage of
     DAMON in production environments.

  "stop passing a writeback_control to swap/shmem writeout" (Christoph Hellwig)
     is a cleanup to the writeback code which removes a couple of
     pointers from struct writeback_control.

  "drivers/base/node.c: optimization and cleanups" (Donet Tom)
     contains largely uncorrelated cleanups to the NUMA node setup and
     management code.

  "mm: userfaultfd: assorted fixes and cleanups" (Tal Zussman)
     does some maintenance work on the userfaultfd code.

  "Readahead tweaks for larger folios" (Ryan Roberts)
     implements some tuneups for pagecache readahead when it is reading
     into order>0 folios.

  "selftests/mm: Tweaks to the cow test" (Mark Brown)
     provides some cleanups and consistency improvements to the
     selftests code.

  "Optimize mremap() for large folios" (Dev Jain)
     does that. A 37% reduction in execution time was measured in a
     memset+mremap+munmap microbenchmark.

  "Remove zero_user()" (Matthew Wilcox)
     expunges zero_user() in favor of the more modern memzero_page().

  "mm/huge_memory: vmf_insert_folio_*() and vmf_insert_pfn_pud() fixes" (David Hildenbrand)
     addresses some warts which David noticed in the huge page code.
     These were not known to be causing any issues at this time.

  "mm/damon: use alloc_migrate_target() for DAMOS_MIGRATE_{HOT,COLD" (SeongJae Park)
     provides some cleanup and consolidation work in DAMON.

  "use vm_flags_t consistently" (Lorenzo Stoakes)
     uses vm_flags_t in places where we were inappropriately using other
     types.

  "mm/memfd: Reserve hugetlb folios before allocation" (Vivek Kasireddy)
     increases the reliability of large page allocation in the memfd
     code.

  "mm: Remove pXX_devmap page table bit and pfn_t type" (Alistair Popple)
     removes several now-unneeded PFN_* flags.

  "mm/damon: decouple sysfs from core" (SeongJae Park)
     implememnts some cleanup and maintainability work in the DAMON
     sysfs layer.

  "madvise cleanup" (Lorenzo Stoakes)
     does quite a lot of cleanup/maintenance work in the madvise() code.

  "madvise anon_name cleanups" (Vlastimil Babka)
     provides additional cleanups on top or Lorenzo's effort.

  "Implement numa node notifier" (Oscar Salvador)
     creates a standalone notifier for NUMA node memory state changes.
     Previously these were lumped under the more general memory
     on/offline notifier.

  "Make MIGRATE_ISOLATE a standalone bit" (Zi Yan)
     cleans up the pageblock isolation code and fixes a potential issue
     which doesn't seem to cause any problems in practice.

  "selftests/damon: add python and drgn based DAMON sysfs functionality tests" (SeongJae Park)
     adds additional drgn- and python-based DAMON selftests which are
     more comprehensive than the existing selftest suite.

  "Misc rework on hugetlb faulting path" (Oscar Salvador)
     fixes a rather obscure deadlock in the hugetlb fault code and
     follows that fix with a series of cleanups.

  "cma: factor out allocation logic from __cma_declare_contiguous_nid" (Mike Rapoport)
     rationalizes and cleans up the highmem-specific code in the CMA
     allocator.

  "mm/migration: rework movable_ops page migration (part 1)" (David Hildenbrand)
     provides cleanups and future-preparedness to the migration code.

  "mm/damon: add trace events for auto-tuned monitoring intervals and DAMOS quota" (SeongJae Park)
     adds some tracepoints to some DAMON auto-tuning code.

  "mm/damon: fix misc bugs in DAMON modules" (SeongJae Park)
     does that.

  "mm/damon: misc cleanups" (SeongJae Park)
     also does what it claims.

  "mm: folio_pte_batch() improvements" (David Hildenbrand)
     cleans up the large folio PTE batching code.

  "mm/damon/vaddr: Allow interleaving in migrate_{hot,cold} actions" (SeongJae Park)
     facilitates dynamic alteration of DAMON's inter-node allocation
     policy.

  "Remove unmap_and_put_page()" (Vishal Moola)
     provides a couple of page->folio conversions.

  "mm: per-node proactive reclaim" (Davidlohr Bueso)
     implements a per-node control of proactive reclaim - beyond the
     current memcg-based implementation.

  "mm/damon: remove damon_callback" (SeongJae Park)
     replaces the damon_callback interface with a more general and
     powerful damon_call()+damos_walk() interface.

  "mm/mremap: permit mremap() move of multiple VMAs" (Lorenzo Stoakes)
     implements a number of mremap cleanups (of course) in preparation
     for adding new mremap() functionality: newly permit the remapping
     of multiple VMAs when the user is specifying MREMAP_FIXED. It still
     excludes some specialized situations where this cannot be performed
     reliably.

  "drop hugetlb_free_pgd_range()" (Anthony Yznaga)
     switches some sparc hugetlb code over to the generic version and
     removes the thus-unneeded hugetlb_free_pgd_range().

  "mm/damon/sysfs: support periodic and automated stats update" (SeongJae Park)
     augments the present userspace-requested update of DAMON sysfs
     monitoring files. Automatic update is now provided, along with a
     tunable to control the update interval.

  "Some randome fixes and cleanups to swapfile" (Kemeng Shi)
     does what is claims.

  "mm: introduce snapshot_page" (Luiz Capitulino and David Hildenbrand)
     provides (and uses) a means by which debug-style functions can grab
     a copy of a pageframe and inspect it locklessly without tripping
     over the races inherent in operating on the live pageframe
     directly.

  "use per-vma locks for /proc/pid/maps reads" (Suren Baghdasaryan)
     addresses the large contention issues which can be triggered by
     reads from that procfs file. Latencies are reduced by more than
     half in some situations. The series also introduces several new
     selftests for the /proc/pid/maps interface.

  "__folio_split() clean up" (Zi Yan)
     cleans up __folio_split()!

  "Optimize mprotect() for large folios" (Dev Jain)
     provides some quite large (>3x) speedups to mprotect() when dealing
     with large folios.

  "selftests/mm: reuse FORCE_READ to replace "asm volatile("" : "+r" (XXX));" and some cleanup" (wang lian)
     does some cleanup work in the selftests code.

  "tools/testing: expand mremap testing" (Lorenzo Stoakes)
     extends the mremap() selftest in several ways, including adding
     more checking of Lorenzo's recently added "permit mremap() move of
     multiple VMAs" feature.

  "selftests/damon/sysfs.py: test all parameters" (SeongJae Park)
     extends the DAMON sysfs interface selftest so that it tests all
     possible user-requested parameters. Rather than the present minimal
     subset"

* tag 'mm-stable-2025-07-30-15-25' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (370 commits)
  MAINTAINERS: add missing headers to mempory policy & migration section
  MAINTAINERS: add missing file to cgroup section
  MAINTAINERS: add MM MISC section, add missing files to MISC and CORE
  MAINTAINERS: add missing zsmalloc file
  MAINTAINERS: add missing files to page alloc section
  MAINTAINERS: add missing shrinker files
  MAINTAINERS: move memremap.[ch] to hotplug section
  MAINTAINERS: add missing mm_slot.h file THP section
  MAINTAINERS: add missing interval_tree.c to memory mapping section
  MAINTAINERS: add missing percpu-internal.h file to per-cpu section
  mm/page_alloc: remove trace_mm_alloc_contig_migrate_range_info()
  selftests/damon: introduce _common.sh to host shared function
  selftests/damon/sysfs.py: test runtime reduction of DAMON parameters
  selftests/damon/sysfs.py: test non-default parameters runtime commit
  selftests/damon/sysfs.py: generalize DAMON context commit assertion
  selftests/damon/sysfs.py: generalize monitoring attributes commit assertion
  selftests/damon/sysfs.py: generalize DAMOS schemes commit assertion
  selftests/damon/sysfs.py: test DAMOS filters commitment
  selftests/damon/sysfs.py: generalize DAMOS scheme commit assertion
  selftests/damon/sysfs.py: test DAMOS destinations commitment
  ...
2025-07-31 14:57:54 -07:00
Davidlohr BuesoandAndrew Morton b980077899 mm: introduce per-node proactive reclaim interface
This adds support for allowing proactive reclaim in general on a NUMA
system.  A per-node interface extends support for beyond a memcg-specific
interface, respecting the current semantics of memory.reclaim: respecting
aging LRU and not supporting artificially triggering eviction on nodes
belonging to non-bottom tiers.

This patch allows userspace to do:

     echo "512M swappiness=10" > /sys/devices/system/node/nodeX/reclaim

One of the premises for this is to semantically align as best as possible
with memory.reclaim.  During a brief time memcg did support nodemask until
55ab834a86 (Revert "mm: add nodes= arg to memory.reclaim"), for which
semantics around reclaim (eviction) vs demotion were not clear, rendering
charging expectations to be broken.

With this approach:

1. Users who do not use memcg can benefit from proactive reclaim.  The
   memcg interface is not NUMA aware and there are usecases that are
   focusing on NUMA balancing rather than workload memory footprint.

2. Proactive reclaim on top tiers will trigger demotion, for which
   memory is still byte-addressable.  Reclaiming on the bottom nodes will
   trigger evicting to swap (the traditional sense of reclaim).  This
   follows the semantics of what is today part of the aging process on
   tiered memory, mirroring what every other form of reclaim does
   (reactive and memcg proactive reclaim).  Furthermore per-node proactive
   reclaim is not as susceptible to the memcg charging problem mentioned
   above.

3. Unlike the nodes= arg, this interface avoids confusing semantics,
   such as what exactly the user wants when mixing top-tier and low-tier
   nodes in the nodemask.  Further per-node interface is less exposed to
   "free up memory in my container" usecases, where eviction is intended.

4. Users that *really* want to free up memory can use proactive
   reclaim on nodes knowingly to be on the bottom tiers to force eviction
   in a natural way - higher access latencies are still better than swap. 
   If compelled, while no guarantees and perhaps not worth the effort,
   users could also also potentially follow a ladder-like approach to
   eventually free up the memory.  Alternatively, perhaps an 'evict'
   option could be added to the parameters for both memory.reclaim and
   per-node interfaces to force this action unconditionally.

[akpm@linux-foundation.org: user_proactive_reclaim(): return -EBUSY on PGDAT_RECLAIM_LOCKED contention, per Roman]
[dave@stgolabs.net: memcg && node is also a bogus case, per Shakeel]
  Link: https://lkml.kernel.org/r/20250717235604.2atyx2aobwowpge3@offworld
Link: https://lkml.kernel.org/r/20250623185851.830632-5-dave@stgolabs.net
Signed-off-by: Davidlohr Bueso <dave@stgolabs.net>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Yosry Ahmed <yosryahmed@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-07-19 18:59:53 -07:00
Vlastimil BabkaandAndrew Morton 8356a5a3b0 mm, vmstat: remove the NR_WRITEBACK_TEMP node_stat_item counter
The only user of the counter (FUSE) was removed in commit 0c58a97f91
("fuse: remove tmp folio for writebacks and internal rb tree") so follow
the established pattern of removing the counter and hardcoding 0 in
meminfo output, as done recently with NR_BOUNCE.  Update documentation for
procfs, including for the value for Bounce that was missed when removing
its counter.

Also remove the mention of NR_WRITEBACK_TEMP implications from a comment
in wb_position_ratio(). The rest of the comment there about fuse setting
bdi->max_ratio to 1% is still correct.

[vbabka@suse.cz: v2]
  Link: https://lkml.kernel.org/r/5a848e15-6a57-4ecb-a015-d4f358b8a5d3@suse.cz
Link: https://lkml.kernel.org/r/20250625-nr_writeback_removal-v1-1-7f2a0df70faa@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Brendan Jackman <jackmanb@google.com>
Cc: Danilo Krummrich <dakr@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Jeff Layton <jlayton@kernel.org>
Cc: Jeffle Xu <jefflexu@linux.alibaba.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Joanne Koong <joannelkoong@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kirill A. Shuemov <kirill.shutemov@linux.intel.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Maxim Patlasov <mpatlasov@parallels.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Miklos Szeredi <mszeredi@redhat.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Zach O'Keefe <zokeefe@google.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-07-19 18:59:47 -07:00
Oscar SalvadorandAndrew Morton 67929de108 mm,memory_hotplug: implement numa node notifier
There are at least six consumers of hotplug_memory_notifier that what they
really are interested in is whether any numa node changed its state, e.g:
going from having memory to not having memory and vice versa.

Implement a specific notifier for numa nodes when their state gets
changed, which will later be used by those consumers that are only
interested in numa node state changes.

Add documentation as well.

[dan.carpenter@linaro.org: set failure reason in offline_pages()]
  Link: https://lkml.kernel.org/r/be4fd31b-7d09-46b0-8329-6d0464ffa7a5@sabinyo.mountain
Link: https://lkml.kernel.org/r/20250616135158.450136-4-osalvador@suse.de
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Harry Yoo <harry.yoo@oracle.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Rakie Kim <rakie.kim@sk.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-07-13 16:38:15 -07:00
Donet TomandAndrew Morton a5352f8a40 drivers/base/node: rename __register_one_node() to register_one_node()
The register_one_node() function was a simple wrapper around
__register_one_node().  To simplify the code, register_one_node() has been
removed, and __register_one_node() has been renamed to
register_one_node().

Link: https://lkml.kernel.org/r/8262cd0f44eeb048a1fcd3ac8382760d7f7dea60.1748452242.git.donettom@linux.ibm.com
Signed-off-by: Donet Tom <donettom@linux.ibm.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Mike Rapoport (Microsoft) <rppt@kernel.org>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-07-09 22:42:00 -07:00
Donet TomandAndrew Morton 10f09d82f8 drivers/base/node: rename register_memory_blocks_under_node() and remove context argument
The function register_memory_blocks_under_node() is now only called from
the memory hotplug path, as register_memory_blocks_under_node_early()
handles registration during early boot.  Therefore, the context argument
used to differentiate between early boot and hotplug is no longer needed
and was removed.

Since the function is only called from the hotplug path, we renamed
register_memory_blocks_under_node() to
register_memory_blocks_under_node_hotplug()

Link: https://lkml.kernel.org/r/907c22292b0ee4975107876efc875c75c11badd9.1748452242.git.donettom@linux.ibm.com
Signed-off-by: Donet Tom <donettom@linux.ibm.com>
Acked-by: Oscar Salvador <osalvador@suse.de>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-07-09 22:42:00 -07:00
Donet TomandAndrew Morton 69e944b160 drivers/base/node: remove register_mem_block_under_node_early()
The function register_mem_block_under_node_early() is no longer used, as
register_memory_blocks_under_node_early() now handles memory block
registration during early boot.

Removed register_mem_block_under_node_early() and get_nid_for_pfn(), the
latter was only used by the former.

Link: https://lkml.kernel.org/r/22e0c5d20f1d33a91d0436ad22d96628cf084d1b.1748452242.git.donettom@linux.ibm.com
Signed-off-by: Donet Tom <donettom@linux.ibm.com>
Acked-by: Oscar Salvador <osalvador@suse.de>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-07-09 22:41:59 -07:00
Donet TomandAndrew Morton 4f745def81 drivers/base/node: optimize memory block registration to reduce boot time
Patch series "drivers/base/node.c: optimization and cleanups", v7.


This patch (of 7)

During node device initialization, `memory blocks` are registered under
each NUMA node.  The `memory blocks` to be registered are identified using
the node's start and end PFNs, which are obtained from the node's pg_data

However, not all PFNs within this range necessarily belong to the same
node—some may belong to other nodes.  Additionally, due to the
discontiguous nature of physical memory, certain sections within a `memory
block` may be absent.

As a result, `memory blocks` that fall between a node's start and end PFNs
may span across multiple nodes, and some sections within those blocks may
be missing.  `Memory blocks` have a fixed size, which is architecture
dependent.

Due to these considerations, the memory block registration is currently
performed as follows:

for_each_online_node(nid):
    start_pfn = pgdat->node_start_pfn;
    end_pfn = pgdat->node_start_pfn + node_spanned_pages;
    for_each_memory_block_between(PFN_PHYS(start_pfn), PFN_PHYS(end_pfn))
        mem_blk = memory_block_id(pfn_to_section_nr(pfn));
        pfn_mb_start=section_nr_to_pfn(mem_blk->start_section_nr)
        pfn_mb_end = pfn_start + memory_block_pfns - 1
        for (pfn = pfn_mb_start; pfn < pfn_mb_end; pfn++):
            if (get_nid_for_pfn(pfn) != nid):
                continue;
            else
                do_register_memory_block_under_node(nid, mem_blk,
                                                        MEMINIT_EARLY);

Here, we derive the start and end PFNs from the node's pg_data, then
determine the memory blocks that may belong to the node.  For each `memory
block` in this range, we inspect all PFNs it contains and check their
associated NUMA node ID.  If a PFN within the block matches the current
node, the memory block is registered under that node.

If CONFIG_DEFERRED_STRUCT_PAGE_INIT is enabled, get_nid_for_pfn() performs
a binary search in the `memblock regions` to determine the NUMA node ID
for a given PFN.  If it is not enabled, the node ID is retrieved directly
from the struct page.

On large systems, this process can become time-consuming, especially since
we iterate over each `memory block` and all PFNs within it until a match
is found.  When CONFIG_DEFERRED_STRUCT_PAGE_INIT is enabled, the
additional overhead of the binary search increases the execution time
significantly, potentially leading to soft lockups during boot.

In this patch, we iterate over `memblock region` to identify the `memory
blocks` that belong to the current NUMA node.  `memblock regions` are
contiguous memory ranges, each associated with a single NUMA node, and
they do not span across multiple nodes.

for_each_memory_region(r): // r => region
  if (!node_online(r->nid)):
    continue;
  else
    for_each_memory_block_between(r->base, r->base + r->size - 1):
      do_register_memory_block_under_node(r->nid, mem_blk, MEMINIT_EARLY);

We iterate over all memblock regions, and if the node associated with the
region is online, we calculate the start and end memory blocks based on
the region's start and end PFNs.  We then register all the memory blocks
within that range under the region node.

Test Results on My system with 32TB RAM
=======================================
1. Boot time with CONFIG_DEFERRED_STRUCT_PAGE_INIT enabled.

Without this patch
------------------
Startup finished in 1min 16.528s (kernel)

With this patch
---------------
Startup finished in 17.236s (kernel) - 78% Improvement

2. Boot time with CONFIG_DEFERRED_STRUCT_PAGE_INIT disabled.

Without this patch
------------------
Startup finished in 28.320s (kernel)

With this patch
---------------
Startup finished in 15.621s (kernel) - 46% Improvement

[donettom@linux.ibm.com: restore removed extra line]
  Link: https://lkml.kernel.org/r/20250609140354.467908-1-donettom@linux.ibm.com
Link: https://lkml.kernel.org/r/2a0a05c2dffc62a742bf1dd030098be4ce99be28.1748452241.git.donettom@linux.ibm.com
Link: https://lkml.kernel.org/r/2a0a05c2dffc62a742bf1dd030098be4ce99be28.1748452241.git.donettom@linux.ibm.com
Signed-off-by: Donet Tom <donettom@linux.ibm.com>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Oscar Salvador <osalvador@suse.de>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Acked-by: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-07-09 22:41:59 -07:00
Thomas WeißschuhandGreg Kroah-Hartman fb506e31b3 sysfs: treewide: switch back to attribute_group::bin_attrs
The normal bin_attrs field can now handle const pointers.
This makes the _new variant unnecessary.
Switch all users back.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Link: https://lore.kernel.org/r/20250530-sysfs-const-bin_attr-final-v3-4-724bfcf05b99@weissschuh.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-06-17 10:44:15 +02:00
Linus Torvalds 00c010e130 Merge tag 'mm-stable-2025-05-31-14-50' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:

 - "Add folio_mk_pte()" from Matthew Wilcox simplifies the act of
   creating a pte which addresses the first page in a folio and reduces
   the amount of plumbing which architecture must implement to provide
   this.

 - "Misc folio patches for 6.16" from Matthew Wilcox is a shower of
   largely unrelated folio infrastructure changes which clean things up
   and better prepare us for future work.

 - "memory,x86,acpi: hotplug memory alignment advisement" from Gregory
   Price adds early-init code to prevent x86 from leaving physical
   memory unused when physical address regions are not aligned to memory
   block size.

 - "mm/compaction: allow more aggressive proactive compaction" from
   Michal Clapinski provides some tuning of the (sadly, hard-coded (more
   sadly, not auto-tuned)) thresholds for our invokation of proactive
   compaction. In a simple test case, the reduction of a guest VM's
   memory consumption was dramatic.

 - "Minor cleanups and improvements to swap freeing code" from Kemeng
   Shi provides some code cleaups and a small efficiency improvement to
   this part of our swap handling code.

 - "ptrace: introduce PTRACE_SET_SYSCALL_INFO API" from Dmitry Levin
   adds the ability for a ptracer to modify syscalls arguments. At this
   time we can alter only "system call information that are used by
   strace system call tampering, namely, syscall number, syscall
   arguments, and syscall return value.

   This series should have been incorporated into mm.git's "non-MM"
   branch, but I goofed.

 - "fs/proc: extend the PAGEMAP_SCAN ioctl to report guard regions" from
   Andrei Vagin extends the info returned by the PAGEMAP_SCAN ioctl
   against /proc/pid/pagemap. This permits CRIU to more efficiently get
   at the info about guard regions.

 - "Fix parameter passed to page_mapcount_is_type()" from Gavin Shan
   implements that fix. No runtime effect is expected because
   validate_page_before_insert() happens to fix up this error.

 - "kernel/events/uprobes: uprobe_write_opcode() rewrite" from David
   Hildenbrand basically brings uprobe text poking into the current
   decade. Remove a bunch of hand-rolled implementation in favor of
   using more current facilities.

 - "mm/ptdump: Drop assumption that pxd_val() is u64" from Anshuman
   Khandual provides enhancements and generalizations to the pte dumping
   code. This might be needed when 128-bit Page Table Descriptors are
   enabled for ARM.

 - "Always call constructor for kernel page tables" from Kevin Brodsky
   ensures that the ctor/dtor is always called for kernel pgtables, as
   it already is for user pgtables.

   This permits the addition of more functionality such as "insert hooks
   to protect page tables". This change does result in various
   architectures performing unnecesary work, but this is fixed up where
   it is anticipated to occur.

 - "Rust support for mm_struct, vm_area_struct, and mmap" from Alice
   Ryhl adds plumbing to permit Rust access to core MM structures.

 - "fix incorrectly disallowed anonymous VMA merges" from Lorenzo
   Stoakes takes advantage of some VMA merging opportunities which we've
   been missing for 15 years.

 - "mm/madvise: batch tlb flushes for MADV_DONTNEED and MADV_FREE" from
   SeongJae Park optimizes process_madvise()'s TLB flushing.

   Instead of flushing each address range in the provided iovec, we
   batch the flushing across all the iovec entries. The syscall's cost
   was approximately halved with a microbenchmark which was designed to
   load this particular operation.

 - "Track node vacancy to reduce worst case allocation counts" from
   Sidhartha Kumar makes the maple tree smarter about its node
   preallocation.

   stress-ng mmap performance increased by single-digit percentages and
   the amount of unnecessarily preallocated memory was dramaticelly
   reduced.

 - "mm/gup: Minor fix, cleanup and improvements" from Baoquan He removes
   a few unnecessary things which Baoquan noted when reading the code.

 - ""Enhance sysfs handling for memory hotplug in weighted interleave"
   from Rakie Kim "enhances the weighted interleave policy in the memory
   management subsystem by improving sysfs handling, fixing memory
   leaks, and introducing dynamic sysfs updates for memory hotplug
   support". Fixes things on error paths which we are unlikely to hit.

 - "mm/damon: auto-tune DAMOS for NUMA setups including tiered memory"
   from SeongJae Park introduces new DAMOS quota goal metrics which
   eliminate the manual tuning which is required when utilizing DAMON
   for memory tiering.

 - "mm/vmalloc.c: code cleanup and improvements" from Baoquan He
   provides cleanups and small efficiency improvements which Baoquan
   found via code inspection.

 - "vmscan: enforce mems_effective during demotion" from Gregory Price
   changes reclaim to respect cpuset.mems_effective during demotion when
   possible. because presently, reclaim explicitly ignores
   cpuset.mems_effective when demoting, which may cause the cpuset
   settings to violated.

   This is useful for isolating workloads on a multi-tenant system from
   certain classes of memory more consistently.

 - "Clean up split_huge_pmd_locked() and remove unnecessary folio
   pointers" from Gavin Guo provides minor cleanups and efficiency gains
   in in the huge page splitting and migrating code.

 - "Use kmem_cache for memcg alloc" from Huan Yang creates a slab cache
   for `struct mem_cgroup', yielding improved memory utilization.

 - "add max arg to swappiness in memory.reclaim and lru_gen" from
   Zhongkun He adds a new "max" argument to the "swappiness=" argument
   for memory.reclaim MGLRU's lru_gen.

   This directs proactive reclaim to reclaim from only anon folios
   rather than file-backed folios.

 - "kexec: introduce Kexec HandOver (KHO)" from Mike Rapoport is the
   first step on the path to permitting the kernel to maintain existing
   VMs while replacing the host kernel via file-based kexec. At this
   time only memblock's reserve_mem is preserved.

 - "mm: Introduce for_each_valid_pfn()" from David Woodhouse provides
   and uses a smarter way of looping over a pfn range. By skipping
   ranges of invalid pfns.

 - "sched/numa: Skip VMA scanning on memory pinned to one NUMA node via
   cpuset.mems" from Libo Chen removes a lot of pointless VMA scanning
   when a task is pinned a single NUMA mode.

   Dramatic performance benefits were seen in some real world cases.

 - "JFS: Implement migrate_folio for jfs_metapage_aops" from Shivank
   Garg addresses a warning which occurs during memory compaction when
   using JFS.

 - "move all VMA allocation, freeing and duplication logic to mm" from
   Lorenzo Stoakes moves some VMA code from kernel/fork.c into the more
   appropriate mm/vma.c.

 - "mm, swap: clean up swap cache mapping helper" from Kairui Song
   provides code consolidation and cleanups related to the folio_index()
   function.

 - "mm/gup: Cleanup memfd_pin_folios()" from Vishal Moola does that.

 - "memcg: Fix test_memcg_min/low test failures" from Waiman Long
   addresses some bogus failures which are being reported by the
   test_memcontrol selftest.

 - "eliminate mmap() retry merge, add .mmap_prepare hook" from Lorenzo
   Stoakes commences the deprecation of file_operations.mmap() in favor
   of the new file_operations.mmap_prepare().

   The latter is more restrictive and prevents drivers from messing with
   things in ways which, amongst other problems, may defeat VMA merging.

 - "memcg: decouple memcg and objcg stocks"" from Shakeel Butt decouples
   the per-cpu memcg charge cache from the objcg's one.

   This is a step along the way to making memcg and objcg charging
   NMI-safe, which is a BPF requirement.

 - "mm/damon: minor fixups and improvements for code, tests, and
   documents" from SeongJae Park is yet another batch of miscellaneous
   DAMON changes. Fix and improve minor problems in code, tests and
   documents.

 - "memcg: make memcg stats irq safe" from Shakeel Butt converts memcg
   stats to be irq safe. Another step along the way to making memcg
   charging and stats updates NMI-safe, a BPF requirement.

 - "Let unmap_hugepage_range() and several related functions take folio
   instead of page" from Fan Ni provides folio conversions in the
   hugetlb code.

* tag 'mm-stable-2025-05-31-14-50' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (285 commits)
  mm: pcp: increase pcp->free_count threshold to trigger free_high
  mm/hugetlb: convert use of struct page to folio in __unmap_hugepage_range()
  mm/hugetlb: refactor __unmap_hugepage_range() to take folio instead of page
  mm/hugetlb: refactor unmap_hugepage_range() to take folio instead of page
  mm/hugetlb: pass folio instead of page to unmap_ref_private()
  memcg: objcg stock trylock without irq disabling
  memcg: no stock lock for cpu hot-unplug
  memcg: make __mod_memcg_lruvec_state re-entrant safe against irqs
  memcg: make count_memcg_events re-entrant safe against irqs
  memcg: make mod_memcg_state re-entrant safe against irqs
  memcg: move preempt disable to callers of memcg_rstat_updated
  memcg: memcg_rstat_updated re-entrant safe against irqs
  mm: khugepaged: decouple SHMEM and file folios' collapse
  selftests/eventfd: correct test name and improve messages
  alloc_tag: check mem_profiling_support in alloc_tag_init
  Docs/damon: update titles and brief introductions to explain DAMOS
  selftests/damon/_damon_sysfs: read tried regions directories in order
  mm/damon/tests/core-kunit: add a test for damos_set_filters_default_reject()
  mm/damon/paddr: remove unused variable, folio_list, in damon_pa_stat()
  mm/damon/sysfs-schemes: fix wrong comment on damons_sysfs_quota_goal_metric_strs
  ...
2025-05-31 15:44:16 -07:00
Joshua HahnandAndrew Morton e341f9c3c8 mm/mempolicy: Weighted Interleave Auto-tuning
On machines with multiple memory nodes, interleaving page allocations
across nodes allows for better utilization of each node's bandwidth. 
Previous work by Gregory Price [1] introduced weighted interleave, which
allowed for pages to be allocated across nodes according to user-set
ratios.

Ideally, these weights should be proportional to their bandwidth, so that
under bandwidth pressure, each node uses its maximal efficient bandwidth
and prevents latency from increasing exponentially.

Previously, weighted interleave's default weights were just 1s -- which
would be equivalent to the (unweighted) interleave mempolicy, which goes
through the nodes in a round-robin fashion, ignoring bandwidth
information.

This patch has two main goals: First, it makes weighted interleave easier
to use for users who wish to relieve bandwidth pressure when using nodes
with varying bandwidth (CXL).  By providing a set of "real" default
weights that just work out of the box, users who might not have the
capability (or wish to) perform experimentation to find the most optimal
weights for their system can still take advantage of bandwidth-informed
weighted interleave.

Second, it allows for weighted interleave to dynamically adjust to
hotplugged memory with new bandwidth information.  Instead of manually
updating node weights every time new bandwidth information is reported or
taken off, weighted interleave adjusts and provides a new set of default
weights for weighted interleave to use when there is a change in bandwidth
information.

To meet these goals, this patch introduces an auto-configuration mode for
the interleave weights that provides a reasonable set of default weights,
calculated using bandwidth data reported by the system.  In auto mode,
weights are dynamically adjusted based on whatever the current bandwidth
information reports (and responds to hotplug events).

This patch still supports users manually writing weights into the nodeN
sysfs interface by entering into manual mode.  When a user enters manual
mode, the system stops dynamically updating any of the node weights, even
during hotplug events that shift the optimal weight distribution.

A new sysfs interface "auto" is introduced, which allows users to switch
between the auto (writing 1 or Y) and manual (writing 0 or N) modes.  The
system also automatically enters manual mode when a nodeN interface is
manually written to.

There is one functional change that this patch makes to the existing
weighted_interleave ABI: previously, writing 0 directly to a nodeN
interface was said to reset the weight to the system default.  Before this
patch, the default for all weights were 1, which meant that writing 0 and
1 were functionally equivalent.  With this patch, writing 0 is invalid.

Link: https://lkml.kernel.org/r/20250520141236.2987309-1-joshua.hahnjy@gmail.com
[joshua.hahnjy@gmail.com: wordsmithing changes, simplification, fixes]
  Link: https://lkml.kernel.org/r/20250511025840.2410154-1-joshua.hahnjy@gmail.com
[joshua.hahnjy@gmail.com: remove auto_kobj_attr field from struct sysfs_wi_group]
  Link: https://lkml.kernel.org/r/20250512142511.3959833-1-joshua.hahnjy@gmail.com
https://lore.kernel.org/linux-mm/20240202170238.90004-1-gregory.price@memverge.com/ [1]
Link: https://lkml.kernel.org/r/20250505182328.4148265-1-joshua.hahnjy@gmail.com
Co-developed-by: Gregory Price <gourry@gourry.net>
Signed-off-by: Gregory Price <gourry@gourry.net>
Signed-off-by: Joshua Hahn <joshua.hahnjy@gmail.com>
Suggested-by: Yunjeong Mun <yunjeong.mun@sk.com>
Suggested-by: Oscar Salvador <osalvador@suse.de>
Suggested-by: Ying Huang <ying.huang@linux.alibaba.com>
Suggested-by: Harry Yoo <harry.yoo@oracle.com>
Reviewed-by: Harry Yoo <harry.yoo@oracle.com>
Reviewed-by: Huang Ying <ying.huang@linux.alibaba.com>
Reviewed-by: Honggyu Kim <honggyu.kim@sk.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Joanthan Cameron <Jonathan.Cameron@huawei.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Len Brown <lenb@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-05-21 09:55:15 -07:00
Christoph HellwigandJens Axboe 194df9f66d mm: remove NR_BOUNCE zone stat
The stat is always 0 now, so remove it and hardwire the user visible
output to 0.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20250505081138.3435992-8-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-05-05 13:22:39 -06:00
Dave Jiang 84b25926fa acpi: numa: Add support to enumerate and store extended linear address mode
Store the address mode as part of the cache attriutes. Export the mode
attribute to sysfs as all other cache attributes.

Link: https://lore.kernel.org/linux-cxl/668333b17e4b2_5639294fd@dwillia2-xfh.jf.intel.com.notmuch/
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Li Ming <ming.li@zohomail.com>
Reviewed-by: Alison Schofield <alison.schofield@intel.com>
Link: https://patch.msgid.link/20250226162224.3633792-2-dave.jiang@intel.com
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
2025-02-26 13:45:22 -07:00
Thomas WeißschuhandGreg Kroah-Hartman 5943c0dc79 driver core: Constify bin_attribute definitions
Mark all 'struct bin_attribute' instances as const to protect against
accidental and malicious modifications.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Link: https://lore.kernel.org/r/20241115-b4-sysfs-const-bin_attr-group-v1-2-2c9bb12dfc48@weissschuh.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-11-15 19:29:16 +01:00