linux/mm
Vlastimil Babka 838de63b10 mm/slab: move and adjust kernel-doc for kmem_cache_alloc
Alexander reports an issue with the kmem_cache_alloc() comment in
mm/slab.c:

> The current comment mentioned that the flags only matters if the
> cache has no available objects. It's different for the __GFP_ZERO
> flag which will ensure that the returned object is always zeroed
> in any case.

> I have the feeling I run into this question already two times if
> the user need to zero the object or not, but the user does not need
> to zero the object afterwards. However another use of __GFP_ZERO
> and only zero the object if the cache has no available objects would
> also make no sense.

and suggests thus mentioning __GFP_ZERO as the exception. But on closer
inspection, the part about flags being only relevant if cache has no
available objects is misleading. The slab user has no reliable way to
determine if there are available objects, and e.g. the might_sleep()
debug check can be performed even if objects are available, so passing
correct flags given the allocation context always matters.

Thus remove that sentence completely, and while at it, move the comment
to from SLAB-specific mm/slab.c to the common include/linux/slab.h
The comment otherwise refers flags description for kmalloc(), so add
__GFP_ZERO comment there and remove a very misleading GFP_HIGHUSER
(not applicable to slab) description from there. Mention kzalloc() and
kmem_cache_zalloc() shortcuts.

Reported-by: Alexander Aring <aahringo@redhat.com>
Link: https://lore.kernel.org/all/20221011145413.8025-1-aahringo@redhat.com/
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2022-11-21 10:19:46 +01:00
..
damon - Alistair Popple has a series which addresses a race which causes page 2022-10-14 12:28:43 -07:00
kasan Random number generator fixes for Linux 6.1-rc1. 2022-10-16 15:27:07 -07:00
kfence - Yu Zhao's Multi-Gen LRU patches are here. They've been under test in 2022-10-10 17:53:04 -07:00
kmsan x86: kmsan: handle CPU entry area 2022-10-03 14:03:26 -07:00
backing-dev.c mm: backing-dev: Remove the unneeded result variable 2022-09-11 20:26:02 -07:00
balloon_compaction.c mm: Convert all PageMovable users to movable_operations 2022-08-02 12:34:03 -04:00
bootmem_info.c bootmem: remove the vmemmap pages from kmemleak in put_page_bootmem 2022-08-28 14:02:45 -07:00
cma.c Revert "mm/cma.c: remove redundant cma_mutex lock" 2022-05-13 15:11:26 -07:00
cma.h mm/cma: provide option to opt out from exposing pages on activation failure 2022-03-22 15:57:09 -07:00
cma_debug.c mm/cma_debug: show complete cma name in debugfs directories 2022-09-11 20:25:50 -07:00
cma_sysfs.c
compaction.c - Alistair Popple has a series which addresses a race which causes page 2022-10-14 12:28:43 -07:00
debug.c mm: remove the vma linked list 2022-09-26 19:46:26 -07:00
debug_page_ref.c
debug_vm_pgtable.c docs: rename Documentation/vm to Documentation/mm 2022-06-27 12:52:53 -07:00
dmapool.c mm/dmapool.c: revert "make dma pool to use kmalloc_node" 2022-01-15 16:30:28 +02:00
early_ioremap.c mm/early_ioremap: declare early_memremap_pgprot_adjust() 2022-03-22 15:57:11 -07:00
fadvise.c riscv: compat: syscall: Add compat_sys_call_table implementation 2022-04-26 13:36:25 -07:00
failslab.c mm: fix missing handler for __GFP_NOWARN 2022-05-19 14:08:55 -07:00
filemap.c - Yu Zhao's Multi-Gen LRU patches are here. They've been under test in 2022-10-10 17:53:04 -07:00
folio-compat.c mm: remove try_to_free_swap() 2022-10-03 14:02:53 -07:00
frontswap.c frontswap: don't call ->init if no ops are registered 2022-09-26 12:14:34 -07:00
gup.c Five hotfixes - three for nilfs2, two for MM. For are cc:stable, one is 2022-10-12 11:16:58 -07:00
gup_test.c mm: rename is_pinnable_page() to is_longterm_pinnable_page() 2022-07-17 17:14:27 -07:00
gup_test.h
highmem.c highmem: fix kmap_to_page() for kmap_local_page() addresses 2022-10-12 18:51:51 -07:00
hmm.c mm/swap: add swp_offset_pfn() to fetch PFN from swap entry 2022-09-26 19:46:05 -07:00
huge_memory.c mm/huge_memory: do not clobber swp_entry_t during THP split 2022-10-20 21:27:24 -07:00
hugetlb.c hugetlb: fix memory leak associated with vma_lock structure 2022-10-20 21:27:23 -07:00
hugetlb_cgroup.c hugetlb_cgroup: use helper for_each_hstate and hstate_index 2022-09-11 20:25:53 -07:00
hugetlb_vmemmap.c mm: hugetlb_vmemmap: simplify reset_struct_pages() 2022-09-11 20:25:58 -07:00
hugetlb_vmemmap.h mm: hugetlb_vmemmap: improve hugetlb_vmemmap code readability 2022-08-08 18:06:43 -07:00
hwpoison-inject.c mm/hwpoison: add __init/__exit annotations to module init/exit funcs 2022-10-03 14:03:05 -07:00
init-mm.c mm: remove rb tree. 2022-09-26 19:46:16 -07:00
internal.h mm/page_alloc: make boot_nodestats static 2022-10-03 14:03:30 -07:00
interval_tree.c
io-mapping.c
ioremap.c mm: ioremap: Add ioremap/iounmap_allowed() 2022-06-27 12:22:31 +01:00
Kconfig - Yu Zhao's Multi-Gen LRU patches are here. They've been under test in 2022-10-10 17:53:04 -07:00
Kconfig.debug Two followon fixes for the post-5.19 series "Use pageblock_order for cma 2022-05-27 11:40:49 -07:00
khugepaged.c - Yu Zhao's Multi-Gen LRU patches are here. They've been under test in 2022-10-10 17:53:04 -07:00
kmemleak.c mm/kmemleak: make create_object return void 2022-09-11 20:26:10 -07:00
ksm.c ksm: use a folio in replace_page() 2022-10-03 14:02:53 -07:00
list_lru.c mm: kmem: make mem_cgroup_from_obj() vmalloc()-safe 2022-06-16 19:48:31 -07:00
maccess.c asm-generic updates for 5.18 2022-03-23 18:03:08 -07:00
madvise.c madvise: convert madvise_free_pte_range() to use a folio 2022-10-03 14:02:52 -07:00
Makefile mm: memcontrol: drop dead CONFIG_MEMCG_SWAP config symbol 2022-10-03 14:03:36 -07:00
mapping_dirty_helpers.c mm: move tlb_flush_pending inline helpers to mm_inline.h 2022-01-15 16:30:27 +02:00
memblock.c mm: add pageblock_align() macro 2022-10-03 14:03:04 -07:00
memcontrol.c - Yu Zhao's Multi-Gen LRU patches are here. They've been under test in 2022-10-10 17:53:04 -07:00
memfd.c memfd: fix F_SEAL_WRITE after shmem huge page allocated 2022-03-05 11:08:32 -08:00
memory-failure.c rmap: remove page_unlock_anon_vma_read() 2022-10-03 14:02:54 -07:00
memory-tiers.c mm/demotion: expose memory tier details via sysfs 2022-09-26 19:46:13 -07:00
memory.c mm: use update_mmu_tlb() on the second thread 2022-10-12 18:51:50 -07:00
memory_hotplug.c mm: add pageblock_aligned() macro 2022-10-03 14:03:04 -07:00
mempolicy.c mm/mempolicy: fix mbind_range() arguments to vma_merge() 2022-10-20 21:27:21 -07:00
mempool.c mm/mempool: use might_alloc() 2022-06-16 19:48:30 -07:00
memremap.c mm/memremap.c: take a pgmap reference on page allocation 2022-10-12 18:51:49 -07:00
memtest.c
migrate.c mm/memory.c: fix race when faulting a device private page 2022-10-12 18:51:49 -07:00
migrate_device.c mm/migrate_device.c: add migrate_device_range() 2022-10-12 18:51:49 -07:00
mincore.c mm: teach core mm about pte markers 2022-05-13 07:20:09 -07:00
mlock.c mm/mlock: drop dead code in count_mm_mlocked_page_nr() 2022-09-26 19:46:27 -07:00
mm_init.c mm: multi-gen LRU: groundwork 2022-09-26 19:46:09 -07:00
mm_slot.h mm: introduce common struct mm_slot 2022-10-03 14:02:43 -07:00
mmap.c mm/mmap: fix MAP_FIXED address return on VMA merge 2022-10-20 21:27:23 -07:00
mmap_lock.c
mmu_gather.c kmsan: unpoison @tlb in arch_tlb_gather_mmu() 2022-10-12 18:51:48 -07:00
mmu_notifier.c mm/mmu_notifier.c: fix race in mmu_interval_notifier_remove() 2022-04-21 20:01:10 -07:00
mmzone.c mm: multi-gen LRU: groundwork 2022-09-26 19:46:09 -07:00
mprotect.c mm/uffd: fix warning without PTE_MARKER_UFFD_WP compiled in 2022-10-12 15:56:46 -07:00
mremap.c mm: add merging after mremap resize 2022-09-26 19:46:28 -07:00
msync.c mm/msync: use vma_find() instead of vma linked list 2022-09-26 19:46:25 -07:00
nommu.c mm: remove the vma linked list 2022-09-26 19:46:26 -07:00
oom_kill.c mm: reduce noise in show_mem for lowmem allocations 2022-09-26 19:46:29 -07:00
page-writeback.c mm: export balance_dirty_pages_ratelimited_flags() 2022-09-26 12:28:07 +02:00
page_alloc.c mm/page_alloc: reduce potential fragmentation in make_alloc_exact() 2022-10-20 21:27:23 -07:00
page_counter.c mm: page_counter: remove unneeded atomic ops for low/min 2022-09-11 20:26:01 -07:00
page_ext.c page_ext: introduce boot parameter 'early_page_ext' 2022-09-11 20:26:02 -07:00
page_idle.c mm: don't be stuck to rmap lock on reclaim path 2022-05-19 14:08:54 -07:00
page_io.c swap: convert swap_writepage() to use a folio 2022-10-03 14:02:52 -07:00
page_isolation.c mm: add pageblock_aligned() macro 2022-10-03 14:03:04 -07:00
page_owner.c mm: reuse pageblock_start/end_pfn() macro 2022-10-03 14:03:03 -07:00
page_poison.c
page_reporting.c
page_reporting.h
page_table_check.c mm/page_table_check: fix typos 2022-10-03 14:03:27 -07:00
page_vma_mapped.c mm/swap: add swp_offset_pfn() to fetch PFN from swap entry 2022-09-26 19:46:05 -07:00
pagewalk.c - Yu Zhao's Multi-Gen LRU patches are here. They've been under test in 2022-10-10 17:53:04 -07:00
percpu-internal.h percpu: improve percpu_alloc_percpu event trace 2022-05-13 07:20:18 -07:00
percpu-km.c
percpu-stats.c mm: use vmalloc_array and vcalloc for array allocations 2022-03-08 09:30:46 -05:00
percpu-vm.c
percpu.c mm: percpu: use kmemleak_ignore_phys() instead of kmemleak_free() 2022-07-17 17:14:47 -07:00
pgalloc-track.h
pgtable-generic.c mm: avoid unnecessary flush on change_huge_pmd() 2022-05-13 07:20:05 -07:00
process_vm_access.c
ptdump.c mm: pagewalk: Fix race between unmap and page walker 2022-09-03 10:13:13 -07:00
readahead.c mm: add PSI accounting around ->read_folio and ->readahead calls 2022-09-20 08:24:38 -06:00
rmap.c - Yu Zhao's Multi-Gen LRU patches are here. They've been under test in 2022-10-10 17:53:04 -07:00
rodata_test.c mm/rodata_test: use PAGE_ALIGNED() helper 2022-10-03 14:03:05 -07:00
secretmem.c mm/secretmem: remove reduntant return value 2022-10-03 14:03:36 -07:00
shmem.c treewide: use get_random_u32() when possible 2022-10-11 17:42:58 -06:00
shrinker_debug.c mm: shrinkers: fix double kfree on shrinker name 2022-07-29 18:07:13 -07:00
shuffle.c mm/shuffle: convert module_param_call to module_param_cb 2022-10-03 14:03:07 -07:00
shuffle.h
slab.c mm/slab: move and adjust kernel-doc for kmem_cache_alloc 2022-11-21 10:19:46 +01:00
slab.h - Yu Zhao's Multi-Gen LRU patches are here. They've been under test in 2022-10-10 17:53:04 -07:00
slab_common.c - Yu Zhao's Multi-Gen LRU patches are here. They've been under test in 2022-10-10 17:53:04 -07:00
slob.c Merge branch 'slab/for-6.1/kmalloc_size_roundup' into slab/for-next 2022-09-29 11:30:55 +02:00
slub.c mm/slub, percpu: correct the calculation of early percpu allocation size 2022-11-21 10:19:46 +01:00
sparse-vmemmap.c mm: hugetlb_vmemmap: move vmemmap code related to HugeTLB to hugetlb_vmemmap.c 2022-08-08 18:06:42 -07:00
sparse.c mm: memory_hotplug: enumerate all supported section flags 2022-07-03 18:08:49 -07:00
swap.c mm: add folio_add_lru_vma() 2022-10-03 14:02:45 -07:00
swap.h mm: remove lookup_swap_cache() 2022-10-03 14:02:51 -07:00
swap_cgroup.c mm: memcontrol: don't allocate cgroup swap arrays when memcg is disabled 2022-10-03 14:03:36 -07:00
swap_slots.c mm/swap: convert put_swap_page() to put_swap_folio() 2022-10-03 14:02:46 -07:00
swap_state.c swap_state: convert free_swap_cache() to use a folio 2022-10-03 14:02:51 -07:00
swapfile.c - Yu Zhao's Multi-Gen LRU patches are here. They've been under test in 2022-10-10 17:53:04 -07:00
truncate.c mm: add split_folio() 2022-10-03 14:02:45 -07:00
usercopy.c usercopy: use unsigned long instead of uintptr_t 2022-07-01 17:03:38 -07:00
userfaultfd.c hugetlb: use new vma_lock for pmd sharing synchronization 2022-10-03 14:03:17 -07:00
util.c - Yu Zhao's Multi-Gen LRU patches are here. They've been under test in 2022-10-10 17:53:04 -07:00
vmalloc.c mm: kmsan: maintain KMSAN metadata for page operations 2022-10-03 14:03:20 -07:00
vmpressure.c
vmscan.c mglru: mm/vmscan.c: fix imprecise comments 2022-10-07 14:28:40 -07:00
vmstat.c - Yu Zhao's Multi-Gen LRU patches are here. They've been under test in 2022-10-10 17:53:04 -07:00
workingset.c mm: multi-gen LRU: minimal implementation 2022-09-26 19:46:09 -07:00
z3fold.c mm: Convert all PageMovable users to movable_operations 2022-08-02 12:34:03 -04:00
zbud.c
zpool.c zpool: remove the list of pools_head 2022-01-15 16:30:31 +02:00
zsmalloc.c zsmalloc: zs_destroy_pool: add size_class NULL check 2022-10-20 21:27:21 -07:00
zswap.c mm/swap: remove the end_write_func argument to __swap_writepage 2022-09-11 20:25:50 -07:00