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authorLinus Torvalds <torvalds@linux-foundation.org>2024-05-13 10:28:34 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2024-05-13 10:28:34 -0700
commitcd97950cbcabe662cd8a9fd0a08a247c1ea1fb28 (patch)
tree83fe99fd41d313b350c3ac87a496aab1bd22a2a7 /lib
parentc07ea940a011343fdaec12cd74b4ff947ba6f893 (diff)
parent7338999ca3468404f547b1540211114cbdb26d06 (diff)
Merge tag 'slab-for-6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab
Pull slab updates from Vlastimil Babka: "This time it's mostly random cleanups and fixes, with two performance fixes that might have significant impact, but limited to systems experiencing particular bad corner case scenarios rather than general performance improvements. The memcg hook changes are going through the mm tree due to dependencies. - Prevent stalls when reading /proc/slabinfo (Jianfeng Wang) This fixes the long-standing problem that can happen with workloads that have alloc/free patterns resulting in many partially used slabs (in e.g. dentry cache). Reading /proc/slabinfo will traverse the long partial slab list under spinlock with disabled irqs and thus can stall other processes or even trigger the lockup detection. The traversal is only done to count free objects so that <active_objs> column can be reported along with <num_objs>. To avoid affecting fast paths with another shared counter (attempted in the past) or complex partial list traversal schemes that allow rescheduling, the chosen solution resorts to approximation - when the partial list is over 10000 slabs long, we will only traverse first 5000 slabs from head and tail each and use the average of those to estimate the whole list. Both head and tail are used as the slabs near head to tend to have more free objects than the slabs towards the tail. It is expected the approximation should not break existing /proc/slabinfo consumers. The <num_objs> field is still accurate and reflects the overall kmem_cache footprint. The <active_objs> was already imprecise due to cpu and percpu-partial slabs, so can't be relied upon to determine exact cache usage. The difference between <active_objs> and <num_objs> is mainly useful to determine the slab fragmentation, and that will be possible even with the approximation in place. - Prevent allocating many slabs when a NUMA node is full (Chen Jun) Currently, on NUMA systems with a node under significantly bigger pressure than other nodes, the fallback strategy may result in each kmalloc_node() that can't be safisfied from the preferred node, to allocate a new slab on a fallback node, and not reuse the slabs already on that node's partial list. This is now fixed and partial lists of fallback nodes are checked even for kmalloc_node() allocations. It's still preferred to allocate a new slab on the requested node before a fallback, but only with a GFP_NOWAIT attempt, which will fail quickly when the node is under a significant memory pressure. - More SLAB removal related cleanups (Xiu Jianfeng, Hyunmin Lee) - Fix slub_kunit self-test with hardened freelists (Guenter Roeck) - Mark racy accesses for KCSAN (linke li) - Misc cleanups (Xiongwei Song, Haifeng Xu, Sangyun Kim)" * tag 'slab-for-6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab: mm/slub: remove the check for NULL kmalloc_caches mm/slub: create kmalloc 96 and 192 caches regardless cache size order mm/slub: mark racy access on slab->freelist slub: use count_partial_free_approx() in slab_out_of_memory() slub: introduce count_partial_free_approx() slub: Set __GFP_COMP in kmem_cache by default mm/slub: remove duplicate initialization for early_kmem_cache_node_alloc() mm/slub: correct comment in do_slab_free() mm/slub, kunit: Use inverted data to corrupt kmem cache mm/slub: simplify get_partial_node() mm/slub: add slub_get_cpu_partial() helper mm/slub: remove the check of !kmem_cache_has_cpu_partial() mm/slub: Reduce memory consumption in extreme scenarios mm/slub: mark racy accesses on slab->slabs mm/slub: remove dummy slabinfo functions
Diffstat (limited to 'lib')
-rw-r--r--lib/slub_kunit.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/lib/slub_kunit.c b/lib/slub_kunit.c
index d4a3730b08fa..4ce960438806 100644
--- a/lib/slub_kunit.c
+++ b/lib/slub_kunit.c
@@ -55,7 +55,7 @@ static void test_next_pointer(struct kunit *test)
ptr_addr = (unsigned long *)(p + s->offset);
tmp = *ptr_addr;
- p[s->offset] = 0x12;
+ p[s->offset] = ~p[s->offset];
/*
* Expecting three errors.