The patch titled Subject: mm, slub: check new pages with restored irqs has been added to the -mm tree. Its filename is mm-slub-check-new-pages-with-restored-irqs.patch This patch should soon appear at https://ozlabs.org/~akpm/mmots/broken-out/mm-slub-check-new-pages-with-restored-irqs.patch and later at https://ozlabs.org/~akpm/mmotm/broken-out/mm-slub-check-new-pages-with-restored-irqs.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Vlastimil Babka <vbabka@xxxxxxx> Subject: mm, slub: check new pages with restored irqs Building on top of the previous patch, re-enable irqs before checking new pages. alloc_debug_processing() is now called with enabled irqs so we need to remove VM_BUG_ON(!irqs_disabled()); in check_slab() - there doesn't seem to be a need for it anyway. Link: https://lkml.kernel.org/r/20210805152000.12817-18-vbabka@xxxxxxx Signed-off-by: Vlastimil Babka <vbabka@xxxxxxx> Cc: Christoph Lameter <cl@xxxxxxxxx> Cc: David Rientjes <rientjes@xxxxxxxxxx> Cc: Jann Horn <jannh@xxxxxxxxxx> Cc: Jesper Dangaard Brouer <brouer@xxxxxxxxxx> Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx> Cc: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx> Cc: Mike Galbraith <efault@xxxxxx> Cc: Pekka Enberg <penberg@xxxxxxxxxx> Cc: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/slub.c | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-) --- a/mm/slub.c~mm-slub-check-new-pages-with-restored-irqs +++ a/mm/slub.c @@ -995,8 +995,6 @@ static int check_slab(struct kmem_cache { int maxobj; - VM_BUG_ON(!irqs_disabled()); - if (!PageSlab(page)) { slab_err(s, page, "Not a valid slab page"); return 0; @@ -2775,10 +2773,10 @@ new_objects: lockdep_assert_irqs_disabled(); freelist = get_partial(s, gfpflags, node, &page); + local_irq_restore(flags); if (freelist) goto check_new_page; - local_irq_restore(flags); put_cpu_ptr(s->cpu_slab); page = new_slab(s, gfpflags, node); c = get_cpu_ptr(s->cpu_slab); @@ -2788,7 +2786,6 @@ new_objects: return NULL; } - local_irq_save(flags); /* * No other reference to the page yet so we can * muck around with it freely without cmpxchg @@ -2803,7 +2800,6 @@ check_new_page: if (kmem_cache_debug(s)) { if (!alloc_debug_processing(s, page, freelist, addr)) { /* Slab failed checks. Next slab needed */ - local_irq_restore(flags); goto new_slab; } else { /* @@ -2821,6 +2817,7 @@ check_new_page: */ goto return_single; + local_irq_save(flags); if (unlikely(c->page)) flush_slab(s, c); c->page = page; @@ -2829,6 +2826,7 @@ check_new_page: return_single: + local_irq_save(flags); if (unlikely(c->page)) flush_slab(s, c); c->page = page; _ Patches currently in -mm which might be from vbabka@xxxxxxx are mm-slub-fix-slub_debug-disablement-for-list-of-slabs.patch mm-slub-dont-call-flush_all-from-slab_debug_trace_open.patch mm-slub-allocate-private-object-map-for-debugfs-listings.patch mm-slub-allocate-private-object-map-for-validate_slab_cache.patch mm-slub-dont-disable-irq-for-debug_check_no_locks_freed.patch mm-slub-remove-redundant-unfreeze_partials-from-put_cpu_partial.patch mm-slub-unify-cmpxchg_double_slab-and-__cmpxchg_double_slab.patch mm-slub-extract-get_partial-from-new_slab_objects.patch mm-slub-dissolve-new_slab_objects-into-___slab_alloc.patch mm-slub-return-slab-page-from-get_partial-and-set-c-page-afterwards.patch mm-slub-restructure-new-page-checks-in-___slab_alloc.patch mm-slub-simplify-kmem_cache_cpu-and-tid-setup.patch mm-slub-move-disabling-enabling-irqs-to-___slab_alloc.patch mm-slub-do-initial-checks-in-___slab_alloc-with-irqs-enabled.patch mm-slub-move-disabling-irqs-closer-to-get_partial-in-___slab_alloc.patch mm-slub-restore-irqs-around-calling-new_slab.patch mm-slub-validate-slab-from-partial-list-or-page-allocator-before-making-it-cpu-slab.patch mm-slub-check-new-pages-with-restored-irqs.patch mm-slub-stop-disabling-irqs-around-get_partial.patch mm-slub-move-reset-of-c-page-and-freelist-out-of-deactivate_slab.patch mm-slub-make-locking-in-deactivate_slab-irq-safe.patch mm-slub-call-deactivate_slab-without-disabling-irqs.patch mm-slub-move-irq-control-into-unfreeze_partials.patch mm-slub-discard-slabs-in-unfreeze_partials-without-irqs-disabled.patch mm-slub-detach-whole-partial-list-at-once-in-unfreeze_partials.patch mm-slub-separate-detaching-of-partial-list-in-unfreeze_partials-from-unfreezing.patch mm-slub-only-disable-irq-with-spin_lock-in-__unfreeze_partials.patch mm-slub-dont-disable-irqs-in-slub_cpu_dead.patch mm-slab-make-flush_slab-possible-to-call-with-irqs-enabled.patch mm-slub-optionally-save-restore-irqs-in-slab_lock.patch mm-slub-make-slab_lock-disable-irqs-with-preempt_rt.patch mm-slub-protect-put_cpu_partial-with-disabled-irqs-instead-of-cmpxchg.patch mm-slub-use-migrate_disable-on-preempt_rt.patch mm-slub-convert-kmem_cpu_slab-protection-to-local_lock.patch