The patch titled slab allocators: Remove SLAB_DEBUG_INITIAL flag has been added to the -mm tree. Its filename is slub-slab-allocators-remove-slab_debug_initial-flag.patch *** Remember to use Documentation/SubmitChecklist when testing your code *** See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find out what to do about this ------------------------------------------------------ Subject: slab allocators: Remove SLAB_DEBUG_INITIAL flag From: Christoph Lameter <clameter@xxxxxxx> I have never seen a use of SLAB_DEBUG_INITIAL. It is only supported by SLAB. I think its purpose was to have a callback after an object has been freed to verify that the state is the constructor state again? The callback is performed before each freeing of an object. I would think that it is much easier to check the object state manually before the free. That also places the check near the code object manipulation of the object. Also the SLAB_DEBUG_INITIAL callback is only performed if the kernel was compiled with SLAB debugging on. If there would be code in a constructor handling SLAB_DEBUG_INITIAL then it would have to be conditional on SLAB_DEBUG otherwise it would just be dead code. But there is no such code in the kernel. I think SLUB_DEBUG_INITIAL is too problematic to make real use of, difficult to understand and there are easier ways to accomplish the same effect (i.e. add debug code before kfree). There is a related flag SLAB_CTOR_VERIFY that is frequently checked to be clear in fs inode caches. Remove the pointless checks (they would even be pointless without removeal of SLAB_DEBUG_INITIAL) from the fs constructors. This is the last slab flag that SLUB did not support. Remove the check for unimplemented flags from SLUB. Signed-off-by: Christoph Lameter <clameter@xxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/slub.c | 10 ---------- 1 files changed, 10 deletions(-) diff -puN mm/slub.c~slub-slab-allocators-remove-slab_debug_initial-flag mm/slub.c --- a/mm/slub.c~slub-slab-allocators-remove-slab_debug_initial-flag +++ a/mm/slub.c @@ -97,9 +97,6 @@ * * - Support PAGE_ALLOC_DEBUG. Should be easy to do. * - * - SLAB_DEBUG_INITIAL is not supported but I have never seen a use of - * it. - * * - Variable sizing of the per node arrays */ @@ -126,11 +123,6 @@ #endif /* - * Flags from the regular SLAB that SLUB does not support: - */ -#define SLUB_UNIMPLEMENTED (SLAB_DEBUG_INITIAL) - -/* * Mininum number of partial slabs. These will be left on the partial * lists even if they are empty. kmem_cache_shrink may reclaim them. */ @@ -1748,8 +1740,6 @@ static int kmem_cache_open(struct kmem_c s->flags = flags; s->align = align; - BUG_ON(flags & SLUB_UNIMPLEMENTED); - /* * The page->offset field is only 16 bit wide. This is an offset * in units of words from the beginning of an object. If the slab _ Patches currently in -mm which might be from clameter@xxxxxxx are origin.patch slab-introduce-krealloc.patch add-apply_to_page_range-which-applies-a-function-to-a-pte-range.patch safer-nr_node_ids-and-nr_node_ids-determination-and-initial.patch use-zvc-counters-to-establish-exact-size-of-dirtyable-pages.patch slab-ensure-cache_alloc_refill-terminates.patch smaps-extract-pmd-walker-from-smaps-code.patch smaps-add-pages-referenced-count-to-smaps.patch smaps-add-clear_refs-file-to-clear-reference.patch slab-use-num_possible_cpus-in-enable_cpucache.patch i386-use-page-allocator-to-allocate-thread_info-structure.patch make-page-private-usable-in-compound-pages-v1.patch optimize-compound_head-by-avoiding-a-shared-page.patch add-virt_to_head_page-and-consolidate-code-in-slab-and-slub.patch quicklists-for-page-table-pages.patch quicklist-support-for-sparc64.patch slab-allocators-remove-obsolete-slab_must_hwcache_align.patch kmem_cache-simplify-slab-cache-creation.patch slab-allocators-remove-multiple-alignment-specifications.patch fault-injection-fix-failslab-with-config_numa.patch mm-fix-handling-of-panic_on_oom-when-cpusets-are-in-use.patch slab-allocators-remove-slab_debug_initial-flag.patch slab-allocators-remove-slab_ctor_atomic.patch slab-allocators-remove-useless-__gfp_no_grow-flag.patch page-migration-only-migrate-pages-if-allocation-in-the-highest-zone-is-possible.patch slub-core.patch slub-change-default-alignments.patch slub-allocate-smallest-object-size-if-the-user-asks-for-0-bytes.patch powerpc-disable-slub-for-configurations-in-which-slab-page-structs-are-modified.patch slub-make-page-private-usable-in-compound-pages-v1.patch slub-add-virt_to_head_page-and-consolidate-code-in-slab-and-slub.patch slub-fix-object-tracking.patch slub-enable-tracking-of-full-slabs.patch slub-validation-of-slabs-metadata-and-guard-zones.patch slub-add-min_partial.patch slub-add-ability-to-list-alloc--free-callers-per-slab.patch slub-free-slabs-and-sort-partial-slab-lists-in-kmem_cache_shrink.patch slub-remove-object-activities-out-of-checking-functions.patch slub-user-documentation.patch slub-add-slabinfo-tool.patch slub-slab-allocators-remove-obsolete-slab_must_hwcache_align.patch slub-slab-allocators-remove-slab_debug_initial-flag.patch slub-slab-allocators-remove-slab_ctor_atomic.patch slub-slab-allocators-remove-useless-__gfp_no_grow-flag.patch quicklist-support-for-ia64.patch quicklist-support-for-x86_64.patch slub-exploit-page-mobility-to-increase-allocation-order.patch slub-mm-only-make-slub-the-default-slab-allocator.patch slub-i386-support.patch remove-constructor-from-buffer_head.patch slab-shutdown-cache_reaper-when-cpu-goes-down.patch mm-implement-swap-prefetching.patch revoke-core-code-slab-allocators-remove-slab_debug_initial-flag-revoke.patch vmstat-use-our-own-timer-events.patch make-vm-statistics-update-interval-configurable.patch make-vm-statistics-update-interval-configurable-fix.patch readahead-state-based-method-aging-accounting.patch - To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html