The patch titled Subject: slub: disable tracing and failslab for merged slabs has been added to the -mm tree. Its filename is slub-disable-tracing-and-failslab-for-merged-slabs.patch This patch should soon appear at http://ozlabs.org/~akpm/mmots/broken-out/slub-disable-tracing-and-failslab-for-merged-slabs.patch and later at http://ozlabs.org/~akpm/mmotm/broken-out/slub-disable-tracing-and-failslab-for-merged-slabs.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/SubmitChecklist when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Christoph Lameter <cl@xxxxxxxxx> Subject: slub: disable tracing and failslab for merged slabs Tracing of mergeable slabs as well as uses of failslab are confusing since the objects of multiple slab caches will be affected. Moreover this creates a situation where a mergeable slab will become unmergeable. If tracing or failslab testing is desired then it may be best to switch merging off for starters. Signed-off-by: Christoph Lameter <cl@xxxxxxxxx> Tested-by: WANG Chao <chaowang@xxxxxxxxxx> Cc: Pekka Enberg <penberg@xxxxxxxxxx> Cc: David Rientjes <rientjes@xxxxxxxxxx> Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/slub.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff -puN mm/slub.c~slub-disable-tracing-and-failslab-for-merged-slabs mm/slub.c --- a/mm/slub.c~slub-disable-tracing-and-failslab-for-merged-slabs +++ a/mm/slub.c @@ -4604,6 +4604,14 @@ static ssize_t trace_show(struct kmem_ca static ssize_t trace_store(struct kmem_cache *s, const char *buf, size_t length) { + /* + * Tracing a merged cache is going to give confusing results + * as well as cause other issues like converting a mergeable + * cache into an umergeable one. + */ + if (s->refcount > 1) + return -EINVAL; + s->flags &= ~SLAB_TRACE; if (buf[0] == '1') { s->flags &= ~__CMPXCHG_DOUBLE; @@ -4721,6 +4729,9 @@ static ssize_t failslab_show(struct kmem static ssize_t failslab_store(struct kmem_cache *s, const char *buf, size_t length) { + if (s->refcount > 1) + return -EINVAL; + s->flags &= ~SLAB_FAILSLAB; if (buf[0] == '1') s->flags |= SLAB_FAILSLAB; _ Patches currently in -mm which might be from cl@xxxxxxxxx are origin.patch mm-slab_commonc-suppress-warning.patch mm-slab_common-move-kmem_cache-definition-to-internal-header.patch mm-slb-always-track-caller-in-kmalloc_node_track_caller.patch mm-slab-move-cache_flusharray-out-of-unlikelytext-section.patch mm-slab-noinline-__ac_put_obj.patch mm-slab-factor-out-unlikely-part-of-cache_free_alien.patch slub-disable-tracing-and-failslab-for-merged-slabs.patch mm-thp-dont-hold-mmap_sem-in-khugepaged-when-allocating-thp.patch mm-compaction-defer-each-zone-individually-instead-of-preferred-zone.patch mm-compaction-defer-each-zone-individually-instead-of-preferred-zone-fix.patch mm-compaction-do-not-count-compact_stall-if-all-zones-skipped-compaction.patch mm-compaction-do-not-recheck-suitable_migration_target-under-lock.patch mm-compaction-move-pageblock-checks-up-from-isolate_migratepages_range.patch mm-compaction-reduce-zone-checking-frequency-in-the-migration-scanner.patch mm-compaction-khugepaged-should-not-give-up-due-to-need_resched.patch mm-compaction-khugepaged-should-not-give-up-due-to-need_resched-fix.patch mm-compaction-periodically-drop-lock-and-restore-irqs-in-scanners.patch mm-compaction-skip-rechecks-when-lock-was-already-held.patch mm-compaction-remember-position-within-pageblock-in-free-pages-scanner.patch mm-compaction-skip-buddy-pages-by-their-order-in-the-migrate-scanner.patch mm-rename-allocflags_to_migratetype-for-clarity.patch mm-compaction-pass-gfp-mask-to-compact_control.patch mm-use-__seq_open_private-instead-of-seq_open.patch vmstat-on-demand-vmstat-workers-v8.patch vmstat-on-demand-vmstat-workers-v8-do-not-open-code-alloc_cpumask_var.patch vmstat-on-demand-vmstat-workers-v8-fix-2.patch linux-next.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