The patch titled
slub: add ability to list alloc / free callers per slab
has been added to the -mm tree. Its filename is
slub-add-ability-to-list-alloc--free-callers-per-slab.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: slub: add ability to list alloc / free callers per slab
From: Christoph Lameter <clameter@xxxxxxx>
This patch enables listing the callers who allocated or freed objects in a
cache.
For example to list the allocators for kmalloc-128 do
cat /sys/slab/kmalloc-128/alloc_calls
7 sn_io_slot_fixup+0x40/0x700
7 sn_io_slot_fixup+0x80/0x700
9 sn_bus_fixup+0xe0/0x380
6 param_sysfs_setup+0xf0/0x280
276 percpu_populate+0xf0/0x1a0
19 __register_chrdev_region+0x30/0x360
8 expand_files+0x2e0/0x6e0
1 sys_epoll_create+0x60/0x200
1 __mounts_open+0x140/0x2c0
65 kmem_alloc+0x110/0x280
3 alloc_disk_node+0xe0/0x200
33 as_get_io_context+0x90/0x280
74 kobject_kset_add_dir+0x40/0x140
12 pci_create_bus+0x2a0/0x5c0
1 acpi_ev_create_gpe_block+0x120/0x9e0
41 con_insert_unipair+0x100/0x1c0
1 uart_open+0x1c0/0xba0
1 dma_pool_create+0xe0/0x340
2 neigh_table_init_no_netlink+0x260/0x4c0
6 neigh_parms_alloc+0x30/0x200
1 netlink_kernel_create+0x130/0x320
5 fz_hash_alloc+0x50/0xe0
2 sn_common_hubdev_init+0xd0/0x6e0
28 kernel_param_sysfs_setup+0x30/0x180
72 process_zones+0x70/0x2e0
cat /sys/slab/kmalloc-128/free_calls
558 <not-available>
3 sn_io_slot_fixup+0x600/0x700
84 free_fdtable_rcu+0x120/0x260
2 seq_release+0x40/0x60
6 kmem_free+0x70/0xc0
24 free_as_io_context+0x20/0x200
1 acpi_get_object_info+0x3a0/0x3e0
1 acpi_add_single_object+0xcf0/0x1e40
2 con_release_unimap+0x80/0x140
1 free+0x20/0x40
SLAB_STORE_USER must be enabled for a slab cache by either booting with
"slab_debug" or enabling user tracking specifically for the slab of interest.
Signed-off-by: Christoph Lameter <clameter@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/slub.c | 184 +++++++++++++++++++++++++++++++++++++++++++++++++++-
1 files changed, 181 insertions(+), 3 deletions(-)
diff -puN mm/slub.c~slub-add-ability-to-list-alloc--free-callers-per-slab mm/slub.c
--- a/mm/slub.c~slub-add-ability-to-list-alloc--free-callers-per-slab
+++ a/mm/slub.c
@@ -67,9 +67,6 @@
*
* - Support PAGE_ALLOC_DEBUG. Should be easy to do.
*
- * - Support DEBUG_SLAB_LEAK. Trouble is we do not know where the full
- * slabs are in SLUB.
- *
* - SLAB_DEBUG_INITIAL is not supported but I have never seen a use of
* it.
*
@@ -2407,6 +2404,169 @@ static unsigned long validate_slab_cache
return count;
}
+/*
+ * Generate lists of locations where slabcache objects are allocated
+ * and freed.
+ */
+
+struct location {
+ unsigned long count;
+ void *addr;
+};
+
+struct loc_track {
+ unsigned long max;
+ unsigned long count;
+ struct location *loc;
+};
+
+static void free_loc_track(struct loc_track *t)
+{
+ if (t->max)
+ free_pages((unsigned long)t->loc,
+ get_order(sizeof(struct location) * t->max));
+}
+
+static int alloc_loc_track(struct loc_track *t, unsigned long max)
+{
+ struct location *l;
+ int order;
+
+ if (!max)
+ max = PAGE_SIZE / sizeof(struct location);
+
+ order = get_order(sizeof(struct location) * max);
+
+ l = (void *)__get_free_pages(GFP_KERNEL, order);
+
+ if (!l)
+ return 0;
+
+ if (t->count) {
+ memcpy(l, t->loc, sizeof(struct location) * t->count);
+ free_loc_track(t);
+ }
+ t->max = max;
+ t->loc = l;
+ return 1;
+}
+
+static int add_location(struct loc_track *t, struct kmem_cache *s,
+ void *addr)
+{
+ long start, end, pos;
+ struct location *l;
+ void *caddr;
+
+ start = -1;
+ end = t->count;
+
+ for(;;) {
+ pos = start + (end - start + 1) / 2;
+
+ /*
+ * There is nothing at "end". If we end up there
+ * we need to add something to before end.
+ */
+ if (pos == end)
+ break;
+
+ caddr = t->loc[pos].addr;
+ if (addr == caddr) {
+ t->loc[pos].count++;
+ return 1;
+ }
+
+ if (addr < caddr)
+ end = pos;
+ else
+ start = pos;
+ }
+
+ /*
+ * Not found. Insert new tracking element
+ */
+ if (t->count >= t->max && !alloc_loc_track(t, 2 * t->max))
+ return 0;
+
+ l = t->loc + pos;
+ if (pos < t->count)
+ memmove(l + 1, l,
+ (t->count - pos) * sizeof(struct location));
+ t->count++;
+ l->count = 1;
+ l->addr = addr;
+ return 1;
+}
+
+static void process_slab(struct loc_track *t, struct kmem_cache *s,
+ struct page *page, enum track_item alloc)
+{
+ void *addr = page_address(page);
+ unsigned long map[BITS_TO_LONGS(s->objects)];
+ void *p;
+
+ bitmap_zero(map, s->objects);
+ for(p = page->freelist; p; p = get_freepointer(s, p))
+ set_bit((p - addr) / s->size, map);
+
+ for(p = addr; p < addr + s->objects * s->size; p += s->size)
+ if (!test_bit((p - addr) / s->size, map)) {
+ void *addr = get_track(s, p, alloc)->addr;
+
+ add_location(t, s, addr);
+ }
+}
+
+static int list_locations(struct kmem_cache *s, char *buf,
+ enum track_item alloc)
+{
+ int n = 0;
+ unsigned long i;
+ struct loc_track t;
+ int node;
+
+ t.count = 0;
+ t.max = 0;
+
+ /* Push back cpu slabs */
+ flush_all(s);
+
+ for_each_online_node(node) {
+ struct kmem_cache_node *n = get_node(s, node);
+ unsigned long flags;
+ struct page *page;
+
+ if (!atomic_read(&n->nr_slabs))
+ continue;
+
+ spin_lock_irqsave(&n->list_lock, flags);
+ list_for_each_entry(page, &n->partial, lru)
+ process_slab(&t, s, page, alloc);
+ list_for_each_entry(page, &n->full, lru)
+ process_slab(&t, s, page, alloc);
+ spin_unlock_irqrestore(&n->list_lock, flags);
+ }
+
+ for (i = 0; i < t.count; i++) {
+ void *addr = t.loc[i].addr;
+
+ if (n > PAGE_SIZE - 100)
+ break;
+ n += sprintf(buf + n, "%7ld ", t.loc[i].count);
+ if (addr)
+ n += sprint_symbol(buf + n, (unsigned long)t.loc[i].addr);
+ else
+ n += sprintf(buf + n, "<not-available>");
+ n += sprintf(buf + n, "\n");
+ }
+
+ free_loc_track(&t);
+ if (!t.count)
+ n += sprintf(buf, "No data\n");
+ return n;
+}
+
static unsigned long count_partial(struct kmem_cache_node *n)
{
unsigned long flags;
@@ -2757,6 +2917,22 @@ static ssize_t validate_store(struct kme
}
SLAB_ATTR(validate);
+static ssize_t alloc_calls_show(struct kmem_cache *s, char *buf)
+{
+ if (!(s->flags & SLAB_STORE_USER))
+ return -ENOSYS;
+ return list_locations(s, buf, TRACK_ALLOC);
+}
+SLAB_ATTR_RO(alloc_calls);
+
+static ssize_t free_calls_show(struct kmem_cache *s, char *buf)
+{
+ if (!(s->flags & SLAB_STORE_USER))
+ return -ENOSYS;
+ return list_locations(s, buf, TRACK_FREE);
+}
+SLAB_ATTR_RO(free_calls);
+
#ifdef CONFIG_NUMA
static ssize_t defrag_ratio_show(struct kmem_cache *s, char *buf)
{
@@ -2797,6 +2973,8 @@ static struct attribute * slab_attrs[] =
&poison_attr.attr,
&store_user_attr.attr,
&validate_attr.attr,
+ &alloc_calls_attr.attr,
+ &free_calls_attr.attr,
#ifdef CONFIG_ZONE_DMA
&cache_dma_attr.attr,
#endif
_
Patches currently in -mm which might be from clameter@xxxxxxx are
slab-introduce-krealloc.patch
slab-introduce-krealloc-fix.patch
paravirt_ops-allow-paravirt-backend-to-choose-kernel-pmd-sharing.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
smaps-add-clear_refs-file-to-clear-reference-fix.patch
smaps-add-clear_refs-file-to-clear-reference-fix-fix.patch
slab-use-num_possible_cpus-in-enable_cpucache.patch
i386-use-page-allocator-to-allocate-thread_info-structure.patch
slub-core.patch
slub-fix-numa-bootstrap.patch
slub-use-correct-flags-to-check-for-dma-cache.patch
slub-treat-slab_hwcache_align-as-a-mininum-and-not-as-the-alignment.patch
slub-core-minor-fixes.patch
slub-core-use-enum-for-tracking-modes-instead-of-integers.patch
slub-core-fix-another-numa-bootstrap-issue.patch
slub-core-fix-object-counting.patch
slub-add-slabinfo-tool.patch
slub-add-slabinfo-tool-update-slabinfoc.patch
make-page-private-usable-in-compound-pages-v1.patch
make-page-private-usable-in-compound-pages-v1-hugetlb-fix.patch
optimize-compound_head-by-avoiding-a-shared-page.patch
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-ability-to-list-alloc--free-callers-per-slab.patch
drop-version-number.patch
quicklists-for-page-table-pages.patch
quicklists-for-page-table-pages-avoid-useless-virt_to_page-conversion.patch
quicklist-support-for-ia64.patch
quicklist-support-for-x86_64.patch
quicklist-support-for-sparc64.patch
extend-print_symbol-capability-fix.patch
slab-shutdown-cache_reaper-when-cpu-goes-down.patch
mm-implement-swap-prefetching.patch
readahead-state-based-method-aging-accounting.patch
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