alloc_calls and free_calls implementation in sysfs have two issues,
one is PAGE_SIZE limitiation of sysfs and other is it does not adhere
to "one value per file" rule.
To overcome this issues, move the alloc_calls and free_calls implemeation
to debugfs.
Signed-off-by: Faiyaz Mohammed <faiyazm@xxxxxxxxxxxxxx>
---
mm/slub.c | 518 ++++++++++++++++++++++++++++++++++----------------------------
1 file changed, 286 insertions(+), 232 deletions(-)
diff --git a/mm/slub.c b/mm/slub.c
index 3021ce9..4d20ee0 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -36,6 +36,7 @@
#include <linux/memcontrol.h>
#include <linux/random.h>
+#include <linux/debugfs.h>
#include <trace/events/kmem.h>
#include "internal.h"
@@ -225,6 +226,12 @@ static inline int sysfs_slab_alias(struct kmem_cache *s, const char *p)
{ return 0; }
#endif
+#ifdef CONFIG_DEBUG_FS
+static void debugfs_slab_add(struct kmem_cache *);
+#else
+static inline void debugfs_slab_add(struct kmem_cache *) { }
+#endif
+
static inline void stat(const struct kmem_cache *s, enum stat_item si)
{
#ifdef CONFIG_SLUB_STATS
@@ -4542,6 +4549,8 @@ int __kmem_cache_create(struct kmem_cache *s, slab_flags_t flags)
if (err)
__kmem_cache_release(s);
+ debugfs_slab_add(s);
+
return err;
}
@@ -4682,221 +4691,6 @@ static long validate_slab_cache(struct kmem_cache *s)
return count;
}
-/*
- * Generate lists of code addresses where slabcache objects are allocated
- * and freed.
- */
-
-struct location {
- unsigned long count;
- unsigned long addr;
- long long sum_time;
- long min_time;
- long max_time;
- long min_pid;
- long max_pid;
- DECLARE_BITMAP(cpus, NR_CPUS);
- nodemask_t nodes;
-};
-
-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, gfp_t flags)
-{
- struct location *l;
- int order;
-
- order = get_order(sizeof(struct location) * max);
-
- l = (void *)__get_free_pages(flags, 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,
- const struct track *track)
-{
- long start, end, pos;
- struct location *l;
- unsigned long caddr;
- unsigned long age = jiffies - track->when;
-
- 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 (track->addr == caddr) {
-
- l = &t->loc[pos];
- l->count++;
- if (track->when) {
- l->sum_time += age;
- if (age < l->min_time)
- l->min_time = age;
- if (age > l->max_time)
- l->max_time = age;
-
- if (track->pid < l->min_pid)
- l->min_pid = track->pid;
- if (track->pid > l->max_pid)
- l->max_pid = track->pid;
-
- cpumask_set_cpu(track->cpu,
- to_cpumask(l->cpus));
- }
- node_set(page_to_nid(virt_to_page(track)), l->nodes);
- return 1;
- }
-
- if (track->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, GFP_ATOMIC))
- 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 = track->addr;
- l->sum_time = age;
- l->min_time = age;
- l->max_time = age;
- l->min_pid = track->pid;
- l->max_pid = track->pid;
- cpumask_clear(to_cpumask(l->cpus));
- cpumask_set_cpu(track->cpu, to_cpumask(l->cpus));
- nodes_clear(l->nodes);
- node_set(page_to_nid(virt_to_page(track)), l->nodes);
- 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);
- void *p;
- unsigned long *map;
-
- map = get_map(s, page);
- for_each_object(p, s, addr, page->objects)
- if (!test_bit(__obj_to_index(s, addr, p), map))
- add_location(t, s, get_track(s, p, alloc));
- put_map(map);
-}
-
-static int list_locations(struct kmem_cache *s, char *buf,
- enum track_item alloc)
-{
- int len = 0;
- unsigned long i;
- struct loc_track t = { 0, 0, NULL };
- int node;
- struct kmem_cache_node *n;
-
- if (!alloc_loc_track(&t, PAGE_SIZE / sizeof(struct location),
- GFP_KERNEL)) {
- return sysfs_emit(buf, "Out of memory\n");
- }
- /* Push back cpu slabs */
- flush_all(s);
-
- for_each_kmem_cache_node(s, node, n) {
- unsigned long flags;
- struct page *page;
-
- if (!atomic_long_read(&n->nr_slabs))
- continue;
-
- spin_lock_irqsave(&n->list_lock, flags);
- list_for_each_entry(page, &n->partial, slab_list)
- process_slab(&t, s, page, alloc);
- list_for_each_entry(page, &n->full, slab_list)
- process_slab(&t, s, page, alloc);
- spin_unlock_irqrestore(&n->list_lock, flags);
- }
-
- for (i = 0; i < t.count; i++) {
- struct location *l = &t.loc[i];
-
- len += sysfs_emit_at(buf, len, "%7ld ", l->count);
-
- if (l->addr)
- len += sysfs_emit_at(buf, len, "%pS", (void *)l->addr);
- else
- len += sysfs_emit_at(buf, len, "<not-available>");
-
- if (l->sum_time != l->min_time)
- len += sysfs_emit_at(buf, len, " age=%ld/%ld/%ld",
- l->min_time,
- (long)div_u64(l->sum_time,
- l->count),
- l->max_time);
- else
- len += sysfs_emit_at(buf, len, " age=%ld", l->min_time);
-
- if (l->min_pid != l->max_pid)
- len += sysfs_emit_at(buf, len, " pid=%ld-%ld",
- l->min_pid, l->max_pid);
- else
- len += sysfs_emit_at(buf, len, " pid=%ld",
- l->min_pid);
-
- if (num_online_cpus() > 1 &&
- !cpumask_empty(to_cpumask(l->cpus)))
- len += sysfs_emit_at(buf, len, " cpus=%*pbl",
- cpumask_pr_args(to_cpumask(l->cpus)));
-
- if (nr_online_nodes > 1 && !nodes_empty(l->nodes))
- len += sysfs_emit_at(buf, len, " nodes=%*pbl",
- nodemask_pr_args(&l->nodes));
-
- len += sysfs_emit_at(buf, len, "\n");
- }
-
- free_loc_track(&t);
- if (!t.count)
- len += sysfs_emit_at(buf, len, "No data\n");
-
- return len;
-}
#endif /* CONFIG_SLUB_DEBUG */
#ifdef SLUB_RESILIENCY_TEST
@@ -5346,21 +5140,6 @@ static ssize_t validate_store(struct kmem_cache *s,
}
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);
#endif /* CONFIG_SLUB_DEBUG */
#ifdef CONFIG_FAILSLAB
@@ -5524,8 +5303,6 @@ static struct attribute *slab_attrs[] = {
&poison_attr.attr,
&store_user_attr.attr,
&validate_attr.attr,
- &alloc_calls_attr.attr,
- &free_calls_attr.attr,
#endif
#ifdef CONFIG_ZONE_DMA
&cache_dma_attr.attr,
@@ -5814,6 +5591,283 @@ static int __init slab_sysfs_init(void)
__initcall(slab_sysfs_init);
#endif /* CONFIG_SYSFS */
+#if defined(CONFIG_DEBUG_FS) && defined(CONFIG_SLUB_DEBUG)
+/*
+ * Generate lists of code addresses where slabcache objects are allocated
+ * and freed.
+ */
+
+struct location {
+ unsigned long count;
+ unsigned long addr;
+ long long sum_time;
+ long min_time;
+ long max_time;
+ long min_pid;
+ long max_pid;
+ DECLARE_BITMAP(cpus, NR_CPUS);
+ nodemask_t nodes;
+};
+
+struct loc_track {
+ unsigned long max;
+ unsigned long count;
+ struct location *loc;
+};
+
+static struct dentry *slab_debugfs_root;
+
+static struct dentry *slab_debugfs_cache;
+
+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, gfp_t flags)
+{
+ struct location *l;
+ int order;
+
+ order = get_order(sizeof(struct location) * max);
+
+ l = (void *)__get_free_pages(flags, 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,
+ const struct track *track)
+{
+ long start, end, pos;
+ struct location *l;
+ unsigned long caddr;
+ unsigned long age = jiffies - track->when;
+
+ 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 (track->addr == caddr) {
+
+ l = &t->loc[pos];
+ l->count++;
+ if (track->when) {
+ l->sum_time += age;
+ if (age < l->min_time)
+ l->min_time = age;
+ if (age > l->max_time)
+ l->max_time = age;
+
+ if (track->pid < l->min_pid)
+ l->min_pid = track->pid;
+ if (track->pid > l->max_pid)
+ l->max_pid = track->pid;
+
+ cpumask_set_cpu(track->cpu,
+ to_cpumask(l->cpus));
+ }
+ node_set(page_to_nid(virt_to_page(track)), l->nodes);
+ return 1;
+ }
+
+ if (track->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, GFP_ATOMIC))
+ 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 = track->addr;
+ l->sum_time = age;
+ l->min_time = age;
+ l->max_time = age;
+ l->min_pid = track->pid;
+ l->max_pid = track->pid;
+ cpumask_clear(to_cpumask(l->cpus));
+ cpumask_set_cpu(track->cpu, to_cpumask(l->cpus));
+ nodes_clear(l->nodes);
+ node_set(page_to_nid(virt_to_page(track)), l->nodes);
+ 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);
+ void *p;
+ unsigned long *map;
+
+ map = get_map(s, page);
+ for_each_object(p, s, addr, page->objects)
+ if (!test_bit(__obj_to_index(s, addr, p), map))
+ add_location(t, s, get_track(s, p, alloc));
+ put_map(map);
+}
+
+static int list_locations(struct seq_file *seq, struct kmem_cache *s,
+ enum track_item alloc)
+{
+ unsigned long i;
+ struct loc_track t = { 0, 0, NULL };
+ int node;
+ struct kmem_cache_node *n;
+
+ if (!alloc_loc_track(&t, PAGE_SIZE / sizeof(struct location),
+ GFP_KERNEL)) {
+ seq_puts(seq, "Out of memory\n");
+ return -ENOMEM;
+ }
+ /* Push back cpu slabs */
+ flush_all(s);
+
+ for_each_kmem_cache_node(s, node, n) {
+ unsigned long flags;
+ struct page *page;
+
+ if (!atomic_long_read(&n->nr_slabs))
+ continue;
+
+ spin_lock_irqsave(&n->list_lock, flags);
+ list_for_each_entry(page, &n->partial, slab_list)
+ process_slab(&t, s, page, alloc);
+ list_for_each_entry(page, &n->full, slab_list)
+ process_slab(&t, s, page, alloc);
+ spin_unlock_irqrestore(&n->list_lock, flags);
+ }
+
+ for (i = 0; i < t.count; i++) {
+ struct location *l = &t.loc[i];
+
+ seq_printf(seq, "%7ld ", l->count);
+
+ if (l->addr)
+ seq_printf(seq, "%pS", (void *)l->addr);
+ else
+ seq_puts(seq, "<not-available>");
+
+ if (l->sum_time != l->min_time) {
+ seq_printf(seq, " age=%ld/%ld/%ld",
+ l->min_time,
+ (long)div_u64(l->sum_time, l->count),
+ l->max_time);
+ } else
+ seq_printf(seq, " age=%ld",
+ l->min_time);
+
+ if (l->min_pid != l->max_pid)
+ seq_printf(seq, " pid=%ld-%ld",
+ l->min_pid, l->max_pid);
+ else
+ seq_printf(seq, " pid=%ld",
+ l->min_pid);
+
+ if (num_online_cpus() > 1 &&
+ !cpumask_empty(to_cpumask(l->cpus)))
+ seq_printf(seq, " cpus=%*pbl",
+ cpumask_pr_args(to_cpumask(l->cpus)));
+
+ if (nr_online_nodes > 1 && !nodes_empty(l->nodes))
+ seq_printf(seq, " nodes=%*pbl",
+ nodemask_pr_args(&l->nodes));
+
+ seq_puts(seq, "\n");
+ }
+
+ free_loc_track(&t);
+ if (!t.count)
+ seq_puts(seq, "No data\n");
+ return 0;
+}
+
+static int slab_debug_trace(struct seq_file *seq, void *ignored)
+{
+ struct kmem_cache *s = seq->private;
+
+ if (!(s->flags & SLAB_STORE_USER))
+ return 0;
+
+ if (strcmp(seq->file->f_path.dentry->d_name.name, "alloc_trace") == 0)
+ return list_locations(seq, s, TRACK_ALLOC);
+ else
+ return list_locations(seq, s, TRACK_FREE);
+
+ return 0;
+}
+
+static int slab_debug_trace_open(struct inode *inode, struct file *filp)
+{
+ return single_open(filp, slab_debug_trace,
+ file_inode(filp)->i_private);
+}
+
+static const struct file_operations slab_debug_fops = {
+ .open = slab_debug_trace_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
+
+static void debugfs_slab_add(struct kmem_cache *s)
+{
+ if (unlikely(!slab_debugfs_root))
+ return;
+
+ slab_debugfs_cache = debugfs_create_dir(s->name, slab_debugfs_root);
+ if (!IS_ERR(slab_debugfs_cache)) {
+ debugfs_create_file("alloc_trace", 0400,
+ slab_debugfs_cache, s, &slab_debug_fops);
+
+ debugfs_create_file("free_trace", 0400,
+ slab_debugfs_cache, s, &slab_debug_fops);
+ }
+}
+
+static void __init slab_debugfs_init(void)
+{
+ struct kmem_cache *s;
+
+ slab_debugfs_root = debugfs_create_dir("slab", NULL);
+ if (!IS_ERR(slab_debugfs_root))
+ list_for_each_entry(s, &slab_caches, list)
+ debugfs_slab_add(s);
+ else
+ pr_err("Cannot create slab debugfs.\n");
+
+}
+__initcall(slab_debugfs_init);
+#endif
/*
* The /proc/slabinfo ABI
*/
--
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member of the Code Aurora Forum, hosted by The Linux Foundation
