Debugfs interface: it creates a file
/sys/kernel/debug/pmalloc/pools
which exposes statistics about all the pools and memory nodes in use.
Signed-off-by: Igor Stoppa <igor.stoppa@xxxxxxxxxx>
---
mm/Kconfig | 11 ++++++
mm/pmalloc.c | 113 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 124 insertions(+)
diff --git a/mm/Kconfig b/mm/Kconfig
index beb7a45..dfbdc07 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -539,6 +539,17 @@ config CMA_AREAS
If unsure, leave the default value "7".
+config PMALLOC_DEBUG
+ bool "Protectable Memory Allocator debugging"
+ depends on DEBUG_KERNEL
+ default y
+ help
+ Debugfs support for dumping information about memory pools.
+ It shows internal stats: free/used/total space, protection
+ status, data overhead, etc.
+
+ If unsure, say "y".
+
config MEM_SOFT_DIRTY
bool "Track memory changes"
depends on CHECKPOINT_RESTORE && HAVE_ARCH_SOFT_DIRTY && PROC_FS
diff --git a/mm/pmalloc.c b/mm/pmalloc.c
index c73d60c..6dd6bbe 100644
--- a/mm/pmalloc.c
+++ b/mm/pmalloc.c
@@ -225,3 +225,116 @@ int __init pmalloc_init(void)
return 0;
}
EXPORT_SYMBOL(pmalloc_init);
+
+#ifdef CONFIG_PMALLOC_DEBUG
+#include <linux/debugfs.h>
+static struct dentry *pmalloc_root;
+
+static void *__pmalloc_seq_start(struct seq_file *s, loff_t *pos)
+{
+ if (*pos)
+ return NULL;
+ return pos;
+}
+
+static void *__pmalloc_seq_next(struct seq_file *s, void *v, loff_t *pos)
+{
+ return NULL;
+}
+
+static void __pmalloc_seq_stop(struct seq_file *s, void *v)
+{
+}
+
+static __always_inline
+void __seq_printf_node(struct seq_file *s, struct pmalloc_node *node)
+{
+ unsigned long total_space, node_pages, end_of_node,
+ used_space, available_space;
+ int total_words, used_words, available_words;
+
+ used_words = atomic_read(&node->used_words);
+ total_words = node->total_words;
+ available_words = total_words - used_words;
+ used_space = used_words * WORD_SIZE;
+ total_space = total_words * WORD_SIZE;
+ available_space = total_space - used_space;
+ node_pages = (total_space + HEADER_SIZE) / PAGE_SIZE;
+ end_of_node = total_space + HEADER_SIZE + (unsigned long) node;
+ seq_printf(s, " - node:\t\t%p\n", node);
+ seq_printf(s, " - start of data ptr:\t%p\n", node->data);
+ seq_printf(s, " - end of node ptr:\t%p\n", (void *)end_of_node);
+ seq_printf(s, " - total words:\t%d\n", total_words);
+ seq_printf(s, " - used words:\t%d\n", used_words);
+ seq_printf(s, " - available words:\t%d\n", available_words);
+ seq_printf(s, " - pages:\t\t%lu\n", node_pages);
+ seq_printf(s, " - total space:\t%lu\n", total_space);
+ seq_printf(s, " - used space:\t%lu\n", used_space);
+ seq_printf(s, " - available space:\t%lu\n", available_space);
+}
+
+static __always_inline
+void __seq_printf_pool(struct seq_file *s, struct pmalloc_pool *pool)
+{
+ struct pmalloc_node *node;
+
+ seq_printf(s, "pool:\t\t\t%p\n", pool);
+ seq_printf(s, " - name:\t\t%s\n", pool->name);
+ seq_printf(s, " - protected:\t\t%u\n", pool->protected);
+ seq_printf(s, " - nodes count:\t\t%u\n",
+ atomic_read(&pool->nodes_count));
+ rcu_read_lock();
+ hlist_for_each_entry_rcu(node, &pool->nodes_list_head, nodes_list)
+ __seq_printf_node(s, node);
+ rcu_read_unlock();
+}
+
+static int __pmalloc_seq_show(struct seq_file *s, void *v)
+{
+ struct pmalloc_pool *pool;
+
+ seq_printf(s, "pools count:\t\t%u\n",
+ atomic_read(&pmalloc_data->pools_count));
+ seq_printf(s, "page size:\t\t%lu\n", PAGE_SIZE);
+ seq_printf(s, "word size:\t\t%lu\n", WORD_SIZE);
+ seq_printf(s, "node header size:\t%lu\n", HEADER_SIZE);
+ rcu_read_lock();
+ hlist_for_each_entry_rcu(pool, &pmalloc_data->pools_list_head,
+ pools_list)
+ __seq_printf_pool(s, pool);
+ rcu_read_unlock();
+ return 0;
+}
+
+static const struct seq_operations pmalloc_seq_ops = {
+ .start = __pmalloc_seq_start,
+ .next = __pmalloc_seq_next,
+ .stop = __pmalloc_seq_stop,
+ .show = __pmalloc_seq_show,
+};
+
+static int __pmalloc_open(struct inode *inode, struct file *file)
+{
+ return seq_open(file, &pmalloc_seq_ops);
+}
+
+static const struct file_operations pmalloc_file_ops = {
+ .owner = THIS_MODULE,
+ .open = __pmalloc_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release
+};
+
+
+static int __init __pmalloc_init_track_pool(void)
+{
+ struct dentry *de = NULL;
+
+ pmalloc_root = debugfs_create_dir("pmalloc", NULL);
+ debugfs_create_file("pools", 0644, pmalloc_root, NULL,
+ &pmalloc_file_ops);
+ return 0;
+}
+late_initcall(__pmalloc_init_track_pool);
+#endif
--
2.9.3
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