Debugfs interface: it creates the file /sys/kernel/debug/pmalloc/pools
which exposes statistics about all the pools and memory nodes in use. Signed-off-by: Igor Stoppa <igor.sto...@huawei.com> --- 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 8050dea..09ce7f3 100644 --- a/mm/pmalloc.c +++ b/mm/pmalloc.c @@ -224,3 +224,116 @@ int __init pmalloc_init(void) atomic_set(&pmalloc_data->pools_count, 0); return 0; } + +#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%pK\n", node); + seq_printf(s, " - start of data ptr:\t%pK\n", node->data); + seq_printf(s, " - end of node ptr:\t%pK\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%pK\n", pool); + seq_printf(s, " - name:\t\t%s\n", pool->name); + seq_printf(s, " - protected:\t\t%u\n", atomic_read(&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