diff options
| -rw-r--r-- | include/linux/relay.h | 7 | ||||
| -rw-r--r-- | kernel/relay.c | 30 |
2 files changed, 37 insertions, 0 deletions
diff --git a/include/linux/relay.h b/include/linux/relay.h index cd77eb285a48..5310967f9d74 100644 --- a/include/linux/relay.h +++ b/include/linux/relay.h @@ -31,6 +31,12 @@ /* * Relay buffer statistics */ +enum { + RELAY_STATS_BUF_FULL = (1 << 0), + + RELAY_STATS_LAST = RELAY_STATS_BUF_FULL, +}; + struct rchan_buf_stats { unsigned int full_count; /* counter for buffer full */ @@ -167,6 +173,7 @@ struct rchan *relay_open(const char *base_filename, void *private_data); extern void relay_close(struct rchan *chan); extern void relay_flush(struct rchan *chan); +size_t relay_stats(struct rchan *chan, int flags); extern void relay_subbufs_consumed(struct rchan *chan, unsigned int cpu, size_t consumed); diff --git a/kernel/relay.c b/kernel/relay.c index 4b07efddc2cf..2fc27c0e771e 100644 --- a/kernel/relay.c +++ b/kernel/relay.c @@ -701,6 +701,36 @@ void relay_flush(struct rchan *chan) EXPORT_SYMBOL_GPL(relay_flush); /** + * relay_stats - get channel buffer statistics + * @chan: the channel + * @flags: select particular information to get + * + * Returns the count of certain field that caller specifies. + */ +size_t relay_stats(struct rchan *chan, int flags) +{ + unsigned int i, count = 0; + struct rchan_buf *rbuf; + + if (!chan || flags > RELAY_STATS_LAST) + return 0; + + if (chan->is_global) { + rbuf = *per_cpu_ptr(chan->buf, 0); + if (flags & RELAY_STATS_BUF_FULL) + count = rbuf->stats.full_count; + } else { + for_each_online_cpu(i) { + rbuf = *per_cpu_ptr(chan->buf, i); + if (rbuf && flags & RELAY_STATS_BUF_FULL) + count += rbuf->stats.full_count; + } + } + + return count; +} + +/** * relay_file_open - open file op for relay files * @inode: the inode * @filp: the file |