diff options
| author | Jason Xing <kernelxing@tencent.com> | 2025-06-12 14:11:59 +0800 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2025-07-09 22:57:51 -0700 |
| commit | a53202ce7fbafd24f854865b02eff891e246c550 (patch) | |
| tree | 5e9ff87c1286c4542387937e8c8db3fcff783381 | |
| parent | ca01a90ae7bf9bb22137e719366bdc0f387675c2 (diff) | |
relayfs: introduce getting relayfs statistics function
In this version, only support getting the counter for buffer full and
implement the framework of how it works.
Users can pass certain flag to fetch what field/statistics they expect to
know. Each time it only returns one result. So do not pass multiple
flags.
Link: https://lkml.kernel.org/r/20250612061201.34272-4-kerneljasonxing@gmail.com
Signed-off-by: Jason Xing <kernelxing@tencent.com>
Reviewed-by: Yushan Zhou <katrinzhou@tencent.com>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| -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 |