Re: [PATCH] ceph: clean-up metrics data structures to reduce code duplication
From: Jeff Layton
Date: Mon Nov 01 2021 - 08:13:46 EST
On Fri, 2021-10-29 at 15:09 +0100, Luís Henriques wrote:
> This patch modifies struct ceph_client_metric so that each metric block
> (read, write and metadata) becomes an element in a array. This allows to
> also re-write the helper functions that handle these blocks, making them
> simpler and, above all, reduce the amount of copy&paste every time a new
> metric is added.
>
> Thus, for each of these metrics there will be a new struct ceph_metric
> entry that'll will contain all the sizes and latencies fields (and a lock).
> Note however that the metadata metric doesn't really use the size_fields,
> and thus this metric won't be shown in the debugfs '../metrics/size' file.
>
> Signed-off-by: Luís Henriques <lhenriques@xxxxxxx>
> ---
> fs/ceph/debugfs.c | 87 ++++++++++++++-----------------
> fs/ceph/metric.c | 128 ++++++++++++----------------------------------
> fs/ceph/metric.h | 80 ++++++++++++++++-------------
> 3 files changed, 115 insertions(+), 180 deletions(-)
>
> diff --git a/fs/ceph/debugfs.c b/fs/ceph/debugfs.c
> index 55426514491b..72825ed3a0b8 100644
> --- a/fs/ceph/debugfs.c
> +++ b/fs/ceph/debugfs.c
> @@ -164,44 +164,34 @@ static int metrics_file_show(struct seq_file *s, void *p)
> return 0;
> }
>
> +static const char * const metric_str[] = {
> + "read",
> + "write",
> + "metadata"
> +};
> static int metrics_latency_show(struct seq_file *s, void *p)
> {
> struct ceph_fs_client *fsc = s->private;
> - struct ceph_client_metric *m = &fsc->mdsc->metric;
> + struct ceph_client_metric *cm = &fsc->mdsc->metric;
> + struct ceph_metric *m;
> s64 total, sum, avg, min, max, sq;
> + int i;
>
> seq_printf(s, "item total avg_lat(us) min_lat(us) max_lat(us) stdev(us)\n");
> seq_printf(s, "-----------------------------------------------------------------------------------\n");
>
> - spin_lock(&m->read_metric_lock);
> - total = m->total_reads;
> - sum = m->read_latency_sum;
> - avg = total > 0 ? DIV64_U64_ROUND_CLOSEST(sum, total) : 0;
> - min = m->read_latency_min;
> - max = m->read_latency_max;
> - sq = m->read_latency_sq_sum;
> - spin_unlock(&m->read_metric_lock);
> - CEPH_LAT_METRIC_SHOW("read", total, avg, min, max, sq);
> -
> - spin_lock(&m->write_metric_lock);
> - total = m->total_writes;
> - sum = m->write_latency_sum;
> - avg = total > 0 ? DIV64_U64_ROUND_CLOSEST(sum, total) : 0;
> - min = m->write_latency_min;
> - max = m->write_latency_max;
> - sq = m->write_latency_sq_sum;
> - spin_unlock(&m->write_metric_lock);
> - CEPH_LAT_METRIC_SHOW("write", total, avg, min, max, sq);
> -
> - spin_lock(&m->metadata_metric_lock);
> - total = m->total_metadatas;
> - sum = m->metadata_latency_sum;
> - avg = total > 0 ? DIV64_U64_ROUND_CLOSEST(sum, total) : 0;
> - min = m->metadata_latency_min;
> - max = m->metadata_latency_max;
> - sq = m->metadata_latency_sq_sum;
> - spin_unlock(&m->metadata_metric_lock);
> - CEPH_LAT_METRIC_SHOW("metadata", total, avg, min, max, sq);
> + for (i = 0; i < METRIC_MAX; i++) {
> + m = &cm->metric[i];
> + spin_lock(&m->lock);
> + total = m->total;
> + sum = m->latency_sum;
> + avg = total > 0 ? DIV64_U64_ROUND_CLOSEST(sum, total) : 0;
> + min = m->latency_min;
> + max = m->latency_max;
> + sq = m->latency_sq_sum;
> + spin_unlock(&m->lock);
> + CEPH_LAT_METRIC_SHOW(metric_str[i], total, avg, min, max, sq);
> + }
>
> return 0;
> }
> @@ -209,30 +199,29 @@ static int metrics_latency_show(struct seq_file *s, void *p)
> static int metrics_size_show(struct seq_file *s, void *p)
> {
> struct ceph_fs_client *fsc = s->private;
> - struct ceph_client_metric *m = &fsc->mdsc->metric;
> + struct ceph_client_metric *cm = &fsc->mdsc->metric;
> + struct ceph_metric *m;
> s64 total;
> - u64 sum_sz, avg_sz, min_sz, max_sz;
> + u64 sum, avg, min, max;
> + int i;
>
> seq_printf(s, "item total avg_sz(bytes) min_sz(bytes) max_sz(bytes) total_sz(bytes)\n");
> seq_printf(s, "----------------------------------------------------------------------------------------\n");
>
> - spin_lock(&m->read_metric_lock);
> - total = m->total_reads;
> - sum_sz = m->read_size_sum;
> - avg_sz = total > 0 ? DIV64_U64_ROUND_CLOSEST(sum_sz, total) : 0;
> - min_sz = m->read_size_min;
> - max_sz = m->read_size_max;
> - spin_unlock(&m->read_metric_lock);
> - CEPH_SZ_METRIC_SHOW("read", total, avg_sz, min_sz, max_sz, sum_sz);
> -
> - spin_lock(&m->write_metric_lock);
> - total = m->total_writes;
> - sum_sz = m->write_size_sum;
> - avg_sz = total > 0 ? DIV64_U64_ROUND_CLOSEST(sum_sz, total) : 0;
> - min_sz = m->write_size_min;
> - max_sz = m->write_size_max;
> - spin_unlock(&m->write_metric_lock);
> - CEPH_SZ_METRIC_SHOW("write", total, avg_sz, min_sz, max_sz, sum_sz);
> + for (i = 0; i < METRIC_MAX; i++) {
> + /* skip 'metadata' as it doesn't use the size metric */
> + if (i == METRIC_METADATA)
> + continue;
> + m = &cm->metric[i];
> + spin_lock(&m->lock);
> + total = m->total;
> + sum = m->size_sum;
> + avg = total > 0 ? DIV64_U64_ROUND_CLOSEST(sum, total) : 0;
> + min = m->size_min;
> + max = m->size_max;
> + spin_unlock(&m->lock);
> + CEPH_SZ_METRIC_SHOW(metric_str[i], total, avg, min, max, sum);
> + }
>
> return 0;
> }
> diff --git a/fs/ceph/metric.c b/fs/ceph/metric.c
> index 04d5df29bbbf..c57699d8408d 100644
> --- a/fs/ceph/metric.c
> +++ b/fs/ceph/metric.c
> @@ -62,7 +62,7 @@ static bool ceph_mdsc_send_metrics(struct ceph_mds_client *mdsc,
> read->header.ver = 1;
> read->header.compat = 1;
> read->header.data_len = cpu_to_le32(sizeof(*read) - header_len);
> - sum = m->read_latency_sum;
> + sum = m->metric[METRIC_READ].latency_sum;
> jiffies_to_timespec64(sum, &ts);
> read->sec = cpu_to_le32(ts.tv_sec);
> read->nsec = cpu_to_le32(ts.tv_nsec);
> @@ -74,7 +74,7 @@ static bool ceph_mdsc_send_metrics(struct ceph_mds_client *mdsc,
> write->header.ver = 1;
> write->header.compat = 1;
> write->header.data_len = cpu_to_le32(sizeof(*write) - header_len);
> - sum = m->write_latency_sum;
> + sum = m->metric[METRIC_WRITE].latency_sum;
> jiffies_to_timespec64(sum, &ts);
> write->sec = cpu_to_le32(ts.tv_sec);
> write->nsec = cpu_to_le32(ts.tv_nsec);
> @@ -86,7 +86,7 @@ static bool ceph_mdsc_send_metrics(struct ceph_mds_client *mdsc,
> meta->header.ver = 1;
> meta->header.compat = 1;
> meta->header.data_len = cpu_to_le32(sizeof(*meta) - header_len);
> - sum = m->metadata_latency_sum;
> + sum = m->metric[METRIC_METADATA].latency_sum;
> jiffies_to_timespec64(sum, &ts);
> meta->sec = cpu_to_le32(ts.tv_sec);
> meta->nsec = cpu_to_le32(ts.tv_nsec);
> @@ -141,8 +141,8 @@ static bool ceph_mdsc_send_metrics(struct ceph_mds_client *mdsc,
> rsize->header.ver = 1;
> rsize->header.compat = 1;
> rsize->header.data_len = cpu_to_le32(sizeof(*rsize) - header_len);
> - rsize->total_ops = cpu_to_le64(m->total_reads);
> - rsize->total_size = cpu_to_le64(m->read_size_sum);
> + rsize->total_ops = cpu_to_le64(m->metric[METRIC_READ].total);
> + rsize->total_size = cpu_to_le64(m->metric[METRIC_READ].size_sum);
> items++;
>
> /* encode the write io size metric */
> @@ -151,8 +151,8 @@ static bool ceph_mdsc_send_metrics(struct ceph_mds_client *mdsc,
> wsize->header.ver = 1;
> wsize->header.compat = 1;
> wsize->header.data_len = cpu_to_le32(sizeof(*wsize) - header_len);
> - wsize->total_ops = cpu_to_le64(m->total_writes);
> - wsize->total_size = cpu_to_le64(m->write_size_sum);
> + wsize->total_ops = cpu_to_le64(m->metric[METRIC_WRITE].total);
> + wsize->total_size = cpu_to_le64(m->metric[METRIC_WRITE].size_sum);
> items++;
>
> put_unaligned_le32(items, &head->num);
> @@ -220,7 +220,8 @@ static void metric_delayed_work(struct work_struct *work)
>
> int ceph_metric_init(struct ceph_client_metric *m)
> {
> - int ret;
> + struct ceph_metric *metric;
> + int ret, i;
>
> if (!m)
> return -EINVAL;
> @@ -243,32 +244,18 @@ int ceph_metric_init(struct ceph_client_metric *m)
> if (ret)
> goto err_i_caps_mis;
>
> - spin_lock_init(&m->read_metric_lock);
> - m->read_latency_sq_sum = 0;
> - m->read_latency_min = KTIME_MAX;
> - m->read_latency_max = 0;
> - m->total_reads = 0;
> - m->read_latency_sum = 0;
> - m->read_size_min = U64_MAX;
> - m->read_size_max = 0;
> - m->read_size_sum = 0;
> -
> - spin_lock_init(&m->write_metric_lock);
> - m->write_latency_sq_sum = 0;
> - m->write_latency_min = KTIME_MAX;
> - m->write_latency_max = 0;
> - m->total_writes = 0;
> - m->write_latency_sum = 0;
> - m->write_size_min = U64_MAX;
> - m->write_size_max = 0;
> - m->write_size_sum = 0;
> -
> - spin_lock_init(&m->metadata_metric_lock);
> - m->metadata_latency_sq_sum = 0;
> - m->metadata_latency_min = KTIME_MAX;
> - m->metadata_latency_max = 0;
> - m->total_metadatas = 0;
> - m->metadata_latency_sum = 0;
> + for (i = 0; i < METRIC_MAX; i++) {
> + metric = &m->metric[i];
> + spin_lock_init(&metric->lock);
> + metric->size_sum = 0;
> + metric->size_min = U64_MAX;
> + metric->size_max = 0;
> + metric->total = 0;
> + metric->latency_sum = 0;
> + metric->latency_sq_sum = 0;
> + metric->latency_min = KTIME_MAX;
> + metric->latency_max = 0;
> + }
>
> atomic64_set(&m->opened_files, 0);
> ret = percpu_counter_init(&m->opened_inodes, 0, GFP_KERNEL);
> @@ -338,9 +325,9 @@ static inline void __update_stdev(ktime_t total, ktime_t lsum,
> *sq_sump += sq;
> }
>
> -void ceph_update_read_metrics(struct ceph_client_metric *m,
> - ktime_t r_start, ktime_t r_end,
> - unsigned int size, int rc)
> +void ceph_update_metrics(struct ceph_metric *m,
> + ktime_t r_start, ktime_t r_end,
> + unsigned int size, int rc)
> {
> ktime_t lat = ktime_sub(r_end, r_start);
> ktime_t total;
> @@ -348,63 +335,12 @@ void ceph_update_read_metrics(struct ceph_client_metric *m,
> if (unlikely(rc < 0 && rc != -ENOENT && rc != -ETIMEDOUT))
> return;
>
> - spin_lock(&m->read_metric_lock);
> - total = ++m->total_reads;
> - m->read_size_sum += size;
> - m->read_latency_sum += lat;
> - METRIC_UPDATE_MIN_MAX(m->read_size_min,
> - m->read_size_max,
> - size);
> - METRIC_UPDATE_MIN_MAX(m->read_latency_min,
> - m->read_latency_max,
> - lat);
> - __update_stdev(total, m->read_latency_sum,
> - &m->read_latency_sq_sum, lat);
> - spin_unlock(&m->read_metric_lock);
> -}
> -
> -void ceph_update_write_metrics(struct ceph_client_metric *m,
> - ktime_t r_start, ktime_t r_end,
> - unsigned int size, int rc)
> -{
> - ktime_t lat = ktime_sub(r_end, r_start);
> - ktime_t total;
> -
> - if (unlikely(rc && rc != -ETIMEDOUT))
> - return;
> -
> - spin_lock(&m->write_metric_lock);
> - total = ++m->total_writes;
> - m->write_size_sum += size;
> - m->write_latency_sum += lat;
> - METRIC_UPDATE_MIN_MAX(m->write_size_min,
> - m->write_size_max,
> - size);
> - METRIC_UPDATE_MIN_MAX(m->write_latency_min,
> - m->write_latency_max,
> - lat);
> - __update_stdev(total, m->write_latency_sum,
> - &m->write_latency_sq_sum, lat);
> - spin_unlock(&m->write_metric_lock);
> -}
> -
> -void ceph_update_metadata_metrics(struct ceph_client_metric *m,
> - ktime_t r_start, ktime_t r_end,
> - int rc)
> -{
> - ktime_t lat = ktime_sub(r_end, r_start);
> - ktime_t total;
> -
> - if (unlikely(rc && rc != -ENOENT))
> - return;
> -
> - spin_lock(&m->metadata_metric_lock);
> - total = ++m->total_metadatas;
> - m->metadata_latency_sum += lat;
> - METRIC_UPDATE_MIN_MAX(m->metadata_latency_min,
> - m->metadata_latency_max,
> - lat);
> - __update_stdev(total, m->metadata_latency_sum,
> - &m->metadata_latency_sq_sum, lat);
> - spin_unlock(&m->metadata_metric_lock);
> + spin_lock(&m->lock);
> + total = ++m->total;
> + m->size_sum += size;
> + METRIC_UPDATE_MIN_MAX(m->size_min, m->size_max, size);
> + m->latency_sum += lat;
> + METRIC_UPDATE_MIN_MAX(m->latency_min, m->latency_max, lat);
> + __update_stdev(total, m->latency_sum, &m->latency_sq_sum, lat);
> + spin_unlock(&m->lock);
> }
> diff --git a/fs/ceph/metric.h b/fs/ceph/metric.h
> index 0133955a3c6a..e67fc997760b 100644
> --- a/fs/ceph/metric.h
> +++ b/fs/ceph/metric.h
> @@ -125,6 +125,25 @@ struct ceph_metric_head {
> __le32 num; /* the number of metrics that will be sent */
> } __packed;
>
> +enum metric_type {
> + METRIC_READ,
> + METRIC_WRITE,
> + METRIC_METADATA,
> + METRIC_MAX
> +};
> +
> +struct ceph_metric {
> + spinlock_t lock;
> + u64 total;
> + u64 size_sum;
> + u64 size_min;
> + u64 size_max;
> + ktime_t latency_sum;
> + ktime_t latency_sq_sum;
> + ktime_t latency_min;
> + ktime_t latency_max;
> +};
> +
> /* This is the global metrics */
> struct ceph_client_metric {
> atomic64_t total_dentries;
> @@ -135,32 +154,7 @@ struct ceph_client_metric {
> struct percpu_counter i_caps_hit;
> struct percpu_counter i_caps_mis;
>
> - spinlock_t read_metric_lock;
> - u64 total_reads;
> - u64 read_size_sum;
> - u64 read_size_min;
> - u64 read_size_max;
> - ktime_t read_latency_sum;
> - ktime_t read_latency_sq_sum;
> - ktime_t read_latency_min;
> - ktime_t read_latency_max;
> -
> - spinlock_t write_metric_lock;
> - u64 total_writes;
> - u64 write_size_sum;
> - u64 write_size_min;
> - u64 write_size_max;
> - ktime_t write_latency_sum;
> - ktime_t write_latency_sq_sum;
> - ktime_t write_latency_min;
> - ktime_t write_latency_max;
> -
> - spinlock_t metadata_metric_lock;
> - u64 total_metadatas;
> - ktime_t metadata_latency_sum;
> - ktime_t metadata_latency_sq_sum;
> - ktime_t metadata_latency_min;
> - ktime_t metadata_latency_max;
> + struct ceph_metric metric[METRIC_MAX];
>
> /* The total number of directories and files that are opened */
> atomic64_t opened_files;
> @@ -195,13 +189,29 @@ static inline void ceph_update_cap_mis(struct ceph_client_metric *m)
> percpu_counter_inc(&m->i_caps_mis);
> }
>
> -extern void ceph_update_read_metrics(struct ceph_client_metric *m,
> - ktime_t r_start, ktime_t r_end,
> - unsigned int size, int rc);
> -extern void ceph_update_write_metrics(struct ceph_client_metric *m,
> - ktime_t r_start, ktime_t r_end,
> - unsigned int size, int rc);
> -extern void ceph_update_metadata_metrics(struct ceph_client_metric *m,
> - ktime_t r_start, ktime_t r_end,
> - int rc);
> +extern void ceph_update_metrics(struct ceph_metric *m,
> + ktime_t r_start, ktime_t r_end,
> + unsigned int size, int rc);
> +
> +static inline void ceph_update_read_metrics(struct ceph_client_metric *m,
> + ktime_t r_start, ktime_t r_end,
> + unsigned int size, int rc)
> +{
> + ceph_update_metrics(&m->metric[METRIC_READ],
> + r_start, r_end, size, rc);
> +}
> +static inline void ceph_update_write_metrics(struct ceph_client_metric *m,
> + ktime_t r_start, ktime_t r_end,
> + unsigned int size, int rc)
> +{
> + ceph_update_metrics(&m->metric[METRIC_WRITE],
> + r_start, r_end, size, rc);
> +}
> +static inline void ceph_update_metadata_metrics(struct ceph_client_metric *m,
> + ktime_t r_start, ktime_t r_end,
> + int rc)
> +{
> + ceph_update_metrics(&m->metric[METRIC_METADATA],
> + r_start, r_end, 0, rc);
> +}
> #endif /* _FS_CEPH_MDS_METRIC_H */
Thanks, merged into testing.
Cheers,
--
Jeff Layton <jlayton@xxxxxxxxxx>