[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20100405185850.GK876@redhat.com>
Date: Mon, 5 Apr 2010 14:58:50 -0400
From: Vivek Goyal <vgoyal@...hat.com>
To: Divyesh Shah <dpshah@...gle.com>
Cc: jens.axboe@...cle.com, linux-kernel@...r.kernel.org,
nauman@...gle.com, ctalbott@...gle.com
Subject: Re: [PATCH 2/3][v2] blkio: Add io controller stats like
On Fri, Apr 02, 2010 at 06:56:35PM -0700, Divyesh Shah wrote:
[..]
> +static uint64_t blkio_get_typed_stat(struct blkio_group *blkg,
> + struct cgroup_map_cb *cb, get_var *getvar, dev_t dev)
> +{
> + uint64_t disk_total;
> + char key_str[MAX_KEY_LEN];
> + int type;
> +
> + for (type = 0; type < IO_TYPE_TOTAL; type++) {
> + blkio_get_key_name(type, dev, key_str, MAX_KEY_LEN);
> + cb->fill(cb, key_str, getvar(blkg, type));
> + }
> + disk_total = getvar(blkg, IO_READ) + getvar(blkg, IO_WRITE);
> + blkio_get_key_name(IO_TYPE_TOTAL, dev, key_str, MAX_KEY_LEN);
> + cb->fill(cb, key_str, disk_total);
> + return disk_total;
> +}
> +
> +static uint64_t blkio_get_stat(struct blkio_group *blkg,
> + struct cgroup_map_cb *cb, get_var *getvar, dev_t dev)
> +{
> + uint64_t var = getvar(blkg, 0);
> + char str[10];
> +
> + snprintf(str, 10, "%u:%u", MAJOR(dev), MINOR(dev));
What is the significance of limiting major:minor string to 10 characters?
I see BDEVT_SIZE being used in genhd.c. But it looks like it is valid
only if we printing numbers in hex.
In genhd.c:diskstats_show(), we seem to be using %4d and %7d for major
minor numbers. In extended minor allocation scheme, we seem to be having
20 bits for minor numbers, so 7 decimal places for representing max minor
number will make sense. Not sure about major number though.
So it might be safe to just to follow diskstats_show convention and at
least keep the buffer size as 12 (4:7).
Vivek
> + cb->fill(cb, str, var);
> + return var;
> +}
> +
> +#define GET_STAT_INDEXED(__VAR) \
> +uint64_t blkio_get_##__VAR##_stat(struct blkio_group *blkg, int type) \
> +{ \
> + return blkg->stats.__VAR[type]; \
> +} \
> +
> +GET_STAT_INDEXED(io_service_bytes);
> +GET_STAT_INDEXED(io_serviced);
> +GET_STAT_INDEXED(io_service_time);
> +GET_STAT_INDEXED(io_wait_time);
> +#undef GET_STAT_INDEXED
> +
> +#define GET_STAT(__VAR) \
> +uint64_t blkio_get_##__VAR##_stat(struct blkio_group *blkg, int dummy) \
> +{ \
> + return blkg->stats.__VAR; \
> +}
> +
> +GET_STAT(time);
> +GET_STAT(sectors);
> +#ifdef CONFIG_DEBUG_BLK_CGROUP
> +GET_STAT(dequeue);
> +#endif
> +#undef GET_STAT
> +
> +#define SHOW_FUNCTION_PER_GROUP(__VAR, get_stats, getvar, show_total) \
> static int blkiocg_##__VAR##_read(struct cgroup *cgroup, \
> - struct cftype *cftype, struct seq_file *m) \
> + struct cftype *cftype, struct cgroup_map_cb *cb) \
> { \
> struct blkio_cgroup *blkcg; \
> struct blkio_group *blkg; \
> struct hlist_node *n; \
> + uint64_t cgroup_total = 0; \
> \
> if (!cgroup_lock_live_group(cgroup)) \
> return -ENODEV; \
> @@ -184,19 +295,32 @@ static int blkiocg_##__VAR##_read(struct cgroup *cgroup, \
> blkcg = cgroup_to_blkio_cgroup(cgroup); \
> rcu_read_lock(); \
> hlist_for_each_entry_rcu(blkg, n, &blkcg->blkg_list, blkcg_node) {\
> - if (blkg->dev) \
> - seq_printf(m, "%u:%u %lu\n", MAJOR(blkg->dev), \
> - MINOR(blkg->dev), blkg->__VAR); \
> + if (blkg->dev) { \
> + spin_lock_irq(&blkg->stats_lock); \
> + cgroup_total += get_stats(blkg, cb, getvar, \
> + blkg->dev); \
> + spin_unlock_irq(&blkg->stats_lock); \
> + } \
> } \
> + if (show_total) \
> + cb->fill(cb, "Total", cgroup_total); \
> rcu_read_unlock(); \
> cgroup_unlock(); \
> return 0; \
> }
>
> -SHOW_FUNCTION_PER_GROUP(time);
> -SHOW_FUNCTION_PER_GROUP(sectors);
> +SHOW_FUNCTION_PER_GROUP(time, blkio_get_stat, blkio_get_time_stat, 0);
> +SHOW_FUNCTION_PER_GROUP(sectors, blkio_get_stat, blkio_get_sectors_stat, 0);
> +SHOW_FUNCTION_PER_GROUP(io_service_bytes, blkio_get_typed_stat,
> + blkio_get_io_service_bytes_stat, 1);
> +SHOW_FUNCTION_PER_GROUP(io_serviced, blkio_get_typed_stat,
> + blkio_get_io_serviced_stat, 1);
> +SHOW_FUNCTION_PER_GROUP(io_service_time, blkio_get_typed_stat,
> + blkio_get_io_service_time_stat, 1);
> +SHOW_FUNCTION_PER_GROUP(io_wait_time, blkio_get_typed_stat,
> + blkio_get_io_wait_time_stat, 1);
> #ifdef CONFIG_DEBUG_BLK_CGROUP
> -SHOW_FUNCTION_PER_GROUP(dequeue);
> +SHOW_FUNCTION_PER_GROUP(dequeue, blkio_get_stat, blkio_get_dequeue_stat, 0);
> #endif
> #undef SHOW_FUNCTION_PER_GROUP
>
> @@ -204,7 +328,7 @@ SHOW_FUNCTION_PER_GROUP(dequeue);
> void blkiocg_update_blkio_group_dequeue_stats(struct blkio_group *blkg,
> unsigned long dequeue)
> {
> - blkg->dequeue += dequeue;
> + blkg->stats.dequeue += dequeue;
> }
> EXPORT_SYMBOL_GPL(blkiocg_update_blkio_group_dequeue_stats);
> #endif
> @@ -217,16 +341,39 @@ struct cftype blkio_files[] = {
> },
> {
> .name = "time",
> - .read_seq_string = blkiocg_time_read,
> + .read_map = blkiocg_time_read,
> + .write_u64 = blkiocg_reset_write,
> },
> {
> .name = "sectors",
> - .read_seq_string = blkiocg_sectors_read,
> + .read_map = blkiocg_sectors_read,
> + .write_u64 = blkiocg_reset_write,
> + },
> + {
> + .name = "io_service_bytes",
> + .read_map = blkiocg_io_service_bytes_read,
> + .write_u64 = blkiocg_reset_write,
> + },
> + {
> + .name = "io_serviced",
> + .read_map = blkiocg_io_serviced_read,
> + .write_u64 = blkiocg_reset_write,
> + },
> + {
> + .name = "io_service_time",
> + .read_map = blkiocg_io_service_time_read,
> + .write_u64 = blkiocg_reset_write,
> + },
> + {
> + .name = "io_wait_time",
> + .read_map = blkiocg_io_wait_time_read,
> + .write_u64 = blkiocg_reset_write,
> },
> #ifdef CONFIG_DEBUG_BLK_CGROUP
> {
> .name = "dequeue",
> - .read_seq_string = blkiocg_dequeue_read,
> + .read_map = blkiocg_dequeue_read,
> + .write_u64 = blkiocg_reset_write,
> },
> #endif
> };
> diff --git a/block/blk-cgroup.h b/block/blk-cgroup.h
> index fe44517..e8600b0 100644
> --- a/block/blk-cgroup.h
> +++ b/block/blk-cgroup.h
> @@ -23,6 +23,14 @@ extern struct cgroup_subsys blkio_subsys;
> #define blkio_subsys_id blkio_subsys.subsys_id
> #endif
>
> +enum io_type {
> + IO_READ = 0,
> + IO_WRITE,
> + IO_SYNC,
> + IO_ASYNC,
> + IO_TYPE_TOTAL
> +};
> +
> struct blkio_cgroup {
> struct cgroup_subsys_state css;
> unsigned int weight;
> @@ -30,6 +38,23 @@ struct blkio_cgroup {
> struct hlist_head blkg_list;
> };
>
> +struct blkio_group_stats {
> + /* total disk time and nr sectors dispatched by this group */
> + uint64_t time;
> + uint64_t sectors;
> + /* Total disk time used by IOs in ns */
> + uint64_t io_service_time[IO_TYPE_TOTAL];
> + uint64_t io_service_bytes[IO_TYPE_TOTAL]; /* Total bytes transferred */
> + /* Total IOs serviced, post merge */
> + uint64_t io_serviced[IO_TYPE_TOTAL];
> + /* Total time spent waiting in scheduler queue in ns */
> + uint64_t io_wait_time[IO_TYPE_TOTAL];
> +#ifdef CONFIG_DEBUG_BLK_CGROUP
> + /* How many times this group has been removed from service tree */
> + unsigned long dequeue;
> +#endif
> +};
> +
> struct blkio_group {
> /* An rcu protected unique identifier for the group */
> void *key;
> @@ -38,15 +63,13 @@ struct blkio_group {
> #ifdef CONFIG_DEBUG_BLK_CGROUP
> /* Store cgroup path */
> char path[128];
> - /* How many times this group has been removed from service tree */
> - unsigned long dequeue;
> #endif
> /* The device MKDEV(major, minor), this group has been created for */
> - dev_t dev;
> + dev_t dev;
>
> - /* total disk time and nr sectors dispatched by this group */
> - unsigned long time;
> - unsigned long sectors;
> + /* Need to serialize the stats in the case of reset/update */
> + spinlock_t stats_lock;
> + struct blkio_group_stats stats;
> };
>
> typedef void (blkio_unlink_group_fn) (void *key, struct blkio_group *blkg);
> @@ -105,8 +128,8 @@ extern void blkiocg_add_blkio_group(struct blkio_cgroup *blkcg,
> extern int blkiocg_del_blkio_group(struct blkio_group *blkg);
> extern struct blkio_group *blkiocg_lookup_group(struct blkio_cgroup *blkcg,
> void *key);
> -void blkiocg_update_blkio_group_stats(struct blkio_group *blkg,
> - unsigned long time);
> +void blkiocg_update_timeslice_used(struct blkio_group *blkg,
> + unsigned long time);
> #else
> struct cgroup;
> static inline struct blkio_cgroup *
> @@ -122,7 +145,7 @@ blkiocg_del_blkio_group(struct blkio_group *blkg) { return 0; }
>
> static inline struct blkio_group *
> blkiocg_lookup_group(struct blkio_cgroup *blkcg, void *key) { return NULL; }
> -static inline void blkiocg_update_blkio_group_stats(struct blkio_group *blkg,
> +static inline void blkiocg_update_timeslice_used(struct blkio_group *blkg,
> unsigned long time) {}
> #endif
> #endif /* _BLK_CGROUP_H */
> diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
> index c18e348..d91df9f 100644
> --- a/block/cfq-iosched.c
> +++ b/block/cfq-iosched.c
> @@ -914,7 +914,7 @@ static void cfq_group_served(struct cfq_data *cfqd, struct cfq_group *cfqg,
>
> cfq_log_cfqg(cfqd, cfqg, "served: vt=%llu min_vt=%llu", cfqg->vdisktime,
> st->min_vdisktime);
> - blkiocg_update_blkio_group_stats(&cfqg->blkg, used_sl);
> + blkiocg_update_timeslice_used(&cfqg->blkg, used_sl);
> }
>
> #ifdef CONFIG_CFQ_GROUP_IOSCHED
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists