From 08a9ad8bf607388d768a341957d53eae64250c2d Mon Sep 17 00:00:00 2001 From: Bart Van Assche Date: Thu, 17 Jun 2021 17:44:55 -0700 Subject: block/mq-deadline: Add cgroup support Maintain statistics per cgroup and export these to user space. These statistics are essential for verifying whether the proper I/O priorities have been assigned to requests. An example of the statistics data with this patch applied: $ cat /sys/fs/cgroup/io.stat 11:2 rbytes=0 wbytes=0 rios=3 wios=0 dbytes=0 dios=0 [NONE] dispatched=0 inserted=0 merged=171 [RT] dispatched=0 inserted=0 merged=0 [BE] dispatched=0 inserted=0 merged=0 [IDLE] dispatched=0 inserted=0 merged=0 8:32 rbytes=2142720 wbytes=0 rios=105 wios=0 dbytes=0 dios=0 [NONE] dispatched=0 inserted=0 merged=171 [RT] dispatched=0 inserted=0 merged=0 [BE] dispatched=0 inserted=0 merged=0 [IDLE] dispatched=0 inserted=0 merged=0 Cc: Damien Le Moal Cc: Hannes Reinecke Cc: Christoph Hellwig Cc: Ming Lei Cc: Johannes Thumshirn Cc: Himanshu Madhani Signed-off-by: Bart Van Assche Link: https://lore.kernel.org/r/20210618004456.7280-16-bvanassche@acm.org Signed-off-by: Jens Axboe --- block/mq-deadline-cgroup.h | 114 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 114 insertions(+) create mode 100644 block/mq-deadline-cgroup.h (limited to 'block/mq-deadline-cgroup.h') diff --git a/block/mq-deadline-cgroup.h b/block/mq-deadline-cgroup.h new file mode 100644 index 000000000000..0143fd74f3ce --- /dev/null +++ b/block/mq-deadline-cgroup.h @@ -0,0 +1,114 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#if !defined(_MQ_DEADLINE_CGROUP_H_) +#define _MQ_DEADLINE_CGROUP_H_ + +#include + +struct request_queue; + +/** + * struct io_stats_per_prio - I/O statistics per I/O priority class. + * @inserted: Number of inserted requests. + * @merged: Number of merged requests. + * @dispatched: Number of dispatched requests. + * @completed: Number of I/O completions. + */ +struct io_stats_per_prio { + local_t inserted; + local_t merged; + local_t dispatched; + local_t completed; +}; + +/* I/O statistics per I/O cgroup per I/O priority class (IOPRIO_CLASS_*). */ +struct blkcg_io_stats { + struct io_stats_per_prio stats[4]; +}; + +/** + * struct dd_blkcg - Per cgroup data. + * @cpd: blkcg_policy_data structure. + * @stats: I/O statistics. + */ +struct dd_blkcg { + struct blkcg_policy_data cpd; /* must be the first member */ + struct blkcg_io_stats __percpu *stats; +}; + +/* + * Count one event of type 'event_type' and with I/O priority class + * 'prio_class'. + */ +#define ddcg_count(ddcg, event_type, prio_class) do { \ +if (ddcg) { \ + struct blkcg_io_stats *io_stats = get_cpu_ptr((ddcg)->stats); \ + \ + BUILD_BUG_ON(!__same_type((ddcg), struct dd_blkcg *)); \ + BUILD_BUG_ON(!__same_type((prio_class), u8)); \ + local_inc(&io_stats->stats[(prio_class)].event_type); \ + put_cpu_ptr(io_stats); \ +} \ +} while (0) + +/* + * Returns the total number of ddcg_count(ddcg, event_type, prio_class) calls + * across all CPUs. No locking or barriers since it is fine if the returned + * sum is slightly outdated. + */ +#define ddcg_sum(ddcg, event_type, prio) ({ \ + unsigned int cpu; \ + u32 sum = 0; \ + \ + BUILD_BUG_ON(!__same_type((ddcg), struct dd_blkcg *)); \ + BUILD_BUG_ON(!__same_type((prio), u8)); \ + for_each_present_cpu(cpu) \ + sum += local_read(&per_cpu_ptr((ddcg)->stats, cpu)-> \ + stats[(prio)].event_type); \ + sum; \ +}) + +#ifdef CONFIG_BLK_CGROUP + +/** + * struct dd_blkg - Per (cgroup, request queue) data. + * @pd: blkg_policy_data structure. + */ +struct dd_blkg { + struct blkg_policy_data pd; /* must be the first member */ +}; + +struct dd_blkcg *dd_blkcg_from_bio(struct bio *bio); +int dd_activate_policy(struct request_queue *q); +void dd_deactivate_policy(struct request_queue *q); +int __init dd_blkcg_init(void); +void __exit dd_blkcg_exit(void); + +#else /* CONFIG_BLK_CGROUP */ + +static inline struct dd_blkcg *dd_blkcg_from_bio(struct bio *bio) +{ + return NULL; +} + +static inline int dd_activate_policy(struct request_queue *q) +{ + return 0; +} + +static inline void dd_deactivate_policy(struct request_queue *q) +{ +} + +static inline int dd_blkcg_init(void) +{ + return 0; +} + +static inline void dd_blkcg_exit(void) +{ +} + +#endif /* CONFIG_BLK_CGROUP */ + +#endif /* _MQ_DEADLINE_CGROUP_H_ */ -- cgit v1.2.3