forked from Minki/linux
d3d32e69fa
blkcg stats handling is a mess. None of the stats has much to do with blkcg core but they are all implemented in blkcg core. Code sharing is achieved by mixing common code with hard-coded cases for each stat counter. This patch restructures statistics printing such that * Common logic exists as helper functions and specific print functions use the helpers to implement specific cases. * Printing functions serving multiple counters don't require hardcoded switching on specific counters. * Printing uses read_seq_string callback (other methods will be phased out). This change enables further cleanups and relocating stats code to the policy implementation it belongs to. Signed-off-by: Tejun Heo <tj@kernel.org>
527 lines
16 KiB
C
527 lines
16 KiB
C
#ifndef _BLK_CGROUP_H
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#define _BLK_CGROUP_H
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/*
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* Common Block IO controller cgroup interface
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*
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* Based on ideas and code from CFQ, CFS and BFQ:
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* Copyright (C) 2003 Jens Axboe <axboe@kernel.dk>
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*
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* Copyright (C) 2008 Fabio Checconi <fabio@gandalf.sssup.it>
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* Paolo Valente <paolo.valente@unimore.it>
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*
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* Copyright (C) 2009 Vivek Goyal <vgoyal@redhat.com>
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* Nauman Rafique <nauman@google.com>
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*/
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#include <linux/cgroup.h>
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#include <linux/u64_stats_sync.h>
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enum blkio_policy_id {
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BLKIO_POLICY_PROP = 0, /* Proportional Bandwidth division */
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BLKIO_POLICY_THROTL, /* Throttling */
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BLKIO_NR_POLICIES,
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};
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/* Max limits for throttle policy */
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#define THROTL_IOPS_MAX UINT_MAX
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#ifdef CONFIG_BLK_CGROUP
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/* cft->private [un]packing for stat printing */
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#define BLKCG_STAT_PRIV(pol, off) (((unsigned)(pol) << 16) | (off))
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#define BLKCG_STAT_POL(prv) ((unsigned)(prv) >> 16)
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#define BLKCG_STAT_OFF(prv) ((unsigned)(prv) & 0xffff)
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enum blkg_rwstat_type {
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BLKG_RWSTAT_READ,
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BLKG_RWSTAT_WRITE,
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BLKG_RWSTAT_SYNC,
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BLKG_RWSTAT_ASYNC,
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BLKG_RWSTAT_NR,
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BLKG_RWSTAT_TOTAL = BLKG_RWSTAT_NR,
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};
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/* blkg state flags */
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enum blkg_state_flags {
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BLKG_waiting = 0,
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BLKG_idling,
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BLKG_empty,
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};
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/* cgroup files owned by proportional weight policy */
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enum blkcg_file_name_prop {
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BLKIO_PROP_weight = 1,
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BLKIO_PROP_weight_device,
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};
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/* cgroup files owned by throttle policy */
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enum blkcg_file_name_throtl {
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BLKIO_THROTL_read_bps_device,
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BLKIO_THROTL_write_bps_device,
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BLKIO_THROTL_read_iops_device,
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BLKIO_THROTL_write_iops_device,
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};
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struct blkio_cgroup {
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struct cgroup_subsys_state css;
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unsigned int weight;
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spinlock_t lock;
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struct hlist_head blkg_list;
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/* for policies to test whether associated blkcg has changed */
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uint64_t id;
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};
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struct blkg_stat {
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struct u64_stats_sync syncp;
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uint64_t cnt;
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};
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struct blkg_rwstat {
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struct u64_stats_sync syncp;
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uint64_t cnt[BLKG_RWSTAT_NR];
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};
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struct blkio_group_stats {
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/* number of ios merged */
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struct blkg_rwstat merged;
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/* total time spent on device in ns, may not be accurate w/ queueing */
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struct blkg_rwstat service_time;
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/* total time spent waiting in scheduler queue in ns */
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struct blkg_rwstat wait_time;
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/* number of IOs queued up */
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struct blkg_rwstat queued;
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/* total disk time and nr sectors dispatched by this group */
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struct blkg_stat time;
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#ifdef CONFIG_DEBUG_BLK_CGROUP
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/* time not charged to this cgroup */
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struct blkg_stat unaccounted_time;
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/* sum of number of ios queued across all samples */
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struct blkg_stat avg_queue_size_sum;
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/* count of samples taken for average */
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struct blkg_stat avg_queue_size_samples;
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/* how many times this group has been removed from service tree */
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struct blkg_stat dequeue;
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/* total time spent waiting for it to be assigned a timeslice. */
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struct blkg_stat group_wait_time;
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/* time spent idling for this blkio_group */
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struct blkg_stat idle_time;
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/* total time with empty current active q with other requests queued */
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struct blkg_stat empty_time;
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/* fields after this shouldn't be cleared on stat reset */
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uint64_t start_group_wait_time;
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uint64_t start_idle_time;
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uint64_t start_empty_time;
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uint16_t flags;
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#endif
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};
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/* Per cpu blkio group stats */
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struct blkio_group_stats_cpu {
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/* total bytes transferred */
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struct blkg_rwstat service_bytes;
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/* total IOs serviced, post merge */
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struct blkg_rwstat serviced;
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/* total sectors transferred */
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struct blkg_stat sectors;
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};
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struct blkio_group_conf {
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unsigned int weight;
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unsigned int iops[2];
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u64 bps[2];
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};
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/* per-blkg per-policy data */
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struct blkg_policy_data {
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/* the blkg this per-policy data belongs to */
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struct blkio_group *blkg;
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/* Configuration */
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struct blkio_group_conf conf;
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struct blkio_group_stats stats;
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/* Per cpu stats pointer */
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struct blkio_group_stats_cpu __percpu *stats_cpu;
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/* pol->pdata_size bytes of private data used by policy impl */
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char pdata[] __aligned(__alignof__(unsigned long long));
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};
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struct blkio_group {
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/* Pointer to the associated request_queue */
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struct request_queue *q;
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struct list_head q_node;
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struct hlist_node blkcg_node;
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struct blkio_cgroup *blkcg;
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/* Store cgroup path */
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char path[128];
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/* reference count */
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int refcnt;
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struct blkg_policy_data *pd[BLKIO_NR_POLICIES];
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/* List of blkg waiting for per cpu stats memory to be allocated */
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struct list_head alloc_node;
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struct rcu_head rcu_head;
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};
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typedef void (blkio_init_group_fn)(struct blkio_group *blkg);
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typedef void (blkio_update_group_weight_fn)(struct request_queue *q,
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struct blkio_group *blkg, unsigned int weight);
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typedef void (blkio_update_group_read_bps_fn)(struct request_queue *q,
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struct blkio_group *blkg, u64 read_bps);
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typedef void (blkio_update_group_write_bps_fn)(struct request_queue *q,
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struct blkio_group *blkg, u64 write_bps);
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typedef void (blkio_update_group_read_iops_fn)(struct request_queue *q,
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struct blkio_group *blkg, unsigned int read_iops);
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typedef void (blkio_update_group_write_iops_fn)(struct request_queue *q,
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struct blkio_group *blkg, unsigned int write_iops);
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struct blkio_policy_ops {
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blkio_init_group_fn *blkio_init_group_fn;
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blkio_update_group_weight_fn *blkio_update_group_weight_fn;
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blkio_update_group_read_bps_fn *blkio_update_group_read_bps_fn;
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blkio_update_group_write_bps_fn *blkio_update_group_write_bps_fn;
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blkio_update_group_read_iops_fn *blkio_update_group_read_iops_fn;
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blkio_update_group_write_iops_fn *blkio_update_group_write_iops_fn;
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};
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struct blkio_policy_type {
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struct list_head list;
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struct blkio_policy_ops ops;
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enum blkio_policy_id plid;
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size_t pdata_size; /* policy specific private data size */
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};
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extern int blkcg_init_queue(struct request_queue *q);
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extern void blkcg_drain_queue(struct request_queue *q);
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extern void blkcg_exit_queue(struct request_queue *q);
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/* Blkio controller policy registration */
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extern void blkio_policy_register(struct blkio_policy_type *);
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extern void blkio_policy_unregister(struct blkio_policy_type *);
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extern void blkg_destroy_all(struct request_queue *q, bool destroy_root);
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extern void update_root_blkg_pd(struct request_queue *q,
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enum blkio_policy_id plid);
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/**
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* blkg_to_pdata - get policy private data
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* @blkg: blkg of interest
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* @pol: policy of interest
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*
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* Return pointer to private data associated with the @blkg-@pol pair.
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*/
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static inline void *blkg_to_pdata(struct blkio_group *blkg,
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struct blkio_policy_type *pol)
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{
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return blkg ? blkg->pd[pol->plid]->pdata : NULL;
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}
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/**
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* pdata_to_blkg - get blkg associated with policy private data
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* @pdata: policy private data of interest
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*
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* @pdata is policy private data. Determine the blkg it's associated with.
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*/
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static inline struct blkio_group *pdata_to_blkg(void *pdata)
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{
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if (pdata) {
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struct blkg_policy_data *pd =
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container_of(pdata, struct blkg_policy_data, pdata);
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return pd->blkg;
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}
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return NULL;
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}
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static inline char *blkg_path(struct blkio_group *blkg)
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{
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return blkg->path;
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}
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/**
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* blkg_get - get a blkg reference
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* @blkg: blkg to get
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*
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* The caller should be holding queue_lock and an existing reference.
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*/
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static inline void blkg_get(struct blkio_group *blkg)
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{
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lockdep_assert_held(blkg->q->queue_lock);
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WARN_ON_ONCE(!blkg->refcnt);
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blkg->refcnt++;
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}
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void __blkg_release(struct blkio_group *blkg);
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/**
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* blkg_put - put a blkg reference
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* @blkg: blkg to put
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*
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* The caller should be holding queue_lock.
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*/
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static inline void blkg_put(struct blkio_group *blkg)
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{
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lockdep_assert_held(blkg->q->queue_lock);
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WARN_ON_ONCE(blkg->refcnt <= 0);
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if (!--blkg->refcnt)
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__blkg_release(blkg);
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}
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/**
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* blkg_stat_add - add a value to a blkg_stat
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* @stat: target blkg_stat
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* @val: value to add
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*
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* Add @val to @stat. The caller is responsible for synchronizing calls to
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* this function.
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*/
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static inline void blkg_stat_add(struct blkg_stat *stat, uint64_t val)
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{
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u64_stats_update_begin(&stat->syncp);
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stat->cnt += val;
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u64_stats_update_end(&stat->syncp);
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}
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/**
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* blkg_stat_read - read the current value of a blkg_stat
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* @stat: blkg_stat to read
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*
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* Read the current value of @stat. This function can be called without
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* synchroniztion and takes care of u64 atomicity.
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*/
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static inline uint64_t blkg_stat_read(struct blkg_stat *stat)
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{
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unsigned int start;
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uint64_t v;
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do {
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start = u64_stats_fetch_begin(&stat->syncp);
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v = stat->cnt;
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} while (u64_stats_fetch_retry(&stat->syncp, start));
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return v;
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}
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/**
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* blkg_stat_reset - reset a blkg_stat
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* @stat: blkg_stat to reset
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*/
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static inline void blkg_stat_reset(struct blkg_stat *stat)
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{
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stat->cnt = 0;
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}
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/**
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* blkg_rwstat_add - add a value to a blkg_rwstat
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* @rwstat: target blkg_rwstat
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* @rw: mask of REQ_{WRITE|SYNC}
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* @val: value to add
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*
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* Add @val to @rwstat. The counters are chosen according to @rw. The
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* caller is responsible for synchronizing calls to this function.
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*/
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static inline void blkg_rwstat_add(struct blkg_rwstat *rwstat,
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int rw, uint64_t val)
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{
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u64_stats_update_begin(&rwstat->syncp);
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if (rw & REQ_WRITE)
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rwstat->cnt[BLKG_RWSTAT_WRITE] += val;
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else
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rwstat->cnt[BLKG_RWSTAT_READ] += val;
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if (rw & REQ_SYNC)
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rwstat->cnt[BLKG_RWSTAT_SYNC] += val;
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else
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rwstat->cnt[BLKG_RWSTAT_ASYNC] += val;
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u64_stats_update_end(&rwstat->syncp);
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}
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/**
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* blkg_rwstat_read - read the current values of a blkg_rwstat
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* @rwstat: blkg_rwstat to read
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*
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* Read the current snapshot of @rwstat and return it as the return value.
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* This function can be called without synchronization and takes care of
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* u64 atomicity.
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*/
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static struct blkg_rwstat blkg_rwstat_read(struct blkg_rwstat *rwstat)
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{
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unsigned int start;
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struct blkg_rwstat tmp;
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do {
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start = u64_stats_fetch_begin(&rwstat->syncp);
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tmp = *rwstat;
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} while (u64_stats_fetch_retry(&rwstat->syncp, start));
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return tmp;
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}
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/**
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* blkg_rwstat_sum - read the total count of a blkg_rwstat
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* @rwstat: blkg_rwstat to read
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*
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* Return the total count of @rwstat regardless of the IO direction. This
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* function can be called without synchronization and takes care of u64
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* atomicity.
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*/
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static inline uint64_t blkg_rwstat_sum(struct blkg_rwstat *rwstat)
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{
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struct blkg_rwstat tmp = blkg_rwstat_read(rwstat);
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return tmp.cnt[BLKG_RWSTAT_READ] + tmp.cnt[BLKG_RWSTAT_WRITE];
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}
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/**
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* blkg_rwstat_reset - reset a blkg_rwstat
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* @rwstat: blkg_rwstat to reset
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*/
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static inline void blkg_rwstat_reset(struct blkg_rwstat *rwstat)
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{
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memset(rwstat->cnt, 0, sizeof(rwstat->cnt));
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}
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#else
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struct blkio_group {
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};
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struct blkio_policy_type {
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};
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static inline int blkcg_init_queue(struct request_queue *q) { return 0; }
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static inline void blkcg_drain_queue(struct request_queue *q) { }
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static inline void blkcg_exit_queue(struct request_queue *q) { }
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static inline void blkio_policy_register(struct blkio_policy_type *blkiop) { }
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static inline void blkio_policy_unregister(struct blkio_policy_type *blkiop) { }
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static inline void blkg_destroy_all(struct request_queue *q,
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bool destory_root) { }
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static inline void update_root_blkg_pd(struct request_queue *q,
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enum blkio_policy_id plid) { }
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static inline void *blkg_to_pdata(struct blkio_group *blkg,
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struct blkio_policy_type *pol) { return NULL; }
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static inline struct blkio_group *pdata_to_blkg(void *pdata,
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struct blkio_policy_type *pol) { return NULL; }
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static inline char *blkg_path(struct blkio_group *blkg) { return NULL; }
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static inline void blkg_get(struct blkio_group *blkg) { }
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static inline void blkg_put(struct blkio_group *blkg) { }
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#endif
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#define BLKIO_WEIGHT_MIN 10
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#define BLKIO_WEIGHT_MAX 1000
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#define BLKIO_WEIGHT_DEFAULT 500
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#ifdef CONFIG_DEBUG_BLK_CGROUP
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void blkiocg_update_avg_queue_size_stats(struct blkio_group *blkg,
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struct blkio_policy_type *pol);
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void blkiocg_update_dequeue_stats(struct blkio_group *blkg,
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struct blkio_policy_type *pol,
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unsigned long dequeue);
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void blkiocg_update_set_idle_time_stats(struct blkio_group *blkg,
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struct blkio_policy_type *pol);
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void blkiocg_update_idle_time_stats(struct blkio_group *blkg,
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struct blkio_policy_type *pol);
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void blkiocg_set_start_empty_time(struct blkio_group *blkg,
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struct blkio_policy_type *pol);
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#define BLKG_FLAG_FNS(name) \
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static inline void blkio_mark_blkg_##name( \
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struct blkio_group_stats *stats) \
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{ \
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stats->flags |= (1 << BLKG_##name); \
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} \
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static inline void blkio_clear_blkg_##name( \
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struct blkio_group_stats *stats) \
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{ \
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stats->flags &= ~(1 << BLKG_##name); \
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} \
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static inline int blkio_blkg_##name(struct blkio_group_stats *stats) \
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{ \
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return (stats->flags & (1 << BLKG_##name)) != 0; \
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} \
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BLKG_FLAG_FNS(waiting)
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BLKG_FLAG_FNS(idling)
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BLKG_FLAG_FNS(empty)
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#undef BLKG_FLAG_FNS
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#else
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static inline void blkiocg_update_avg_queue_size_stats(struct blkio_group *blkg,
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struct blkio_policy_type *pol) { }
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static inline void blkiocg_update_dequeue_stats(struct blkio_group *blkg,
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struct blkio_policy_type *pol, unsigned long dequeue) { }
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static inline void blkiocg_update_set_idle_time_stats(struct blkio_group *blkg,
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struct blkio_policy_type *pol) { }
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static inline void blkiocg_update_idle_time_stats(struct blkio_group *blkg,
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struct blkio_policy_type *pol) { }
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static inline void blkiocg_set_start_empty_time(struct blkio_group *blkg,
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struct blkio_policy_type *pol) { }
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#endif
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#ifdef CONFIG_BLK_CGROUP
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extern struct blkio_cgroup blkio_root_cgroup;
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extern struct blkio_cgroup *cgroup_to_blkio_cgroup(struct cgroup *cgroup);
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extern struct blkio_cgroup *bio_blkio_cgroup(struct bio *bio);
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extern struct blkio_group *blkg_lookup(struct blkio_cgroup *blkcg,
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struct request_queue *q);
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struct blkio_group *blkg_lookup_create(struct blkio_cgroup *blkcg,
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struct request_queue *q,
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bool for_root);
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void blkiocg_update_timeslice_used(struct blkio_group *blkg,
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struct blkio_policy_type *pol,
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unsigned long time,
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unsigned long unaccounted_time);
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void blkiocg_update_dispatch_stats(struct blkio_group *blkg,
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struct blkio_policy_type *pol,
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uint64_t bytes, bool direction, bool sync);
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void blkiocg_update_completion_stats(struct blkio_group *blkg,
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struct blkio_policy_type *pol,
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uint64_t start_time,
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uint64_t io_start_time, bool direction,
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bool sync);
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void blkiocg_update_io_merged_stats(struct blkio_group *blkg,
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struct blkio_policy_type *pol,
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bool direction, bool sync);
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void blkiocg_update_io_add_stats(struct blkio_group *blkg,
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struct blkio_policy_type *pol,
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struct blkio_group *curr_blkg, bool direction,
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bool sync);
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void blkiocg_update_io_remove_stats(struct blkio_group *blkg,
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struct blkio_policy_type *pol,
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bool direction, bool sync);
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#else
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struct cgroup;
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static inline struct blkio_cgroup *
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cgroup_to_blkio_cgroup(struct cgroup *cgroup) { return NULL; }
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static inline struct blkio_cgroup *
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bio_blkio_cgroup(struct bio *bio) { return NULL; }
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static inline struct blkio_group *blkg_lookup(struct blkio_cgroup *blkcg,
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void *key) { return NULL; }
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static inline void blkiocg_update_timeslice_used(struct blkio_group *blkg,
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struct blkio_policy_type *pol, unsigned long time,
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unsigned long unaccounted_time) { }
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static inline void blkiocg_update_dispatch_stats(struct blkio_group *blkg,
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struct blkio_policy_type *pol, uint64_t bytes,
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bool direction, bool sync) { }
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static inline void blkiocg_update_completion_stats(struct blkio_group *blkg,
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struct blkio_policy_type *pol, uint64_t start_time,
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uint64_t io_start_time, bool direction, bool sync) { }
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static inline void blkiocg_update_io_merged_stats(struct blkio_group *blkg,
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struct blkio_policy_type *pol, bool direction,
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bool sync) { }
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static inline void blkiocg_update_io_add_stats(struct blkio_group *blkg,
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struct blkio_policy_type *pol,
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struct blkio_group *curr_blkg, bool direction,
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bool sync) { }
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static inline void blkiocg_update_io_remove_stats(struct blkio_group *blkg,
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struct blkio_policy_type *pol, bool direction,
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bool sync) { }
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#endif
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#endif /* _BLK_CGROUP_H */
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