X-Git-Url: http://git.samba.org/samba.git/?a=blobdiff_plain;f=block%2Fblk-cgroup.c;h=bcaf16ee6ad1ba321836413ee8841ab0bbde8f5e;hb=f780bdb7c1c73009cb57adcf99ef50027d80bf3c;hp=34bfcefdd924c0c5e7f222c726ca5d30f05aed26;hpb=5624a4e445e2ec27582984b068d7bf7f127cee10;p=sfrench%2Fcifs-2.6.git diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c index 34bfcefdd924..bcaf16ee6ad1 100644 --- a/block/blk-cgroup.c +++ b/block/blk-cgroup.c @@ -30,10 +30,8 @@ EXPORT_SYMBOL_GPL(blkio_root_cgroup); static struct cgroup_subsys_state *blkiocg_create(struct cgroup_subsys *, struct cgroup *); -static int blkiocg_can_attach(struct cgroup_subsys *, struct cgroup *, - struct task_struct *, bool); -static void blkiocg_attach(struct cgroup_subsys *, struct cgroup *, - struct cgroup *, struct task_struct *, bool); +static int blkiocg_can_attach_task(struct cgroup *, struct task_struct *); +static void blkiocg_attach_task(struct cgroup *, struct task_struct *); static void blkiocg_destroy(struct cgroup_subsys *, struct cgroup *); static int blkiocg_populate(struct cgroup_subsys *, struct cgroup *); @@ -46,8 +44,8 @@ static int blkiocg_populate(struct cgroup_subsys *, struct cgroup *); struct cgroup_subsys blkio_subsys = { .name = "blkio", .create = blkiocg_create, - .can_attach = blkiocg_can_attach, - .attach = blkiocg_attach, + .can_attach_task = blkiocg_can_attach_task, + .attach_task = blkiocg_attach_task, .destroy = blkiocg_destroy, .populate = blkiocg_populate, #ifdef CONFIG_BLK_CGROUP @@ -400,14 +398,25 @@ void blkiocg_update_dispatch_stats(struct blkio_group *blkg, uint64_t bytes, bool direction, bool sync) { struct blkio_group_stats_cpu *stats_cpu; + unsigned long flags; + + /* + * Disabling interrupts to provide mutual exclusion between two + * writes on same cpu. It probably is not needed for 64bit. Not + * optimizing that case yet. + */ + local_irq_save(flags); stats_cpu = this_cpu_ptr(blkg->stats_cpu); + u64_stats_update_begin(&stats_cpu->syncp); stats_cpu->sectors += bytes >> 9; blkio_add_stat(stats_cpu->stat_arr_cpu[BLKIO_STAT_CPU_SERVICED], 1, direction, sync); blkio_add_stat(stats_cpu->stat_arr_cpu[BLKIO_STAT_CPU_SERVICE_BYTES], bytes, direction, sync); + u64_stats_update_end(&stats_cpu->syncp); + local_irq_restore(flags); } EXPORT_SYMBOL_GPL(blkiocg_update_dispatch_stats); @@ -430,15 +439,27 @@ void blkiocg_update_completion_stats(struct blkio_group *blkg, } EXPORT_SYMBOL_GPL(blkiocg_update_completion_stats); +/* Merged stats are per cpu. */ void blkiocg_update_io_merged_stats(struct blkio_group *blkg, bool direction, bool sync) { + struct blkio_group_stats_cpu *stats_cpu; unsigned long flags; - spin_lock_irqsave(&blkg->stats_lock, flags); - blkio_add_stat(blkg->stats.stat_arr[BLKIO_STAT_MERGED], 1, direction, - sync); - spin_unlock_irqrestore(&blkg->stats_lock, flags); + /* + * Disabling interrupts to provide mutual exclusion between two + * writes on same cpu. It probably is not needed for 64bit. Not + * optimizing that case yet. + */ + local_irq_save(flags); + + stats_cpu = this_cpu_ptr(blkg->stats_cpu); + + u64_stats_update_begin(&stats_cpu->syncp); + blkio_add_stat(stats_cpu->stat_arr_cpu[BLKIO_STAT_CPU_MERGED], 1, + direction, sync); + u64_stats_update_end(&stats_cpu->syncp); + local_irq_restore(flags); } EXPORT_SYMBOL_GPL(blkiocg_update_io_merged_stats); @@ -526,6 +547,30 @@ struct blkio_group *blkiocg_lookup_group(struct blkio_cgroup *blkcg, void *key) } EXPORT_SYMBOL_GPL(blkiocg_lookup_group); +static void blkio_reset_stats_cpu(struct blkio_group *blkg) +{ + struct blkio_group_stats_cpu *stats_cpu; + int i, j, k; + /* + * Note: On 64 bit arch this should not be an issue. This has the + * possibility of returning some inconsistent value on 32bit arch + * as 64bit update on 32bit is non atomic. Taking care of this + * corner case makes code very complicated, like sending IPIs to + * cpus, taking care of stats of offline cpus etc. + * + * reset stats is anyway more of a debug feature and this sounds a + * corner case. So I am not complicating the code yet until and + * unless this becomes a real issue. + */ + for_each_possible_cpu(i) { + stats_cpu = per_cpu_ptr(blkg->stats_cpu, i); + stats_cpu->sectors = 0; + for(j = 0; j < BLKIO_STAT_CPU_NR; j++) + for (k = 0; k < BLKIO_STAT_TOTAL; k++) + stats_cpu->stat_arr_cpu[j][k] = 0; + } +} + static int blkiocg_reset_stats(struct cgroup *cgroup, struct cftype *cftype, u64 val) { @@ -570,7 +615,11 @@ blkiocg_reset_stats(struct cgroup *cgroup, struct cftype *cftype, u64 val) } #endif spin_unlock(&blkg->stats_lock); + + /* Reset Per cpu stats which don't take blkg->stats_lock */ + blkio_reset_stats_cpu(blkg); } + spin_unlock_irq(&blkcg->lock); return 0; } @@ -622,15 +671,21 @@ static uint64_t blkio_read_stat_cpu(struct blkio_group *blkg, { int cpu; struct blkio_group_stats_cpu *stats_cpu; - uint64_t val = 0; + u64 val = 0, tval; for_each_possible_cpu(cpu) { + unsigned int start; stats_cpu = per_cpu_ptr(blkg->stats_cpu, cpu); - if (type == BLKIO_STAT_CPU_SECTORS) - val += stats_cpu->sectors; - else - val += stats_cpu->stat_arr_cpu[type][sub_type]; + do { + start = u64_stats_fetch_begin(&stats_cpu->syncp); + if (type == BLKIO_STAT_CPU_SECTORS) + tval = stats_cpu->sectors; + else + tval = stats_cpu->stat_arr_cpu[type][sub_type]; + } while(u64_stats_fetch_retry(&stats_cpu->syncp, start)); + + val += tval; } return val; @@ -1199,7 +1254,7 @@ static int blkiocg_file_read_map(struct cgroup *cgrp, struct cftype *cft, BLKIO_STAT_WAIT_TIME, 1, 0); case BLKIO_PROP_io_merged: return blkio_read_blkg_stats(blkcg, cft, cb, - BLKIO_STAT_MERGED, 1, 0); + BLKIO_STAT_CPU_MERGED, 1, 1); case BLKIO_PROP_io_queued: return blkio_read_blkg_stats(blkcg, cft, cb, BLKIO_STAT_QUEUED, 1, 0); @@ -1559,9 +1614,7 @@ done: * of the main cic data structures. For now we allow a task to change * its cgroup only if it's the only owner of its ioc. */ -static int blkiocg_can_attach(struct cgroup_subsys *subsys, - struct cgroup *cgroup, struct task_struct *tsk, - bool threadgroup) +static int blkiocg_can_attach_task(struct cgroup *cgrp, struct task_struct *tsk) { struct io_context *ioc; int ret = 0; @@ -1576,9 +1629,7 @@ static int blkiocg_can_attach(struct cgroup_subsys *subsys, return ret; } -static void blkiocg_attach(struct cgroup_subsys *subsys, struct cgroup *cgroup, - struct cgroup *prev, struct task_struct *tsk, - bool threadgroup) +static void blkiocg_attach_task(struct cgroup *cgrp, struct task_struct *tsk) { struct io_context *ioc;