From 7af6fd9112ba310a889c60d0606b4b74049cfe14 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 6 Jun 2019 12:26:21 +0200 Subject: blk-cgroup: introduce a new struct blkg_rwstat_sample When sampling the blkcg counts we don't need atomics or per-cpu variables. Introduce a new structure just containing plain u64 counters. Acked-by: Tejun Heo Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe --- block/bfq-cgroup.c | 10 ++++------ block/blk-cgroup.c | 39 +++++++++++++++++++-------------------- 2 files changed, 23 insertions(+), 26 deletions(-) (limited to 'block') diff --git a/block/bfq-cgroup.c b/block/bfq-cgroup.c index 66abc82179f3..624374a99c6e 100644 --- a/block/bfq-cgroup.c +++ b/block/bfq-cgroup.c @@ -935,7 +935,7 @@ static u64 bfqg_prfill_stat_recursive(struct seq_file *sf, static u64 bfqg_prfill_rwstat_recursive(struct seq_file *sf, struct blkg_policy_data *pd, int off) { - struct blkg_rwstat sum; + struct blkg_rwstat_sample sum; blkg_rwstat_recursive_sum(pd_to_blkg(pd), &blkcg_policy_bfq, off, &sum); return __blkg_prfill_rwstat(sf, pd, &sum); @@ -975,15 +975,13 @@ static int bfqg_print_stat_sectors(struct seq_file *sf, void *v) static u64 bfqg_prfill_sectors_recursive(struct seq_file *sf, struct blkg_policy_data *pd, int off) { - struct blkg_rwstat tmp; - u64 sum; + struct blkg_rwstat_sample tmp; blkg_rwstat_recursive_sum(pd->blkg, NULL, offsetof(struct blkcg_gq, stat_bytes), &tmp); - sum = atomic64_read(&tmp.aux_cnt[BLKG_RWSTAT_READ]) + - atomic64_read(&tmp.aux_cnt[BLKG_RWSTAT_WRITE]); - return __blkg_prfill_u64(sf, pd, sum >> 9); + return __blkg_prfill_u64(sf, pd, + (tmp.cnt[BLKG_RWSTAT_READ] + tmp.cnt[BLKG_RWSTAT_WRITE]) >> 9); } static int bfqg_print_stat_sectors_recursive(struct seq_file *sf, void *v) diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c index db039a869d95..664c09866839 100644 --- a/block/blk-cgroup.c +++ b/block/blk-cgroup.c @@ -544,7 +544,7 @@ EXPORT_SYMBOL_GPL(__blkg_prfill_u64); * Print @rwstat to @sf for the device assocaited with @pd. */ u64 __blkg_prfill_rwstat(struct seq_file *sf, struct blkg_policy_data *pd, - const struct blkg_rwstat *rwstat) + const struct blkg_rwstat_sample *rwstat) { static const char *rwstr[] = { [BLKG_RWSTAT_READ] = "Read", @@ -562,12 +562,12 @@ u64 __blkg_prfill_rwstat(struct seq_file *sf, struct blkg_policy_data *pd, for (i = 0; i < BLKG_RWSTAT_NR; i++) seq_printf(sf, "%s %s %llu\n", dname, rwstr[i], - (unsigned long long)atomic64_read(&rwstat->aux_cnt[i])); + rwstat->cnt[i]); - v = atomic64_read(&rwstat->aux_cnt[BLKG_RWSTAT_READ]) + - atomic64_read(&rwstat->aux_cnt[BLKG_RWSTAT_WRITE]) + - atomic64_read(&rwstat->aux_cnt[BLKG_RWSTAT_DISCARD]); - seq_printf(sf, "%s Total %llu\n", dname, (unsigned long long)v); + v = rwstat->cnt[BLKG_RWSTAT_READ] + + rwstat->cnt[BLKG_RWSTAT_WRITE] + + rwstat->cnt[BLKG_RWSTAT_DISCARD]; + seq_printf(sf, "%s Total %llu\n", dname, v); return v; } EXPORT_SYMBOL_GPL(__blkg_prfill_rwstat); @@ -597,7 +597,7 @@ EXPORT_SYMBOL_GPL(blkg_prfill_stat); u64 blkg_prfill_rwstat(struct seq_file *sf, struct blkg_policy_data *pd, int off) { - struct blkg_rwstat rwstat = { }; + struct blkg_rwstat_sample rwstat = { }; blkg_rwstat_read((void *)pd + off, &rwstat); return __blkg_prfill_rwstat(sf, pd, &rwstat); @@ -607,7 +607,7 @@ EXPORT_SYMBOL_GPL(blkg_prfill_rwstat); static u64 blkg_prfill_rwstat_field(struct seq_file *sf, struct blkg_policy_data *pd, int off) { - struct blkg_rwstat rwstat = { }; + struct blkg_rwstat_sample rwstat = { }; blkg_rwstat_read((void *)pd->blkg + off, &rwstat); return __blkg_prfill_rwstat(sf, pd, &rwstat); @@ -651,7 +651,7 @@ static u64 blkg_prfill_rwstat_field_recursive(struct seq_file *sf, struct blkg_policy_data *pd, int off) { - struct blkg_rwstat rwstat; + struct blkg_rwstat_sample rwstat; blkg_rwstat_recursive_sum(pd->blkg, NULL, off, &rwstat); return __blkg_prfill_rwstat(sf, pd, &rwstat); @@ -734,7 +734,7 @@ EXPORT_SYMBOL_GPL(blkg_stat_recursive_sum); * @blkg: blkg of interest * @pol: blkcg_policy which contains the blkg_rwstat * @off: offset to the blkg_rwstat in blkg_policy_data or @blkg - * @sum: blkg_rwstat structure containing the results + * @sum: blkg_rwstat_sample structure containing the results * * Collect the blkg_rwstat specified by @blkg, @pol and @off and all its * online descendants and their aux counts. The caller must be holding the @@ -744,7 +744,7 @@ EXPORT_SYMBOL_GPL(blkg_stat_recursive_sum); * is at @off bytes into @blkg's blkg_policy_data of the policy. */ void blkg_rwstat_recursive_sum(struct blkcg_gq *blkg, struct blkcg_policy *pol, - int off, struct blkg_rwstat *sum) + int off, struct blkg_rwstat_sample *sum) { struct blkcg_gq *pos_blkg; struct cgroup_subsys_state *pos_css; @@ -765,8 +765,7 @@ void blkg_rwstat_recursive_sum(struct blkcg_gq *blkg, struct blkcg_policy *pol, rwstat = (void *)pos_blkg + off; for (i = 0; i < BLKG_RWSTAT_NR; i++) - atomic64_set(&sum->aux_cnt[i], - blkg_rwstat_read_counter(rwstat, i)); + sum->cnt[i] = blkg_rwstat_read_counter(rwstat, i); } rcu_read_unlock(); } @@ -934,7 +933,7 @@ static int blkcg_print_stat(struct seq_file *sf, void *v) hlist_for_each_entry_rcu(blkg, &blkcg->blkg_list, blkcg_node) { const char *dname; char *buf; - struct blkg_rwstat rwstat; + struct blkg_rwstat_sample rwstat; u64 rbytes, wbytes, rios, wios, dbytes, dios; size_t size = seq_get_buf(sf, &buf), off = 0; int i; @@ -956,15 +955,15 @@ static int blkcg_print_stat(struct seq_file *sf, void *v) blkg_rwstat_recursive_sum(blkg, NULL, offsetof(struct blkcg_gq, stat_bytes), &rwstat); - rbytes = atomic64_read(&rwstat.aux_cnt[BLKG_RWSTAT_READ]); - wbytes = atomic64_read(&rwstat.aux_cnt[BLKG_RWSTAT_WRITE]); - dbytes = atomic64_read(&rwstat.aux_cnt[BLKG_RWSTAT_DISCARD]); + rbytes = rwstat.cnt[BLKG_RWSTAT_READ]; + wbytes = rwstat.cnt[BLKG_RWSTAT_WRITE]; + dbytes = rwstat.cnt[BLKG_RWSTAT_DISCARD]; blkg_rwstat_recursive_sum(blkg, NULL, offsetof(struct blkcg_gq, stat_ios), &rwstat); - rios = atomic64_read(&rwstat.aux_cnt[BLKG_RWSTAT_READ]); - wios = atomic64_read(&rwstat.aux_cnt[BLKG_RWSTAT_WRITE]); - dios = atomic64_read(&rwstat.aux_cnt[BLKG_RWSTAT_DISCARD]); + rios = rwstat.cnt[BLKG_RWSTAT_READ]; + wios = rwstat.cnt[BLKG_RWSTAT_WRITE]; + dios = rwstat.cnt[BLKG_RWSTAT_DISCARD]; spin_unlock_irq(&blkg->q->queue_lock); -- cgit v1.2.3-55-g7522