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authorTejun Heo <tj@kernel.org>2019-11-07 11:18:04 -0800
committerJens Axboe <axboe@kernel.dk>2019-11-07 12:28:13 -0700
commit1d156646e0d8ec390e5d5ac288137df02d4207be (patch)
treeac8219a4da32a25ace792ac1d8775e890c34b127 /block/blk-cgroup-rwstat.c
parentf73316482977ac401ac37245c9df48079d4e11f3 (diff)
blk-cgroup: separate out blkg_rwstat under CONFIG_BLK_CGROUP_RWSTAT
blkg_rwstat is now only used by bfq-iosched and blk-throtl when on cgroup1. Let's move it into its own files and gate it behind a config option. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block/blk-cgroup-rwstat.c')
-rw-r--r--block/blk-cgroup-rwstat.c129
1 files changed, 129 insertions, 0 deletions
diff --git a/block/blk-cgroup-rwstat.c b/block/blk-cgroup-rwstat.c
new file mode 100644
index 000000000000..85d5790ac49b
--- /dev/null
+++ b/block/blk-cgroup-rwstat.c
@@ -0,0 +1,129 @@
+/* SPDX-License-Identifier: GPL-2.0
+ *
+ * Legacy blkg rwstat helpers enabled by CONFIG_BLK_CGROUP_RWSTAT.
+ * Do not use in new code.
+ */
+#include "blk-cgroup-rwstat.h"
+
+int blkg_rwstat_init(struct blkg_rwstat *rwstat, gfp_t gfp)
+{
+ int i, ret;
+
+ for (i = 0; i < BLKG_RWSTAT_NR; i++) {
+ ret = percpu_counter_init(&rwstat->cpu_cnt[i], 0, gfp);
+ if (ret) {
+ while (--i >= 0)
+ percpu_counter_destroy(&rwstat->cpu_cnt[i]);
+ return ret;
+ }
+ atomic64_set(&rwstat->aux_cnt[i], 0);
+ }
+ return 0;
+}
+EXPORT_SYMBOL_GPL(blkg_rwstat_init);
+
+void blkg_rwstat_exit(struct blkg_rwstat *rwstat)
+{
+ int i;
+
+ for (i = 0; i < BLKG_RWSTAT_NR; i++)
+ percpu_counter_destroy(&rwstat->cpu_cnt[i]);
+}
+EXPORT_SYMBOL_GPL(blkg_rwstat_exit);
+
+/**
+ * __blkg_prfill_rwstat - prfill helper for a blkg_rwstat
+ * @sf: seq_file to print to
+ * @pd: policy private data of interest
+ * @rwstat: rwstat to print
+ *
+ * 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_sample *rwstat)
+{
+ static const char *rwstr[] = {
+ [BLKG_RWSTAT_READ] = "Read",
+ [BLKG_RWSTAT_WRITE] = "Write",
+ [BLKG_RWSTAT_SYNC] = "Sync",
+ [BLKG_RWSTAT_ASYNC] = "Async",
+ [BLKG_RWSTAT_DISCARD] = "Discard",
+ };
+ const char *dname = blkg_dev_name(pd->blkg);
+ u64 v;
+ int i;
+
+ if (!dname)
+ return 0;
+
+ for (i = 0; i < BLKG_RWSTAT_NR; i++)
+ seq_printf(sf, "%s %s %llu\n", dname, rwstr[i],
+ rwstat->cnt[i]);
+
+ 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);
+
+/**
+ * blkg_prfill_rwstat - prfill callback for blkg_rwstat
+ * @sf: seq_file to print to
+ * @pd: policy private data of interest
+ * @off: offset to the blkg_rwstat in @pd
+ *
+ * prfill callback for printing a blkg_rwstat.
+ */
+u64 blkg_prfill_rwstat(struct seq_file *sf, struct blkg_policy_data *pd,
+ int off)
+{
+ struct blkg_rwstat_sample rwstat = { };
+
+ blkg_rwstat_read((void *)pd + off, &rwstat);
+ return __blkg_prfill_rwstat(sf, pd, &rwstat);
+}
+EXPORT_SYMBOL_GPL(blkg_prfill_rwstat);
+
+/**
+ * blkg_rwstat_recursive_sum - collect hierarchical blkg_rwstat
+ * @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_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
+ * queue lock for online tests.
+ *
+ * If @pol is NULL, blkg_rwstat is at @off bytes into @blkg; otherwise, it
+ * 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_sample *sum)
+{
+ struct blkcg_gq *pos_blkg;
+ struct cgroup_subsys_state *pos_css;
+ unsigned int i;
+
+ lockdep_assert_held(&blkg->q->queue_lock);
+
+ rcu_read_lock();
+ blkg_for_each_descendant_pre(pos_blkg, pos_css, blkg) {
+ struct blkg_rwstat *rwstat;
+
+ if (!pos_blkg->online)
+ continue;
+
+ if (pol)
+ rwstat = (void *)blkg_to_pd(pos_blkg, pol) + off;
+ else
+ rwstat = (void *)pos_blkg + off;
+
+ for (i = 0; i < BLKG_RWSTAT_NR; i++)
+ sum->cnt[i] = blkg_rwstat_read_counter(rwstat, i);
+ }
+ rcu_read_unlock();
+}
+EXPORT_SYMBOL_GPL(blkg_rwstat_recursive_sum);