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authorChristoph Hellwig <hch@lst.de>2019-06-06 12:26:20 +0200
committerJens Axboe <axboe@kernel.dk>2019-06-20 10:32:34 -0600
commit5d0b6e48cbef3219c0ed75e0e746c4ed259303c2 (patch)
tree44575646c0c302eb4ce682d3b554a558fe6d5679 /block
parent239eeb085753d4356f731a773f363eb5bed4fe81 (diff)
blk-cgroup: pass blkg_rwstat structures by reference
Returning a structure generates rather bad code, so switch to passing by reference. Also don't require the structure to be zeroed and add to the 0-initialized counters, but actually set the counters to the calculated value. Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block')
-rw-r--r--block/bfq-cgroup.c15
-rw-r--r--block/blk-cgroup.c31
2 files changed, 25 insertions, 21 deletions
diff --git a/block/bfq-cgroup.c b/block/bfq-cgroup.c
index b3796a40a61a..66abc82179f3 100644
--- a/block/bfq-cgroup.c
+++ b/block/bfq-cgroup.c
@@ -935,9 +935,9 @@ 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 = blkg_rwstat_recursive_sum(pd_to_blkg(pd),
- &blkcg_policy_bfq,
- off);
+ struct blkg_rwstat sum;
+
+ blkg_rwstat_recursive_sum(pd_to_blkg(pd), &blkcg_policy_bfq, off, &sum);
return __blkg_prfill_rwstat(sf, pd, &sum);
}
@@ -975,9 +975,12 @@ 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 = blkg_rwstat_recursive_sum(pd->blkg, NULL,
- offsetof(struct blkcg_gq, stat_bytes));
- u64 sum = atomic64_read(&tmp.aux_cnt[BLKG_RWSTAT_READ]) +
+ struct blkg_rwstat tmp;
+ u64 sum;
+
+ 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);
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 0778e52b1db2..db039a869d95 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -597,8 +597,9 @@ 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 = blkg_rwstat_read((void *)pd + off);
+ struct blkg_rwstat rwstat = { };
+ blkg_rwstat_read((void *)pd + off, &rwstat);
return __blkg_prfill_rwstat(sf, pd, &rwstat);
}
EXPORT_SYMBOL_GPL(blkg_prfill_rwstat);
@@ -606,8 +607,9 @@ 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 = blkg_rwstat_read((void *)pd->blkg + off);
+ struct blkg_rwstat rwstat = { };
+ blkg_rwstat_read((void *)pd->blkg + off, &rwstat);
return __blkg_prfill_rwstat(sf, pd, &rwstat);
}
@@ -649,8 +651,9 @@ static u64 blkg_prfill_rwstat_field_recursive(struct seq_file *sf,
struct blkg_policy_data *pd,
int off)
{
- struct blkg_rwstat rwstat = blkg_rwstat_recursive_sum(pd->blkg,
- NULL, off);
+ struct blkg_rwstat rwstat;
+
+ blkg_rwstat_recursive_sum(pd->blkg, NULL, off, &rwstat);
return __blkg_prfill_rwstat(sf, pd, &rwstat);
}
@@ -731,6 +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
*
* 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
@@ -739,12 +743,11 @@ EXPORT_SYMBOL_GPL(blkg_stat_recursive_sum);
* 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.
*/
-struct blkg_rwstat blkg_rwstat_recursive_sum(struct blkcg_gq *blkg,
- struct blkcg_policy *pol, int off)
+void blkg_rwstat_recursive_sum(struct blkcg_gq *blkg, struct blkcg_policy *pol,
+ int off, struct blkg_rwstat *sum)
{
struct blkcg_gq *pos_blkg;
struct cgroup_subsys_state *pos_css;
- struct blkg_rwstat sum = { };
unsigned int i;
lockdep_assert_held(&blkg->q->queue_lock);
@@ -762,12 +765,10 @@ struct blkg_rwstat blkg_rwstat_recursive_sum(struct blkcg_gq *blkg,
rwstat = (void *)pos_blkg + off;
for (i = 0; i < BLKG_RWSTAT_NR; i++)
- atomic64_add(blkg_rwstat_read_counter(rwstat, i),
- &sum.aux_cnt[i]);
+ atomic64_set(&sum->aux_cnt[i],
+ blkg_rwstat_read_counter(rwstat, i));
}
rcu_read_unlock();
-
- return sum;
}
EXPORT_SYMBOL_GPL(blkg_rwstat_recursive_sum);
@@ -953,14 +954,14 @@ static int blkcg_print_stat(struct seq_file *sf, void *v)
spin_lock_irq(&blkg->q->queue_lock);
- rwstat = blkg_rwstat_recursive_sum(blkg, NULL,
- offsetof(struct blkcg_gq, stat_bytes));
+ 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]);
- rwstat = blkg_rwstat_recursive_sum(blkg, NULL,
- offsetof(struct blkcg_gq, stat_ios));
+ 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]);