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authorTejun Heo <tj@kernel.org>2012-04-16 13:57:23 -0700
committerJens Axboe <axboe@kernel.dk>2012-04-20 10:06:16 +0200
commit54e7ed12bad1e3aa2a28558fab6850240465f973 (patch)
tree907eb0451782f4eb1ad3f9236e51ec4acb7fb941 /block
parentc94bed89995e638e43a6663177358b9d20617361 (diff)
downloadlinux-linaro-stable-54e7ed12bad1e3aa2a28558fab6850240465f973.tar.gz
blkcg: remove blkio_group->path[]
blkio_group->path[] stores the path of the associated cgroup and is used only for debug messages. Just format the path from blkg->cgroup when printing debug messages. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block')
-rw-r--r--block/blk-cgroup.c1
-rw-r--r--block/blk-cgroup.h21
-rw-r--r--block/blk-throttle.c9
-rw-r--r--block/cfq-iosched.c21
4 files changed, 37 insertions, 15 deletions
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index b1807d4ecedb..63337024e4d7 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -114,7 +114,6 @@ static struct blkio_group *blkg_alloc(struct blkio_cgroup *blkcg,
INIT_LIST_HEAD(&blkg->q_node);
blkg->blkcg = blkcg;
blkg->refcnt = 1;
- cgroup_path(blkcg->css.cgroup, blkg->path, sizeof(blkg->path));
for (i = 0; i < BLKCG_MAX_POLS; i++) {
struct blkio_policy_type *pol = blkio_policy[i];
diff --git a/block/blk-cgroup.h b/block/blk-cgroup.h
index ef6550a67a69..c524267e4f7f 100644
--- a/block/blk-cgroup.h
+++ b/block/blk-cgroup.h
@@ -77,8 +77,6 @@ struct blkio_group {
struct list_head q_node;
struct hlist_node blkcg_node;
struct blkio_cgroup *blkcg;
- /* Store cgroup path */
- char path[128];
/* reference count */
int refcnt;
@@ -167,9 +165,24 @@ static inline struct blkio_group *pdata_to_blkg(void *pdata)
return NULL;
}
-static inline char *blkg_path(struct blkio_group *blkg)
+/**
+ * blkg_path - format cgroup path of blkg
+ * @blkg: blkg of interest
+ * @buf: target buffer
+ * @buflen: target buffer length
+ *
+ * Format the path of the cgroup of @blkg into @buf.
+ */
+static inline int blkg_path(struct blkio_group *blkg, char *buf, int buflen)
{
- return blkg->path;
+ int ret;
+
+ rcu_read_lock();
+ ret = cgroup_path(blkg->blkcg->css.cgroup, buf, buflen);
+ rcu_read_unlock();
+ if (ret)
+ strncpy(buf, "<unavailable>", buflen);
+ return ret;
}
/**
diff --git a/block/blk-throttle.c b/block/blk-throttle.c
index e2aaf27e1f10..e9b7a47f6da0 100644
--- a/block/blk-throttle.c
+++ b/block/blk-throttle.c
@@ -155,9 +155,12 @@ static inline int throtl_tg_##name(const struct throtl_grp *tg) \
THROTL_TG_FNS(on_rr);
-#define throtl_log_tg(td, tg, fmt, args...) \
- blk_add_trace_msg((td)->queue, "throtl %s " fmt, \
- blkg_path(tg_to_blkg(tg)), ##args); \
+#define throtl_log_tg(td, tg, fmt, args...) do { \
+ char __pbuf[128]; \
+ \
+ blkg_path(tg_to_blkg(tg), __pbuf, sizeof(__pbuf)); \
+ blk_add_trace_msg((td)->queue, "throtl %s " fmt, __pbuf, ##args); \
+} while (0)
#define throtl_log(td, fmt, args...) \
blk_add_trace_msg((td)->queue, "throtl " fmt, ##args)
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index eb07eb64e85b..901286b5f5cb 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -573,14 +573,21 @@ static inline void cfqg_put(struct cfq_group *cfqg)
return blkg_put(cfqg_to_blkg(cfqg));
}
-#define cfq_log_cfqq(cfqd, cfqq, fmt, args...) \
+#define cfq_log_cfqq(cfqd, cfqq, fmt, args...) do { \
+ char __pbuf[128]; \
+ \
+ blkg_path(cfqg_to_blkg((cfqq)->cfqg), __pbuf, sizeof(__pbuf)); \
blk_add_trace_msg((cfqd)->queue, "cfq%d%c %s " fmt, (cfqq)->pid, \
- cfq_cfqq_sync((cfqq)) ? 'S' : 'A', \
- blkg_path(cfqg_to_blkg((cfqq)->cfqg)), ##args)
-
-#define cfq_log_cfqg(cfqd, cfqg, fmt, args...) \
- blk_add_trace_msg((cfqd)->queue, "%s " fmt, \
- blkg_path(cfqg_to_blkg((cfqg))), ##args) \
+ cfq_cfqq_sync((cfqq)) ? 'S' : 'A', \
+ __pbuf, ##args); \
+} while (0)
+
+#define cfq_log_cfqg(cfqd, cfqg, fmt, args...) do { \
+ char __pbuf[128]; \
+ \
+ blkg_path(cfqg_to_blkg(cfqg), __pbuf, sizeof(__pbuf)); \
+ blk_add_trace_msg((cfqd)->queue, "%s " fmt, __pbuf, ##args); \
+} while (0)
static inline void cfqg_stats_update_io_add(struct cfq_group *cfqg,
struct cfq_group *curr_cfqg, int rw)