lkml.org 
[lkml]   [2017]   [Jun]   [2]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 11/11] block: use standard blktrace API to output cgroup info for debug notes
Date
From: Shaohua Li <shli@fb.com>

Currently cfq/bfq/blk-throttle output cgroup info in trace in their own
way. Now we have standard blktrace API for this, so convert them to use
it.

Note, this changes the behavior a little bit. cgroup info isn't output
by default, we only do this with 'blk_cgroup' option enabled. cgroup
info isn't output as a string by default too, we only do this with
'blk_cgname' option enabled. Also cgroup info is output in different
position of the note string. I think these behavior changes aren't a big
issue (actually we make trace data shorter which is good), since the
blktrace note is solely for debugging.

Signed-off-by: Shaohua Li <shli@fb.com>
---
block/bfq-iosched.h | 16 ++++++----------
block/blk-throttle.c | 6 ++----
block/cfq-iosched.c | 15 ++++++---------
include/linux/blk-cgroup.h | 14 --------------
include/linux/blktrace_api.h | 12 ++++++++----
kernel/trace/blktrace.c | 10 +++++++---
6 files changed, 29 insertions(+), 44 deletions(-)

diff --git a/block/bfq-iosched.h b/block/bfq-iosched.h
index ae783c0..e4d5b56 100644
--- a/block/bfq-iosched.h
+++ b/block/bfq-iosched.h
@@ -910,19 +910,15 @@ void bfq_add_bfqq_busy(struct bfq_data *bfqd, struct bfq_queue *bfqq);
struct bfq_group *bfqq_group(struct bfq_queue *bfqq);

#define bfq_log_bfqq(bfqd, bfqq, fmt, args...) do { \
- char __pbuf[128]; \
- \
- blkg_path(bfqg_to_blkg(bfqq_group(bfqq)), __pbuf, sizeof(__pbuf)); \
- blk_add_trace_msg((bfqd)->queue, "bfq%d%c %s " fmt, (bfqq)->pid, \
- bfq_bfqq_sync((bfqq)) ? 'S' : 'A', \
- __pbuf, ##args); \
+ blk_add_cgroup_trace_msg((bfqd)->queue, \
+ bfqg_to_blkg(bfqq_group(bfqq))->blkcg, \
+ "bfq%d%c " fmt, (bfqq)->pid, \
+ bfq_bfqq_sync((bfqq)) ? 'S' : 'A', ##args); \
} while (0)

#define bfq_log_bfqg(bfqd, bfqg, fmt, args...) do { \
- char __pbuf[128]; \
- \
- blkg_path(bfqg_to_blkg(bfqg), __pbuf, sizeof(__pbuf)); \
- blk_add_trace_msg((bfqd)->queue, "%s " fmt, __pbuf, ##args); \
+ blk_add_cgroup_trace_msg((bfqd)->queue, \
+ bfqg_to_blkg(bfqg)->blkcg, fmt, ##args); \
} while (0)

#else /* CONFIG_BFQ_GROUP_IOSCHED */
diff --git a/block/blk-throttle.c b/block/blk-throttle.c
index 53d3e3d..46e85e0 100644
--- a/block/blk-throttle.c
+++ b/block/blk-throttle.c
@@ -352,10 +352,8 @@ static unsigned int tg_iops_limit(struct throtl_grp *tg, int rw)
if (likely(!blk_trace_note_message_enabled(__td->queue))) \
break; \
if ((__tg)) { \
- char __pbuf[128]; \
- \
- blkg_path(tg_to_blkg(__tg), __pbuf, sizeof(__pbuf)); \
- blk_add_trace_msg(__td->queue, "throtl %s " fmt, __pbuf, ##args); \
+ blk_add_cgroup_trace_msg(__td->queue, \
+ tg_to_blkg(__tg)->blkcg, "throtl " fmt, ##args);\
} else { \
blk_add_trace_msg(__td->queue, "throtl " fmt, ##args); \
} \
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index da69b07..5f59f37 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -652,20 +652,17 @@ static inline void cfqg_put(struct cfq_group *cfqg)
}

#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%c %s " fmt, (cfqq)->pid, \
+ blk_add_cgroup_trace_msg((cfqd)->queue, \
+ cfqg_to_blkg((cfqq)->cfqg)->blkcg, \
+ "cfq%d%c%c " fmt, (cfqq)->pid, \
cfq_cfqq_sync((cfqq)) ? 'S' : 'A', \
cfqq_type((cfqq)) == SYNC_NOIDLE_WORKLOAD ? 'N' : ' ',\
- __pbuf, ##args); \
+ ##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); \
+ blk_add_cgroup_trace_msg((cfqd)->queue, \
+ cfqg_to_blkg(cfqg)->blkcg, fmt, ##args); \
} while (0)

static inline void cfqg_stats_update_io_add(struct cfq_group *cfqg,
diff --git a/include/linux/blk-cgroup.h b/include/linux/blk-cgroup.h
index d176247..b06f107 100644
--- a/include/linux/blk-cgroup.h
+++ b/include/linux/blk-cgroup.h
@@ -334,19 +334,6 @@ static inline struct blkcg *cpd_to_blkcg(struct blkcg_policy_data *cpd)
}

/**
- * 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 blkcg_gq *blkg, char *buf, int buflen)
-{
- return cgroup_path(blkg->blkcg->css.cgroup, buf, buflen);
-}
-
-/**
* blkg_get - get a blkg reference
* @blkg: blkg to get
*
@@ -758,7 +745,6 @@ static inline struct blkcg *bio_blkcg(struct bio *bio) { return NULL; }
static inline struct blkg_policy_data *blkg_to_pd(struct blkcg_gq *blkg,
struct blkcg_policy *pol) { return NULL; }
static inline struct blkcg_gq *pd_to_blkg(struct blkg_policy_data *pd) { return NULL; }
-static inline char *blkg_path(struct blkcg_gq *blkg) { return NULL; }
static inline void blkg_get(struct blkcg_gq *blkg) { }
static inline void blkg_put(struct blkcg_gq *blkg) { }

diff --git a/include/linux/blktrace_api.h b/include/linux/blktrace_api.h
index d2e9085..cbfadd0 100644
--- a/include/linux/blktrace_api.h
+++ b/include/linux/blktrace_api.h
@@ -28,10 +28,12 @@ struct blk_trace {
atomic_t dropped;
};

+struct blkcg;
+
extern int blk_trace_ioctl(struct block_device *, unsigned, char __user *);
extern void blk_trace_shutdown(struct request_queue *);
-extern __printf(2, 3)
-void __trace_note_message(struct blk_trace *, const char *fmt, ...);
+extern __printf(3, 4)
+void __trace_note_message(struct blk_trace *, struct blkcg *blkcg, const char *fmt, ...);

/**
* blk_add_trace_msg - Add a (simple) message to the blktrace stream
@@ -46,12 +48,14 @@ void __trace_note_message(struct blk_trace *, const char *fmt, ...);
* NOTE: Can not use 'static inline' due to presence of var args...
*
**/
-#define blk_add_trace_msg(q, fmt, ...) \
+#define blk_add_cgroup_trace_msg(q, cg, fmt, ...) \
do { \
struct blk_trace *bt = (q)->blk_trace; \
if (unlikely(bt)) \
- __trace_note_message(bt, fmt, ##__VA_ARGS__); \
+ __trace_note_message(bt, cg, fmt, ##__VA_ARGS__);\
} while (0)
+#define blk_add_trace_msg(q, fmt, ...) \
+ blk_add_cgroup_trace_msg(q, NULL, fmt, ##__VA_ARGS__)
#define BLK_TN_MAX_MSG 128

static inline bool blk_trace_note_message_enabled(struct request_queue *q)
diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index 18cbc02..9e135dd 100644
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -154,7 +154,8 @@ static void trace_note_time(struct blk_trace *bt)
local_irq_restore(flags);
}

-void __trace_note_message(struct blk_trace *bt, const char *fmt, ...)
+void __trace_note_message(struct blk_trace *bt, struct blkcg *blkcg,
+ const char *fmt, ...)
{
int n;
va_list args;
@@ -178,7 +179,10 @@ void __trace_note_message(struct blk_trace *bt, const char *fmt, ...)
n = vscnprintf(buf, BLK_TN_MAX_MSG, fmt, args);
va_end(args);

- trace_note(bt, 0, BLK_TN_MESSAGE, buf, n, NULL);
+ if (!(blk_tracer_flags.val & TRACE_BLK_OPT_CGROUP))
+ blkcg = NULL;
+ trace_note(bt, 0, BLK_TN_MESSAGE, buf, n,
+ blkcg ? cgroup_get_node_id(blkcg->css.cgroup) : NULL);
local_irq_restore(flags);
}
EXPORT_SYMBOL_GPL(__trace_note_message);
@@ -375,7 +379,7 @@ static ssize_t blk_msg_write(struct file *filp, const char __user *buffer,
return PTR_ERR(msg);

bt = filp->private_data;
- __trace_note_message(bt, "%s", msg);
+ __trace_note_message(bt, NULL, "%s", msg);
kfree(msg);

return count;
--
2.9.3
\
 
 \ /
  Last update: 2017-06-05 00:16    [W:0.150 / U:0.152 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site