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authorShaohua Li <shli@fb.com>2017-07-12 11:49:56 -0700
committerJens Axboe <axboe@kernel.dk>2017-07-29 09:00:03 -0600
commit35fe6d763229e8fc0eb5f9b93a401673cfcb5e1e (patch)
treeea38b526a62121671ef7bfff76f7d23e29804b42 /kernel
parent69fd5c391763bd94a40dd152bc72a7f230137150 (diff)
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block: use standard blktrace API to output cgroup info for debug notes
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> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/trace/blktrace.c12
1 files changed, 10 insertions, 2 deletions
diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index e90974ed4532..7724de18d2fe 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 +179,14 @@ void __trace_note_message(struct blk_trace *bt, const char *fmt, ...)
n = vscnprintf(buf, BLK_TN_MAX_MSG, fmt, args);
va_end(args);
+ if (!(blk_tracer_flags.val & TRACE_BLK_OPT_CGROUP))
+ blkcg = NULL;
+#ifdef CONFIG_BLK_CGROUP
+ trace_note(bt, 0, BLK_TN_MESSAGE, buf, n,
+ blkcg ? cgroup_get_kernfs_id(blkcg->css.cgroup) : NULL);
+#else
trace_note(bt, 0, BLK_TN_MESSAGE, buf, n, NULL);
+#endif
local_irq_restore(flags);
}
EXPORT_SYMBOL_GPL(__trace_note_message);
@@ -375,7 +383,7 @@ 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;