Commit-ID: fdb372ed4cadbfe9dbba0e932a77d0523682e690
Gitweb: http://git.kernel.org/tip/fdb372ed4cadbfe9dbba0e932a77d0523682e690
Author: Li Zefan <lizf@xxxxxxxxxxxxxx>
AuthorDate: Tue, 8 Dec 2009 11:15:59 +0800
Committer: Frederic Weisbecker <fweisbec@xxxxxxxxx>
CommitDate: Sun, 13 Dec 2009 18:37:27 +0100
tracing: Use seq file for trace_options
Code simplification for reading trace_options.
Signed-off-by: Li Zefan <lizf@xxxxxxxxxxxxxx>
Acked-by: Steven Rostedt <rostedt@xxxxxxxxxxx>
LKML-reference: <4B1DC4EF.3090106@xxxxxxxxxxxxxx>
Signed-off-by: Frederic Weisbecker <fweisbec@xxxxxxxxx>
---
kernel/trace/trace.c | 60 ++++++++++++++-----------------------------------
1 files changed, 17 insertions(+), 43 deletions(-)
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 88bd9ae..a6c41cc 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -2316,67 +2316,32 @@ static const struct file_operations tracing_cpumask_fops = {
.write = tracing_cpumask_write,
};
-static ssize_t
-tracing_trace_options_read(struct file *filp, char __user *ubuf,
- size_t cnt, loff_t *ppos)
+static int tracing_trace_options_show(struct seq_file *m, void *v)
{
struct tracer_opt *trace_opts;
u32 tracer_flags;
- int len = 0;
- char *buf;
- int r = 0;
int i;
-
- /* calculate max size */
- for (i = 0; trace_options[i]; i++) {
- len += strlen(trace_options[i]);
- len += 3; /* "no" and newline */
- }
-
mutex_lock(&trace_types_lock);
tracer_flags = current_trace->flags->val;
trace_opts = current_trace->flags->opts;
- /*
- * Increase the size with names of options specific
- * of the current tracer.
- */
- for (i = 0; trace_opts[i].name; i++) {
- len += strlen(trace_opts[i].name);
- len += 3; /* "no" and newline */
- }
-
- /* +1 for \0 */
- buf = kmalloc(len + 1, GFP_KERNEL);
- if (!buf) {
- mutex_unlock(&trace_types_lock);
- return -ENOMEM;
- }
-
for (i = 0; trace_options[i]; i++) {
if (trace_flags & (1 << i))
- r += sprintf(buf + r, "%s\n", trace_options[i]);
+ seq_printf(m, "%s\n", trace_options[i]);
else
- r += sprintf(buf + r, "no%s\n", trace_options[i]);
+ seq_printf(m, "no%s\n", trace_options[i]);
}
for (i = 0; trace_opts[i].name; i++) {
if (tracer_flags & trace_opts[i].bit)
- r += sprintf(buf + r, "%s\n",
- trace_opts[i].name);
+ seq_printf(m, "%s\n", trace_opts[i].name);
else
- r += sprintf(buf + r, "no%s\n",
- trace_opts[i].name);
+ seq_printf(m, "no%s\n", trace_opts[i].name);
}
mutex_unlock(&trace_types_lock);
- WARN_ON(r >= len + 1);
-
- r = simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
-
- kfree(buf);
- return r;
+ return 0;
}
/* Try to assign a tracer specific option */
@@ -2471,9 +2436,18 @@ tracing_trace_options_write(struct file *filp, const char __user *ubuf,
return cnt;
}
+static int tracing_trace_options_open(struct inode *inode, struct file *file)
+{
+ if (tracing_disabled)
+ return -ENODEV;
+ return single_open(file, tracing_trace_options_show, NULL);
+}
+
static const struct file_operations tracing_iter_fops = {
- .open = tracing_open_generic,
- .read = tracing_trace_options_read,
+ .open = tracing_trace_options_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = single_release,
.write = tracing_trace_options_write,
};
--
To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
|