diff options
| author |   Lai Jiangshan <laijs@cn.fujitsu.com> | 2009-04-02 15:16:59 +0800 |
|---|---|---|
| committer |   Ingo Molnar <mingo@elte.hu> | 2009-04-10 12:44:43 +0200 |
| commit | ddd538f3e6a1a4bec2f6942f83a753263e6577b4 (patch) | |
| tree | b28047205b75d7e06ecf3eb0aca08c056ed4f51c /kernel | |
| parent | tracing: disable seeking for trace_pipe_raw (diff) | |
| download | linux-dev-ddd538f3e6a1a4bec2f6942f83a753263e6577b4.tar.xz linux-dev-ddd538f3e6a1a4bec2f6942f83a753263e6577b4.zip | |
tracing: allocate page when needed
Impact: Cleanup
Sometimes, we open trace_pipe_raw, but we don't read(2) it,
we just splice(2) it, thus, the page is not used.
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <srostedt@redhat.com>
LKML-Reference: <49D4666B.4010608@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/trace/trace.c | 16 |
1 files changed, 8 insertions, 8 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 24b0168f1a29..8e189ffb899a 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -3277,19 +3277,13 @@ static int tracing_buffers_open(struct inode *inode, struct file *filp) info->tr = &global_trace; info->cpu = cpu; - info->spare = ring_buffer_alloc_read_page(info->tr->buffer); + info->spare = NULL; /* Force reading ring buffer for first read */ info->read = (unsigned int)-1; - if (!info->spare) - goto out; filp->private_data = info; return nonseekable_open(inode, filp); - - out: - kfree(info); - return -ENOMEM; } static ssize_t @@ -3304,6 +3298,11 @@ tracing_buffers_read(struct file *filp, char __user *ubuf, if (!count) return 0; + if (!info->spare) + info->spare = ring_buffer_alloc_read_page(info->tr->buffer); + if (!info->spare) + return -ENOMEM; + /* Do we have previous read data to read? */ if (info->read < PAGE_SIZE) goto read; @@ -3342,7 +3341,8 @@ static int tracing_buffers_release(struct inode *inode, struct file *file) { struct ftrace_buffer_info *info = file->private_data; - ring_buffer_free_read_page(info->tr->buffer, info->spare); + if (info->spare) + ring_buffer_free_read_page(info->tr->buffer, info->spare); kfree(info); return 0; |