Re: [PATCH v21 26/30] splice: Convert trace/seq to use copy_splice_read()

Steven Rostedt
2023-05-23T14:27:39Z

On Sat, 20 May 2023 01:00:45 +0100
David Howells <dhowells@redhat.com> wrote:

> For the splice from the trace seq buffer, just use copy_splice_read().
>
> In the future, something better can probably be done by gifting pages from
> seq->buf into the pipe, but that would require changing seq->buf into a
> vmap over an array of pages.
>
> Signed-off-by: David Howells <dhowells@redhat.com>
> cc: Christoph Hellwig <hch@lst.de>
> cc: Al Viro <viro@zeniv.linux.org.uk>
> cc: Jens Axboe <axboe@kernel.dk>
> cc: Steven Rostedt <rostedt@goodmis.org>
> cc: Masami Hiramatsu <mhiramat@kernel.org>
> cc: linux-kernel@vger.kernel.org
> cc: linux-trace-kernel@vger.kernel.org
> cc: linux-fsdevel@vger.kernel.org
> cc: linux-block@vger.kernel.org
> cc: linux-mm@kvack.org
> ---
> kernel/trace/trace.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
> index ebc59781456a..c210d02fac97 100644
> --- a/kernel/trace/trace.c
> +++ b/kernel/trace/trace.c
> @@ -5171,7 +5171,7 @@ static const struct file_operations tracing_fops = {
> .open = tracing_open,
> .read = seq_read,
> .read_iter = seq_read_iter,
> - .splice_read = generic_file_splice_read,
> + .splice_read = copy_splice_read,

Anyway, for this change:

Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>

-- Steve

> .write = tracing_write_stub,
> .llseek = tracing_lseek,
> .release = tracing_release,