On Sun, 10 Dec 2023 22:12:50 -0500 Steven Rostedt <[email protected]> wrote:
> From: "Steven Rostedt (Google)" <[email protected]> > > Reading the ring buffer does a swap of a sub-buffer within the ring buffer > with a empty sub-buffer. This allows the reader to have full access to the > content of the sub-buffer that was swapped out without having to worry > about contention with the writer. > > The readers call ring_buffer_alloc_read_page() to allocate a page that > will be used to swap with the ring buffer. When the code is finished with > the reader page, it calls ring_buffer_free_read_page(). Instead of freeing > the page, it stores it as a spare. Then next call to > ring_buffer_alloc_read_page() will return this spare instead of calling > into the memory management system to allocate a new page. > > Unfortunately, on freeing of the ring buffer, this spare page is not > freed, and causes a memory leak. > Oops, Looks good to me. Acked-by: Masami Hiramatsu (Google) <[email protected]> Thanks, > Cc: [email protected] > Fixes: 73a757e63114d ("ring-buffer: Return reader page back into existing > ring buffer") > Signed-off-by: Steven Rostedt (Google) <[email protected]> > --- > kernel/trace/ring_buffer.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c > index a38e5a3c6803..dd37d21d6e55 100644 > --- a/kernel/trace/ring_buffer.c > +++ b/kernel/trace/ring_buffer.c > @@ -1790,6 +1790,8 @@ static void rb_free_cpu_buffer(struct > ring_buffer_per_cpu *cpu_buffer) > free_buffer_page(bpage); > } > > + free_page((unsigned long)cpu_buffer->free_page); > + > kfree(cpu_buffer); > } > > -- > 2.42.0 > -- Masami Hiramatsu (Google) <[email protected]>
