Re: [Patch v3] block: introduce block_rq_error tracepoint

From: Cong Wang
Date: Tue Feb 18 2020 - 13:41:03 EST

Hi, Jens

On Sun, Feb 2, 2020 at 9:37 PM Cong Wang <xiyou.wangcong@xxxxxxxxx> wrote:
> Currently, rasdaemon uses the existing tracepoint block_rq_complete
> and filters out non-error cases in order to capture block disk errors.
> But there are a few problems with this approach:
> 1. Even kernel trace filter could do the filtering work, there is
> still some overhead after we enable this tracepoint.
> 2. The filter is merely based on errno, which does not align with kernel
> logic to check the errors for print_req_error().
> 3. block_rq_complete only provides dev major and minor to identify
> the block device, it is not convenient to use in user-space.
> So introduce a new tracepoint block_rq_error just for the error case
> and provides the device name for convenience too. With this patch,
> rasdaemon could switch to block_rq_error.
> Cc: Jens Axboe <axboe@xxxxxxxxx>
> Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
> Signed-off-by: Cong Wang <xiyou.wangcong@xxxxxxxxx>

Can you take this patch?