Re: [PATCH] blktrace: Add 'P' identifier to mark I/O with REQ_POLLED flag

[Chao Yu]

On 2024/8/23 15:25, Yongpeng Yang wrote:

blk_fill_rwbs function currently does not recognize REQ_POLLED I/O,
it's not convenient to trace the I/O handling process on the
HCTX_TYPE_POLL type hardware queue. Add a 'P' identifier to 'rwbs'
to mark such I/O for tracing.

Signed-off-by: Yongpeng Yang <yangyongpe...@oppo.com>
---
  kernel/trace/blktrace.c | 2 ++
  1 file changed, 2 insertions(+)

diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index 8fd292d34d89..69b7857d0189 100644
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -1908,6 +1908,8 @@ void blk_fill_rwbs(char *rwbs, blk_opf_t opf)
                rwbs[i++] = 'S';
        if (opf & REQ_META)
                rwbs[i++] = 'M';
+       if (opf & REQ_POLLED)
+               rwbs[i++] = 'P';

DECLARE_EVENT_CLASS(bio,
        TP_PROTO(struct bio *bio),
        TP_ARGS(bio),

        TP_STRUCT__entry(
                __field(dev_t,          dev                     )
                __field(sector_t,       sector                  )
                __field(unsigned int,   nr_sector               )
                __array(char,           rwbs,   6               )
        ),

Not sure, maybe we need to expand one more byte for rwbs array, if
REQ_POLLED flag can be Ored w/ other flags.

Thanks,

rwbs[i] = '\0';

  }