Commit 1c849b48 authored by Stefan Roesch's avatar Stefan Roesch Committed by Jens Axboe
Browse files

io_uring: Add tracepoint for short writes 



This adds the io_uring_short_write tracepoint to io_uring. A short write
is issued if not all pages that are required for a write are in the page
cache and the async buffered writes have to return EAGAIN.

Signed-off-by: default avatarStefan Roesch <shr@fb.com>
Link: https://lore.kernel.org/r/20220616212221.2024518-13-shr@fb.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent e053aaf4

include/trace/events/io_uring.h

+25 −0
Original line number Diff line number Diff line
@@ -630,6 +630,31 @@ TRACE_EVENT(io_uring_task_work_run, 
		 __entry->tctx, __entry->count, __entry->loops)

);



TRACE_EVENT(io_uring_short_write,



	TP_PROTO(void *ctx, u64 fpos, u64 wanted, u64 got),



	TP_ARGS(ctx, fpos, wanted, got),



	TP_STRUCT__entry(

		__field(void *,	ctx)

		__field(u64,	fpos)

		__field(u64,	wanted)

		__field(u64,	got)

	),



	TP_fast_assign(

		__entry->ctx	= ctx;

		__entry->fpos	= fpos;

		__entry->wanted	= wanted;

		__entry->got	= got;

	),



	TP_printk("ring %p, fpos %lld, wanted %lld, got %lld",

			  __entry->ctx, __entry->fpos,

			  __entry->wanted, __entry->got)

);



#endif /* _TRACE_IO_URING_H */



/* This part must be outside protection */

io_uring/rw.c

+3 −0
Original line number Diff line number Diff line
@@ -933,6 +933,9 @@ int io_write(struct io_kiocb *req, unsigned int issue_flags) 
		if (ret2 != req->cqe.res && ret2 >= 0 && need_complete_io(req)) {

			struct io_async_rw *rw;



			trace_io_uring_short_write(req->ctx, kiocb->ki_pos - ret2,

						req->cqe.res, ret2);



			/* This is a partial write. The file pos has already been

			 * updated, setup the async struct to complete the request

			 * in the worker. Also update bytes_done to account for