Re: [PATCH 06/10] engines/libblkio: Add option libblkio_write_zeroes_on_trim

[Vincent Fu <vincentfu@gmail.com>]

On 11/21/22 13:28, Alberto Faria wrote:
> When set, trim IOs will be submitted as blkioq_write_zeroes() requests
> instead of blkioq_discard() requests.
> 
> Signed-off-by: Alberto Faria <afaria@redhat.com>
> ---
>   HOWTO.rst          |  5 +++++
>   engines/libblkio.c | 20 ++++++++++++++++++--
>   fio.1              |  4 ++++
>   3 files changed, 27 insertions(+), 2 deletions(-)
> 
> diff --git a/HOWTO.rst b/HOWTO.rst
> index b9c7c8df..7155add6 100644
> --- a/HOWTO.rst
> +++ b/HOWTO.rst
> @@ -2879,6 +2879,11 @@ with the caveat that when used on the command line, they must come after the
>   
>   	Submit vectored read and write requests. Default is 0.
>   
> +.. option:: libblkio_write_zeroes_on_trim=bool : [libblkio]

Same comment here as for libblkio_vectored regarding option types.

> +
> +	Submit trims as "write zeroes" requests instead of discard requests.
> +	Default is 0.
> +
>   I/O depth
>   ~~~~~~~~~
>   
> diff --git a/engines/libblkio.c b/engines/libblkio.c
> index dcf701ad..79af3aa7 100644
> --- a/engines/libblkio.c
> +++ b/engines/libblkio.c
> @@ -29,6 +29,7 @@ struct fio_blkio_options {
>   
>   	unsigned int hipri;
>   	unsigned int vectored;
> +	unsigned int write_zeroes_on_trim;
>   };
>   
>   static struct fio_option options[] = {
> @@ -78,6 +79,16 @@ static struct fio_option options[] = {
>   		.category = FIO_OPT_C_ENGINE,
>   		.group	= FIO_OPT_G_LIBBLKIO,
>   	},
> +	{
> +		.name	= "libblkio_write_zeroes_on_trim",
> +		.lname	= "Use blkioq_write_zeroes() for TRIM",
> +		.type	= FIO_OPT_STR_SET,
> +		.off1	= offsetof(struct fio_blkio_options,
> +				   write_zeroes_on_trim),
> +		.help	= "Use blkioq_write_zeroes() for TRIM instead of blkioq_discard()",
> +		.category = FIO_OPT_C_ENGINE,
> +		.group	= FIO_OPT_G_LIBBLKIO,
> +	},
>   
>   	{
>   		.name = NULL,
> @@ -484,8 +495,13 @@ static enum fio_q_status fio_blkio_queue(struct thread_data *td,
>   			break;
>   
>   		case DDIR_TRIM:
> -			blkioq_discard(data->q, io_u->offset, io_u->xfer_buflen,
> -				       io_u, 0);
> +			if (options->write_zeroes_on_trim) {
> +				blkioq_write_zeroes(data->q, io_u->offset,
> +						    io_u->xfer_buflen, io_u, 0);
> +			} else {
> +				blkioq_discard(data->q, io_u->offset,
> +					       io_u->xfer_buflen, io_u, 0);
> +			}
>   		        break;
>   
>   		case DDIR_SYNC:
> diff --git a/fio.1 b/fio.1
> index a403b415..053c2eda 100644
> --- a/fio.1
> +++ b/fio.1
> @@ -2626,6 +2626,10 @@ Use poll queues.
>   .TP
>   .BI (libblkio)libblkio_vectored \fR=\fPbool
>   Submit vectored read and write requests. Default is 0.
> +.TP
> +.BI (libblkio)libblkio_write_zeroes_on_trim \fR=\fPbool
> +Submit trims as "write zeroes" requests instead of discard requests. Default is
> +0.
>   .SS "I/O depth"
>   .TP
>   .BI iodepth \fR=\fPint