On Fri, Jul 21, 2023 at 08:05:09PM +0900, Damien Le Moal wrote:
> Introduce the new option cmdprio_hint to allow specifying I/O priority
> hints per IO with the io_uring and libaio IO engines. A third acceptable
> format for the cmdprio_bssplit option is also introduced to allow
> specifying an I/O hint in addition to a priority class and level.
>
> Signed-off-by: Damien Le Moal <dlemoal@xxxxxxxxxx>
> ---
> HOWTO.rst | 28 ++++++++++++++++++++++++----
> engines/cmdprio.c | 9 ++++++---
> engines/cmdprio.h | 22 ++++++++++++++++++++++
> engines/io_uring.c | 4 ++--
> fio.1 | 27 +++++++++++++++++++++++----
> options.c | 13 ++++++++++---
> 6 files changed, 87 insertions(+), 16 deletions(-)
>
> diff --git a/HOWTO.rst b/HOWTO.rst
> index d1a476e4..ac8314f3 100644
> --- a/HOWTO.rst
> +++ b/HOWTO.rst
> @@ -2287,6 +2287,16 @@ with the caveat that when used on the command line, they must come after the
> reads and writes. See :manpage:`ionice(1)`. See also the
> :option:`prioclass` option.
>
> +.. option:: cmdprio_hint=int[,int] : [io_uring] [libaio]
> +
> + Set the I/O priority hint to use for I/Os that must be issued with
> + a priority when :option:`cmdprio_percentage` or
> + :option:`cmdprio_bssplit` is set. If not specified when
> + :option:`cmdprio_percentage` or :option:`cmdprio_bssplit` is set,
> + this defaults to 0 (no hint). A single value applies to reads and
> + writes. Comma-separated values may be specified for reads and writes.
> + See also the :option:`priohint` option.
> +
> .. option:: cmdprio=int[,int] : [io_uring] [libaio]
>
> Set the I/O priority value to use for I/Os that must be issued with
> @@ -2313,9 +2323,9 @@ with the caveat that when used on the command line, they must come after the
>
> cmdprio_bssplit=blocksize/percentage:blocksize/percentage
>
> - In this case, each entry will use the priority class and priority
> - level defined by the options :option:`cmdprio_class` and
> - :option:`cmdprio` respectively.
> + In this case, each entry will use the priority class, priority hint
> + and priority level defined by the options :option:`cmdprio_class`,
> + :option:`cmdprio` and :option:`cmdprio_hint` respectively.
>
> The second accepted format for this option is:
>
> @@ -2326,7 +2336,14 @@ with the caveat that when used on the command line, they must come after the
> accepted format does not restrict all entries to have the same priority
> class and priority level.
>
> - For both formats, only the read and write data directions are supported,
> + The third accepted format for this option is:
> +
> + cmdprio_bssplit=blocksize/percentage/class/level/hint:...
> +
> + This is an extension of the second accepted format that allows to also
> + specify a priority hint.
> +
> + For all formats, only the read and write data directions are supported,
> values for trim IOs are ignored. This option is mutually exclusive with
> the :option:`cmdprio_percentage` option.
>
> @@ -3445,6 +3462,9 @@ Threads, processes and job synchronization
> of I/Os so that the device can optimize its internal command scheduling
> according to the latency limits indicated by the user.
>
> + For per-I/O priority hint setting, see the I/O engine specific
> + :option:`cmdprio_hint` option.
> +
> .. option:: cpus_allowed=str
>
> Controls the same options as :option:`cpumask`, but accepts a textual
> diff --git a/engines/cmdprio.c b/engines/cmdprio.c
> index e6ff1fc2..153e3691 100644
> --- a/engines/cmdprio.c
> +++ b/engines/cmdprio.c
> @@ -267,7 +267,8 @@ static int fio_cmdprio_percentage(struct cmdprio *cmdprio, struct io_u *io_u,
> * to be set. If the random percentage value is within the user specified
> * percentage of I/Os that should use a cmdprio priority value (rather than
> * the default priority), then this function updates the io_u with an ioprio
> - * value as defined by the cmdprio/cmdprio_class or cmdprio_bssplit options.
> + * value as defined by the cmdprio/cmdprio_hint/cmdprio_class or
> + * cmdprio_bssplit options.
> *
> * Return true if the io_u ioprio was changed and false otherwise.
> */
> @@ -342,7 +343,8 @@ static int fio_cmdprio_gen_perc(struct thread_data *td, struct cmdprio *cmdprio)
> prio = &cmdprio->perc_entry[ddir];
> prio->perc = options->percentage[ddir];
> prio->prio = ioprio_value(options->class[ddir],
> - options->level[ddir], 0);
> + options->level[ddir],
> + options->hint[ddir]);
> assign_clat_prio_index(prio, &values[ddir]);
>
> ret = init_ts_clat_prio(ts, ddir, &values[ddir]);
> @@ -400,7 +402,8 @@ static int fio_cmdprio_parse_and_gen_bssplit(struct thread_data *td,
> goto err;
>
> implicit_cmdprio = ioprio_value(options->class[ddir],
> - options->level[ddir], 0);
> + options->level[ddir],
> + options->hint[ddir]);
>
> ret = fio_cmdprio_generate_bsprio_desc(&cmdprio->bsprio_desc[ddir],
> &parse_res[ddir],
> diff --git a/engines/cmdprio.h b/engines/cmdprio.h
> index 2c9d87bc..81e6c390 100644
> --- a/engines/cmdprio.h
> +++ b/engines/cmdprio.h
> @@ -40,6 +40,7 @@ struct cmdprio_options {
> unsigned int percentage[CMDPRIO_RWDIR_CNT];
> unsigned int class[CMDPRIO_RWDIR_CNT];
> unsigned int level[CMDPRIO_RWDIR_CNT];
> + unsigned int hint[CMDPRIO_RWDIR_CNT];
> char *bssplit_str;
> };
>
> @@ -74,6 +75,21 @@ struct cmdprio_options {
> .category = FIO_OPT_C_ENGINE, \
> .group = opt_group, \
> }, \
> + { \
> + .name = "cmdprio_hint", \
> + .lname = "Asynchronous I/O priority hint", \
> + .type = FIO_OPT_INT, \
> + .off1 = offsetof(opt_struct, \
> + cmdprio_options.hint[DDIR_READ]), \
> + .off2 = offsetof(opt_struct, \
> + cmdprio_options.hint[DDIR_WRITE]), \
> + .help = "Set asynchronous IO priority hint", \
> + .minval = IOPRIO_MIN_PRIO_HINT, \
> + .maxval = IOPRIO_MAX_PRIO_HINT, \
> + .interval = 1, \
> + .category = FIO_OPT_C_ENGINE, \
> + .group = opt_group, \
> + }, \
> { \
> .name = "cmdprio", \
> .lname = "Asynchronous I/O priority level", \
> @@ -112,6 +128,12 @@ struct cmdprio_options {
> .type = FIO_OPT_UNSUPPORTED, \
> .help = "Platform does not support I/O priority classes", \
> }, \
> + { \
> + .name = "cmdprio_hint", \
> + .lname = "Asynchronous I/O priority hint", \
> + .type = FIO_OPT_UNSUPPORTED, \
> + .help = "Platform does not support I/O priority classes", \
> + }, \
> { \
> .name = "cmdprio", \
> .lname = "Asynchronous I/O priority level", \
> diff --git a/engines/io_uring.c b/engines/io_uring.c
> index 5613c4c6..e1abf688 100644
> --- a/engines/io_uring.c
> +++ b/engines/io_uring.c
> @@ -285,8 +285,8 @@ static int fio_ioring_prep(struct thread_data *td, struct io_u *io_u)
> /*
> * Since io_uring can have a submission context (sqthread_poll)
> * that is different from the process context, we cannot rely on
> - * the IO priority set by ioprio_set() (option prio/prioclass)
> - * to be inherited.
> + * the IO priority set by ioprio_set() (options prio, prioclass,
> + * and priohint) to be inherited.
> * td->ioprio will have the value of the "default prio", so set
> * this unconditionally. This value might get overridden by
> * fio_ioring_cmdprio_prep() if the option cmdprio_percentage or
> diff --git a/fio.1 b/fio.1
> index e2a36327..f62617e7 100644
> --- a/fio.1
> +++ b/fio.1
> @@ -2084,6 +2084,14 @@ is set, this defaults to the highest priority class. A single value applies
> to reads and writes. Comma-separated values may be specified for reads and
> writes. See man \fBionice\fR\|(1). See also the \fBprioclass\fR option.
> .TP
> +.BI (io_uring,libaio)cmdprio_hint \fR=\fPint[,int]
> +Set the I/O priority hint to use for I/Os that must be issued with a
> +priority when \fBcmdprio_percentage\fR or \fBcmdprio_bssplit\fR is set.
> +If not specified when \fBcmdprio_percentage\fR or \fBcmdprio_bssplit\fR
> +is set, this defaults to 0 (no hint). A single value applies to reads and
> +writes. Comma-separated values may be specified for reads and writes.
> +See also the \fBpriohint\fR option.
> +.TP
> .BI (io_uring,libaio)cmdprio \fR=\fPint[,int]
> Set the I/O priority value to use for I/Os that must be issued with a
> priority when \fBcmdprio_percentage\fR or \fBcmdprio_bssplit\fR is set.
> @@ -2109,8 +2117,9 @@ The first accepted format for this option is the same as the format of the
> cmdprio_bssplit=blocksize/percentage:blocksize/percentage
> .RE
> .P
> -In this case, each entry will use the priority class and priority level defined
> -by the options \fBcmdprio_class\fR and \fBcmdprio\fR respectively.
> +In this case, each entry will use the priority class, priority hint and
> +priority level defined by the options \fBcmdprio_class\fR, \fBcmdprio\fR
> +and \fBcmdprio_hint\fR respectively.
> .P
> The second accepted format for this option is:
> .RS
> @@ -2123,7 +2132,16 @@ entry. In comparison with the first accepted format, the second accepted format
> does not restrict all entries to have the same priority class and priority
> level.
> .P
> -For both formats, only the read and write data directions are supported, values
> +The third accepted format for this option is:
> +.RS
> +.P
> +cmdprio_bssplit=blocksize/percentage/class/level/hint:...
> +.RE
> +.P
> +This is an extension of the second accepted format that allows to also
> +specify a priority hint.
> +.P
> +For all formats, only the read and write data directions are supported, values
> for trim IOs are ignored. This option is mutually exclusive with the
> \fBcmdprio_percentage\fR option.
> .RE
> @@ -3150,7 +3168,8 @@ I/O priority classes and to devices with features controlled through priority
> hints, e.g. block devices supporting command duration limits, or CDL. CDL is a
> way to indicate the desired maximum latency of I/Os so that the device can
> optimize its internal command scheduling according to the latency limits
> -indicated by the user.
> +indicated by the user. For per-I/O priority hint setting, see the I/O engine
> +specific \fBcmdprio_hint\fB option.
> .TP
> .BI cpus_allowed \fR=\fPstr
> Controls the same options as \fBcpumask\fR, but accepts a textual
> diff --git a/options.c b/options.c
> index 56672960..48aa0d7b 100644
> --- a/options.c
> +++ b/options.c
> @@ -313,15 +313,17 @@ static int parse_cmdprio_bssplit_entry(struct thread_options *o,
> int matches = 0;
> char *bs_str = NULL;
> long long bs_val;
> - unsigned int perc = 0, class, level;
> + unsigned int perc = 0, class, level, hint;
>
> /*
> * valid entry formats:
> * bs/ - %s/ - set perc to 0, prio to -1.
> * bs/perc - %s/%u - set prio to -1.
> * bs/perc/class/level - %s/%u/%u/%u
> + * bs/perc/class/level/hint - %s/%u/%u/%u/%u
> */
> - matches = sscanf(str, "%m[^/]/%u/%u/%u", &bs_str, &perc, &class, &level);
> + matches = sscanf(str, "%m[^/]/%u/%u/%u/%u",
> + &bs_str, &perc, &class, &level, &hint);
> if (matches < 1) {
> log_err("fio: invalid cmdprio_bssplit format\n");
> return 1;
> @@ -342,9 +344,14 @@ static int parse_cmdprio_bssplit_entry(struct thread_options *o,
> case 2: /* bs/perc case */
> break;
> case 4: /* bs/perc/class/level case */
> + case 5: /* bs/perc/class/level/hint case */
> class = min(class, (unsigned int) IOPRIO_MAX_PRIO_CLASS);
> level = min(level, (unsigned int) IOPRIO_MAX_PRIO);
> - entry->prio = ioprio_value(class, level, 0);
> + if (matches == 5)
> + hint = min(hint, (unsigned int) IOPRIO_MAX_PRIO_HINT);
> + else
> + hint = 0;
> + entry->prio = ioprio_value(class, level, hint);
> break;
> default:
> log_err("fio: invalid cmdprio_bssplit format\n");
> --
> 2.41.0
>
Reviewed-by: Niklas Cassel <niklas.cassel@xxxxxxx>
