Re: [PATCH v2 5/8] multipath-tools: clarify path selector descriptions in multipath.conf.5

[Benjamin Marzinski <bmarzins@redhat.com>]

On Tue, Jun 16, 2026 at 02:29:01PM +0200, Xose Vazquez Perez wrote:
> Selectors operate on the next individual I/O request rather
> than a "bunch" of I/O.
> 
> Suggested-by: Benjamin Marzinski <bmarzins@redhat.com>
> Cc: Martin Wilck <mwilck@suse.com>
> Cc: Benjamin Marzinski <bmarzins@redhat.com>
> Cc: Christophe Varoqui <christophe.varoqui@opensvc.com>
> Cc: DM_DEVEL-ML <dm-devel@lists.linux.dev>
> Signed-off-by: Xose Vazquez Perez <xose.vazquez@gmail.com>
> ---
> v2: fix typo, s/group/groups (spotted by Martin)
> 
>  multipath/multipath.conf.5.in | 12 +++++-------
>  1 file changed, 5 insertions(+), 7 deletions(-)
> 
> diff --git a/multipath/multipath.conf.5.in b/multipath/multipath.conf.5.in
> index 422ab120..5b730801 100644
> --- a/multipath/multipath.conf.5.in
> +++ b/multipath/multipath.conf.5.in
> @@ -2,7 +2,7 @@
>  .\" Update the date below if you make any significant change.
>  .\" ----------------------------------------------------------------------------
>  .
> -.TH MULTIPATH.CONF 5 2026-05-27 Linux
> +.TH MULTIPATH.CONF 5 2026-06-13 Linux
>  .
>  .
>  .\" ----------------------------------------------------------------------------
> @@ -193,20 +193,18 @@ kernel multipath target:
>  .RS
>  .TP
>  .I "round-robin 0"
> -Choose the path for the next bunch of I/O by looping through every path in the
> -path group, sending \fBthe same number of I/O requests\fR to each path.
> -
> +Choose the path for the next I/O request by \fBcycling through the path groups\fR.

This isn't a strong objections, but personally, I'm not sure "groups"
makes this better. It kind of sounds like paths are picked from multiple
path groups. Perhaps:
"cycling through the paths"
or
"cycling through the paths in the path group"

I'm also o.k. with leaving it as you have it.

-Ben

>  .TP
>  .I "queue-length 0"
> -(Since 2.6.31 kernel) Choose the path for the next bunch of I/O based on \fBthe lowest
> +(Since 2.6.31 kernel) Choose the path for the next I/O request based on \fBthe lowest
>  number of outstanding in-flight I/O requests\fR to the path.
>  .TP
>  .I "service-time 0"
> -(Since 2.6.31 kernel) Choose the path for the next bunch of I/O based on \fBthe
> +(Since 2.6.31 kernel) Choose the path for the next I/O request based on \fBthe
>  lowest total size (in bytes) of outstanding in-flight I/O requests\fR to the path.
>  .TP
>  .I "historical-service-time 0"
> -(Since 5.8 kernel) Choose the path for the next bunch of I/O with \fBa dynamic
> +(Since 5.8 kernel) Choose the path for the next I/O request with \fBa dynamic
>  algorithm based on the historical service time and the number of outstanding
>  in-flight I/O requests\fR to the path.
>  .TP
> -- 
> 2.54.0