Re: [PATCH v2] opensm: Modify connect_roots to allow connectivity between all switches

[Yevgeny Kliteynik <kliteyn-LDSdmyG8hGV8YrgS2mwiifqBs+8SCbDb@public.gmane.org>]

Eli,

On 13-Jun-10 6:10 PM, Eli Dorfman (Voltaire) wrote:
> After a second thought and in order not to break current configuration,
> I send this modified patch that does not change connect_roots option but
> changes its functionality in up-down (I think that in fat-tree it is already implemented)
>
> Modify connect_roots option to allow connectivity between
> all switches in up-down routing algorithm and in this way be
> fully IBA compliant
>
> Signed-off-by: Eli Dorfman<elid-smomgflXvOZWk0Htik3J/w@public.gmane.org>
> ---
>   opensm/man/opensm.8.in         |    2 +-
>   opensm/opensm/main.c           |    2 +-
>   opensm/opensm/osm_ucast_updn.c |    4 +---
>   3 files changed, 3 insertions(+), 5 deletions(-)
>
> diff --git a/opensm/man/opensm.8.in b/opensm/man/opensm.8.in
> index 9053611..c67126e 100644
> --- a/opensm/man/opensm.8.in
> +++ b/opensm/man/opensm.8.in
> @@ -174,7 +174,7 @@ the host comes back online.
>   .TP
>   \fB\-z\fR, \fB\-\-connect_roots\fR
>   This option enforces routing engines (up/down and
> -fat-tree) to make connectivity between root switches and in
> +fat-tree) to make connectivity between all switches and in
>   this way to be fully IBA complaint. In many cases this can
>   violate "pure" deadlock free algorithm, so use it carefully.
>   .TP
> diff --git a/opensm/opensm/main.c b/opensm/opensm/main.c
> index 0093aa7..82ca78f 100644
> --- a/opensm/opensm/main.c
> +++ b/opensm/opensm/main.c
> @@ -187,7 +187,7 @@ static void show_usage(void)
>   	       "          Sets the SL to use to communicate with the SM/SA. Defaults to 0.\n\n");
>   	printf("--connect_roots, -z\n"
>   	       "          This option enforces routing engines (up/down and \n"
> -	       "          fat-tree) to make connectivity between root switches\n"
> +	       "          fat-tree) to make connectivity between all switches\n"
>   	       "          and in this way be IBA compliant. In many cases,\n"
>   	       "          this can violate \"pure\" deadlock free algorithm, so\n"
>   	       "          use it carefully.\n\n");
> diff --git a/opensm/opensm/osm_ucast_updn.c b/opensm/opensm/osm_ucast_updn.c
> index 164c6f4..f44ca24 100644
> --- a/opensm/opensm/osm_ucast_updn.c
> +++ b/opensm/opensm/osm_ucast_updn.c
> @@ -314,9 +314,7 @@ static int updn_set_min_hop_table(IN updn_t * p_updn)
>   	     item = cl_qmap_next(item)) {
>   		p_sw = (osm_switch_t *)item;
>   		/* Clear Min Hop Table */
> -		if (p_subn->opt.connect_roots)
> -			updn_clear_non_root_hops(p_updn, p_sw);
> -		else
> +		if (!p_subn->opt.connect_roots)
>   			osm_switch_clear_hops(p_sw);
>   	}
>

What kind of testing was done for this?
I have a strong feeling that it will break up/down.
If the connect_roots option is on, you will not clear
the lid matrix at all, and it will contain also the
down/up routes.

-- Yevgeny
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