[ofa-general] Re: [PATCH] opensm: preserve base lid routes
Hal Rosenstock
hrosenstock at xsigo.com
Tue Jun 17 07:51:54 PDT 2008
Al,
On Mon, 2008-06-16 at 10:56 -0700, Al Chu wrote:
> Hey Sasha,
>
> patch series seems to perform well. As a reminder mvapich 0.9.9 does
> not how to deal with multiple lids, openMPI 1.2.6 does. The "preserve
> lids" condition is labeled "PL".
>
> With LMC > 0, the preserve lids seems to do its job under mvapich 0.9.9,
> and atleast maintains (sometimes increases) performance of openmpi 1.2.6
> with LMC > 0. Numbers are attached.
Maybe I'm not reading this right but here's what I see:
Other than the average bandwidth numbers at the top which show PL > non
PL, the ones in the table seem to be the other way around. Do those
numbers indicate bandwidth ?
Also, you mentioned that mvapich doesn't know how to deal with LMC yet
the numbers seem to go up as LMC does.
-- Hal
> I'd give my thumbs up to the patch. Lets commit it.
>
> Al
>
> On Tue, 2008-06-10 at 05:59 +0300, Sasha Khapyorsky wrote:
> > Basically this addresses the problem described by Al Chu in:
> >
> > http://lists.openfabrics.org/pipermail/general/2008-April/049132.html
> >
> > When base lid paths become completely disbalanced on a fabrics with
> > lmc > 0.
> >
> > One feedback was from Yiftah Shahar:
> >
> > "I think that our requirements should be that even when you are working
> > with LMC>0 then the base LID routing should not be affected.
> > One way to achieve this goal is to first run the base-LID routing (so
> > all base LID improvement will be also in LMC>0) and then start with the
> > other LIDs as round-robbing starting from the base-lid-port + 1
> > according current routing algorithm rules (keeping min-hop, up/down...)."
> >
> > We had some discussion with Al and Yiftah about this and considered that
> > in addition to "pure" base lid paths preservation (which is good thing by
> > itself) proposed method solves original lid disbalancing problem as well.
> >
> > This patch is implementation of the idea above.
> >
> > Signed-off-by: Sasha Khapyorsky <sashak at voltaire.com>
> > ---
> > opensm/include/opensm/osm_switch.h | 4 +
> > opensm/opensm/osm_dump.c | 3 +-
> > opensm/opensm/osm_switch.c | 8 ++-
> > opensm/opensm/osm_ucast_mgr.c | 163 ++++++++++++++++--------------------
> > 4 files changed, 86 insertions(+), 92 deletions(-)
> >
> > diff --git a/opensm/include/opensm/osm_switch.h b/opensm/include/opensm/osm_switch.h
> > index 0e9c5fa..c1521a6 100644
> > --- a/opensm/include/opensm/osm_switch.h
> > +++ b/opensm/include/opensm/osm_switch.h
> > @@ -981,6 +981,7 @@ uint8_t
> > osm_switch_recommend_path(IN const osm_switch_t * const p_sw,
> > IN osm_port_t * p_port,
> > IN const uint16_t lid_ho,
> > + IN unsigned start_from,
> > IN const boolean_t ignore_existing,
> > IN const boolean_t dor);
> > /*
> > @@ -995,6 +996,9 @@ osm_switch_recommend_path(IN const osm_switch_t * const p_sw,
> > * lid_ho
> > * [in] LID value (host order) for which to get a path advisory.
> > *
> > +* start_from
> > +* [in] Port number from where to start balance counting.
> > +*
> > * ignore_existing
> > * [in] Set to cause the switch to choose the optimal route
> > * regardless of existing paths.
> > diff --git a/opensm/opensm/osm_dump.c b/opensm/opensm/osm_dump.c
> > index b96984b..60c6d25 100644
> > --- a/opensm/opensm/osm_dump.c
> > +++ b/opensm/opensm/osm_dump.c
> > @@ -218,7 +218,8 @@ static void dump_ucast_routes(cl_map_item_t *p_map_item, FILE *file, void *cxt)
> > else {
> > /* No LMC Optimization */
> > best_port = osm_switch_recommend_path(p_sw, p_port,
> > - lid_ho, TRUE, dor);
> > + lid_ho, 1, TRUE,
> > + dor);
> > fprintf(file, "No %u hop path possible via port %u!",
> > best_hops, best_port);
> > }
> > diff --git a/opensm/opensm/osm_switch.c b/opensm/opensm/osm_switch.c
> > index 58936e3..a9d13c8 100644
> > --- a/opensm/opensm/osm_switch.c
> > +++ b/opensm/opensm/osm_switch.c
> > @@ -274,6 +274,7 @@ uint8_t
> > osm_switch_recommend_path(IN const osm_switch_t * const p_sw,
> > IN osm_port_t * p_port,
> > IN const uint16_t lid_ho,
> > + IN unsigned start_from,
> > IN const boolean_t ignore_existing,
> > IN const boolean_t dor)
> > {
> > @@ -294,6 +295,7 @@ osm_switch_recommend_path(IN const osm_switch_t * const p_sw,
> > uint8_t port_num;
> > uint8_t num_ports;
> > uint32_t least_paths = 0xFFFFFFFF;
> > + unsigned i;
> > /*
> > The follwing will track the least paths if the
> > route should go through a new system/node
> > @@ -397,8 +399,10 @@ osm_switch_recommend_path(IN const osm_switch_t * const p_sw,
> > */
> >
> > /* port number starts with one and num_ports is 1 + num phys ports */
> > - for (port_num = 1; port_num < num_ports; port_num++) {
> > - if (osm_switch_get_hop_count(p_sw, base_lid, port_num) !=
> > + for (i = start_from; i < start_from + num_ports; i++) {
> > + port_num = i%num_ports;
> > + if (!port_num ||
> > + osm_switch_get_hop_count(p_sw, base_lid, port_num) !=
> > least_hops)
> > continue;
> >
> > diff --git a/opensm/opensm/osm_ucast_mgr.c b/opensm/opensm/osm_ucast_mgr.c
> > index c073037..2aae6d5 100644
> > --- a/opensm/opensm/osm_ucast_mgr.c
> > +++ b/opensm/opensm/osm_ucast_mgr.c
> > @@ -208,7 +208,8 @@ find_and_add_remote_sys(osm_switch_t *sw, uint8_t port,
> > static void
> > __osm_ucast_mgr_process_port(IN osm_ucast_mgr_t * const p_mgr,
> > IN osm_switch_t * const p_sw,
> > - IN osm_port_t * const p_port)
> > + IN osm_port_t * const p_port,
> > + IN unsigned lid_offset)
> > {
> > uint16_t min_lid_ho;
> > uint16_t max_lid_ho;
> > @@ -217,19 +218,14 @@ __osm_ucast_mgr_process_port(IN osm_ucast_mgr_t * const p_mgr,
> > boolean_t is_ignored_by_port_prof;
> > ib_net64_t node_guid;
> > struct osm_routing_engine *p_routing_eng;
> > - /*
> > - The following are temporary structures that will aid
> > - in providing better routing in LMC > 0 situations
> > - */
> > - uint16_t lids_per_port = 1 << p_mgr->p_subn->opt.lmc;
> > - struct osm_remote_node *p_remote_guid_used = NULL;
> > + unsigned start_from = 1;
> >
> > OSM_LOG_ENTER(p_mgr->p_log);
> >
> > osm_port_get_lid_range_ho(p_port, &min_lid_ho, &max_lid_ho);
> >
> > - /* If the lids are zero - then there was some problem with the initialization.
> > - Don't handle this port. */
> > + /* If the lids are zero - then there was some problem with
> > + * the initialization. Don't handle this port. */
> > if (min_lid_ho == 0 || max_lid_ho == 0) {
> > OSM_LOG(p_mgr->p_log, OSM_LOG_ERROR, "ERR 3A04: "
> > "Port 0x%" PRIx64 " has LID 0. An initialization "
> > @@ -238,16 +234,22 @@ __osm_ucast_mgr_process_port(IN osm_ucast_mgr_t * const p_mgr,
> > goto Exit;
> > }
> >
> > - if (osm_log_is_active(p_mgr->p_log, OSM_LOG_DEBUG)) {
> > + lid_ho = min_lid_ho + lid_offset;
> > +
> > + if (lid_ho > max_lid_ho)
> > + goto Exit;
> > +
> > + if (lid_offset)
> > + /* ignore potential overflow - it is handled in osm_switch.c */
> > + start_from = osm_switch_get_port_by_lid(p_sw, lid_ho - 1) + 1;
> > +
> > + if (osm_log_is_active(p_mgr->p_log, OSM_LOG_DEBUG))
> > OSM_LOG(p_mgr->p_log, OSM_LOG_DEBUG,
> > - "Processing port 0x%" PRIx64 ", LIDs [0x%X,0x%X]\n",
> > - cl_ntoh64(osm_port_get_guid(p_port)),
> > + "Processing port 0x%" PRIx64 ", LID %u [0x%X,0x%X]\n",
> > + cl_ntoh64(osm_port_get_guid(p_port)), lid_ho,
> > min_lid_ho, max_lid_ho);
> > - }
> >
> > - /*
> > - TO DO - This should be runtime error, not a CL_ASSERT()
> > - */
> > + /* TODO - This should be runtime error, not a CL_ASSERT() */
> > CL_ASSERT(max_lid_ho < osm_switch_get_fwd_tbl_size(p_sw));
> >
> > node_guid = osm_node_get_node_guid(p_sw->p_node);
> > @@ -260,80 +262,62 @@ __osm_ucast_mgr_process_port(IN osm_ucast_mgr_t * const p_mgr,
> > how best to distribute the LID range across the ports
> > that can reach those LIDs.
> > */
> > - for (lid_ho = min_lid_ho; lid_ho <= max_lid_ho; lid_ho++) {
> > - /* Use the enhanced algorithm only for LMC > 0 */
> > - if (lids_per_port > 1) {
> > - port = osm_switch_recommend_path(p_sw, p_port, lid_ho,
> > - p_mgr->p_subn->
> > - ignore_existing_lfts,
> > - p_mgr->is_dor);
> > - if (port > 0 && port != OSM_NO_PATH && p_port->priv)
> > - p_remote_guid_used =
> > - find_and_add_remote_sys(p_sw, port,
> > - p_port->priv);
> > + port = osm_switch_recommend_path(p_sw, p_port, lid_ho, start_from,
> > + p_mgr->p_subn->ignore_existing_lfts,
> > + p_mgr->is_dor);
> > +
> > + if (port == OSM_NO_PATH) {
> > + /* do not try to overwrite the ppro of non existing port ... */
> > + is_ignored_by_port_prof = TRUE;
> > +
> > + /* Up/Down routing can cause unreachable routes between some
> > + switches so we do not report that as an error in that case */
> > + if (!p_routing_eng->build_lid_matrices) {
> > + OSM_LOG(p_mgr->p_log, OSM_LOG_ERROR, "ERR 3A08: "
> > + "No path to get to LID 0x%X from switch 0x%"
> > + PRIx64 "\n", lid_ho, cl_ntoh64(node_guid));
> > + /* trigger a new sweep - try again ... */
> > + p_mgr->p_subn->subnet_initialization_error = TRUE;
> > } else
> > - port = osm_switch_recommend_path(p_sw, p_port, lid_ho,
> > - p_mgr->p_subn->
> > - ignore_existing_lfts,
> > - p_mgr->is_dor);
> > + OSM_LOG(p_mgr->p_log, OSM_LOG_DEBUG,
> > + "No path to get to LID 0x%X from switch 0x%"
> > + PRIx64 "\n", lid_ho, cl_ntoh64(node_guid));
> > + } else {
> > + OSM_LOG(p_mgr->p_log, OSM_LOG_DEBUG,
> > + "Routing LID 0x%X to port 0x%X"
> > + " for switch 0x%" PRIx64 "\n",
> > + lid_ho, port, cl_ntoh64(node_guid));
> >
> > /*
> > - There might be no path to the target
> > + we would like to optionally ignore this port in equalization
> > + as in the case of the Mellanox Anafa Internal PCI TCA port
> > */
> > - if (port == OSM_NO_PATH) {
> > - /* do not try to overwrite the ppro of non existing port ... */
> > - is_ignored_by_port_prof = TRUE;
> > -
> > - /* Up/Down routing can cause unreachable routes between some
> > - switches so we do not report that as an error in that case */
> > - if (!p_routing_eng->build_lid_matrices) {
> > - OSM_LOG(p_mgr->p_log, OSM_LOG_ERROR, "ERR 3A08: "
> > - "No path to get to LID 0x%X from switch 0x%"
> > - PRIx64 "\n", lid_ho,
> > - cl_ntoh64(node_guid));
> > - /* trigger a new sweep - try again ... */
> > - p_mgr->p_subn->subnet_initialization_error =
> > - TRUE;
> > - } else
> > - OSM_LOG(p_mgr->p_log, OSM_LOG_DEBUG,
> > - "No path to get to LID 0x%X from switch 0x%"
> > - PRIx64 "\n", lid_ho,
> > - cl_ntoh64(node_guid));
> > - } else {
> > - OSM_LOG(p_mgr->p_log, OSM_LOG_DEBUG,
> > - "Routing LID 0x%X to port 0x%X"
> > - " for switch 0x%" PRIx64 "\n",
> > - lid_ho, port, cl_ntoh64(node_guid));
> > -
> > - /*
> > - we would like to optionally ignore this port in equalization
> > - as in the case of the Mellanox Anafa Internal PCI TCA port
> > - */
> > - is_ignored_by_port_prof =
> > - osm_port_prof_is_ignored_port(p_mgr->p_subn,
> > - node_guid, port);
> > -
> > - /*
> > - We also would ignore this route if the target lid is of a switch
> > - and the port_profile_switch_node is not TRUE
> > - */
> > - if (!p_mgr->p_subn->opt.port_profile_switch_nodes) {
> > - is_ignored_by_port_prof |=
> > - (osm_node_get_type(p_port->p_node) ==
> > - IB_NODE_TYPE_SWITCH);
> > - }
> > - }
> > + is_ignored_by_port_prof =
> > + osm_port_prof_is_ignored_port(p_mgr->p_subn,
> > + node_guid, port);
> >
> > /*
> > - We have selected the port for this LID.
> > - Write it to the forwarding tables.
> > + We also would ignore this route if the target lid is of
> > + a switch and the port_profile_switch_node is not TRUE
> > */
> > - p_mgr->lft_buf[lid_ho] = port;
> > - if (!is_ignored_by_port_prof) {
> > - osm_switch_count_path(p_sw, port);
> > - if (p_remote_guid_used)
> > - p_remote_guid_used->forwarded_to++;
> > - }
> > + if (!p_mgr->p_subn->opt.port_profile_switch_nodes)
> > + is_ignored_by_port_prof |=
> > + (osm_node_get_type(p_port->p_node) ==
> > + IB_NODE_TYPE_SWITCH);
> > + }
> > +
> > + /*
> > + We have selected the port for this LID.
> > + Write it to the forwarding tables.
> > + */
> > + p_mgr->lft_buf[lid_ho] = port;
> > + if (!is_ignored_by_port_prof) {
> > + struct osm_remote_node *rem_node_used;
> > + osm_switch_count_path(p_sw, port);
> > + if (port > 0 && p_port->priv &&
> > + (rem_node_used = find_and_add_remote_sys(p_sw, port,
> > + p_port->priv)))
> > + rem_node_used->forwarded_to++;
> > }
> >
> > Exit:
> > @@ -512,6 +496,7 @@ __osm_ucast_mgr_process_tbl(IN cl_map_item_t * const p_map_item,
> > osm_node_t *p_node;
> > osm_port_t *p_port;
> > const cl_qmap_t *p_port_tbl;
> > + unsigned i, lids_per_port;
> >
> > OSM_LOG_ENTER(p_mgr->p_log);
> >
> > @@ -538,12 +523,12 @@ __osm_ucast_mgr_process_tbl(IN cl_map_item_t * const p_map_item,
> > Iterate through every port setting LID routes for each
> > port based on base LID and LMC value.
> > */
> > -
> > - for (p_port = (osm_port_t *) cl_qmap_head(p_port_tbl);
> > - p_port != (osm_port_t *) cl_qmap_end(p_port_tbl);
> > - p_port = (osm_port_t *) cl_qmap_next(&p_port->map_item)) {
> > - __osm_ucast_mgr_process_port(p_mgr, p_sw, p_port);
> > - }
> > + lids_per_port = 1 << p_mgr->p_subn->opt.lmc;
> > + for (i = 0; i < lids_per_port; i++)
> > + for (p_port = (osm_port_t *) cl_qmap_head(p_port_tbl);
> > + p_port != (osm_port_t *) cl_qmap_end(p_port_tbl);
> > + p_port = (osm_port_t *) cl_qmap_next(&p_port->map_item))
> > + __osm_ucast_mgr_process_port(p_mgr, p_sw, p_port, i);
> >
> > osm_ucast_mgr_set_fwd_table(p_mgr, p_sw);
> >
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