On Mon, Oct 24, 2016 at 11:47:35PM -0500, Michael Roth wrote: > Commit 0a417869: > > spapr: Move memory hotplug to RTAS_LOG_V6_HP_ID_DRC_COUNT type > > dropped per-DRC/per-LMB hotplugs event in favor of a bulk add via a > single LMB count value. This was to avoid overrunning the guest EPOW > event queue with hotplug events. This works fine, but relies on the > guest exhaustively scanning for pluggable LMBs to satisfy the > requested count by issuing rtas-get-sensor(DR_ENTITY_SENSE, ...) calls > until all the LMBs associated with the DIMM are identified. > > With newer support for dedicated hotplug event source, this queue > exhaustion is no longer as much of an issue due to implementation > details on the guest side, but we still try to avoid excessive hotplug > events by now supporting both a count and a starting index to avoid > unecessary work. This patch makes use of that approach when the > capability is available. > > Cc: bhar...@linux.vnet.ibm.com > Signed-off-by: Michael Roth <mdr...@linux.vnet.ibm.com>
Reviewed-by: David Gibson <da...@gibson.dropbear.id.au>
> ---
> hw/ppc/spapr.c | 22 ++++++++++++++++++----
> 1 file changed, 18 insertions(+), 4 deletions(-)
>
> diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
> index dc4224b..0b3aa2f 100644
> --- a/hw/ppc/spapr.c
> +++ b/hw/ppc/spapr.c
> @@ -2202,14 +2202,16 @@ static void spapr_nmi(NMIState *n, int cpu_index,
> Error **errp)
> }
> }
>
> -static void spapr_add_lmbs(DeviceState *dev, uint64_t addr, uint64_t size,
> - uint32_t node, Error **errp)
> +static void spapr_add_lmbs(DeviceState *dev, uint64_t addr_start, uint64_t
> size,
> + uint32_t node, bool dedicated_hp_event_source,
> + Error **errp)
> {
> sPAPRDRConnector *drc;
> sPAPRDRConnectorClass *drck;
> uint32_t nr_lmbs = size/SPAPR_MEMORY_BLOCK_SIZE;
> int i, fdt_offset, fdt_size;
> void *fdt;
> + uint64_t addr = addr_start;
>
> for (i = 0; i < nr_lmbs; i++) {
> drc = spapr_dr_connector_by_id(SPAPR_DR_CONNECTOR_TYPE_LMB,
> @@ -2228,7 +2230,17 @@ static void spapr_add_lmbs(DeviceState *dev, uint64_t
> addr, uint64_t size,
> * guest only in case of hotplugged memory
> */
> if (dev->hotplugged) {
> - spapr_hotplug_req_add_by_count(SPAPR_DR_CONNECTOR_TYPE_LMB, nr_lmbs);
> + if (dedicated_hp_event_source) {
> + drc = spapr_dr_connector_by_id(SPAPR_DR_CONNECTOR_TYPE_LMB,
> + addr_start / SPAPR_MEMORY_BLOCK_SIZE);
> + drck = SPAPR_DR_CONNECTOR_GET_CLASS(drc);
> +
> spapr_hotplug_req_add_by_count_indexed(SPAPR_DR_CONNECTOR_TYPE_LMB,
> + nr_lmbs,
> + drck->get_index(drc));
> + } else {
> + spapr_hotplug_req_add_by_count(SPAPR_DR_CONNECTOR_TYPE_LMB,
> + nr_lmbs);
> + }
> }
> }
>
> @@ -2261,7 +2273,9 @@ static void spapr_memory_plug(HotplugHandler
> *hotplug_dev, DeviceState *dev,
> goto out;
> }
>
> - spapr_add_lmbs(dev, addr, size, node, &error_abort);
> + spapr_add_lmbs(dev, addr, size, node,
> + spapr_ovec_test(ms->ov5_cas, OV5_HP_EVT),
> + &error_abort);
>
> out:
> error_propagate(errp, local_err);
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
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