* [PATCH] nvme: Update node paths after adding new path
@ 2018-10-05 15:49 Keith Busch
2018-10-05 18:10 ` Sagi Grimberg
2018-10-08 9:55 ` Christoph Hellwig
0 siblings, 2 replies; 5+ messages in thread
From: Keith Busch @ 2018-10-05 15:49 UTC (permalink / raw)
The nvme namespace paths were being updated only when the current path
was not set or nonoptimized. If a new path comes online that is a better
path for its NUMA node, the multipath selector may continue using the
previously set path on a potentially further node.
This patch re-runs the path assignment after successfully adding a new
optimized path.
Signed-off-by: Keith Busch <keith.busch at intel.com>
---
drivers/nvme/host/multipath.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/drivers/nvme/host/multipath.c b/drivers/nvme/host/multipath.c
index 52987052b7fc..fc3c5c2b3eca 100644
--- a/drivers/nvme/host/multipath.c
+++ b/drivers/nvme/host/multipath.c
@@ -321,6 +321,14 @@ static void nvme_mpath_set_live(struct nvme_ns *ns)
device_add_disk(&head->subsys->dev, head->disk,
nvme_ns_id_attr_groups);
+ if (nvme_path_is_optimized(ns)) {
+ int node, srcu_idx;
+
+ srcu_idx = srcu_read_lock(&head->srcu);
+ for_each_node(node)
+ __nvme_find_path(head, node);
+ srcu_read_unlock(&head->srcu, srcu_idx);
+ }
kblockd_schedule_work(&ns->head->requeue_work);
}
--
2.14.4
^ permalink raw reply related [flat|nested] 5+ messages in thread
* [PATCH] nvme: Update node paths after adding new path
2018-10-05 15:49 [PATCH] nvme: Update node paths after adding new path Keith Busch
@ 2018-10-05 18:10 ` Sagi Grimberg
2018-10-05 18:57 ` Keith Busch
2018-10-08 9:55 ` Christoph Hellwig
1 sibling, 1 reply; 5+ messages in thread
From: Sagi Grimberg @ 2018-10-05 18:10 UTC (permalink / raw)
> The nvme namespace paths were being updated only when the current path
> was not set or nonoptimized. If a new path comes online that is a better
> path for its NUMA node, the multipath selector may continue using the
> previously set path on a potentially further node.
>
> This patch re-runs the path assignment after successfully adding a new
> optimized path.
>
> Signed-off-by: Keith Busch <keith.busch at intel.com>
> ---
> drivers/nvme/host/multipath.c | 8 ++++++++
> 1 file changed, 8 insertions(+)
>
> diff --git a/drivers/nvme/host/multipath.c b/drivers/nvme/host/multipath.c
> index 52987052b7fc..fc3c5c2b3eca 100644
> --- a/drivers/nvme/host/multipath.c
> +++ b/drivers/nvme/host/multipath.c
> @@ -321,6 +321,14 @@ static void nvme_mpath_set_live(struct nvme_ns *ns)
> device_add_disk(&head->subsys->dev, head->disk,
> nvme_ns_id_attr_groups);
>
> + if (nvme_path_is_optimized(ns)) {
> + int node, srcu_idx;
> +
> + srcu_idx = srcu_read_lock(&head->srcu);
> + for_each_node(node)
> + __nvme_find_path(head, node);
> + srcu_read_unlock(&head->srcu, srcu_idx);
> + }
Any reason for interfering with all the numa nodes?
Why not simple call __nvme_find_path(head, ns->ctrl->node_id) ?
^ permalink raw reply [flat|nested] 5+ messages in thread
* [PATCH] nvme: Update node paths after adding new path
2018-10-05 18:10 ` Sagi Grimberg
@ 2018-10-05 18:57 ` Keith Busch
2018-10-05 19:33 ` Sagi Grimberg
0 siblings, 1 reply; 5+ messages in thread
From: Keith Busch @ 2018-10-05 18:57 UTC (permalink / raw)
On Fri, Oct 05, 2018@11:10:59AM -0700, Sagi Grimberg wrote:
>
> > The nvme namespace paths were being updated only when the current path
> > was not set or nonoptimized. If a new path comes online that is a better
> > path for its NUMA node, the multipath selector may continue using the
> > previously set path on a potentially further node.
> >
> > This patch re-runs the path assignment after successfully adding a new
> > optimized path.
> >
> > Signed-off-by: Keith Busch <keith.busch at intel.com>
> > ---
> > drivers/nvme/host/multipath.c | 8 ++++++++
> > 1 file changed, 8 insertions(+)
> >
> > diff --git a/drivers/nvme/host/multipath.c b/drivers/nvme/host/multipath.c
> > index 52987052b7fc..fc3c5c2b3eca 100644
> > --- a/drivers/nvme/host/multipath.c
> > +++ b/drivers/nvme/host/multipath.c
> > @@ -321,6 +321,14 @@ static void nvme_mpath_set_live(struct nvme_ns *ns)
> > device_add_disk(&head->subsys->dev, head->disk,
> > nvme_ns_id_attr_groups);
> > + if (nvme_path_is_optimized(ns)) {
> > + int node, srcu_idx;
> > +
> > + srcu_idx = srcu_read_lock(&head->srcu);
> > + for_each_node(node)
> > + __nvme_find_path(head, node);
> > + srcu_read_unlock(&head->srcu, srcu_idx);
> > + }
>
> Any reason for interfering with all the numa nodes?
>
> Why not simple call __nvme_find_path(head, ns->ctrl->node_id) ?
The new path's local node may be closer to other nodes who's path is
currently set to something else.
Consider the following simplified example of nodes A through D:
----- ----- ----- -----
| A |<-->| B |<-->| C |<-->| D |
----- ----- ----- -----
Let's say we start with a single optimized path that is local to node
"D". That path will initially be the "current_path" for all nodes.
Now attach a new path local to node "A". Updating just node A's
current_path misses updating B away from D, even though A is closer
than D.
^ permalink raw reply [flat|nested] 5+ messages in thread
* [PATCH] nvme: Update node paths after adding new path
2018-10-05 18:57 ` Keith Busch
@ 2018-10-05 19:33 ` Sagi Grimberg
0 siblings, 0 replies; 5+ messages in thread
From: Sagi Grimberg @ 2018-10-05 19:33 UTC (permalink / raw)
>
> The new path's local node may be closer to other nodes who's path is
> currently set to something else.
>
> Consider the following simplified example of nodes A through D:
>
> ----- ----- ----- -----
> | A |<-->| B |<-->| C |<-->| D |
> ----- ----- ----- -----
>
> Let's say we start with a single optimized path that is local to node
> "D". That path will initially be the "current_path" for all nodes.
>
> Now attach a new path local to node "A". Updating just node A's
> current_path misses updating B away from D, even though A is closer
> than D.
>
Git it,
Reviewed-by: Sagi Grimberg <sagi at grimberg.me>
^ permalink raw reply [flat|nested] 5+ messages in thread
* [PATCH] nvme: Update node paths after adding new path
2018-10-05 15:49 [PATCH] nvme: Update node paths after adding new path Keith Busch
2018-10-05 18:10 ` Sagi Grimberg
@ 2018-10-08 9:55 ` Christoph Hellwig
1 sibling, 0 replies; 5+ messages in thread
From: Christoph Hellwig @ 2018-10-08 9:55 UTC (permalink / raw)
Thanks,
applied to nvme-4.20.
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2018-10-08 9:55 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
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2018-10-05 15:49 [PATCH] nvme: Update node paths after adding new path Keith Busch
2018-10-05 18:10 ` Sagi Grimberg
2018-10-05 18:57 ` Keith Busch
2018-10-05 19:33 ` Sagi Grimberg
2018-10-08 9:55 ` Christoph Hellwig
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