Re: [PATCH net-next 05/16] devlink: Add remote reload stats

From: Jiri Pirko
Date: Sat Oct 03 2020 - 05:05:48 EST

Thu, Oct 01, 2020 at 03:59:08PM CEST, moshe@xxxxxxxxxxxx wrote:
>Add remote reload stats to hold the history of actions performed due
>devlink reload commands initiated by remote host. For example, in case
>firmware activation with reset finished successfully but was initiated
>by remote host.
>
>The function devlink_remote_reload_actions_performed() is exported to
>enable drivers update on remote reload actions performed as it was not
>initiated by their own devlink instance.
>
>Expose devlink remote reload stats to the user through devlink dev get
>command.
>
>Examples:
>$ devlink dev show
>pci/0000:82:00.0:
> stats:
> reload_stats:
> driver_reinit 2
> fw_activate 1
> fw_activate_no_reset 0
> remote_reload_stats:
> driver_reinit 0
> fw_activate 0
> fw_activate_no_reset 0
>pci/0000:82:00.1:
> stats:
> reload_stats:
> driver_reinit 1
> fw_activate 0
> fw_activate_no_reset 0
> remote_reload_stats:
> driver_reinit 1
> fw_activate 1
> fw_activate_no_reset 0
>
>$ devlink dev show -jp
>{
> "dev": {
> "pci/0000:82:00.0": {
> "stats": {
> "reload_stats": [ {
> "driver_reinit": 2
> },{
> "fw_activate": 1
> },{
> "fw_activate_no_reset": 0
> } ],
> "remote_reload_stats": [ {
> "driver_reinit": 0
> },{
> "fw_activate": 0
> },{
> "fw_activate_no_reset": 0
> } ]
> }
> },
> "pci/0000:82:00.1": {
> "stats": {
> "reload_stats": [ {
> "driver_reinit": 1
> },{
> "fw_activate": 0
> },{
> "fw_activate_no_reset": 0
> } ],
> "remote_reload_stats": [ {
> "driver_reinit": 1
> },{
> "fw_activate": 1
> },{
> "fw_activate_no_reset": 0
> } ]
> }
> }
> }
>}
>
>Signed-off-by: Moshe Shemesh <moshe@xxxxxxxxxxxx>
>---
>RFCv5 -> v1:
>- Resplit this patch and the previous one by remote/local reload stats
>instead of set/get reload stats
>- Rename reload_action_stats to reload_stats
>RFCv4 -> RFCv5:
>- Add remote actions stats
>- If devlink reload is not supported, show only remote_stats
>RFCv3 -> RFCv4:
>- Renamed DEVLINK_ATTR_RELOAD_ACTION_CNT to
> DEVLINK_ATTR_RELOAD_ACTION_STAT
>- Add stats per action per limit level
>RFCv2 -> RFCv3:
>- Add reload actions counters instead of supported reload actions
> (reload actions counters are only for supported action so no need for
> both)
>RFCv1 -> RFCv2:
>- Removed DEVLINK_ATTR_RELOAD_DEFAULT_LEVEL
>- Removed DEVLINK_ATTR_RELOAD_LEVELS_INFO
>- Have actions instead of levels
>---
> include/net/devlink.h | 1 +
> include/uapi/linux/devlink.h | 1 +
> net/core/devlink.c | 49 +++++++++++++++++++++++++++++++-----
> 3 files changed, 45 insertions(+), 6 deletions(-)
>
>diff --git a/include/net/devlink.h b/include/net/devlink.h
>index 0f3bd23b6c04..a4ccb83bbd2c 100644
>--- a/include/net/devlink.h
>+++ b/include/net/devlink.h
>@@ -42,6 +42,7 @@ struct devlink {
> const struct devlink_ops *ops;
> struct xarray snapshot_ids;
> u32 reload_stats[DEVLINK_RELOAD_STATS_ARRAY_SIZE];
>+ u32 remote_reload_stats[DEVLINK_RELOAD_STATS_ARRAY_SIZE];

Perhaps a nested struct {} stats?


> struct device *dev;
> possible_net_t _net;
> struct mutex lock; /* Serializes access to devlink instance specific objects such as
>diff --git a/include/uapi/linux/devlink.h b/include/uapi/linux/devlink.h
>index 97e0137f6201..f9887d8afdc7 100644
>--- a/include/uapi/linux/devlink.h
>+++ b/include/uapi/linux/devlink.h
>@@ -530,6 +530,7 @@ enum devlink_attr {
> DEVLINK_ATTR_RELOAD_STATS, /* nested */
> DEVLINK_ATTR_RELOAD_STATS_ENTRY, /* nested */
> DEVLINK_ATTR_RELOAD_STATS_VALUE, /* u32 */
>+ DEVLINK_ATTR_REMOTE_RELOAD_STATS, /* nested */
>
> /* add new attributes above here, update the policy in devlink.c */
>
>diff --git a/net/core/devlink.c b/net/core/devlink.c
>index 05516f1e4c3e..3b6bd3b4d346 100644
>--- a/net/core/devlink.c
>+++ b/net/core/devlink.c
>@@ -523,28 +523,35 @@ static int devlink_reload_stat_put(struct sk_buff *msg, enum devlink_reload_acti
> return -EMSGSIZE;
> }
>
>-static int devlink_reload_stats_put(struct sk_buff *msg, struct devlink *devlink)
>+static int devlink_reload_stats_put(struct sk_buff *msg, struct devlink *devlink, bool is_remote)
> {
> struct nlattr *reload_stats_attr;
> int i, j, stat_idx;
> u32 value;
>
>- reload_stats_attr = nla_nest_start(msg, DEVLINK_ATTR_RELOAD_STATS);
>+ if (!is_remote)
>+ reload_stats_attr = nla_nest_start(msg, DEVLINK_ATTR_RELOAD_STATS);
>+ else
>+ reload_stats_attr = nla_nest_start(msg, DEVLINK_ATTR_REMOTE_RELOAD_STATS);
>
> if (!reload_stats_attr)
> return -EMSGSIZE;
>
> for (j = 0; j <= DEVLINK_RELOAD_LIMIT_MAX; j++) {
>- if (j != DEVLINK_RELOAD_LIMIT_UNSPEC &&
>+ if (!is_remote && j != DEVLINK_RELOAD_LIMIT_UNSPEC &&

I don't follow the check "!is_remote" here,

> !devlink_reload_limit_is_supported(devlink, j))
> continue;
> for (i = 0; i <= DEVLINK_RELOAD_ACTION_MAX; i++) {
>- if (!devlink_reload_action_is_supported(devlink, i) ||
>+ if ((!is_remote && !devlink_reload_action_is_supported(devlink, i)) ||

and here. Could you perhaps put in a comment to describe what are you
doing?



>+ i == DEVLINK_RELOAD_ACTION_UNSPEC ||
> devlink_reload_combination_is_invalid(i, j))
> continue;
>
> stat_idx = j * __DEVLINK_RELOAD_ACTION_MAX + i;
>- value = devlink->reload_stats[stat_idx];
>+ if (!is_remote)
>+ value = devlink->reload_stats[stat_idx];
>+ else
>+ value = devlink->remote_reload_stats[stat_idx];
> if (devlink_reload_stat_put(msg, i, j, value))
> goto nla_put_failure;
> }
>@@ -577,7 +584,9 @@ static int devlink_nl_fill(struct sk_buff *msg, struct devlink *devlink,
> if (!dev_stats)
> goto nla_put_failure;
>
>- if (devlink_reload_stats_put(msg, devlink))
>+ if (devlink_reload_stats_put(msg, devlink, false))
>+ goto dev_stats_nest_cancel;
>+ if (devlink_reload_stats_put(msg, devlink, true))
> goto dev_stats_nest_cancel;
>
> nla_nest_end(msg, dev_stats);
>@@ -3100,15 +3109,40 @@ devlink_reload_stats_update(struct devlink *devlink, enum devlink_reload_limit l
> __devlink_reload_stats_update(devlink, devlink->reload_stats, limit, actions_performed);
> }
>
>+/**
>+ * devlink_remote_reload_actions_performed - Update devlink on reload actions
>+ * performed which are not a direct result of devlink reload call.
>+ *
>+ * This should be called by a driver after performing reload actions in case it was not
>+ * a result of devlink reload call. For example fw_activate was performed as a result
>+ * of devlink reload triggered fw_activate on another host.
>+ * The motivation for this function is to keep data on reload actions performed on this
>+ * function whether it was done due to direct devlink reload call or not.
>+ *
>+ * @devlink: devlink
>+ * @limit: reload limit
>+ * @actions_performed: bitmask of actions performed
>+ */
>+void devlink_remote_reload_actions_performed(struct devlink *devlink,
>+ enum devlink_reload_limit limit,
>+ unsigned long actions_performed)
>+{
>+ __devlink_reload_stats_update(devlink, devlink->remote_reload_stats, limit,
>+ actions_performed);
>+}
>+EXPORT_SYMBOL_GPL(devlink_remote_reload_actions_performed);
>+
> static int devlink_reload(struct devlink *devlink, struct net *dest_net,
> enum devlink_reload_action action, enum devlink_reload_limit limit,
> struct netlink_ext_ack *extack, unsigned long *actions_performed)
> {
>+ u32 remote_reload_stats[DEVLINK_RELOAD_STATS_ARRAY_SIZE];
> int err;
>
> if (!devlink->reload_enabled)
> return -EOPNOTSUPP;
>
>+ memcpy(remote_reload_stats, devlink->remote_reload_stats, sizeof(remote_reload_stats));
> err = devlink->ops->reload_down(devlink, !!dest_net, action, limit, extack);
> if (err)
> return err;
>@@ -3122,6 +3156,9 @@ static int devlink_reload(struct devlink *devlink, struct net *dest_net,
> return err;
>
> WARN_ON(!test_bit(action, actions_performed));
>+ /* Catch driver on updating the remote action within devlink reload */
>+ WARN_ON(memcmp(remote_reload_stats, devlink->remote_reload_stats,
>+ sizeof(remote_reload_stats)));
> devlink_reload_stats_update(devlink, limit, *actions_performed);
> return 0;
> }
>--
>2.18.2
>