[PATCH net-next v3 0/2] net, neigh: introduce interval_probe_time for periodic probe

[PATCH net-next v3 0/2] net, neigh: introduce interval_probe_time for periodic probe

[Yuwei Wang]

This series adds a new option `interval_probe_time` in net, neigh
for periodic probe, and add a limitation to prevent it set to 0

Yuwei Wang (2):
  sysctl: add proc_dointvec_jiffies_minmax
  net, neigh: introduce interval_probe_time for periodic probe

 include/linux/sysctl.h         |  2 ++
 include/net/neighbour.h        |  1 +
 include/uapi/linux/neighbour.h |  1 +
 include/uapi/linux/sysctl.h    | 37 +++++++++++++++++-----------------
 kernel/sysctl.c                | 36 +++++++++++++++++++++++++++++++++
 net/core/neighbour.c           | 33 ++++++++++++++++++++++++++++--
 net/decnet/dn_neigh.c          |  1 +
 net/ipv4/arp.c                 |  1 +
 net/ipv6/ndisc.c               |  1 +
 9 files changed, 93 insertions(+), 20 deletions(-)


base-commit: da6e113ff010815fdd21ee1e9af2e8d179a2680f
-- 
2.34.1

[PATCH net-next v3 1/2] sysctl: add proc_dointvec_jiffies_minmax

[Yuwei Wang]

add proc_dointvec_jiffies_minmax to fit jiffies param with a limited
range of values

Signed-off-by: Yuwei Wang <wangyuweihx@gmail.com>
---
 include/linux/sysctl.h |  2 ++
 kernel/sysctl.c        | 36 ++++++++++++++++++++++++++++++++++++
 2 files changed, 38 insertions(+)

diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h
index 80263f7cdb77..0e1c05244350 100644
--- a/include/linux/sysctl.h
+++ b/include/linux/sysctl.h
@@ -75,6 +75,8 @@ int proc_douintvec_minmax(struct ctl_table *table, int write, void *buffer,
 int proc_dou8vec_minmax(struct ctl_table *table, int write, void *buffer,
 			size_t *lenp, loff_t *ppos);
 int proc_dointvec_jiffies(struct ctl_table *, int, void *, size_t *, loff_t *);
+int proc_dointvec_jiffies_minmax(struct ctl_table *table, int write,
+		void *buffer, size_t *lenp, loff_t *ppos);
 int proc_dointvec_userhz_jiffies(struct ctl_table *, int, void *, size_t *,
 		loff_t *);
 int proc_dointvec_ms_jiffies(struct ctl_table *, int, void *, size_t *,
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index e52b6e372c60..4187c389a1eb 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -1189,6 +1189,31 @@ static int do_proc_dointvec_jiffies_conv(bool *negp, unsigned long *lvalp,
 	return 0;
 }
 
+static int do_proc_dointvec_jiffies_minmax_conv(bool *negp, unsigned long *lvalp,
+						int *valp, int write, void *data)
+{
+	int tmp, ret;
+	struct do_proc_dointvec_minmax_conv_param *param = data;
+	/*
+	 * If writing, first do so via a temporary local int so we can
+	 * bounds-check it before touching *valp.
+	 */
+	int *ip = write ? &tmp : valp;
+
+	ret = do_proc_dointvec_jiffies_conv(negp, lvalp, ip, write, data);
+	if (ret)
+		return ret;
+
+	if (write) {
+		if ((param->min && *param->min > tmp) ||
+				(param->max && *param->max < tmp))
+			return -EINVAL;
+		*valp = tmp;
+}
+
+return 0;
+}
+
 static int do_proc_dointvec_userhz_jiffies_conv(bool *negp, unsigned long *lvalp,
 						int *valp,
 						int write, void *data)
@@ -1259,6 +1284,17 @@ int proc_dointvec_jiffies(struct ctl_table *table, int write,
 		    	    do_proc_dointvec_jiffies_conv,NULL);
 }
 
+int proc_dointvec_jiffies_minmax(struct ctl_table *table, int write,
+			  void *buffer, size_t *lenp, loff_t *ppos)
+{
+	struct do_proc_dointvec_minmax_conv_param param = {
+		.min = (int *) table->extra1,
+		.max = (int *) table->extra2,
+	};
+	return do_proc_dointvec(table, write, buffer, lenp, ppos,
+			do_proc_dointvec_jiffies_minmax_conv, &param);
+}
+
 /**
  * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
  * @table: the sysctl table
-- 
2.34.1

[PATCH net-next v3 2/2] net, neigh: introduce interval_probe_time for periodic probe

[Yuwei Wang]

commit ed6cd6a17896 ("net, neigh: Set lower cap for neigh_managed_work rearming")
fixed a case when DELAY_PROBE_TIME is configured to 0, the processing of the
system work queue hog CPU to 100%, and further more we should introduce
a new option used by periodic probe

Signed-off-by: Yuwei Wang <wangyuweihx@gmail.com>
---
v3:
- add limitation to prevent `INTERVAL_PROBE_TIME` to 0
- remove `NETEVENT_INTERVAL_PROBE_TIME_UPDATE`
- add .min to NDTPA_INTERVAL_PROBE_TIME

 include/net/neighbour.h        |  1 +
 include/uapi/linux/neighbour.h |  1 +
 include/uapi/linux/sysctl.h    | 37 +++++++++++++++++-----------------
 net/core/neighbour.c           | 33 ++++++++++++++++++++++++++++--
 net/decnet/dn_neigh.c          |  1 +
 net/ipv4/arp.c                 |  1 +
 net/ipv6/ndisc.c               |  1 +
 7 files changed, 55 insertions(+), 20 deletions(-)

diff --git a/include/net/neighbour.h b/include/net/neighbour.h
index 87419f7f5421..c6a6e652d442 100644
--- a/include/net/neighbour.h
+++ b/include/net/neighbour.h
@@ -48,6 +48,7 @@ enum {
 	NEIGH_VAR_RETRANS_TIME,
 	NEIGH_VAR_BASE_REACHABLE_TIME,
 	NEIGH_VAR_DELAY_PROBE_TIME,
+	NEIGH_VAR_INTERVAL_PROBE_TIME,
 	NEIGH_VAR_GC_STALETIME,
 	NEIGH_VAR_QUEUE_LEN_BYTES,
 	NEIGH_VAR_PROXY_QLEN,
diff --git a/include/uapi/linux/neighbour.h b/include/uapi/linux/neighbour.h
index 39c565e460c7..8713c3ea81b2 100644
--- a/include/uapi/linux/neighbour.h
+++ b/include/uapi/linux/neighbour.h
@@ -154,6 +154,7 @@ enum {
 	NDTPA_QUEUE_LENBYTES,		/* u32 */
 	NDTPA_MCAST_REPROBES,		/* u32 */
 	NDTPA_PAD,
+	NDTPA_INTERVAL_PROBE_TIME,	/* u64, msecs */
 	__NDTPA_MAX
 };
 #define NDTPA_MAX (__NDTPA_MAX - 1)
diff --git a/include/uapi/linux/sysctl.h b/include/uapi/linux/sysctl.h
index 6a3b194c50fe..53f06bfd2a37 100644
--- a/include/uapi/linux/sysctl.h
+++ b/include/uapi/linux/sysctl.h
@@ -584,24 +584,25 @@ enum {
 
 /* /proc/sys/net/<protocol>/neigh/<dev> */
 enum {
-	NET_NEIGH_MCAST_SOLICIT=1,
-	NET_NEIGH_UCAST_SOLICIT=2,
-	NET_NEIGH_APP_SOLICIT=3,
-	NET_NEIGH_RETRANS_TIME=4,
-	NET_NEIGH_REACHABLE_TIME=5,
-	NET_NEIGH_DELAY_PROBE_TIME=6,
-	NET_NEIGH_GC_STALE_TIME=7,
-	NET_NEIGH_UNRES_QLEN=8,
-	NET_NEIGH_PROXY_QLEN=9,
-	NET_NEIGH_ANYCAST_DELAY=10,
-	NET_NEIGH_PROXY_DELAY=11,
-	NET_NEIGH_LOCKTIME=12,
-	NET_NEIGH_GC_INTERVAL=13,
-	NET_NEIGH_GC_THRESH1=14,
-	NET_NEIGH_GC_THRESH2=15,
-	NET_NEIGH_GC_THRESH3=16,
-	NET_NEIGH_RETRANS_TIME_MS=17,
-	NET_NEIGH_REACHABLE_TIME_MS=18,
+	NET_NEIGH_MCAST_SOLICIT = 1,
+	NET_NEIGH_UCAST_SOLICIT = 2,
+	NET_NEIGH_APP_SOLICIT = 3,
+	NET_NEIGH_RETRANS_TIME = 4,
+	NET_NEIGH_REACHABLE_TIME = 5,
+	NET_NEIGH_DELAY_PROBE_TIME = 6,
+	NET_NEIGH_GC_STALE_TIME = 7,
+	NET_NEIGH_UNRES_QLEN = 8,
+	NET_NEIGH_PROXY_QLEN = 9,
+	NET_NEIGH_ANYCAST_DELAY = 10,
+	NET_NEIGH_PROXY_DELAY = 11,
+	NET_NEIGH_LOCKTIME = 12,
+	NET_NEIGH_GC_INTERVAL = 13,
+	NET_NEIGH_GC_THRESH1 = 14,
+	NET_NEIGH_GC_THRESH2 = 15,
+	NET_NEIGH_GC_THRESH3 = 16,
+	NET_NEIGH_RETRANS_TIME_MS = 17,
+	NET_NEIGH_REACHABLE_TIME_MS = 18,
+	NET_NEIGH_INTERVAL_PROBE_TIME = 19,
 };
 
 /* /proc/sys/net/dccp */
diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index 54625287ee5b..845fad952ce2 100644
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -1579,7 +1579,7 @@ static void neigh_managed_work(struct work_struct *work)
 	list_for_each_entry(neigh, &tbl->managed_list, managed_list)
 		neigh_event_send_probe(neigh, NULL, false);
 	queue_delayed_work(system_power_efficient_wq, &tbl->managed_work,
-			   max(NEIGH_VAR(&tbl->parms, DELAY_PROBE_TIME), HZ));
+			   NEIGH_VAR(&tbl->parms, INTERVAL_PROBE_TIME));
 	write_unlock_bh(&tbl->lock);
 }
 
@@ -2100,7 +2100,9 @@ static int neightbl_fill_parms(struct sk_buff *skb, struct neigh_parms *parms)
 	    nla_put_msecs(skb, NDTPA_PROXY_DELAY,
 			  NEIGH_VAR(parms, PROXY_DELAY), NDTPA_PAD) ||
 	    nla_put_msecs(skb, NDTPA_LOCKTIME,
-			  NEIGH_VAR(parms, LOCKTIME), NDTPA_PAD))
+			  NEIGH_VAR(parms, LOCKTIME), NDTPA_PAD) ||
+	    nla_put_msecs(skb, NDTPA_INTERVAL_PROBE_TIME,
+			  NEIGH_VAR(parms, INTERVAL_PROBE_TIME), NDTPA_PAD))
 		goto nla_put_failure;
 	return nla_nest_end(skb, nest);
 
@@ -2255,6 +2257,7 @@ static const struct nla_policy nl_ntbl_parm_policy[NDTPA_MAX+1] = {
 	[NDTPA_ANYCAST_DELAY]		= { .type = NLA_U64 },
 	[NDTPA_PROXY_DELAY]		= { .type = NLA_U64 },
 	[NDTPA_LOCKTIME]		= { .type = NLA_U64 },
+	[NDTPA_INTERVAL_PROBE_TIME]	= { .type = NLA_U64, .min = 1 },
 };
 
 static int neightbl_set(struct sk_buff *skb, struct nlmsghdr *nlh,
@@ -2373,6 +2376,10 @@ static int neightbl_set(struct sk_buff *skb, struct nlmsghdr *nlh,
 					      nla_get_msecs(tbp[i]));
 				call_netevent_notifiers(NETEVENT_DELAY_PROBE_TIME_UPDATE, p);
 				break;
+			case NDTPA_INTERVAL_PROBE_TIME:
+				NEIGH_VAR_SET(p, INTERVAL_PROBE_TIME,
+					      nla_get_msecs(tbp[i]));
+				break;
 			case NDTPA_RETRANS_TIME:
 				NEIGH_VAR_SET(p, RETRANS_TIME,
 					      nla_get_msecs(tbp[i]));
@@ -3562,6 +3569,24 @@ static int neigh_proc_dointvec_zero_intmax(struct ctl_table *ctl, int write,
 	return ret;
 }
 
+static int neigh_proc_dointvec_jiffies_positive(struct ctl_table *ctl, int write,
+						void *buffer, size_t *lenp,
+						loff_t *ppos)
+{
+	struct ctl_table tmp = *ctl;
+	int ret;
+
+	int min = HZ;
+	int max = INT_MAX;
+
+	tmp.extra1 = &min;
+	tmp.extra2 = &max;
+
+	ret = proc_dointvec_jiffies_minmax(&tmp, write, buffer, lenp, ppos);
+	neigh_proc_update(ctl, write);
+	return ret;
+}
+
 int neigh_proc_dointvec(struct ctl_table *ctl, int write, void *buffer,
 			size_t *lenp, loff_t *ppos)
 {
@@ -3658,6 +3683,9 @@ static int neigh_proc_base_reachable_time(struct ctl_table *ctl, int write,
 #define NEIGH_SYSCTL_USERHZ_JIFFIES_ENTRY(attr, name) \
 	NEIGH_SYSCTL_ENTRY(attr, attr, name, 0644, neigh_proc_dointvec_userhz_jiffies)
 
+#define NEIGH_SYSCTL_JIFFIES_POSITIVE_ENTRY(attr, name) \
+	NEIGH_SYSCTL_ENTRY(attr, attr, name, 0644, neigh_proc_dointvec_jiffies_positive)
+
 #define NEIGH_SYSCTL_MS_JIFFIES_REUSED_ENTRY(attr, data_attr, name) \
 	NEIGH_SYSCTL_ENTRY(attr, data_attr, name, 0644, neigh_proc_dointvec_ms_jiffies)
 
@@ -3676,6 +3704,7 @@ static struct neigh_sysctl_table {
 		NEIGH_SYSCTL_USERHZ_JIFFIES_ENTRY(RETRANS_TIME, "retrans_time"),
 		NEIGH_SYSCTL_JIFFIES_ENTRY(BASE_REACHABLE_TIME, "base_reachable_time"),
 		NEIGH_SYSCTL_JIFFIES_ENTRY(DELAY_PROBE_TIME, "delay_first_probe_time"),
+		NEIGH_SYSCTL_JIFFIES_POSITIVE_ENTRY(INTERVAL_PROBE_TIME, "interval_probe_time"),
 		NEIGH_SYSCTL_JIFFIES_ENTRY(GC_STALETIME, "gc_stale_time"),
 		NEIGH_SYSCTL_ZERO_INTMAX_ENTRY(QUEUE_LEN_BYTES, "unres_qlen_bytes"),
 		NEIGH_SYSCTL_ZERO_INTMAX_ENTRY(PROXY_QLEN, "proxy_qlen"),
diff --git a/net/decnet/dn_neigh.c b/net/decnet/dn_neigh.c
index fbd98ac853ea..995b22841ebf 100644
--- a/net/decnet/dn_neigh.c
+++ b/net/decnet/dn_neigh.c
@@ -94,6 +94,7 @@ struct neigh_table dn_neigh_table = {
 			[NEIGH_VAR_RETRANS_TIME] = 1 * HZ,
 			[NEIGH_VAR_BASE_REACHABLE_TIME] = 30 * HZ,
 			[NEIGH_VAR_DELAY_PROBE_TIME] = 5 * HZ,
+			[NEIGH_VAR_INTERVAL_PROBE_TIME] = 5 * HZ,
 			[NEIGH_VAR_GC_STALETIME] = 60 * HZ,
 			[NEIGH_VAR_QUEUE_LEN_BYTES] = SK_WMEM_MAX,
 			[NEIGH_VAR_PROXY_QLEN] = 0,
diff --git a/net/ipv4/arp.c b/net/ipv4/arp.c
index ab4a5601c82a..dbea1f7a7e2b 100644
--- a/net/ipv4/arp.c
+++ b/net/ipv4/arp.c
@@ -168,6 +168,7 @@ struct neigh_table arp_tbl = {
 			[NEIGH_VAR_RETRANS_TIME] = 1 * HZ,
 			[NEIGH_VAR_BASE_REACHABLE_TIME] = 30 * HZ,
 			[NEIGH_VAR_DELAY_PROBE_TIME] = 5 * HZ,
+			[NEIGH_VAR_INTERVAL_PROBE_TIME] = 5 * HZ,
 			[NEIGH_VAR_GC_STALETIME] = 60 * HZ,
 			[NEIGH_VAR_QUEUE_LEN_BYTES] = SK_WMEM_MAX,
 			[NEIGH_VAR_PROXY_QLEN] = 64,
diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c
index b0dfe97ea4ee..aa9dc032bac5 100644
--- a/net/ipv6/ndisc.c
+++ b/net/ipv6/ndisc.c
@@ -128,6 +128,7 @@ struct neigh_table nd_tbl = {
 			[NEIGH_VAR_RETRANS_TIME] = ND_RETRANS_TIMER,
 			[NEIGH_VAR_BASE_REACHABLE_TIME] = ND_REACHABLE_TIME,
 			[NEIGH_VAR_DELAY_PROBE_TIME] = 5 * HZ,
+			[NEIGH_VAR_INTERVAL_PROBE_TIME] = 5 * HZ,
 			[NEIGH_VAR_GC_STALETIME] = 60 * HZ,
 			[NEIGH_VAR_QUEUE_LEN_BYTES] = SK_WMEM_MAX,
 			[NEIGH_VAR_PROXY_QLEN] = 64,
-- 
2.34.1

Re: [PATCH net-next v3 1/2] sysctl: add proc_dointvec_jiffies_minmax

[Jakub Kicinski]

On Thu,  9 Jun 2022 10:57:24 +0000 Yuwei Wang wrote:
> +		*valp = tmp;
> +}
> +
> +return 0;
> +}
> +

Looks whitespace damaged

Re: [PATCH net-next v3 2/2] net, neigh: introduce interval_probe_time for periodic probe

[Jakub Kicinski]

On Thu,  9 Jun 2022 10:57:25 +0000 Yuwei Wang wrote:
> commit ed6cd6a17896 ("net, neigh: Set lower cap for neigh_managed_work rearming")
> fixed a case when DELAY_PROBE_TIME is configured to 0, the processing of the
> system work queue hog CPU to 100%, and further more we should introduce
> a new option used by periodic probe
> 
> Signed-off-by: Yuwei Wang <wangyuweihx@gmail.com>

The new sysctl needs to be documented in
Documentation/networking/ip-sysctl

Re: [PATCH net-next v3 2/2] net, neigh: introduce interval_probe_time for periodic probe

[Nikolay Aleksandrov]

On 09/06/2022 13:57, Yuwei Wang wrote:
> commit ed6cd6a17896 ("net, neigh: Set lower cap for neigh_managed_work rearming")
> fixed a case when DELAY_PROBE_TIME is configured to 0, the processing of the
> system work queue hog CPU to 100%, and further more we should introduce
> a new option used by periodic probe
> 
> Signed-off-by: Yuwei Wang <wangyuweihx@gmail.com>
> ---
> v3:
> - add limitation to prevent `INTERVAL_PROBE_TIME` to 0
> - remove `NETEVENT_INTERVAL_PROBE_TIME_UPDATE`
> - add .min to NDTPA_INTERVAL_PROBE_TIME
> 
>  include/net/neighbour.h        |  1 +
>  include/uapi/linux/neighbour.h |  1 +
>  include/uapi/linux/sysctl.h    | 37 +++++++++++++++++-----------------
>  net/core/neighbour.c           | 33 ++++++++++++++++++++++++++++--
>  net/decnet/dn_neigh.c          |  1 +
>  net/ipv4/arp.c                 |  1 +
>  net/ipv6/ndisc.c               |  1 +
>  7 files changed, 55 insertions(+), 20 deletions(-)
> 
[snip]
> diff --git a/include/uapi/linux/neighbour.h b/include/uapi/linux/neighbour.h
> index 39c565e460c7..8713c3ea81b2 100644
> --- a/include/uapi/linux/neighbour.h
> +++ b/include/uapi/linux/neighbour.h
> @@ -154,6 +154,7 @@ enum {
>  	NDTPA_QUEUE_LENBYTES,		/* u32 */
>  	NDTPA_MCAST_REPROBES,		/* u32 */
>  	NDTPA_PAD,
> +	NDTPA_INTERVAL_PROBE_TIME,	/* u64, msecs */
>  	__NDTPA_MAX
>  };
>  #define NDTPA_MAX (__NDTPA_MAX - 1)
[snip]
>  /* /proc/sys/net/dccp */
> diff --git a/net/core/neighbour.c b/net/core/neighbour.c
> index 54625287ee5b..845fad952ce2 100644
> --- a/net/core/neighbour.c
> +++ b/net/core/neighbour.c
> @@ -1579,7 +1579,7 @@ static void neigh_managed_work(struct work_struct *work)
>  	list_for_each_entry(neigh, &tbl->managed_list, managed_list)
>  		neigh_event_send_probe(neigh, NULL, false);
>  	queue_delayed_work(system_power_efficient_wq, &tbl->managed_work,
> -			   max(NEIGH_VAR(&tbl->parms, DELAY_PROBE_TIME), HZ));
> +			   NEIGH_VAR(&tbl->parms, INTERVAL_PROBE_TIME));
>  	write_unlock_bh(&tbl->lock);
>  }
>  
> @@ -2100,7 +2100,9 @@ static int neightbl_fill_parms(struct sk_buff *skb, struct neigh_parms *parms)
>  	    nla_put_msecs(skb, NDTPA_PROXY_DELAY,
>  			  NEIGH_VAR(parms, PROXY_DELAY), NDTPA_PAD) ||
>  	    nla_put_msecs(skb, NDTPA_LOCKTIME,
> -			  NEIGH_VAR(parms, LOCKTIME), NDTPA_PAD))
> +			  NEIGH_VAR(parms, LOCKTIME), NDTPA_PAD) ||
> +	    nla_put_msecs(skb, NDTPA_INTERVAL_PROBE_TIME,
> +			  NEIGH_VAR(parms, INTERVAL_PROBE_TIME), NDTPA_PAD))
>  		goto nla_put_failure;
>  	return nla_nest_end(skb, nest);
>  
> @@ -2255,6 +2257,7 @@ static const struct nla_policy nl_ntbl_parm_policy[NDTPA_MAX+1] = {
>  	[NDTPA_ANYCAST_DELAY]		= { .type = NLA_U64 },
>  	[NDTPA_PROXY_DELAY]		= { .type = NLA_U64 },
>  	[NDTPA_LOCKTIME]		= { .type = NLA_U64 },
> +	[NDTPA_INTERVAL_PROBE_TIME]	= { .type = NLA_U64, .min = 1 },

shouldn't the min be MSEC_PER_SEC (1 sec minimum) ?

>  };
>  
>  static int neightbl_set(struct sk_buff *skb, struct nlmsghdr *nlh,
> @@ -2373,6 +2376,10 @@ static int neightbl_set(struct sk_buff *skb, struct nlmsghdr *nlh,
>  					      nla_get_msecs(tbp[i]));
>  				call_netevent_notifiers(NETEVENT_DELAY_PROBE_TIME_UPDATE, p);
>  				break;
> +			case NDTPA_INTERVAL_PROBE_TIME:
> +				NEIGH_VAR_SET(p, INTERVAL_PROBE_TIME,
> +					      nla_get_msecs(tbp[i]));
> +				break;
>  			case NDTPA_RETRANS_TIME:
>  				NEIGH_VAR_SET(p, RETRANS_TIME,
>  					      nla_get_msecs(tbp[i]));
> @@ -3562,6 +3569,24 @@ static int neigh_proc_dointvec_zero_intmax(struct ctl_table *ctl, int write,
>  	return ret;
>  }
>  
> +static int neigh_proc_dointvec_jiffies_positive(struct ctl_table *ctl, int write,
> +						void *buffer, size_t *lenp,
> +						loff_t *ppos)

Do we need the proc entry to be in jiffies when the netlink option is in ms?
Why not make it directly in ms (with _ms similar to other neigh _ms time options) ?

IMO, it would be better to be consistent with the netlink option which sets it in ms.

It seems the _ms options were added later and usually people want a more understandable
value, I haven't seen anyone wanting a jiffies version of a ms interval variable. :)

> +{
> +	struct ctl_table tmp = *ctl;
> +	int ret;
> +
> +	int min = HZ;
> +	int max = INT_MAX;
> +
> +	tmp.extra1 = &min;
> +	tmp.extra2 = &max;

hmm, I don't think these min/max match the netlink attribute's min/max.

> +
> +	ret = proc_dointvec_jiffies_minmax(&tmp, write, buffer, lenp, ppos);
> +	neigh_proc_update(ctl, write);
> +	return ret;
> +}
> +
>  int neigh_proc_dointvec(struct ctl_table *ctl, int write, void *buffer,
>  			size_t *lenp, loff_t *ppos)
>  {
> @@ -3658,6 +3683,9 @@ static int neigh_proc_base_reachable_time(struct ctl_table *ctl, int write,
>  #define NEIGH_SYSCTL_USERHZ_JIFFIES_ENTRY(attr, name) \
>  	NEIGH_SYSCTL_ENTRY(attr, attr, name, 0644, neigh_proc_dointvec_userhz_jiffies)
>  
[snip]
Cheers,
 Nik

Re: [PATCH net-next v3 2/2] net, neigh: introduce interval_probe_time for periodic probe

[Yuwei Wang]

On Tue, 14 Jun 2022 at 17:10, Nikolay Aleksandrov <razor@blackwall.org> wrote:
> > @@ -2255,6 +2257,7 @@ static const struct nla_policy nl_ntbl_parm_policy[NDTPA_MAX+1] = {
> >       [NDTPA_ANYCAST_DELAY]           = { .type = NLA_U64 },
> >       [NDTPA_PROXY_DELAY]             = { .type = NLA_U64 },
> >       [NDTPA_LOCKTIME]                = { .type = NLA_U64 },
> > +     [NDTPA_INTERVAL_PROBE_TIME]     = { .type = NLA_U64, .min = 1 },
>
> shouldn't the min be MSEC_PER_SEC (1 sec minimum) ?

thanks, I will make it match the option ;)

> >
> > +static int neigh_proc_dointvec_jiffies_positive(struct ctl_table *ctl, int write,
> > +                                             void *buffer, size_t *lenp,
> > +                                             loff_t *ppos)
>
> Do we need the proc entry to be in jiffies when the netlink option is in ms?
> Why not make it directly in ms (with _ms similar to other neigh _ms time options) ?
>
> IMO, it would be better to be consistent with the netlink option which sets it in ms.
>
> It seems the _ms options were added later and usually people want a more understandable
> value, I haven't seen anyone wanting a jiffies version of a ms interval variable. :)
>

It was in jiffies because this entry was separated from `DELAY_PROBE_TIME`,
it keeps nearly all the things the same as `DELAY_PROBE_TIME`,
they are both configured by seconds and read to jiffies, was `ms` in
netlink attribute,
I think it's ok to keep this consistency, and is there a demand
required to configure it by ms?
If there is that demand, we can make it configured as ms.

> > +{
> > +     struct ctl_table tmp = *ctl;
> > +     int ret;
> > +
> > +     int min = HZ;
> > +     int max = INT_MAX;
> > +
> > +     tmp.extra1 = &min;
> > +     tmp.extra2 = &max;
>
> hmm, I don't think these min/max match the netlink attribute's min/max.

thanks, I will make it match the attribute ;)

>
> > +
> > +     ret = proc_dointvec_jiffies_minmax(&tmp, write, buffer, lenp, ppos);
> > +     neigh_proc_update(ctl, write);
> > +     return ret;
> > +}
> > +
> >  int neigh_proc_dointvec(struct ctl_table *ctl, int write, void *buffer,
> >                       size_t *lenp, loff_t *ppos)
> >  {
> > @@ -3658,6 +3683,9 @@ static int neigh_proc_base_reachable_time(struct ctl_table *ctl, int write,
> >  #define NEIGH_SYSCTL_USERHZ_JIFFIES_ENTRY(attr, name) \
> >       NEIGH_SYSCTL_ENTRY(attr, attr, name, 0644, neigh_proc_dointvec_userhz_jiffies)
> >
> [snip]
> Cheers,
>  Nik

Thanks,
Yuwei Wang

Re: [PATCH net-next v3 2/2] net, neigh: introduce interval_probe_time for periodic probe

[Yuwei Wang]

On Tue, 14 Jun 2022 at 14:02, Jakub Kicinski <kuba@kernel.org> wrote:
>
> On Thu,  9 Jun 2022 10:57:25 +0000 Yuwei Wang wrote:
> > commit ed6cd6a17896 ("net, neigh: Set lower cap for neigh_managed_work rearming")
> > fixed a case when DELAY_PROBE_TIME is configured to 0, the processing of the
> > system work queue hog CPU to 100%, and further more we should introduce
> > a new option used by periodic probe
> >
> > Signed-off-by: Yuwei Wang <wangyuweihx@gmail.com>
>
> The new sysctl needs to be documented in
> Documentation/networking/ip-sysctl

Oops……I will fix the whitespace and add the doc in the next version

Re: [PATCH net-next v3 2/2] net, neigh: introduce interval_probe_time for periodic probe

[Nikolay Aleksandrov]

On 15 June 2022 18:28:27 EEST, Yuwei Wang <wangyuweihx@gmail.com> wrote:
>On Tue, 14 Jun 2022 at 17:10, Nikolay Aleksandrov <razor@blackwall.org> wrote:
>> > @@ -2255,6 +2257,7 @@ static const struct nla_policy nl_ntbl_parm_policy[NDTPA_MAX+1] = {
>> >       [NDTPA_ANYCAST_DELAY]           = { .type = NLA_U64 },
>> >       [NDTPA_PROXY_DELAY]             = { .type = NLA_U64 },
>> >       [NDTPA_LOCKTIME]                = { .type = NLA_U64 },
>> > +     [NDTPA_INTERVAL_PROBE_TIME]     = { .type = NLA_U64, .min = 1 },
>>
>> shouldn't the min be MSEC_PER_SEC (1 sec minimum) ?
>
>thanks, I will make it match the option ;)
>
>> >
>> > +static int neigh_proc_dointvec_jiffies_positive(struct ctl_table *ctl, int write,
>> > +                                             void *buffer, size_t *lenp,
>> > +                                             loff_t *ppos)
>>
>> Do we need the proc entry to be in jiffies when the netlink option is in ms?
>> Why not make it directly in ms (with _ms similar to other neigh _ms time options) ?
>>
>> IMO, it would be better to be consistent with the netlink option which sets it in ms.
>>
>> It seems the _ms options were added later and usually people want a more understandable
>> value, I haven't seen anyone wanting a jiffies version of a ms interval variable. :)
>>
>
>It was in jiffies because this entry was separated from `DELAY_PROBE_TIME`,
>it keeps nearly all the things the same as `DELAY_PROBE_TIME`,
>they are both configured by seconds and read to jiffies, was `ms` in
>netlink attribute,
>I think it's ok to keep this consistency, and is there a demand
>required to configure it by ms?
>If there is that demand, we can make it configured as ms.
>

no, no demand, just out of user-friendliness :) but 
I get it keeping it as jiffies is also fine 

>> > +{
>> > +     struct ctl_table tmp = *ctl;
>> > +     int ret;
>> > +
>> > +     int min = HZ;
>> > +     int max = INT_MAX;
>> > +
>> > +     tmp.extra1 = &min;
>> > +     tmp.extra2 = &max;
>>
>> hmm, I don't think these min/max match the netlink attribute's min/max.
>
>thanks, I will make it match the attribute ;)
>
>>
>> > +
>> > +     ret = proc_dointvec_jiffies_minmax(&tmp, write, buffer, lenp, ppos);
>> > +     neigh_proc_update(ctl, write);
>> > +     return ret;
>> > +}
>> > +
>> >  int neigh_proc_dointvec(struct ctl_table *ctl, int write, void *buffer,
>> >                       size_t *lenp, loff_t *ppos)
>> >  {
>> > @@ -3658,6 +3683,9 @@ static int neigh_proc_base_reachable_time(struct ctl_table *ctl, int write,
>> >  #define NEIGH_SYSCTL_USERHZ_JIFFIES_ENTRY(attr, name) \
>> >       NEIGH_SYSCTL_ENTRY(attr, attr, name, 0644, neigh_proc_dointvec_userhz_jiffies)
>> >
>> [snip]
>> Cheers,
>>  Nik
>
>Thanks,
>Yuwei Wang

Re: [PATCH net-next v3 2/2] net, neigh: introduce interval_probe_time for periodic probe

[Jakub Kicinski]

On Wed, 15 Jun 2022 18:39:53 +0300 Nikolay Aleksandrov wrote:
> >> Do we need the proc entry to be in jiffies when the netlink option is in ms?
> >> Why not make it directly in ms (with _ms similar to other neigh _ms time options) ?
> >>
> >> IMO, it would be better to be consistent with the netlink option which sets it in ms.
> >>
> >> It seems the _ms options were added later and usually people want a more understandable
> >> value, I haven't seen anyone wanting a jiffies version of a ms interval variable. :)
> >>  
> >
> >It was in jiffies because this entry was separated from `DELAY_PROBE_TIME`,
> >it keeps nearly all the things the same as `DELAY_PROBE_TIME`,
> >they are both configured by seconds and read to jiffies, was `ms` in
> >netlink attribute,
> >I think it's ok to keep this consistency, and is there a demand
> >required to configure it by ms?
> >If there is that demand, we can make it configured as ms.
> 
> no, no demand, just out of user-friendliness :) but 
> I get it keeping it as jiffies is also fine 

+1 to using ms

Re: [PATCH net-next v3 2/2] net, neigh: introduce interval_probe_time for periodic probe

[Yuwei Wang]

On Thu, 16 Jun 2022 at 07:33, Jakub Kicinski <kuba@kernel.org> wrote:
>
> On Wed, 15 Jun 2022 18:39:53 +0300 Nikolay Aleksandrov wrote:
> > >> Do we need the proc entry to be in jiffies when the netlink option is in ms?
> > >> Why not make it directly in ms (with _ms similar to other neigh _ms time options) ?
> > >>
> > >> IMO, it would be better to be consistent with the netlink option which sets it in ms.
> > >>
> > >> It seems the _ms options were added later and usually people want a more understandable
> > >> value, I haven't seen anyone wanting a jiffies version of a ms interval variable. :)
> > >>
> > >
> > >It was in jiffies because this entry was separated from `DELAY_PROBE_TIME`,
> > >it keeps nearly all the things the same as `DELAY_PROBE_TIME`,
> > >they are both configured by seconds and read to jiffies, was `ms` in
> > >netlink attribute,
> > >I think it's ok to keep this consistency, and is there a demand
> > >required to configure it by ms?
> > >If there is that demand, we can make it configured as ms.
> >
> > no, no demand, just out of user-friendliness :) but
> > I get it keeping it as jiffies is also fine
>
> +1 to using ms

If no one is against this, we can make configured as ms?

so, there will be updates as follow in the next version patch:
- make this option configured as ms, and rename it to `interval_probe_time`
- add documentation to Documentation/networking/ip-sysctl
- fix damaged whitespace
- fix missing `proc_*_jiffies_minmax` on `CONFIG_PROC_SYSCTL` is not defined

Re: [PATCH net-next v3 2/2] net, neigh: introduce interval_probe_time for periodic probe

[Yuwei Wang]

On Sat, 18 Jun 2022 at 18:24, Yuwei Wang <wangyuweihx@gmail.com> wrote:
>
> - make this option configured as ms, and rename it to `interval_probe_time`

typo: make this option configured as ms, and rename it to
`interval_probe_time_ms`

> - add documentation to Documentation/networking/ip-sysctl
> - fix damaged whitespace
> - fix missing `proc_*_jiffies_minmax` on `CONFIG_PROC_SYSCTL` is not defined