* [PATCH] event/eth_tx: prefetch mbuf headers
@ 2025-03-28 5:43 Mattias Rönnblom
2025-03-28 6:07 ` Mattias Rönnblom
` (2 more replies)
0 siblings, 3 replies; 8+ messages in thread
From: Mattias Rönnblom @ 2025-03-28 5:43 UTC (permalink / raw)
To: dev
Cc: Mattias Rönnblom, Naga Harish K S V, Jerin Jacob,
Mattias Rönnblom, Peter Nilsson
Prefetch mbuf headers, resulting in ~10% throughput improvement when
the Ethernet RX and TX Adapters are hosted on the same core (likely
~2x in case a dedicated TX core is used).
Signed-off-by: Mattias Rönnblom <mattias.ronnblom@ericsson.com>
Tested-by: Peter Nilsson <peter.j.nilsson@ericsson.com>
---
lib/eventdev/rte_event_eth_tx_adapter.c | 20 ++++++++++++++++++++
1 file changed, 20 insertions(+)
diff --git a/lib/eventdev/rte_event_eth_tx_adapter.c b/lib/eventdev/rte_event_eth_tx_adapter.c
index 67fff8b7d6..d740ae00f9 100644
--- a/lib/eventdev/rte_event_eth_tx_adapter.c
+++ b/lib/eventdev/rte_event_eth_tx_adapter.c
@@ -598,6 +598,12 @@ txa_process_event_vector(struct txa_service_data *txa,
return nb_tx;
}
+static inline void
+txa_prefetch_mbuf(struct rte_mbuf *mbuf)
+{
+ rte_mbuf_prefetch_part1(mbuf);
+}
+
static void
txa_service_tx(struct txa_service_data *txa, struct rte_event *ev,
uint32_t n)
@@ -608,6 +614,20 @@ txa_service_tx(struct txa_service_data *txa, struct rte_event *ev,
stats = &txa->stats;
+ for (i = 0; i < n; i++) {
+ struct rte_event *event = &ev[i];
+
+ if (unlikely(event->event_type & RTE_EVENT_TYPE_VECTOR)) {
+ struct rte_event_vector *vec = event->vec;
+ struct rte_mbuf **mbufs = vec->mbufs;
+ uint32_t k;
+
+ for (k = 0; k < vec->nb_elem; k++)
+ txa_prefetch_mbuf(mbufs[k]);
+ } else
+ txa_prefetch_mbuf(event->mbuf);
+ }
+
nb_tx = 0;
for (i = 0; i < n; i++) {
uint16_t port;
--
2.43.0
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH] event/eth_tx: prefetch mbuf headers
2025-03-28 5:43 [PATCH] event/eth_tx: prefetch mbuf headers Mattias Rönnblom
@ 2025-03-28 6:07 ` Mattias Rönnblom
2025-05-20 12:56 ` Mattias Rönnblom
2025-05-27 5:01 ` [EXTERNAL] " Jerin Jacob
2025-05-27 10:55 ` Naga Harish K, S V
2 siblings, 1 reply; 8+ messages in thread
From: Mattias Rönnblom @ 2025-03-28 6:07 UTC (permalink / raw)
To: Mattias Rönnblom, dev; +Cc: Naga Harish K S V, Jerin Jacob, Peter Nilsson
On 2025-03-28 06:43, Mattias Rönnblom wrote:
> Prefetch mbuf headers, resulting in ~10% throughput improvement when
> the Ethernet RX and TX Adapters are hosted on the same core (likely
> ~2x in case a dedicated TX core is used).
>
> Signed-off-by: Mattias Rönnblom <mattias.ronnblom@ericsson.com>
> Tested-by: Peter Nilsson <peter.j.nilsson@ericsson.com>
What should be added is that what's been tested is the
non-RTE_EVENT_TYPE_VECTOR case.
> ---
> lib/eventdev/rte_event_eth_tx_adapter.c | 20 ++++++++++++++++++++
> 1 file changed, 20 insertions(+)
>
> diff --git a/lib/eventdev/rte_event_eth_tx_adapter.c b/lib/eventdev/rte_event_eth_tx_adapter.c
> index 67fff8b7d6..d740ae00f9 100644
> --- a/lib/eventdev/rte_event_eth_tx_adapter.c
> +++ b/lib/eventdev/rte_event_eth_tx_adapter.c
> @@ -598,6 +598,12 @@ txa_process_event_vector(struct txa_service_data *txa,
> return nb_tx;
> }
>
> +static inline void
> +txa_prefetch_mbuf(struct rte_mbuf *mbuf)
> +{
> + rte_mbuf_prefetch_part1(mbuf);
> +}
> +
> static void
> txa_service_tx(struct txa_service_data *txa, struct rte_event *ev,
> uint32_t n)
> @@ -608,6 +614,20 @@ txa_service_tx(struct txa_service_data *txa, struct rte_event *ev,
>
> stats = &txa->stats;
>
> + for (i = 0; i < n; i++) {
> + struct rte_event *event = &ev[i];
> +
> + if (unlikely(event->event_type & RTE_EVENT_TYPE_VECTOR)) {
> + struct rte_event_vector *vec = event->vec;
> + struct rte_mbuf **mbufs = vec->mbufs;
> + uint32_t k;
> +
> + for (k = 0; k < vec->nb_elem; k++)
> + txa_prefetch_mbuf(mbufs[k]);
> + } else
> + txa_prefetch_mbuf(event->mbuf);
> + }
> +
> nb_tx = 0;
> for (i = 0; i < n; i++) {
> uint16_t port;
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH] event/eth_tx: prefetch mbuf headers
2025-03-28 6:07 ` Mattias Rönnblom
@ 2025-05-20 12:56 ` Mattias Rönnblom
0 siblings, 0 replies; 8+ messages in thread
From: Mattias Rönnblom @ 2025-05-20 12:56 UTC (permalink / raw)
To: Mattias Rönnblom, dev; +Cc: Naga Harish K S V, Jerin Jacob, Peter Nilsson
On 2025-03-28 07:07, Mattias Rönnblom wrote:
> On 2025-03-28 06:43, Mattias Rönnblom wrote:
>> Prefetch mbuf headers, resulting in ~10% throughput improvement when
>> the Ethernet RX and TX Adapters are hosted on the same core (likely
>> ~2x in case a dedicated TX core is used).
>>
>> Signed-off-by: Mattias Rönnblom <mattias.ronnblom@ericsson.com>
>> Tested-by: Peter Nilsson <peter.j.nilsson@ericsson.com>
>
<snip>
Naga, could you comment on this patch?
^ permalink raw reply [flat|nested] 8+ messages in thread
* RE: [EXTERNAL] [PATCH] event/eth_tx: prefetch mbuf headers
2025-03-28 5:43 [PATCH] event/eth_tx: prefetch mbuf headers Mattias Rönnblom
2025-03-28 6:07 ` Mattias Rönnblom
@ 2025-05-27 5:01 ` Jerin Jacob
2025-05-27 10:55 ` Naga Harish K, S V
2 siblings, 0 replies; 8+ messages in thread
From: Jerin Jacob @ 2025-05-27 5:01 UTC (permalink / raw)
To: Mattias Rönnblom, dev, Naga Harish K S V
Cc: Mattias Rönnblom, Peter Nilsson
[-- Attachment #1: Type: text/html, Size: 8086 bytes --]
^ permalink raw reply [flat|nested] 8+ messages in thread
* RE: [PATCH] event/eth_tx: prefetch mbuf headers
2025-03-28 5:43 [PATCH] event/eth_tx: prefetch mbuf headers Mattias Rönnblom
2025-03-28 6:07 ` Mattias Rönnblom
2025-05-27 5:01 ` [EXTERNAL] " Jerin Jacob
@ 2025-05-27 10:55 ` Naga Harish K, S V
2025-07-02 20:19 ` Mattias Rönnblom
2 siblings, 1 reply; 8+ messages in thread
From: Naga Harish K, S V @ 2025-05-27 10:55 UTC (permalink / raw)
To: Mattias Rönnblom, dev
Cc: Mattias Rönnblom, Jerin Jacob, Peter Nilsson
> -----Original Message-----
> From: Mattias Rönnblom <mattias.ronnblom@ericsson.com>
> Sent: Friday, March 28, 2025 11:14 AM
> To: dev@dpdk.org
> Cc: Mattias Rönnblom <hofors@lysator.liu.se>; Naga Harish K, S V
> <s.v.naga.harish.k@intel.com>; Jerin Jacob <jerinj@marvell.com>; Mattias
> Rönnblom <mattias.ronnblom@ericsson.com>; Peter Nilsson
> <peter.j.nilsson@ericsson.com>
> Subject: [PATCH] event/eth_tx: prefetch mbuf headers
>
> Prefetch mbuf headers, resulting in ~10% throughput improvement when the
> Ethernet RX and TX Adapters are hosted on the same core (likely ~2x in case a
> dedicated TX core is used).
>
> Signed-off-by: Mattias Rönnblom <mattias.ronnblom@ericsson.com>
> Tested-by: Peter Nilsson <peter.j.nilsson@ericsson.com>
> ---
> lib/eventdev/rte_event_eth_tx_adapter.c | 20 ++++++++++++++++++++
> 1 file changed, 20 insertions(+)
>
> diff --git a/lib/eventdev/rte_event_eth_tx_adapter.c
> b/lib/eventdev/rte_event_eth_tx_adapter.c
> index 67fff8b7d6..d740ae00f9 100644
> --- a/lib/eventdev/rte_event_eth_tx_adapter.c
> +++ b/lib/eventdev/rte_event_eth_tx_adapter.c
> @@ -598,6 +598,12 @@ txa_process_event_vector(struct txa_service_data
> *txa,
> return nb_tx;
> }
>
> +static inline void
> +txa_prefetch_mbuf(struct rte_mbuf *mbuf) {
> + rte_mbuf_prefetch_part1(mbuf);
> +}
> +
> static void
> txa_service_tx(struct txa_service_data *txa, struct rte_event *ev,
> uint32_t n)
> @@ -608,6 +614,20 @@ txa_service_tx(struct txa_service_data *txa, struct
> rte_event *ev,
>
> stats = &txa->stats;
>
> + for (i = 0; i < n; i++) {
> + struct rte_event *event = &ev[i];
> +
> + if (unlikely(event->event_type & RTE_EVENT_TYPE_VECTOR))
This gives a branch prediction advantage to non-vector events. Is that the intention?
> {
> + struct rte_event_vector *vec = event->vec;
> + struct rte_mbuf **mbufs = vec->mbufs;
> + uint32_t k;
> +
> + for (k = 0; k < vec->nb_elem; k++)
> + txa_prefetch_mbuf(mbufs[k]);
> + } else
> + txa_prefetch_mbuf(event->mbuf);
> + }
> +
> nb_tx = 0;
> for (i = 0; i < n; i++) {
> uint16_t port;
> --
> 2.43.0
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH] event/eth_tx: prefetch mbuf headers
2025-05-27 10:55 ` Naga Harish K, S V
@ 2025-07-02 20:19 ` Mattias Rönnblom
2025-07-07 9:00 ` Naga Harish K, S V
0 siblings, 1 reply; 8+ messages in thread
From: Mattias Rönnblom @ 2025-07-02 20:19 UTC (permalink / raw)
To: Naga Harish K, S V, Mattias Rönnblom, dev; +Cc: Jerin Jacob, Peter Nilsson
On 2025-05-27 12:55, Naga Harish K, S V wrote:
>
>
>> -----Original Message-----
>> From: Mattias Rönnblom <mattias.ronnblom@ericsson.com>
>> Sent: Friday, March 28, 2025 11:14 AM
>> To: dev@dpdk.org
>> Cc: Mattias Rönnblom <hofors@lysator.liu.se>; Naga Harish K, S V
>> <s.v.naga.harish.k@intel.com>; Jerin Jacob <jerinj@marvell.com>; Mattias
>> Rönnblom <mattias.ronnblom@ericsson.com>; Peter Nilsson
>> <peter.j.nilsson@ericsson.com>
>> Subject: [PATCH] event/eth_tx: prefetch mbuf headers
>>
>> Prefetch mbuf headers, resulting in ~10% throughput improvement when the
>> Ethernet RX and TX Adapters are hosted on the same core (likely ~2x in case a
>> dedicated TX core is used).
>>
>> Signed-off-by: Mattias Rönnblom <mattias.ronnblom@ericsson.com>
>> Tested-by: Peter Nilsson <peter.j.nilsson@ericsson.com>
>> ---
>> lib/eventdev/rte_event_eth_tx_adapter.c | 20 ++++++++++++++++++++
>> 1 file changed, 20 insertions(+)
>>
>> diff --git a/lib/eventdev/rte_event_eth_tx_adapter.c
>> b/lib/eventdev/rte_event_eth_tx_adapter.c
>> index 67fff8b7d6..d740ae00f9 100644
>> --- a/lib/eventdev/rte_event_eth_tx_adapter.c
>> +++ b/lib/eventdev/rte_event_eth_tx_adapter.c
>> @@ -598,6 +598,12 @@ txa_process_event_vector(struct txa_service_data
>> *txa,
>> return nb_tx;
>> }
>>
>> +static inline void
>> +txa_prefetch_mbuf(struct rte_mbuf *mbuf) {
>> + rte_mbuf_prefetch_part1(mbuf);
>> +}
>> +
>> static void
>> txa_service_tx(struct txa_service_data *txa, struct rte_event *ev,
>> uint32_t n)
>> @@ -608,6 +614,20 @@ txa_service_tx(struct txa_service_data *txa, struct
>> rte_event *ev,
>>
>> stats = &txa->stats;
>>
>> + for (i = 0; i < n; i++) {
>> + struct rte_event *event = &ev[i];
>> +
>> + if (unlikely(event->event_type & RTE_EVENT_TYPE_VECTOR))
>
>
> This gives a branch prediction advantage to non-vector events. Is that the intention?
>
Yes.
>> {
>> + struct rte_event_vector *vec = event->vec;
>> + struct rte_mbuf **mbufs = vec->mbufs;
>> + uint32_t k;
>> +
>> + for (k = 0; k < vec->nb_elem; k++)
>> + txa_prefetch_mbuf(mbufs[k]);
>> + } else
>> + txa_prefetch_mbuf(event->mbuf);
>> + }
>> +
>> nb_tx = 0;
>> for (i = 0; i < n; i++) {
>> uint16_t port;
>> --
>> 2.43.0
>
^ permalink raw reply [flat|nested] 8+ messages in thread
* RE: [PATCH] event/eth_tx: prefetch mbuf headers
2025-07-02 20:19 ` Mattias Rönnblom
@ 2025-07-07 9:00 ` Naga Harish K, S V
2025-07-07 11:57 ` Mattias Rönnblom
0 siblings, 1 reply; 8+ messages in thread
From: Naga Harish K, S V @ 2025-07-07 9:00 UTC (permalink / raw)
To: Mattias Rönnblom, Mattias Rönnblom, dev
Cc: Jerin Jacob, Peter Nilsson
> -----Original Message-----
> From: Mattias Rönnblom <hofors@lysator.liu.se>
> Sent: Thursday, July 3, 2025 1:50 AM
> To: Naga Harish K, S V <s.v.naga.harish.k@intel.com>; Mattias Rönnblom
> <mattias.ronnblom@ericsson.com>; dev@dpdk.org
> Cc: Jerin Jacob <jerinj@marvell.com>; Peter Nilsson
> <peter.j.nilsson@ericsson.com>
> Subject: Re: [PATCH] event/eth_tx: prefetch mbuf headers
>
> On 2025-05-27 12:55, Naga Harish K, S V wrote:
> >
> >
> >> -----Original Message-----
> >> From: Mattias Rönnblom <mattias.ronnblom@ericsson.com>
> >> Sent: Friday, March 28, 2025 11:14 AM
> >> To: dev@dpdk.org
> >> Cc: Mattias Rönnblom <hofors@lysator.liu.se>; Naga Harish K, S V
> >> <s.v.naga.harish.k@intel.com>; Jerin Jacob <jerinj@marvell.com>;
> >> Mattias Rönnblom <mattias.ronnblom@ericsson.com>; Peter Nilsson
> >> <peter.j.nilsson@ericsson.com>
> >> Subject: [PATCH] event/eth_tx: prefetch mbuf headers
> >>
> >> Prefetch mbuf headers, resulting in ~10% throughput improvement when
> >> the Ethernet RX and TX Adapters are hosted on the same core (likely
> >> ~2x in case a dedicated TX core is used).
> >>
> >> Signed-off-by: Mattias Rönnblom <mattias.ronnblom@ericsson.com>
> >> Tested-by: Peter Nilsson <peter.j.nilsson@ericsson.com>
> >> ---
> >> lib/eventdev/rte_event_eth_tx_adapter.c | 20 ++++++++++++++++++++
> >> 1 file changed, 20 insertions(+)
> >>
> >> diff --git a/lib/eventdev/rte_event_eth_tx_adapter.c
> >> b/lib/eventdev/rte_event_eth_tx_adapter.c
> >> index 67fff8b7d6..d740ae00f9 100644
> >> --- a/lib/eventdev/rte_event_eth_tx_adapter.c
> >> +++ b/lib/eventdev/rte_event_eth_tx_adapter.c
> >> @@ -598,6 +598,12 @@ txa_process_event_vector(struct
> txa_service_data
> >> *txa,
> >> return nb_tx;
> >> }
> >>
> >> +static inline void
> >> +txa_prefetch_mbuf(struct rte_mbuf *mbuf) {
> >> + rte_mbuf_prefetch_part1(mbuf);
> >> +}
> >> +
> >> static void
> >> txa_service_tx(struct txa_service_data *txa, struct rte_event *ev,
> >> uint32_t n)
> >> @@ -608,6 +614,20 @@ txa_service_tx(struct txa_service_data *txa,
> >> struct rte_event *ev,
> >>
> >> stats = &txa->stats;
> >>
> >> + for (i = 0; i < n; i++) {
> >> + struct rte_event *event = &ev[i];
> >> +
> >> + if (unlikely(event->event_type & RTE_EVENT_TYPE_VECTOR))
> >
> >
> > This gives a branch prediction advantage to non-vector events. Is that the
> intention?
> >
>
> Yes.
I think all event-types need to be equally weighted. My ask was to remove the "unlikely" for vector events.
>
> >> {
> >> + struct rte_event_vector *vec = event->vec;
> >> + struct rte_mbuf **mbufs = vec->mbufs;
> >> + uint32_t k;
> >> +
> >> + for (k = 0; k < vec->nb_elem; k++)
> >> + txa_prefetch_mbuf(mbufs[k]);
> >> + } else
> >> + txa_prefetch_mbuf(event->mbuf);
> >> + }
> >> +
> >> nb_tx = 0;
> >> for (i = 0; i < n; i++) {
> >> uint16_t port;
> >> --
> >> 2.43.0
> >
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH] event/eth_tx: prefetch mbuf headers
2025-07-07 9:00 ` Naga Harish K, S V
@ 2025-07-07 11:57 ` Mattias Rönnblom
0 siblings, 0 replies; 8+ messages in thread
From: Mattias Rönnblom @ 2025-07-07 11:57 UTC (permalink / raw)
To: Naga Harish K, S V, Mattias Rönnblom, dev; +Cc: Jerin Jacob, Peter Nilsson
On 2025-07-07 11:00, Naga Harish K, S V wrote:
>
>
>> -----Original Message-----
>> From: Mattias Rönnblom <hofors@lysator.liu.se>
>> Sent: Thursday, July 3, 2025 1:50 AM
>> To: Naga Harish K, S V <s.v.naga.harish.k@intel.com>; Mattias Rönnblom
>> <mattias.ronnblom@ericsson.com>; dev@dpdk.org
>> Cc: Jerin Jacob <jerinj@marvell.com>; Peter Nilsson
>> <peter.j.nilsson@ericsson.com>
>> Subject: Re: [PATCH] event/eth_tx: prefetch mbuf headers
>>
>> On 2025-05-27 12:55, Naga Harish K, S V wrote:
>>>
>>>
>>>> -----Original Message-----
>>>> From: Mattias Rönnblom <mattias.ronnblom@ericsson.com>
>>>> Sent: Friday, March 28, 2025 11:14 AM
>>>> To: dev@dpdk.org
>>>> Cc: Mattias Rönnblom <hofors@lysator.liu.se>; Naga Harish K, S V
>>>> <s.v.naga.harish.k@intel.com>; Jerin Jacob <jerinj@marvell.com>;
>>>> Mattias Rönnblom <mattias.ronnblom@ericsson.com>; Peter Nilsson
>>>> <peter.j.nilsson@ericsson.com>
>>>> Subject: [PATCH] event/eth_tx: prefetch mbuf headers
>>>>
>>>> Prefetch mbuf headers, resulting in ~10% throughput improvement when
>>>> the Ethernet RX and TX Adapters are hosted on the same core (likely
>>>> ~2x in case a dedicated TX core is used).
>>>>
>>>> Signed-off-by: Mattias Rönnblom <mattias.ronnblom@ericsson.com>
>>>> Tested-by: Peter Nilsson <peter.j.nilsson@ericsson.com>
>>>> ---
>>>> lib/eventdev/rte_event_eth_tx_adapter.c | 20 ++++++++++++++++++++
>>>> 1 file changed, 20 insertions(+)
>>>>
>>>> diff --git a/lib/eventdev/rte_event_eth_tx_adapter.c
>>>> b/lib/eventdev/rte_event_eth_tx_adapter.c
>>>> index 67fff8b7d6..d740ae00f9 100644
>>>> --- a/lib/eventdev/rte_event_eth_tx_adapter.c
>>>> +++ b/lib/eventdev/rte_event_eth_tx_adapter.c
>>>> @@ -598,6 +598,12 @@ txa_process_event_vector(struct
>> txa_service_data
>>>> *txa,
>>>> return nb_tx;
>>>> }
>>>>
>>>> +static inline void
>>>> +txa_prefetch_mbuf(struct rte_mbuf *mbuf) {
>>>> + rte_mbuf_prefetch_part1(mbuf);
>>>> +}
>>>> +
>>>> static void
>>>> txa_service_tx(struct txa_service_data *txa, struct rte_event *ev,
>>>> uint32_t n)
>>>> @@ -608,6 +614,20 @@ txa_service_tx(struct txa_service_data *txa,
>>>> struct rte_event *ev,
>>>>
>>>> stats = &txa->stats;
>>>>
>>>> + for (i = 0; i < n; i++) {
>>>> + struct rte_event *event = &ev[i];
>>>> +
>>>> + if (unlikely(event->event_type & RTE_EVENT_TYPE_VECTOR))
>>>
>>>
>>> This gives a branch prediction advantage to non-vector events. Is that the
>> intention?
>>>
>>
>> Yes.
>
> I think all event-types need to be equally weighted. My ask was to remove the "unlikely" for vector events.
>
This is not possible. One branch will always be cheaper. If you leave
out unlikely()/likely(), you leave all control to compiler heuristics.
In this case, I think the resulting object code will be identical (on GCC).
RTE_EVENT_TYPE_VECTOR will result in fewer events, and thus the
per-event overhead is less of an issue. So if you weigh the importance
of vector and non-vector use cases equally, you should optimize for the
non-vector case.
>>
>>>> {
>>>> + struct rte_event_vector *vec = event->vec;
>>>> + struct rte_mbuf **mbufs = vec->mbufs;
>>>> + uint32_t k;
>>>> +
>>>> + for (k = 0; k < vec->nb_elem; k++)
>>>> + txa_prefetch_mbuf(mbufs[k]);
>>>> + } else
>>>> + txa_prefetch_mbuf(event->mbuf);
>>>> + }
>>>> +
>>>> nb_tx = 0;
>>>> for (i = 0; i < n; i++) {
>>>> uint16_t port;
>>>> --
>>>> 2.43.0
>>>
>
^ permalink raw reply [flat|nested] 8+ messages in thread
end of thread, other threads:[~2025-07-07 11:57 UTC | newest]
Thread overview: 8+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2025-03-28 5:43 [PATCH] event/eth_tx: prefetch mbuf headers Mattias Rönnblom
2025-03-28 6:07 ` Mattias Rönnblom
2025-05-20 12:56 ` Mattias Rönnblom
2025-05-27 5:01 ` [EXTERNAL] " Jerin Jacob
2025-05-27 10:55 ` Naga Harish K, S V
2025-07-02 20:19 ` Mattias Rönnblom
2025-07-07 9:00 ` Naga Harish K, S V
2025-07-07 11:57 ` Mattias Rönnblom
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).