* [dpdk-dev] [PATCH] examples/l3fwd: fix TX burst queue drain edge case
@ 2021-02-23 18:23 Kathleen Capella
2021-03-24 17:15 ` Thomas Monjalon
2021-04-08 21:35 ` [dpdk-dev] [PATCH v2] examples/l3fwd: skip TX queue drain on first iteration Kathleen Capella
0 siblings, 2 replies; 5+ messages in thread
From: Kathleen Capella @ 2021-02-23 18:23 UTC (permalink / raw)
To: dev; +Cc: nd, honnappa.nagarahalli, kathleen.capella
Initialize prev_tsc to cur_tsc. This avoids running the TX queue drain
in the first iteration of the packet processing loop.
Fixes: af75078fece3 ("first public release")
Signed-off-by: Kathleen Capella <kathleen.capella@arm.com>
Reviewed-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
---
examples/l3fwd/l3fwd_em.c | 9 +++++----
examples/l3fwd/l3fwd_lpm.c | 9 +++++----
2 files changed, 10 insertions(+), 8 deletions(-)
diff --git a/examples/l3fwd/l3fwd_em.c b/examples/l3fwd/l3fwd_em.c
index 9996bfba3..01f8dff48 100644
--- a/examples/l3fwd/l3fwd_em.c
+++ b/examples/l3fwd/l3fwd_em.c
@@ -629,8 +629,6 @@ em_main_loop(__rte_unused void *dummy)
const uint64_t drain_tsc = (rte_get_tsc_hz() + US_PER_S - 1) /
US_PER_S * BURST_TX_DRAIN_US;
- prev_tsc = 0;
-
lcore_id = rte_lcore_id();
qconf = &lcore_conf[lcore_id];
@@ -650,9 +648,10 @@ em_main_loop(__rte_unused void *dummy)
lcore_id, portid, queueid);
}
- while (!force_quit) {
+ cur_tsc = rte_rdtsc();
+ prev_tsc = cur_tsc;
- cur_tsc = rte_rdtsc();
+ while (!force_quit) {
/*
* TX burst queue drain
@@ -692,6 +691,8 @@ em_main_loop(__rte_unused void *dummy)
portid, qconf);
#endif
}
+
+ cur_tsc = rte_rdtsc();
}
return 0;
diff --git a/examples/l3fwd/l3fwd_lpm.c b/examples/l3fwd/l3fwd_lpm.c
index 3dcf1fef1..375746fef 100644
--- a/examples/l3fwd/l3fwd_lpm.c
+++ b/examples/l3fwd/l3fwd_lpm.c
@@ -185,8 +185,6 @@ lpm_main_loop(__rte_unused void *dummy)
const uint64_t drain_tsc = (rte_get_tsc_hz() + US_PER_S - 1) /
US_PER_S * BURST_TX_DRAIN_US;
- prev_tsc = 0;
-
lcore_id = rte_lcore_id();
qconf = &lcore_conf[lcore_id];
@@ -206,9 +204,10 @@ lpm_main_loop(__rte_unused void *dummy)
lcore_id, portid, queueid);
}
- while (!force_quit) {
+ cur_tsc = rte_rdtsc();
+ prev_tsc = cur_tsc;
- cur_tsc = rte_rdtsc();
+ while (!force_quit) {
/*
* TX burst queue drain
@@ -249,6 +248,8 @@ lpm_main_loop(__rte_unused void *dummy)
portid, qconf);
#endif /* X86 */
}
+
+ cur_tsc = rte_rdtsc();
}
return 0;
--
2.17.1
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [dpdk-dev] [PATCH] examples/l3fwd: fix TX burst queue drain edge case
2021-02-23 18:23 [dpdk-dev] [PATCH] examples/l3fwd: fix TX burst queue drain edge case Kathleen Capella
@ 2021-03-24 17:15 ` Thomas Monjalon
2021-03-26 16:27 ` Kathleen Capella
2021-04-08 21:35 ` [dpdk-dev] [PATCH v2] examples/l3fwd: skip TX queue drain on first iteration Kathleen Capella
1 sibling, 1 reply; 5+ messages in thread
From: Thomas Monjalon @ 2021-03-24 17:15 UTC (permalink / raw)
To: Kathleen Capella; +Cc: dev, nd, honnappa.nagarahalli
23/02/2021 19:23, Kathleen Capella:
> Initialize prev_tsc to cur_tsc. This avoids running the TX queue drain
> in the first iteration of the packet processing loop.
Is it really a fix? What was broken?
Isn't it an optimization?
> Fixes: af75078fece3 ("first public release")
If it's really a fix, we should probably backport it, so
Cc: stable@dpdk.org
> Signed-off-by: Kathleen Capella <kathleen.capella@arm.com>
> Reviewed-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [dpdk-dev] [PATCH] examples/l3fwd: fix TX burst queue drain edge case
2021-03-24 17:15 ` Thomas Monjalon
@ 2021-03-26 16:27 ` Kathleen Capella
0 siblings, 0 replies; 5+ messages in thread
From: Kathleen Capella @ 2021-03-26 16:27 UTC (permalink / raw)
To: thomas; +Cc: dev, nd, Honnappa Nagarahalli
> -----Original Message-----
> From: Thomas Monjalon <thomas@monjalon.net>
> Sent: Wednesday, March 24, 2021 1:16 PM
> To: Kathleen Capella <Kathleen.Capella@arm.com>
> Cc: dev@dpdk.org; nd <nd@arm.com>; Honnappa Nagarahalli
> <Honnappa.Nagarahalli@arm.com>
> Subject: Re: [dpdk-dev] [PATCH] examples/l3fwd: fix TX burst queue drain edge
> case
>
> 23/02/2021 19:23, Kathleen Capella:
> > Initialize prev_tsc to cur_tsc. This avoids running the TX queue drain
> > in the first iteration of the packet processing loop.
>
> Is it really a fix? What was broken?
> Isn't it an optimization?
It could be considered an optimization since effectively it prevents entering the if statement on the
first iteration of the loop. I will remove the "fixes" line and reword the subject line.
>
> > Fixes: af75078fece3 ("first public release")
>
> If it's really a fix, we should probably backport it, so
> Cc: stable@dpdk.org
[Kathleen Capella]
It is not really a significant problem to be fixed in previous releases so it does not need to be backported.
>
> > Signed-off-by: Kathleen Capella <kathleen.capella@arm.com>
> > Reviewed-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
>
>
^ permalink raw reply [flat|nested] 5+ messages in thread
* [dpdk-dev] [PATCH v2] examples/l3fwd: skip TX queue drain on first iteration
2021-02-23 18:23 [dpdk-dev] [PATCH] examples/l3fwd: fix TX burst queue drain edge case Kathleen Capella
2021-03-24 17:15 ` Thomas Monjalon
@ 2021-04-08 21:35 ` Kathleen Capella
2021-04-20 1:12 ` Thomas Monjalon
1 sibling, 1 reply; 5+ messages in thread
From: Kathleen Capella @ 2021-04-08 21:35 UTC (permalink / raw)
To: dev; +Cc: nd, honnappa.nagarahalli, kathleen.capella, thomas
Initialize prev_tsc to cur_tsc. This avoids running the TX queue drain
in the first iteration of the packet processing loop.
Signed-off-by: Kathleen Capella <kathleen.capella@arm.com>
Reviewed-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
---
examples/l3fwd/l3fwd_em.c | 9 +++++----
examples/l3fwd/l3fwd_lpm.c | 9 +++++----
2 files changed, 10 insertions(+), 8 deletions(-)
diff --git a/examples/l3fwd/l3fwd_em.c b/examples/l3fwd/l3fwd_em.c
index 9996bfba3..01f8dff48 100644
--- a/examples/l3fwd/l3fwd_em.c
+++ b/examples/l3fwd/l3fwd_em.c
@@ -629,8 +629,6 @@ em_main_loop(__rte_unused void *dummy)
const uint64_t drain_tsc = (rte_get_tsc_hz() + US_PER_S - 1) /
US_PER_S * BURST_TX_DRAIN_US;
- prev_tsc = 0;
-
lcore_id = rte_lcore_id();
qconf = &lcore_conf[lcore_id];
@@ -650,9 +648,10 @@ em_main_loop(__rte_unused void *dummy)
lcore_id, portid, queueid);
}
- while (!force_quit) {
+ cur_tsc = rte_rdtsc();
+ prev_tsc = cur_tsc;
- cur_tsc = rte_rdtsc();
+ while (!force_quit) {
/*
* TX burst queue drain
@@ -692,6 +691,8 @@ em_main_loop(__rte_unused void *dummy)
portid, qconf);
#endif
}
+
+ cur_tsc = rte_rdtsc();
}
return 0;
diff --git a/examples/l3fwd/l3fwd_lpm.c b/examples/l3fwd/l3fwd_lpm.c
index 3dcf1fef1..375746fef 100644
--- a/examples/l3fwd/l3fwd_lpm.c
+++ b/examples/l3fwd/l3fwd_lpm.c
@@ -185,8 +185,6 @@ lpm_main_loop(__rte_unused void *dummy)
const uint64_t drain_tsc = (rte_get_tsc_hz() + US_PER_S - 1) /
US_PER_S * BURST_TX_DRAIN_US;
- prev_tsc = 0;
-
lcore_id = rte_lcore_id();
qconf = &lcore_conf[lcore_id];
@@ -206,9 +204,10 @@ lpm_main_loop(__rte_unused void *dummy)
lcore_id, portid, queueid);
}
- while (!force_quit) {
+ cur_tsc = rte_rdtsc();
+ prev_tsc = cur_tsc;
- cur_tsc = rte_rdtsc();
+ while (!force_quit) {
/*
* TX burst queue drain
@@ -249,6 +248,8 @@ lpm_main_loop(__rte_unused void *dummy)
portid, qconf);
#endif /* X86 */
}
+
+ cur_tsc = rte_rdtsc();
}
return 0;
--
2.17.1
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2021-04-20 1:12 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-02-23 18:23 [dpdk-dev] [PATCH] examples/l3fwd: fix TX burst queue drain edge case Kathleen Capella
2021-03-24 17:15 ` Thomas Monjalon
2021-03-26 16:27 ` Kathleen Capella
2021-04-08 21:35 ` [dpdk-dev] [PATCH v2] examples/l3fwd: skip TX queue drain on first iteration Kathleen Capella
2021-04-20 1:12 ` Thomas Monjalon
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).