| Message ID | 20230314030532.9238-3-kerneljasonxing@gmail.com (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | add some detailed data when reading softnet_stat | expand |
On Tue, Mar 14, 2023 at 11:05:32AM +0800, Jason Xing wrote: > From: Jason Xing <kernelxing@tencent.com> > > When we encounter some performance issue and then get lost on how > to tune the budget limit and time limit in net_rx_action() function, > we can separately counting both of them to avoid the confusion. > > Signed-off-by: Jason Xing <kernelxing@tencent.com> As per my comment on patch 1/2, I'd drop the "/* keep it untouched */" comment. That notwithstanding: Reviewed-by: Simon Horman <simon.horman@corigine.com> > --- > v2: > 1) change the coding style suggested by Stephen and Simon > 2) Keep the display of the old data (time_squeeze) untouched suggested > by Kui-Feng > Link: https://lore.kernel.org/lkml/20230311163614.92296-1-kerneljasonxing@gmail.com/ > --- > include/linux/netdevice.h | 1 + > net/core/dev.c | 12 ++++++++---- > net/core/net-procfs.c | 9 ++++++--- > 3 files changed, 15 insertions(+), 7 deletions(-) > > diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h > index 6a14b7b11766..5736311a2133 100644 > --- a/include/linux/netdevice.h > +++ b/include/linux/netdevice.h > @@ -3157,6 +3157,7 @@ struct softnet_data { > /* stats */ > unsigned int processed; > unsigned int time_squeeze; > + unsigned int budget_squeeze; > #ifdef CONFIG_RPS > struct softnet_data *rps_ipi_list; > #endif > diff --git a/net/core/dev.c b/net/core/dev.c > index 253584777101..1518a366783b 100644 > --- a/net/core/dev.c > +++ b/net/core/dev.c > @@ -6637,6 +6637,7 @@ static __latent_entropy void net_rx_action(struct softirq_action *h) > unsigned long time_limit = jiffies + > usecs_to_jiffies(READ_ONCE(netdev_budget_usecs)); > int budget = READ_ONCE(netdev_budget); > + bool done = false; > LIST_HEAD(list); > LIST_HEAD(repoll); > > @@ -6644,7 +6645,7 @@ static __latent_entropy void net_rx_action(struct softirq_action *h) > list_splice_init(&sd->poll_list, &list); > local_irq_enable(); > > - for (;;) { > + while (!done) { > struct napi_struct *n; > > skb_defer_free_flush(sd); > @@ -6662,10 +6663,13 @@ static __latent_entropy void net_rx_action(struct softirq_action *h) > * Allow this to run for 2 jiffies since which will allow > * an average latency of 1.5/HZ. > */ > - if (unlikely(budget <= 0 || > - time_after_eq(jiffies, time_limit))) { > + if (unlikely(budget <= 0)) { > + sd->budget_squeeze++; > + done = true; > + } > + if (unlikely(time_after_eq(jiffies, time_limit))) { > sd->time_squeeze++; > - break; > + done = true; > } > } > > diff --git a/net/core/net-procfs.c b/net/core/net-procfs.c > index 2809b663e78d..25810ee46a04 100644 > --- a/net/core/net-procfs.c > +++ b/net/core/net-procfs.c > @@ -179,14 +179,17 @@ static int softnet_seq_show(struct seq_file *seq, void *v) > */ > seq_printf(seq, > "%08x %08x %08x %08x %08x %08x %08x %08x %08x %08x %08x %08x %08x " > - "%08x %08x\n", > - sd->processed, sd->dropped, sd->time_squeeze, 0, > + "%08x %08x %08x %08x\n", > + sd->processed, sd->dropped, > + sd->time_squeeze + sd->budget_squeeze, /* keep it untouched */ > + 0, > 0, 0, 0, 0, /* was fastroute */ > 0, /* was cpu_collision */ > sd->received_rps, flow_limit_count, > softnet_backlog_len(sd), /* keep it untouched */ > (int)seq->index, > - softnet_input_pkt_queue_len(sd), softnet_process_queue_len(sd)); > + softnet_input_pkt_queue_len(sd), softnet_process_queue_len(sd), > + sd->time_squeeze, sd->budget_squeeze); > return 0; > } > > -- > 2.37.3 >
On Tue, Mar 14, 2023 at 8:04 PM Simon Horman <simon.horman@corigine.com> wrote: > > On Tue, Mar 14, 2023 at 11:05:32AM +0800, Jason Xing wrote: > > From: Jason Xing <kernelxing@tencent.com> > > > > When we encounter some performance issue and then get lost on how > > to tune the budget limit and time limit in net_rx_action() function, > > we can separately counting both of them to avoid the confusion. > > > > Signed-off-by: Jason Xing <kernelxing@tencent.com> > > As per my comment on patch 1/2, I'd drop the "/* keep it untouched */" > comment. I think you're right. I'll drop this. Thanks, Jason > > That notwithstanding: > > Reviewed-by: Simon Horman <simon.horman@corigine.com> > > > --- > > v2: > > 1) change the coding style suggested by Stephen and Simon > > 2) Keep the display of the old data (time_squeeze) untouched suggested > > by Kui-Feng > > Link: https://lore.kernel.org/lkml/20230311163614.92296-1-kerneljasonxing@gmail.com/ > > --- > > include/linux/netdevice.h | 1 + > > net/core/dev.c | 12 ++++++++---- > > net/core/net-procfs.c | 9 ++++++--- > > 3 files changed, 15 insertions(+), 7 deletions(-) > > > > diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h > > index 6a14b7b11766..5736311a2133 100644 > > --- a/include/linux/netdevice.h > > +++ b/include/linux/netdevice.h > > @@ -3157,6 +3157,7 @@ struct softnet_data { > > /* stats */ > > unsigned int processed; > > unsigned int time_squeeze; > > + unsigned int budget_squeeze; > > #ifdef CONFIG_RPS > > struct softnet_data *rps_ipi_list; > > #endif > > diff --git a/net/core/dev.c b/net/core/dev.c > > index 253584777101..1518a366783b 100644 > > --- a/net/core/dev.c > > +++ b/net/core/dev.c > > @@ -6637,6 +6637,7 @@ static __latent_entropy void net_rx_action(struct softirq_action *h) > > unsigned long time_limit = jiffies + > > usecs_to_jiffies(READ_ONCE(netdev_budget_usecs)); > > int budget = READ_ONCE(netdev_budget); > > + bool done = false; > > LIST_HEAD(list); > > LIST_HEAD(repoll); > > > > @@ -6644,7 +6645,7 @@ static __latent_entropy void net_rx_action(struct softirq_action *h) > > list_splice_init(&sd->poll_list, &list); > > local_irq_enable(); > > > > - for (;;) { > > + while (!done) { > > struct napi_struct *n; > > > > skb_defer_free_flush(sd); > > @@ -6662,10 +6663,13 @@ static __latent_entropy void net_rx_action(struct softirq_action *h) > > * Allow this to run for 2 jiffies since which will allow > > * an average latency of 1.5/HZ. > > */ > > - if (unlikely(budget <= 0 || > > - time_after_eq(jiffies, time_limit))) { > > + if (unlikely(budget <= 0)) { > > + sd->budget_squeeze++; > > + done = true; > > + } > > + if (unlikely(time_after_eq(jiffies, time_limit))) { > > sd->time_squeeze++; > > - break; > > + done = true; > > } > > } > > > > diff --git a/net/core/net-procfs.c b/net/core/net-procfs.c > > index 2809b663e78d..25810ee46a04 100644 > > --- a/net/core/net-procfs.c > > +++ b/net/core/net-procfs.c > > @@ -179,14 +179,17 @@ static int softnet_seq_show(struct seq_file *seq, void *v) > > */ > > seq_printf(seq, > > "%08x %08x %08x %08x %08x %08x %08x %08x %08x %08x %08x %08x %08x " > > - "%08x %08x\n", > > - sd->processed, sd->dropped, sd->time_squeeze, 0, > > + "%08x %08x %08x %08x\n", > > + sd->processed, sd->dropped, > > + sd->time_squeeze + sd->budget_squeeze, /* keep it untouched */ > > + 0, > > 0, 0, 0, 0, /* was fastroute */ > > 0, /* was cpu_collision */ > > sd->received_rps, flow_limit_count, > > softnet_backlog_len(sd), /* keep it untouched */ > > (int)seq->index, > > - softnet_input_pkt_queue_len(sd), softnet_process_queue_len(sd)); > > + softnet_input_pkt_queue_len(sd), softnet_process_queue_len(sd), > > + sd->time_squeeze, sd->budget_squeeze); > > return 0; > > } > > > > -- > > 2.37.3 > >
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 6a14b7b11766..5736311a2133 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -3157,6 +3157,7 @@ struct softnet_data { /* stats */ unsigned int processed; unsigned int time_squeeze; + unsigned int budget_squeeze; #ifdef CONFIG_RPS struct softnet_data *rps_ipi_list; #endif diff --git a/net/core/dev.c b/net/core/dev.c index 253584777101..1518a366783b 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -6637,6 +6637,7 @@ static __latent_entropy void net_rx_action(struct softirq_action *h) unsigned long time_limit = jiffies + usecs_to_jiffies(READ_ONCE(netdev_budget_usecs)); int budget = READ_ONCE(netdev_budget); + bool done = false; LIST_HEAD(list); LIST_HEAD(repoll); @@ -6644,7 +6645,7 @@ static __latent_entropy void net_rx_action(struct softirq_action *h) list_splice_init(&sd->poll_list, &list); local_irq_enable(); - for (;;) { + while (!done) { struct napi_struct *n; skb_defer_free_flush(sd); @@ -6662,10 +6663,13 @@ static __latent_entropy void net_rx_action(struct softirq_action *h) * Allow this to run for 2 jiffies since which will allow * an average latency of 1.5/HZ. */ - if (unlikely(budget <= 0 || - time_after_eq(jiffies, time_limit))) { + if (unlikely(budget <= 0)) { + sd->budget_squeeze++; + done = true; + } + if (unlikely(time_after_eq(jiffies, time_limit))) { sd->time_squeeze++; - break; + done = true; } } diff --git a/net/core/net-procfs.c b/net/core/net-procfs.c index 2809b663e78d..25810ee46a04 100644 --- a/net/core/net-procfs.c +++ b/net/core/net-procfs.c @@ -179,14 +179,17 @@ static int softnet_seq_show(struct seq_file *seq, void *v) */ seq_printf(seq, "%08x %08x %08x %08x %08x %08x %08x %08x %08x %08x %08x %08x %08x " - "%08x %08x\n", - sd->processed, sd->dropped, sd->time_squeeze, 0, + "%08x %08x %08x %08x\n", + sd->processed, sd->dropped, + sd->time_squeeze + sd->budget_squeeze, /* keep it untouched */ + 0, 0, 0, 0, 0, /* was fastroute */ 0, /* was cpu_collision */ sd->received_rps, flow_limit_count, softnet_backlog_len(sd), /* keep it untouched */ (int)seq->index, - softnet_input_pkt_queue_len(sd), softnet_process_queue_len(sd)); + softnet_input_pkt_queue_len(sd), softnet_process_queue_len(sd), + sd->time_squeeze, sd->budget_squeeze); return 0; }