On Tue, Mar 14, 2023 at 4:07 AM Simon Horman <simon.horman@xxxxxxxxxxxx> wrote: > > On Mon, Mar 13, 2023 at 10:05:18AM +0800, Jason Xing wrote: > > On Sun, Mar 12, 2023 at 12:36 AM Jason Xing <kerneljasonxing@xxxxxxxxx> wrote: > > > > > > From: Jason Xing <kernelxing@xxxxxxxxxxx> > > > > > > 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@xxxxxxxxxxx> > > > --- > > > note: this commit is based on the link as below: > > > https://lore.kernel.org/lkml/20230311151756.83302-1-kerneljasonxing@xxxxxxxxx/ > > > --- > > > 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..bed7a68fdb5d 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 is_continue = true; > > > > I kept thinking during these days, I think it looks not that concise > > and elegant and also the name is not that good though the function can > > work. > > > > In the next submission, I'm going to choose to use 'while()' instead > > of 'for()' suggested by Stephen. > > > > Does anyone else have some advice about this? > > What about: > > int done = false > > while (!done) { > ... > } > > Or: > > for (;;) { > int done = false; > > ... > if (done) > break; > } > Great, that looks much better:) Thanks, Jason > > > > Thanks, > > Jason > > > > > 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 (;;) { > > > + for (; is_continue;) { > > > 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++; > > > + is_continue = false; > > > + } > > > + if (unlikely(time_after_eq(jiffies, time_limit))) { > > > sd->time_squeeze++; > > > - break; > > > + is_continue = false; > > > } > > > } > > > > > > diff --git a/net/core/net-procfs.c b/net/core/net-procfs.c > > > index 97a304e1957a..4d1a499d7c43 100644 > > > --- a/net/core/net-procfs.c > > > +++ b/net/core/net-procfs.c > > > @@ -174,14 +174,17 @@ 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, > > > + 0, /* was old way to count time squeeze */ > > > + 0, > > > 0, 0, 0, 0, /* was fastroute */ > > > 0, /* was cpu_collision */ > > > sd->received_rps, flow_limit_count, > > > 0, /* was len of two backlog queues */ > > > (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 > > > > >
