| Message ID | 20210715060021.43249-1-xiyou.wangcong@gmail.com |
|---|---|
| State | New |
| Headers | show |
| Series | [net-next,resend,v2] net_sched: use %px to print skb address in trace_qdisc_dequeue() | expand |
On 2021/7/15 14:00, Cong Wang wrote: > From: Qitao Xu <qitao.xu@bytedance.com> > > Print format of skbaddr is changed to %px from %p, because we want > to use skb address as a quick way to identify a packet. > > Note, trace ring buffer is only accessible to privileged users, > it is safe to use a real kernel address here. Does it make more sense to use %pK? see: https://lwn.net/Articles/420403/ > > Reviewed-by: Cong Wang <cong.wang@bytedance.com> > Signed-off-by: Qitao Xu <qitao.xu@bytedance.com> > --- > include/trace/events/qdisc.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/include/trace/events/qdisc.h b/include/trace/events/qdisc.h > index 330d32d84485..58209557cb3a 100644 > --- a/include/trace/events/qdisc.h > +++ b/include/trace/events/qdisc.h > @@ -41,7 +41,7 @@ TRACE_EVENT(qdisc_dequeue, > __entry->txq_state = txq->state; > ), > > - TP_printk("dequeue ifindex=%d qdisc handle=0x%X parent=0x%X txq_state=0x%lX packets=%d skbaddr=%p", > + TP_printk("dequeue ifindex=%d qdisc handle=0x%X parent=0x%X txq_state=0x%lX packets=%d skbaddr=%px", > __entry->ifindex, __entry->handle, __entry->parent, > __entry->txq_state, __entry->packets, __entry->skbaddr ) > ); >
On Thu, Jul 15, 2021 at 4:26 AM Yunsheng Lin <linyunsheng@huawei.com> wrote: > > On 2021/7/15 14:00, Cong Wang wrote: > > From: Qitao Xu <qitao.xu@bytedance.com> > > > > Print format of skbaddr is changed to %px from %p, because we want > > to use skb address as a quick way to identify a packet. > > > > Note, trace ring buffer is only accessible to privileged users, > > it is safe to use a real kernel address here. > > Does it make more sense to use %pK? > > see: https://lwn.net/Articles/420403/ I think you have the answer: + * %pK cannot be used in IRQ context because it tests + * CAP_SYSLOG. ;) So, no. Thanks.
diff --git a/include/trace/events/qdisc.h b/include/trace/events/qdisc.h index 330d32d84485..58209557cb3a 100644 --- a/include/trace/events/qdisc.h +++ b/include/trace/events/qdisc.h @@ -41,7 +41,7 @@ TRACE_EVENT(qdisc_dequeue, __entry->txq_state = txq->state; ), - TP_printk("dequeue ifindex=%d qdisc handle=0x%X parent=0x%X txq_state=0x%lX packets=%d skbaddr=%p", + TP_printk("dequeue ifindex=%d qdisc handle=0x%X parent=0x%X txq_state=0x%lX packets=%d skbaddr=%px", __entry->ifindex, __entry->handle, __entry->parent, __entry->txq_state, __entry->packets, __entry->skbaddr ) );