Message ID | 20240930092416.80830-2-kerneljasonxing@gmail.com (mailing list archive) |
---|---|
State | New |
Delegated to: | Netdev Maintainers |
Headers | show |
Series | net-timestamp: add some trivial | expand |
Jason Xing wrote: > From: Jason Xing <kernelxing@tencent.com> > > Even though this case is unlikely to happen, we have to avoid such > a case occurring at an earlier point: the sk_rmem_alloc could get > increased because of inserting more and more skbs into the errqueue > when calling __skb_complete_tx_timestamp(). This bad case would stop > the socket transmitting soon. It is up to the application to read from the error queue frequently enough and/or increase SO_RCVBUF. > Signed-off-by: Jason Xing <kernelxing@tencent.com> > --- > net/core/sock.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/net/core/sock.c b/net/core/sock.c > index fe87f9bd8f16..4bddd6f62e4f 100644 > --- a/net/core/sock.c > +++ b/net/core/sock.c > @@ -905,6 +905,10 @@ int sock_set_timestamping(struct sock *sk, int optname, > if (val & ~SOF_TIMESTAMPING_MASK) > return -EINVAL; > > + if (val & SOF_TIMESTAMPING_TX_RECORD_MASK && > + !(val & SOF_TIMESTAMPING_SOFTWARE)) > + return -EINVAL; > + This breaks hardware timestamping > if (val & SOF_TIMESTAMPING_OPT_ID_TCP && > !(val & SOF_TIMESTAMPING_OPT_ID)) > return -EINVAL; > -- > 2.37.3 >
On 30/09/2024 10:24, Jason Xing wrote: > From: Jason Xing <kernelxing@tencent.com> > > Even though this case is unlikely to happen, we have to avoid such > a case occurring at an earlier point: the sk_rmem_alloc could get > increased because of inserting more and more skbs into the errqueue > when calling __skb_complete_tx_timestamp(). This bad case would stop > the socket transmitting soon. > > Signed-off-by: Jason Xing <kernelxing@tencent.com> > --- > net/core/sock.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/net/core/sock.c b/net/core/sock.c > index fe87f9bd8f16..4bddd6f62e4f 100644 > --- a/net/core/sock.c > +++ b/net/core/sock.c > @@ -905,6 +905,10 @@ int sock_set_timestamping(struct sock *sk, int optname, > if (val & ~SOF_TIMESTAMPING_MASK) > return -EINVAL; > > + if (val & SOF_TIMESTAMPING_TX_RECORD_MASK && > + !(val & SOF_TIMESTAMPING_SOFTWARE)) > + return -EINVAL; SOF_TIMESTAMPING_TX_RECORD_MASK contains SOF_TIMESTAMPING_TX_HARDWARE. That means that there will be no option to enable HW TX timestamping without enabling software timestamping. I believe this is wrong restriction. > + > if (val & SOF_TIMESTAMPING_OPT_ID_TCP && > !(val & SOF_TIMESTAMPING_OPT_ID)) > return -EINVAL;
On Mon, Sep 30, 2024 at 6:48 PM Vadim Fedorenko <vadim.fedorenko@linux.dev> wrote: > > On 30/09/2024 10:24, Jason Xing wrote: > > From: Jason Xing <kernelxing@tencent.com> > > > > Even though this case is unlikely to happen, we have to avoid such > > a case occurring at an earlier point: the sk_rmem_alloc could get > > increased because of inserting more and more skbs into the errqueue > > when calling __skb_complete_tx_timestamp(). This bad case would stop > > the socket transmitting soon. > > > > Signed-off-by: Jason Xing <kernelxing@tencent.com> > > --- > > net/core/sock.c | 4 ++++ > > 1 file changed, 4 insertions(+) > > > > diff --git a/net/core/sock.c b/net/core/sock.c > > index fe87f9bd8f16..4bddd6f62e4f 100644 > > --- a/net/core/sock.c > > +++ b/net/core/sock.c > > @@ -905,6 +905,10 @@ int sock_set_timestamping(struct sock *sk, int optname, > > if (val & ~SOF_TIMESTAMPING_MASK) > > return -EINVAL; > > > > + if (val & SOF_TIMESTAMPING_TX_RECORD_MASK && > > + !(val & SOF_TIMESTAMPING_SOFTWARE)) > > + return -EINVAL; > > SOF_TIMESTAMPING_TX_RECORD_MASK contains SOF_TIMESTAMPING_TX_HARDWARE. > That means that there will be no option to enable HW TX timestamping > without enabling software timestamping. I believe this is wrong > restriction. Thanks! You are right. I should have realized that. I need to get rid of this one. Thanks, Jason
On Mon, Sep 30, 2024 at 6:39 PM Willem de Bruijn <willemdebruijn.kernel@gmail.com> wrote: > > Jason Xing wrote: > > From: Jason Xing <kernelxing@tencent.com> > > > > Even though this case is unlikely to happen, we have to avoid such > > a case occurring at an earlier point: the sk_rmem_alloc could get > > increased because of inserting more and more skbs into the errqueue > > when calling __skb_complete_tx_timestamp(). This bad case would stop > > the socket transmitting soon. > > It is up to the application to read from the error queue frequently > enough and/or increase SO_RCVBUF. Sure thing. If we test it without setting SOF_TIMESTAMPING_SOFTWARE on the loopback, it will soon stop. That's the reason why I tried to add the restriction just in case. > > > Signed-off-by: Jason Xing <kernelxing@tencent.com> > > --- > > net/core/sock.c | 4 ++++ > > 1 file changed, 4 insertions(+) > > > > diff --git a/net/core/sock.c b/net/core/sock.c > > index fe87f9bd8f16..4bddd6f62e4f 100644 > > --- a/net/core/sock.c > > +++ b/net/core/sock.c > > @@ -905,6 +905,10 @@ int sock_set_timestamping(struct sock *sk, int optname, > > if (val & ~SOF_TIMESTAMPING_MASK) > > return -EINVAL; > > > > + if (val & SOF_TIMESTAMPING_TX_RECORD_MASK && > > + !(val & SOF_TIMESTAMPING_SOFTWARE)) > > + return -EINVAL; > > + > > This breaks hardware timestamping Yes, and sorry about that. I'll fix this. > > > if (val & SOF_TIMESTAMPING_OPT_ID_TCP && > > !(val & SOF_TIMESTAMPING_OPT_ID)) > > return -EINVAL; > > -- > > 2.37.3 > > > >
Jason Xing wrote: > On Mon, Sep 30, 2024 at 6:39 PM Willem de Bruijn > <willemdebruijn.kernel@gmail.com> wrote: > > > > Jason Xing wrote: > > > From: Jason Xing <kernelxing@tencent.com> > > > > > > Even though this case is unlikely to happen, we have to avoid such > > > a case occurring at an earlier point: the sk_rmem_alloc could get > > > increased because of inserting more and more skbs into the errqueue > > > when calling __skb_complete_tx_timestamp(). This bad case would stop > > > the socket transmitting soon. > > > > It is up to the application to read from the error queue frequently > > enough and/or increase SO_RCVBUF. > > Sure thing. If we test it without setting SOF_TIMESTAMPING_SOFTWARE on > the loopback, it will soon stop. That's the reason why I tried to add > the restriction just in case. I don't follow at all. That bit does not affect the core issue: that the application is not clearing its error queue quickly enough. > > > > > Signed-off-by: Jason Xing <kernelxing@tencent.com> > > > --- > > > net/core/sock.c | 4 ++++ > > > 1 file changed, 4 insertions(+) > > > > > > diff --git a/net/core/sock.c b/net/core/sock.c > > > index fe87f9bd8f16..4bddd6f62e4f 100644 > > > --- a/net/core/sock.c > > > +++ b/net/core/sock.c > > > @@ -905,6 +905,10 @@ int sock_set_timestamping(struct sock *sk, int optname, > > > if (val & ~SOF_TIMESTAMPING_MASK) > > > return -EINVAL; > > > > > > + if (val & SOF_TIMESTAMPING_TX_RECORD_MASK && > > > + !(val & SOF_TIMESTAMPING_SOFTWARE)) > > > + return -EINVAL; > > > + > > > > This breaks hardware timestamping > > Yes, and sorry about that. I'll fix this. As is I don't understand the purpose of this patch. Please do not just resubmit with a change, but explain the problem and suggested solution first. > > > > > if (val & SOF_TIMESTAMPING_OPT_ID_TCP && > > > !(val & SOF_TIMESTAMPING_OPT_ID)) > > > return -EINVAL; > > > -- > > > 2.37.3 > > > > > > >
On Mon, Sep 30, 2024 at 7:49 PM Willem de Bruijn <willemdebruijn.kernel@gmail.com> wrote: > > Jason Xing wrote: > > On Mon, Sep 30, 2024 at 6:39 PM Willem de Bruijn > > <willemdebruijn.kernel@gmail.com> wrote: > > > > > > Jason Xing wrote: > > > > From: Jason Xing <kernelxing@tencent.com> > > > > > > > > Even though this case is unlikely to happen, we have to avoid such > > > > a case occurring at an earlier point: the sk_rmem_alloc could get > > > > increased because of inserting more and more skbs into the errqueue > > > > when calling __skb_complete_tx_timestamp(). This bad case would stop > > > > the socket transmitting soon. > > > > > > It is up to the application to read from the error queue frequently > > > enough and/or increase SO_RCVBUF. > > > > Sure thing. If we test it without setting SOF_TIMESTAMPING_SOFTWARE on > > the loopback, it will soon stop. That's the reason why I tried to add > > the restriction just in case. > > I don't follow at all. > > That bit does not affect the core issue: that the application is not > clearing its error queue quickly enough. > > > > > > > > Signed-off-by: Jason Xing <kernelxing@tencent.com> > > > > --- > > > > net/core/sock.c | 4 ++++ > > > > 1 file changed, 4 insertions(+) > > > > > > > > diff --git a/net/core/sock.c b/net/core/sock.c > > > > index fe87f9bd8f16..4bddd6f62e4f 100644 > > > > --- a/net/core/sock.c > > > > +++ b/net/core/sock.c > > > > @@ -905,6 +905,10 @@ int sock_set_timestamping(struct sock *sk, int optname, > > > > if (val & ~SOF_TIMESTAMPING_MASK) > > > > return -EINVAL; > > > > > > > > + if (val & SOF_TIMESTAMPING_TX_RECORD_MASK && > > > > + !(val & SOF_TIMESTAMPING_SOFTWARE)) > > > > + return -EINVAL; > > > > + > > > > > > This breaks hardware timestamping > > > > Yes, and sorry about that. I'll fix this. > > As is I don't understand the purpose of this patch. Please do not > just resubmit with a change, but explain the problem and suggested > solution first. > I will drop this patch because I just tested with my program in the local machine and found there is one mistake I made about calculating the diff between those two . Sorry for the noise. Well, I only need to send a V2 patch of patch [3/3] in the next few days. BTW, please allow me to ask one question unrelated to this patch again. I do wonder: if we batch the recv skbs from the errqueue when calling tcp_recvmsg() -> inet_recv_error(), it could break users, right? Thanks, Jason
diff --git a/net/core/sock.c b/net/core/sock.c index fe87f9bd8f16..4bddd6f62e4f 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -905,6 +905,10 @@ int sock_set_timestamping(struct sock *sk, int optname, if (val & ~SOF_TIMESTAMPING_MASK) return -EINVAL; + if (val & SOF_TIMESTAMPING_TX_RECORD_MASK && + !(val & SOF_TIMESTAMPING_SOFTWARE)) + return -EINVAL; + if (val & SOF_TIMESTAMPING_OPT_ID_TCP && !(val & SOF_TIMESTAMPING_OPT_ID)) return -EINVAL;