| Message ID | 20190610115831.175710-1-maowenan@huawei.com |
|---|---|
| State | Changes Requested |
| Delegated to: | David Miller |
| Headers | show |
| Series | [-next] packet: remove unused variable 'status' in __packet_lookup_frame_in_block | expand |
On Mon, Jun 10, 2019 at 8:17 AM Mao Wenan <maowenan@huawei.com> wrote: > > The variable 'status' in __packet_lookup_frame_in_block() is never used since > introduction in commit f6fb8f100b80 ("af-packet: TPACKET_V3 flexible buffer > implementation."), we can remove it. > And when __packet_lookup_frame_in_block() calls prb_retire_current_block(), > it can pass macro TP_STATUS_KERNEL instead of 0. > > Signed-off-by: Mao Wenan <maowenan@huawei.com> > --- > net/packet/af_packet.c | 5 ++--- > 1 file changed, 2 insertions(+), 3 deletions(-) > > diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c > index a29d66d..fb1a79c 100644 > --- a/net/packet/af_packet.c > +++ b/net/packet/af_packet.c > @@ -1003,7 +1003,6 @@ static void prb_fill_curr_block(char *curr, > /* Assumes caller has the sk->rx_queue.lock */ > static void *__packet_lookup_frame_in_block(struct packet_sock *po, > struct sk_buff *skb, > - int status, > unsigned int len > ) > { > @@ -1046,7 +1045,7 @@ static void *__packet_lookup_frame_in_block(struct packet_sock *po, > } > > /* Ok, close the current block */ > - prb_retire_current_block(pkc, po, 0); > + prb_retire_current_block(pkc, po, TP_STATUS_KERNEL); I don't think that 0 is intended to mean TP_STATUS_KERNEL here. prb_retire_current_block calls prb_close_block which sets status to TP_STATUS_USER | stat where stat is 0 or TP_STATUS_BLK_TMO.
On 2019/6/10 21:05, Willem de Bruijn wrote: > On Mon, Jun 10, 2019 at 8:17 AM Mao Wenan <maowenan@huawei.com> wrote: >> >> The variable 'status' in __packet_lookup_frame_in_block() is never used since >> introduction in commit f6fb8f100b80 ("af-packet: TPACKET_V3 flexible buffer >> implementation."), we can remove it. >> And when __packet_lookup_frame_in_block() calls prb_retire_current_block(), >> it can pass macro TP_STATUS_KERNEL instead of 0. >> >> Signed-off-by: Mao Wenan <maowenan@huawei.com> >> --- >> net/packet/af_packet.c | 5 ++--- >> 1 file changed, 2 insertions(+), 3 deletions(-) >> >> diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c >> index a29d66d..fb1a79c 100644 >> --- a/net/packet/af_packet.c >> +++ b/net/packet/af_packet.c >> @@ -1003,7 +1003,6 @@ static void prb_fill_curr_block(char *curr, >> /* Assumes caller has the sk->rx_queue.lock */ >> static void *__packet_lookup_frame_in_block(struct packet_sock *po, >> struct sk_buff *skb, >> - int status, >> unsigned int len >> ) >> { >> @@ -1046,7 +1045,7 @@ static void *__packet_lookup_frame_in_block(struct packet_sock *po, >> } >> >> /* Ok, close the current block */ >> - prb_retire_current_block(pkc, po, 0); >> + prb_retire_current_block(pkc, po, TP_STATUS_KERNEL); > > I don't think that 0 is intended to mean TP_STATUS_KERNEL here. > > prb_retire_current_block calls prb_close_block which sets status to > > TP_STATUS_USER | stat > > where stat is 0 or TP_STATUS_BLK_TMO. #define TP_STATUS_KERNEL 0 #define TP_STATUS_BLK_TMO (1 << 5) Actually, packet_current_rx_frame calls __packet_lookup_frame_in_block with status=TP_STATUS_KERNEL in original code. __packet_lookup_frame_in_block in this function, first is to check whether the currently active block has enough space for the packet, which means status of block should be TP_STATUS_KERNEL, then it calls prb_retire_current_block to retire this block. Since there needs some discussion about means of status, I can send v2 only removing the parameter status of __packet_lookup_frame_in_block? > >
On Mon, Jun 10, 2019 at 10:03 AM maowenan <maowenan@huawei.com> wrote: > > > > On 2019/6/10 21:05, Willem de Bruijn wrote: > > On Mon, Jun 10, 2019 at 8:17 AM Mao Wenan <maowenan@huawei.com> wrote: > >> > >> The variable 'status' in __packet_lookup_frame_in_block() is never used since > >> introduction in commit f6fb8f100b80 ("af-packet: TPACKET_V3 flexible buffer > >> implementation."), we can remove it. > >> And when __packet_lookup_frame_in_block() calls prb_retire_current_block(), > >> it can pass macro TP_STATUS_KERNEL instead of 0. > >> > >> Signed-off-by: Mao Wenan <maowenan@huawei.com> > >> --- > >> /* Ok, close the current block */ > >> - prb_retire_current_block(pkc, po, 0); > >> + prb_retire_current_block(pkc, po, TP_STATUS_KERNEL); > > > > I don't think that 0 is intended to mean TP_STATUS_KERNEL here. > > > > prb_retire_current_block calls prb_close_block which sets status to > > > > TP_STATUS_USER | stat > > > > where stat is 0 or TP_STATUS_BLK_TMO. > > > #define TP_STATUS_KERNEL 0 > #define TP_STATUS_BLK_TMO (1 << 5) > > Actually, packet_current_rx_frame calls __packet_lookup_frame_in_block with status=TP_STATUS_KERNEL > in original code. > > __packet_lookup_frame_in_block in this function, first is to check whether the currently active block > has enough space for the packet, which means status of block should be TP_STATUS_KERNEL, then it calls > prb_retire_current_block to retire this block. I know. I mean that the status here is what is passed to userspace on block retire. It is not intended to be TP_STATUS_USER | TP_STATUS_KERNEL. That makes no sense. > Since there needs some discussion about means of status, I can send v2 only removing the parameter status of > __packet_lookup_frame_in_block? Sounds good.
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index a29d66d..fb1a79c 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -1003,7 +1003,6 @@ static void prb_fill_curr_block(char *curr, /* Assumes caller has the sk->rx_queue.lock */ static void *__packet_lookup_frame_in_block(struct packet_sock *po, struct sk_buff *skb, - int status, unsigned int len ) { @@ -1046,7 +1045,7 @@ static void *__packet_lookup_frame_in_block(struct packet_sock *po, } /* Ok, close the current block */ - prb_retire_current_block(pkc, po, 0); + prb_retire_current_block(pkc, po, TP_STATUS_KERNEL); /* Now, try to dispatch the next block */ curr = (char *)prb_dispatch_next_block(pkc, po); @@ -1075,7 +1074,7 @@ static void *packet_current_rx_frame(struct packet_sock *po, po->rx_ring.head, status); return curr; case TPACKET_V3: - return __packet_lookup_frame_in_block(po, skb, status, len); + return __packet_lookup_frame_in_block(po, skb, len); default: WARN(1, "TPACKET version not supported\n"); BUG();
The variable 'status' in __packet_lookup_frame_in_block() is never used since introduction in commit f6fb8f100b80 ("af-packet: TPACKET_V3 flexible buffer implementation."), we can remove it. And when __packet_lookup_frame_in_block() calls prb_retire_current_block(), it can pass macro TP_STATUS_KERNEL instead of 0. Signed-off-by: Mao Wenan <maowenan@huawei.com> --- net/packet/af_packet.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-)