| Message ID | 1486226225-29997-1-git-send-email-jianbo.liu@linaro.org |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [v3,1/2] net/ixgbe: calculate the correct number of received packets in bulk alloc function | expand |
On 5 February 2017 at 00:37, Jianbo Liu <jianbo.liu@linaro.org> wrote: > To get better performance, Rx bulk alloc recv function will scan 8 descs > in one time, but the statuses are not consistent on ARM platform because > the memory allocated for Rx descriptors is cacheable hugepages. > This patch is to calculate the number of received packets by scan DD bit > sequentially, and stops when meeting the first packet with DD bit unset. > > Signed-off-by: Jianbo Liu <jianbo.liu@linaro.org> > --- > drivers/net/ixgbe/ixgbe_rxtx.c | 16 +++++++++------- > 1 file changed, 9 insertions(+), 7 deletions(-) > > diff --git a/drivers/net/ixgbe/ixgbe_rxtx.c b/drivers/net/ixgbe/ixgbe_rxtx.c > index 36f1c02..613890e 100644 > --- a/drivers/net/ixgbe/ixgbe_rxtx.c > +++ b/drivers/net/ixgbe/ixgbe_rxtx.c There is no change for this patch from v2 to v3. But the other in this patchset, reading desc statuses is changed to be in order, not backward.
diff --git a/drivers/net/ixgbe/ixgbe_rxtx.c b/drivers/net/ixgbe/ixgbe_rxtx.c index 36f1c02..613890e 100644 --- a/drivers/net/ixgbe/ixgbe_rxtx.c +++ b/drivers/net/ixgbe/ixgbe_rxtx.c @@ -1460,17 +1460,19 @@ static inline int __attribute__((always_inline)) for (i = 0; i < RTE_PMD_IXGBE_RX_MAX_BURST; i += LOOK_AHEAD, rxdp += LOOK_AHEAD, rxep += LOOK_AHEAD) { /* Read desc statuses backwards to avoid race condition */ - for (j = LOOK_AHEAD-1; j >= 0; --j) + for (j = 0; j < LOOK_AHEAD; j++) s[j] = rte_le_to_cpu_32(rxdp[j].wb.upper.status_error); - for (j = LOOK_AHEAD - 1; j >= 0; --j) - pkt_info[j] = rte_le_to_cpu_32(rxdp[j].wb.lower. - lo_dword.data); + rte_smp_rmb(); /* Compute how many status bits were set */ - nb_dd = 0; - for (j = 0; j < LOOK_AHEAD; ++j) - nb_dd += s[j] & IXGBE_RXDADV_STAT_DD; + for (nb_dd = 0; nb_dd < LOOK_AHEAD && + (s[nb_dd] & IXGBE_RXDADV_STAT_DD); nb_dd++) + ; + + for (j = 0; j < nb_dd; j++) + pkt_info[j] = rte_le_to_cpu_32(rxdp[j].wb.lower. + lo_dword.data); nb_rx += nb_dd;
To get better performance, Rx bulk alloc recv function will scan 8 descs in one time, but the statuses are not consistent on ARM platform because the memory allocated for Rx descriptors is cacheable hugepages. This patch is to calculate the number of received packets by scan DD bit sequentially, and stops when meeting the first packet with DD bit unset. Signed-off-by: Jianbo Liu <jianbo.liu@linaro.org> --- drivers/net/ixgbe/ixgbe_rxtx.c | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-) -- 1.8.3.1