| Message ID | 20201104223354.63856-5-snelson@pensando.io (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | ionic updates | expand |
On Wed, 2020-11-04 at 14:33 -0800, Shannon Nelson wrote: > We don't need to refill the rx descriptors on every napi > if only a few were handled. Waiting until we can batch up > a few together will save us a few Rx cycles. > > Signed-off-by: Shannon Nelson <snelson@pensando.io> > --- > .../net/ethernet/pensando/ionic/ionic_dev.h | 4 +++- > .../net/ethernet/pensando/ionic/ionic_txrx.c | 18 ++++++++++---- > ---- > 2 files changed, 13 insertions(+), 9 deletions(-) > > diff --git a/drivers/net/ethernet/pensando/ionic/ionic_dev.h > b/drivers/net/ethernet/pensando/ionic/ionic_dev.h > index 6c243b17312c..9064222a087a 100644 > --- a/drivers/net/ethernet/pensando/ionic/ionic_dev.h > +++ b/drivers/net/ethernet/pensando/ionic/ionic_dev.h > @@ -12,8 +12,10 @@ > > #define IONIC_MAX_TX_DESC 8192 > #define IONIC_MAX_RX_DESC 16384 > -#define IONIC_MIN_TXRX_DESC 16 > +#define IONIC_MIN_TXRX_DESC 64 > #define IONIC_DEF_TXRX_DESC 4096 > +#define IONIC_RX_FILL_THRESHOLD 64 isn't 64 a bit high ? 64 is the default napi budget Many drivers do this with bulks of 8/16 but I couldn't find any with higher numbers. also, just for a reference, GRO and XDP they bulk up to 8. but not more. IMHO i think you need to relax the re-fill threshold a bit. > +#define IONIC_RX_FILL_DIV 8 > ... > - if (work_done) > + rx_fill_threshold = min_t(u16, IONIC_RX_FILL_THRESHOLD, > + cq->num_descs / IONIC_RX_FILL_DIV); > + if (work_done && ionic_q_space_avail(cq->bound_q) >= > rx_fill_threshold) > ionic_rx_fill(cq->bound_q); >
On 11/4/20 5:08 PM, Saeed Mahameed wrote: > On Wed, 2020-11-04 at 14:33 -0800, Shannon Nelson wrote: >> We don't need to refill the rx descriptors on every napi >> if only a few were handled. Waiting until we can batch up >> a few together will save us a few Rx cycles. >> >> Signed-off-by: Shannon Nelson <snelson@pensando.io> >> --- >> .../net/ethernet/pensando/ionic/ionic_dev.h | 4 +++- >> .../net/ethernet/pensando/ionic/ionic_txrx.c | 18 ++++++++++---- >> ---- >> 2 files changed, 13 insertions(+), 9 deletions(-) >> >> diff --git a/drivers/net/ethernet/pensando/ionic/ionic_dev.h >> b/drivers/net/ethernet/pensando/ionic/ionic_dev.h >> index 6c243b17312c..9064222a087a 100644 >> --- a/drivers/net/ethernet/pensando/ionic/ionic_dev.h >> +++ b/drivers/net/ethernet/pensando/ionic/ionic_dev.h >> @@ -12,8 +12,10 @@ >> >> #define IONIC_MAX_TX_DESC 8192 >> #define IONIC_MAX_RX_DESC 16384 >> -#define IONIC_MIN_TXRX_DESC 16 >> +#define IONIC_MIN_TXRX_DESC 64 >> #define IONIC_DEF_TXRX_DESC 4096 >> +#define IONIC_RX_FILL_THRESHOLD 64 > isn't 64 a bit high ? 64 is the default napi budget > > Many drivers do this with bulks of 8/16 but I couldn't find any with > higher numbers. > > also, just for a reference, GRO and XDP they bulk up to 8. but not > more. > > IMHO i think you need to relax the re-fill threshold a bit. Yeah, the work being done internally on tuning has been a bit aggressive, I can dial this back a bit. sln > >> +#define IONIC_RX_FILL_DIV 8 >> > ... > >> - if (work_done) >> + rx_fill_threshold = min_t(u16, IONIC_RX_FILL_THRESHOLD, >> + cq->num_descs / IONIC_RX_FILL_DIV); >> + if (work_done && ionic_q_space_avail(cq->bound_q) >= >> rx_fill_threshold) >> ionic_rx_fill(cq->bound_q); >> >
diff --git a/drivers/net/ethernet/pensando/ionic/ionic_dev.h b/drivers/net/ethernet/pensando/ionic/ionic_dev.h index 6c243b17312c..9064222a087a 100644 --- a/drivers/net/ethernet/pensando/ionic/ionic_dev.h +++ b/drivers/net/ethernet/pensando/ionic/ionic_dev.h @@ -12,8 +12,10 @@ #define IONIC_MAX_TX_DESC 8192 #define IONIC_MAX_RX_DESC 16384 -#define IONIC_MIN_TXRX_DESC 16 +#define IONIC_MIN_TXRX_DESC 64 #define IONIC_DEF_TXRX_DESC 4096 +#define IONIC_RX_FILL_THRESHOLD 64 +#define IONIC_RX_FILL_DIV 8 #define IONIC_LIFS_MAX 1024 #define IONIC_WATCHDOG_SECS 5 #define IONIC_ITR_COAL_USEC_DEFAULT 64 diff --git a/drivers/net/ethernet/pensando/ionic/ionic_txrx.c b/drivers/net/ethernet/pensando/ionic/ionic_txrx.c index b3d2250c77d0..9156c9825a16 100644 --- a/drivers/net/ethernet/pensando/ionic/ionic_txrx.c +++ b/drivers/net/ethernet/pensando/ionic/ionic_txrx.c @@ -392,11 +392,6 @@ void ionic_rx_fill(struct ionic_queue *q) q->dbval | q->head_idx); } -static void ionic_rx_fill_cb(void *arg) -{ - ionic_rx_fill(arg); -} - void ionic_rx_empty(struct ionic_queue *q) { struct ionic_desc_info *desc_info; @@ -480,6 +475,7 @@ int ionic_rx_napi(struct napi_struct *napi, int budget) struct ionic_cq *cq = napi_to_cq(napi); struct ionic_dev *idev; struct ionic_lif *lif; + u16 rx_fill_threshold; u32 work_done = 0; u32 flags = 0; @@ -489,7 +485,9 @@ int ionic_rx_napi(struct napi_struct *napi, int budget) work_done = ionic_cq_service(cq, budget, ionic_rx_service, NULL, NULL); - if (work_done) + rx_fill_threshold = min_t(u16, IONIC_RX_FILL_THRESHOLD, + cq->num_descs / IONIC_RX_FILL_DIV); + if (work_done && ionic_q_space_avail(cq->bound_q) >= rx_fill_threshold) ionic_rx_fill(cq->bound_q); if (work_done < budget && napi_complete_done(napi, work_done)) { @@ -518,6 +516,7 @@ int ionic_txrx_napi(struct napi_struct *napi, int budget) struct ionic_dev *idev; struct ionic_lif *lif; struct ionic_cq *txcq; + u16 rx_fill_threshold; u32 rx_work_done = 0; u32 tx_work_done = 0; u32 flags = 0; @@ -531,8 +530,11 @@ int ionic_txrx_napi(struct napi_struct *napi, int budget) rx_work_done = ionic_cq_service(rxcq, budget, ionic_rx_service, NULL, NULL); - if (rx_work_done) - ionic_rx_fill_cb(rxcq->bound_q); + + rx_fill_threshold = min_t(u16, IONIC_RX_FILL_THRESHOLD, + rxcq->num_descs / IONIC_RX_FILL_DIV); + if (rx_work_done && ionic_q_space_avail(rxcq->bound_q) >= rx_fill_threshold) + ionic_rx_fill(rxcq->bound_q); if (rx_work_done < budget && napi_complete_done(napi, rx_work_done)) { ionic_dim_update(qcq);
We don't need to refill the rx descriptors on every napi if only a few were handled. Waiting until we can batch up a few together will save us a few Rx cycles. Signed-off-by: Shannon Nelson <snelson@pensando.io> --- .../net/ethernet/pensando/ionic/ionic_dev.h | 4 +++- .../net/ethernet/pensando/ionic/ionic_txrx.c | 18 ++++++++++-------- 2 files changed, 13 insertions(+), 9 deletions(-)