| Message ID | 20240317100545.96663-11-guwen@linux.alibaba.com (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | net/smc: SMC intra-OS shortcut with loopback-ism | expand |
On 17/03/2024 11:05, Wen Gu wrote: > Since ghost sndbuf shares the same physical memory with peer DMB, > the cursor update processing needs to be adapted to ensure that the > data to be consumed won't be overwritten. > > So in this case, the fin_curs and sndbuf_space that were originally > updated after sending the CDC message should be modified to not be > update until the peer updates cons_curs. > > Signed-off-by: Wen Gu <guwen@linux.alibaba.com> > --- > net/smc/smc_cdc.c | 52 +++++++++++++++++++++++++++++++++++++---------- > 1 file changed, 41 insertions(+), 11 deletions(-) > > diff --git a/net/smc/smc_cdc.c b/net/smc/smc_cdc.c > index 3c06625ceb20..bf5b214ec15a 100644 > --- a/net/smc/smc_cdc.c > +++ b/net/smc/smc_cdc.c > @@ -18,6 +18,7 @@ > #include "smc_tx.h" > #include "smc_rx.h" > #include "smc_close.h" > +#include "smc_ism.h" > > /********************************** send *************************************/ > > @@ -255,17 +256,25 @@ int smcd_cdc_msg_send(struct smc_connection *conn) > return rc; > smc_curs_copy(&conn->rx_curs_confirmed, &curs, conn); > conn->local_rx_ctrl.prod_flags.cons_curs_upd_req = 0; > - /* Calculate transmitted data and increment free send buffer space */ > - diff = smc_curs_diff(conn->sndbuf_desc->len, &conn->tx_curs_fin, > - &conn->tx_curs_sent); > - /* increased by confirmed number of bytes */ > - smp_mb__before_atomic(); > - atomic_add(diff, &conn->sndbuf_space); > - /* guarantee 0 <= sndbuf_space <= sndbuf_desc->len */ > - smp_mb__after_atomic(); > - smc_curs_copy(&conn->tx_curs_fin, &conn->tx_curs_sent, conn); > + if (!smc_ism_support_dmb_nocopy(conn->lgr->smcd)) { > + /* Ghost sndbuf shares the same memory region with > + * peer DMB, so don't update the tx_curs_fin and > + * sndbuf_space until peer has consumed the data. > + */ Hi Wen Gu, move this comment above the if please. Two consecutive multiline comments are difficult to read here. > + /* Calculate transmitted data and increment free > + * send buffer space > + */ > + diff = smc_curs_diff(conn->sndbuf_desc->len, &conn->tx_curs_fin, > + &conn->tx_curs_sent); > + /* increased by confirmed number of bytes */ > + smp_mb__before_atomic(); > + atomic_add(diff, &conn->sndbuf_space); > + /* guarantee 0 <= sndbuf_space <= sndbuf_desc->len */ > + smp_mb__after_atomic(); > + smc_curs_copy(&conn->tx_curs_fin, &conn->tx_curs_sent, conn); > > - smc_tx_sndbuf_nonfull(smc); > + smc_tx_sndbuf_nonfull(smc); > + } > return rc; > } > > @@ -323,7 +332,7 @@ static void smc_cdc_msg_recv_action(struct smc_sock *smc, > { > union smc_host_cursor cons_old, prod_old; > struct smc_connection *conn = &smc->conn; > - int diff_cons, diff_prod; > + int diff_cons, diff_prod, diff_tx; > > smc_curs_copy(&prod_old, &conn->local_rx_ctrl.prod, conn); > smc_curs_copy(&cons_old, &conn->local_rx_ctrl.cons, conn); > @@ -339,6 +348,27 @@ static void smc_cdc_msg_recv_action(struct smc_sock *smc, > atomic_add(diff_cons, &conn->peer_rmbe_space); > /* guarantee 0 <= peer_rmbe_space <= peer_rmbe_size */ > smp_mb__after_atomic(); > + > + if (conn->lgr->is_smcd && > + smc_ism_support_dmb_nocopy(conn->lgr->smcd)) { > + /* Ghost sndbuf shares the same memory region with > + * peer RMB, so update tx_curs_fin and sndbuf_space > + * when peer has consumed the data. > + */ Same as above. Thanks - Jan > + /* calculate peer rmb consumed data */ > + diff_tx = smc_curs_diff(conn->sndbuf_desc->len, > + &conn->tx_curs_fin, > + &conn->local_rx_ctrl.cons); > + /* increase local sndbuf space and fin_curs */ > + smp_mb__before_atomic(); > + atomic_add(diff_tx, &conn->sndbuf_space); > + /* guarantee 0 <= sndbuf_space <= sndbuf_desc->len */ > + smp_mb__after_atomic(); > + smc_curs_copy(&conn->tx_curs_fin, > + &conn->local_rx_ctrl.cons, conn); > + > + smc_tx_sndbuf_nonfull(smc); > + } > } > > diff_prod = smc_curs_diff(conn->rmb_desc->len, &prod_old,
On 2024/3/21 16:12, Jan Karcher wrote: > > > On 17/03/2024 11:05, Wen Gu wrote: >> Since ghost sndbuf shares the same physical memory with peer DMB, >> the cursor update processing needs to be adapted to ensure that the >> data to be consumed won't be overwritten. >> >> So in this case, the fin_curs and sndbuf_space that were originally >> updated after sending the CDC message should be modified to not be >> update until the peer updates cons_curs. >> >> Signed-off-by: Wen Gu <guwen@linux.alibaba.com> >> --- >> net/smc/smc_cdc.c | 52 +++++++++++++++++++++++++++++++++++++---------- >> 1 file changed, 41 insertions(+), 11 deletions(-) >> >> diff --git a/net/smc/smc_cdc.c b/net/smc/smc_cdc.c >> index 3c06625ceb20..bf5b214ec15a 100644 >> --- a/net/smc/smc_cdc.c >> +++ b/net/smc/smc_cdc.c >> @@ -18,6 +18,7 @@ >> #include "smc_tx.h" >> #include "smc_rx.h" >> #include "smc_close.h" >> +#include "smc_ism.h" >> /********************************** send *************************************/ >> @@ -255,17 +256,25 @@ int smcd_cdc_msg_send(struct smc_connection *conn) >> return rc; >> smc_curs_copy(&conn->rx_curs_confirmed, &curs, conn); >> conn->local_rx_ctrl.prod_flags.cons_curs_upd_req = 0; >> - /* Calculate transmitted data and increment free send buffer space */ >> - diff = smc_curs_diff(conn->sndbuf_desc->len, &conn->tx_curs_fin, >> - &conn->tx_curs_sent); >> - /* increased by confirmed number of bytes */ >> - smp_mb__before_atomic(); >> - atomic_add(diff, &conn->sndbuf_space); >> - /* guarantee 0 <= sndbuf_space <= sndbuf_desc->len */ >> - smp_mb__after_atomic(); >> - smc_curs_copy(&conn->tx_curs_fin, &conn->tx_curs_sent, conn); >> + if (!smc_ism_support_dmb_nocopy(conn->lgr->smcd)) { >> + /* Ghost sndbuf shares the same memory region with >> + * peer DMB, so don't update the tx_curs_fin and >> + * sndbuf_space until peer has consumed the data. >> + */ > > Hi Wen Gu, > > move this comment above the if please. Two consecutive multiline comments are difficult to read here. > OK, will move comments above the if. Thanks! >> + /* Calculate transmitted data and increment free >> + * send buffer space >> + */ >> + diff = smc_curs_diff(conn->sndbuf_desc->len, &conn->tx_curs_fin, >> + &conn->tx_curs_sent); >> + /* increased by confirmed number of bytes */ >> + smp_mb__before_atomic(); >> + atomic_add(diff, &conn->sndbuf_space); >> + /* guarantee 0 <= sndbuf_space <= sndbuf_desc->len */ >> + smp_mb__after_atomic(); >> + smc_curs_copy(&conn->tx_curs_fin, &conn->tx_curs_sent, conn); >> - smc_tx_sndbuf_nonfull(smc); >> + smc_tx_sndbuf_nonfull(smc); >> + } >> return rc; >> } >> @@ -323,7 +332,7 @@ static void smc_cdc_msg_recv_action(struct smc_sock *smc, >> { >> union smc_host_cursor cons_old, prod_old; >> struct smc_connection *conn = &smc->conn; >> - int diff_cons, diff_prod; >> + int diff_cons, diff_prod, diff_tx; >> smc_curs_copy(&prod_old, &conn->local_rx_ctrl.prod, conn); >> smc_curs_copy(&cons_old, &conn->local_rx_ctrl.cons, conn); >> @@ -339,6 +348,27 @@ static void smc_cdc_msg_recv_action(struct smc_sock *smc, >> atomic_add(diff_cons, &conn->peer_rmbe_space); >> /* guarantee 0 <= peer_rmbe_space <= peer_rmbe_size */ >> smp_mb__after_atomic(); >> + >> + if (conn->lgr->is_smcd && >> + smc_ism_support_dmb_nocopy(conn->lgr->smcd)) { >> + /* Ghost sndbuf shares the same memory region with >> + * peer RMB, so update tx_curs_fin and sndbuf_space >> + * when peer has consumed the data. >> + */ > > Same as above. > OK, will do. Thanks! > Thanks > - Jan > >> + /* calculate peer rmb consumed data */ >> + diff_tx = smc_curs_diff(conn->sndbuf_desc->len, >> + &conn->tx_curs_fin, >> + &conn->local_rx_ctrl.cons); >> + /* increase local sndbuf space and fin_curs */ >> + smp_mb__before_atomic(); >> + atomic_add(diff_tx, &conn->sndbuf_space); >> + /* guarantee 0 <= sndbuf_space <= sndbuf_desc->len */ >> + smp_mb__after_atomic(); >> + smc_curs_copy(&conn->tx_curs_fin, >> + &conn->local_rx_ctrl.cons, conn); >> + >> + smc_tx_sndbuf_nonfull(smc); >> + } >> } >> diff_prod = smc_curs_diff(conn->rmb_desc->len, &prod_old,
diff --git a/net/smc/smc_cdc.c b/net/smc/smc_cdc.c index 3c06625ceb20..bf5b214ec15a 100644 --- a/net/smc/smc_cdc.c +++ b/net/smc/smc_cdc.c @@ -18,6 +18,7 @@ #include "smc_tx.h" #include "smc_rx.h" #include "smc_close.h" +#include "smc_ism.h" /********************************** send *************************************/ @@ -255,17 +256,25 @@ int smcd_cdc_msg_send(struct smc_connection *conn) return rc; smc_curs_copy(&conn->rx_curs_confirmed, &curs, conn); conn->local_rx_ctrl.prod_flags.cons_curs_upd_req = 0; - /* Calculate transmitted data and increment free send buffer space */ - diff = smc_curs_diff(conn->sndbuf_desc->len, &conn->tx_curs_fin, - &conn->tx_curs_sent); - /* increased by confirmed number of bytes */ - smp_mb__before_atomic(); - atomic_add(diff, &conn->sndbuf_space); - /* guarantee 0 <= sndbuf_space <= sndbuf_desc->len */ - smp_mb__after_atomic(); - smc_curs_copy(&conn->tx_curs_fin, &conn->tx_curs_sent, conn); + if (!smc_ism_support_dmb_nocopy(conn->lgr->smcd)) { + /* Ghost sndbuf shares the same memory region with + * peer DMB, so don't update the tx_curs_fin and + * sndbuf_space until peer has consumed the data. + */ + /* Calculate transmitted data and increment free + * send buffer space + */ + diff = smc_curs_diff(conn->sndbuf_desc->len, &conn->tx_curs_fin, + &conn->tx_curs_sent); + /* increased by confirmed number of bytes */ + smp_mb__before_atomic(); + atomic_add(diff, &conn->sndbuf_space); + /* guarantee 0 <= sndbuf_space <= sndbuf_desc->len */ + smp_mb__after_atomic(); + smc_curs_copy(&conn->tx_curs_fin, &conn->tx_curs_sent, conn); - smc_tx_sndbuf_nonfull(smc); + smc_tx_sndbuf_nonfull(smc); + } return rc; } @@ -323,7 +332,7 @@ static void smc_cdc_msg_recv_action(struct smc_sock *smc, { union smc_host_cursor cons_old, prod_old; struct smc_connection *conn = &smc->conn; - int diff_cons, diff_prod; + int diff_cons, diff_prod, diff_tx; smc_curs_copy(&prod_old, &conn->local_rx_ctrl.prod, conn); smc_curs_copy(&cons_old, &conn->local_rx_ctrl.cons, conn); @@ -339,6 +348,27 @@ static void smc_cdc_msg_recv_action(struct smc_sock *smc, atomic_add(diff_cons, &conn->peer_rmbe_space); /* guarantee 0 <= peer_rmbe_space <= peer_rmbe_size */ smp_mb__after_atomic(); + + if (conn->lgr->is_smcd && + smc_ism_support_dmb_nocopy(conn->lgr->smcd)) { + /* Ghost sndbuf shares the same memory region with + * peer RMB, so update tx_curs_fin and sndbuf_space + * when peer has consumed the data. + */ + /* calculate peer rmb consumed data */ + diff_tx = smc_curs_diff(conn->sndbuf_desc->len, + &conn->tx_curs_fin, + &conn->local_rx_ctrl.cons); + /* increase local sndbuf space and fin_curs */ + smp_mb__before_atomic(); + atomic_add(diff_tx, &conn->sndbuf_space); + /* guarantee 0 <= sndbuf_space <= sndbuf_desc->len */ + smp_mb__after_atomic(); + smc_curs_copy(&conn->tx_curs_fin, + &conn->local_rx_ctrl.cons, conn); + + smc_tx_sndbuf_nonfull(smc); + } } diff_prod = smc_curs_diff(conn->rmb_desc->len, &prod_old,
Since ghost sndbuf shares the same physical memory with peer DMB, the cursor update processing needs to be adapted to ensure that the data to be consumed won't be overwritten. So in this case, the fin_curs and sndbuf_space that were originally updated after sending the CDC message should be modified to not be update until the peer updates cons_curs. Signed-off-by: Wen Gu <guwen@linux.alibaba.com> --- net/smc/smc_cdc.c | 52 +++++++++++++++++++++++++++++++++++++---------- 1 file changed, 41 insertions(+), 11 deletions(-)