Kernel/linux-next
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git synced 2024-12-28 16:52:18 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

net/smc: adapt cursor update when sndbuf and peer DMB are merged

Browse Source 
If the local 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>
Reviewed-by: Wenjia Zhang <wenjia@linux.ibm.com>
Reviewed-and-tested-by: Jan Karcher <jaka@linux.ibm.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
This commit is contained in:
Wen Gu 2024-04-28 14:07:37 +08:00 committed by Paolo Abeni
parent ae2be35cbe
commit cc0ab806fc
1 changed files with 34 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

36
net/smc/smc_cdc.c
View File

@ -18,6 +18,7 @@
#include "smc_tx.h"
#include "smc_rx.h"
#include "smc_close.h"
#include "smc_ism.h"
/********************************** send *************************************/
@ -255,6 +256,14 @@ 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;
if (smc_ism_support_dmb_nocopy(conn->lgr->smcd))
/* if local sndbuf shares the same memory region with
* peer DMB, then don't update the tx_curs_fin
* and sndbuf_space until peer has consumed the data.
*/
return 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);
@ -266,7 +275,7 @@ int smcd_cdc_msg_send(struct smc_connection *conn)
smc_curs_copy(&conn->tx_curs_fin, &conn->tx_curs_sent, conn);
smc_tx_sndbuf_nonfull(smc);
return rc;
return 0;
}
/********************************* receive ***********************************/
@ -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 +348,29 @@ 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 local sndbuf shares the same memory region with
* peer RMB, then update tx_curs_fin and sndbuf_space
* here since peer has already consumed the data.
*/
if (conn->lgr->is_smcd &&
smc_ism_support_dmb_nocopy(conn->lgr->smcd)) {
/* Calculate consumed data and
* increment free send buffer space.
*/
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,