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| author | Sowmini Varadhan <sowmini.varadhan@oracle.com> | 2018-02-15 21:49:36 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2018-02-17 00:04:17 +0300 |
| commit | 0cebaccef3acbdfbc2d85880a2efb765d2f4e2e3 (patch) | |
| tree | a8e355ad69ddb3de228816062631f9e4d356b8cc /net/rds/rds.h | |
| parent | 01883eda72bd3f0a6c81447e4f223de14033fd9d (diff) | |
| download | linux-0cebaccef3acbdfbc2d85880a2efb765d2f4e2e3.tar.xz | |
rds: zerocopy Tx support.
If the MSG_ZEROCOPY flag is specified with rds_sendmsg(), and,
if the SO_ZEROCOPY socket option has been set on the PF_RDS socket,
application pages sent down with rds_sendmsg() are pinned.
The pinning uses the accounting infrastructure added by
Commit a91dbff551a6 ("sock: ulimit on MSG_ZEROCOPY pages")
The payload bytes in the message may not be modified for the
duration that the message has been pinned. A multi-threaded
application using this infrastructure may thus need to be notified
about send-completion so that it can free/reuse the buffers
passed to rds_sendmsg(). Notification of send-completion will
identify each message-buffer by a cookie that the application
must specify as ancillary data to rds_sendmsg().
The ancillary data in this case has cmsg_level == SOL_RDS
and cmsg_type == RDS_CMSG_ZCOPY_COOKIE.
Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/rds/rds.h')
| -rw-r--r-- | net/rds/rds.h | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/net/rds/rds.h b/net/rds/rds.h index 24576bc4a5e9..31cd38852050 100644 --- a/net/rds/rds.h +++ b/net/rds/rds.h @@ -785,7 +785,8 @@ rds_conn_connecting(struct rds_connection *conn) /* message.c */ struct rds_message *rds_message_alloc(unsigned int nents, gfp_t gfp); struct scatterlist *rds_message_alloc_sgs(struct rds_message *rm, int nents); -int rds_message_copy_from_user(struct rds_message *rm, struct iov_iter *from); +int rds_message_copy_from_user(struct rds_message *rm, struct iov_iter *from, + bool zcopy); struct rds_message *rds_message_map_pages(unsigned long *page_addrs, unsigned int total_len); void rds_message_populate_header(struct rds_header *hdr, __be16 sport, __be16 dport, u64 seq); |