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authorSowmini Varadhan <sowmini.varadhan@oracle.com>2018-02-15 21:49:36 +0300
committerDavid S. Miller <davem@davemloft.net>2018-02-17 00:04:17 +0300
commit0cebaccef3acbdfbc2d85880a2efb765d2f4e2e3 (patch)
treea8e355ad69ddb3de228816062631f9e4d356b8cc /net/rds/rds.h
parent01883eda72bd3f0a6c81447e4f223de14033fd9d (diff)
downloadlinux-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.h3
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);