xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

net: Introduce recvmmsg socket syscall

Browse Source 
Meaning receive multiple messages, reducing the number of syscalls and
net stack entry/exit operations.

Next patches will introduce mechanisms where protocols that want to
optimize this operation will provide an unlocked_recvmsg operation.

This takes into account comments made by:

. Paul Moore: sock_recvmsg is called only for the first datagram,
  sock_recvmsg_nosec is used for the rest.

. Caitlin Bestler: recvmmsg now has a struct timespec timeout, that
  works in the same fashion as the ppoll one.

  If the underlying protocol returns a datagram with MSG_OOB set, this
  will make recvmmsg return right away with as many datagrams (+ the OOB
  one) it has received so far.

. Rémi Denis-Courmont & Steven Whitehouse: If we receive N < vlen
  datagrams and then recvmsg returns an error, recvmmsg will return
  the successfully received datagrams, store the error and return it
  in the next call.

This paves the way for a subsequent optimization, sk_prot->unlocked_recvmsg,
where we will be able to acquire the lock only at batch start and end, not at
every underlying recvmsg call.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Arnaldo Carvalho de Melo
2009-10-12 23:40:10 -07:00
committed by David S. Miller
parent c05e85a06e
commit a2e2725541
25 changed files with 261 additions and 50 deletions
Download Patch File Download Diff File Expand all files Collapse all files

4
include/linux/syscalls.h
View File

@@ -25,6 +25,7 @@ struct linux_dirent64;
struct list_head;
struct msgbuf;
struct msghdr;
struct mmsghdr;
struct msqid_ds;
struct new_utsname;
struct nfsctl_arg;
@@ -677,6 +678,9 @@ asmlinkage long sys_recv(int, void __user *, size_t, unsigned);
asmlinkage long sys_recvfrom(int, void __user *, size_t, unsigned,
struct sockaddr __user *, int __user *);
asmlinkage long sys_recvmsg(int fd, struct msghdr __user *msg, unsigned flags);
asmlinkage long sys_recvmmsg(int fd, struct mmsghdr __user *msg,
unsigned int vlen, unsigned flags,
struct timespec __user *timeout);
asmlinkage long sys_socket(int, int, int);
asmlinkage long sys_socketpair(int, int, int, int __user *);
asmlinkage long sys_socketcall(int call, unsigned long __user *args);