d/freebsd-dev
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Reduce the number of unnecessary unlock-relocks on socket buffer mutexes

Browse Source 
associated with performing a wakeup on the socket buffer:

- When performing an sbappend*() followed by a so[rw]wakeup(), explicitly
  acquire the socket buffer lock and use the _locked() variants of both
  calls.  Note that the _locked() sowakeup() versions unlock the mutex on
  return.  This is done in uipc_send(), divert_packet(), mroute
  socket_send(), raw_append(), tcp_reass(), tcp_input(), and udp_append().

- When the socket buffer lock is dropped before a sowakeup(), remove the
  explicit unlock and use the _locked() sowakeup() variant.  This is done
  in soisdisconnecting(), soisdisconnected() when setting the can't send/
  receive flags and dropping data, and in uipc_rcvd() which adjusting
  back-pressure on the sockets.

For UNIX domain sockets running mpsafe with a contention-intensive SMP
mysql benchmark, this results in a 1.6% query rate improvement due to
reduce mutex costs.
This commit is contained in:
Robert Watson 2004-06-26 19:10:39 +00:00
parent df68e345c5
commit 1e4d7da707
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=131151
9 changed files with 64 additions and 49 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

13
sys/kern/uipc_sockbuf.c
View File

@ -169,13 +169,11 @@ soisdisconnecting(so)
SOCK_UNLOCK(so);
SOCKBUF_LOCK(&so->so_rcv);
so->so_rcv.sb_state |= SBS_CANTRCVMORE;
SOCKBUF_UNLOCK(&so->so_rcv);
sorwakeup_locked(so);
SOCKBUF_LOCK(&so->so_snd);
so->so_snd.sb_state |= SBS_CANTSENDMORE;
SOCKBUF_UNLOCK(&so->so_snd);
sowwakeup_locked(so);
wakeup(&so->so_timeo);
sowwakeup(so);
sorwakeup(so);
}
void
@ -188,20 +186,19 @@ soisdisconnected(so)
* SOCKBUF_LOCK(&so->so_rcv) even though they are the same mutex to
* avoid introducing the assumption that they are the same.
*/
/* XXXRW: so_state locking? */
SOCK_LOCK(so);
so->so_state &= ~(SS_ISCONNECTING|SS_ISCONNECTED|SS_ISDISCONNECTING);
so->so_state |= SS_ISDISCONNECTED;
SOCK_UNLOCK(so);
SOCKBUF_LOCK(&so->so_rcv);
so->so_rcv.sb_state |= SBS_CANTRCVMORE;
SOCKBUF_UNLOCK(&so->so_rcv);
sorwakeup_locked(so);
SOCKBUF_LOCK(&so->so_snd);
so->so_snd.sb_state |= SBS_CANTSENDMORE;
sbdrop_locked(&so->so_snd, so->so_snd.sb_cc);
SOCKBUF_UNLOCK(&so->so_snd);
sowwakeup_locked(so);
wakeup(&so->so_timeo);
sowwakeup(so);
sorwakeup(so);
}
/*

13
sys/kern/uipc_socket2.c
View File

@ -169,13 +169,11 @@ soisdisconnecting(so)
SOCK_UNLOCK(so);
SOCKBUF_LOCK(&so->so_rcv);
so->so_rcv.sb_state |= SBS_CANTRCVMORE;
SOCKBUF_UNLOCK(&so->so_rcv);
sorwakeup_locked(so);
SOCKBUF_LOCK(&so->so_snd);
so->so_snd.sb_state |= SBS_CANTSENDMORE;
SOCKBUF_UNLOCK(&so->so_snd);
sowwakeup_locked(so);
wakeup(&so->so_timeo);
sowwakeup(so);
sorwakeup(so);
}
void
@ -188,20 +186,19 @@ soisdisconnected(so)
* SOCKBUF_LOCK(&so->so_rcv) even though they are the same mutex to
* avoid introducing the assumption that they are the same.
*/
/* XXXRW: so_state locking? */
SOCK_LOCK(so);
so->so_state &= ~(SS_ISCONNECTING|SS_ISCONNECTED|SS_ISDISCONNECTING);
so->so_state |= SS_ISDISCONNECTED;
SOCK_UNLOCK(so);
SOCKBUF_LOCK(&so->so_rcv);
so->so_rcv.sb_state |= SBS_CANTRCVMORE;
SOCKBUF_UNLOCK(&so->so_rcv);
sorwakeup_locked(so);
SOCKBUF_LOCK(&so->so_snd);
so->so_snd.sb_state |= SBS_CANTSENDMORE;
sbdrop_locked(&so->so_snd, so->so_snd.sb_cc);
SOCKBUF_UNLOCK(&so->so_snd);
sowwakeup_locked(so);
wakeup(&so->so_timeo);
sowwakeup(so);
sorwakeup(so);
}
/*

9
sys/kern/uipc_usrreq.c
View File

@ -294,8 +294,7 @@ uipc_rcvd(struct socket *so, int flags)
newhiwat, RLIM_INFINITY);
unp->unp_cc = so->so_rcv.sb_cc;
SOCKBUF_UNLOCK(&so->so_rcv);
SOCKBUF_UNLOCK(&so2->so_snd);
sowwakeup(so2);
sowwakeup_locked(so2);
break;
default:
@ -355,8 +354,7 @@ uipc_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam,
from = &sun_noname;
SOCKBUF_LOCK(&so2->so_rcv);
if (sbappendaddr_locked(&so2->so_rcv, from, m, control)) {
SOCKBUF_UNLOCK(&so2->so_rcv);
sorwakeup(so2);
sorwakeup_locked(so2);
m = NULL;
control = NULL;
} else {
@ -412,8 +410,7 @@ uipc_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam,
(void)chgsbsize(so->so_cred->cr_uidinfo, &so->so_snd.sb_hiwat,
newhiwat, RLIM_INFINITY);
unp->unp_conn->unp_cc = so2->so_rcv.sb_cc;
SOCKBUF_UNLOCK(&so2->so_rcv);
sorwakeup(so2);
sorwakeup_locked(so2);
m = NULL;
break;

10
sys/netinet/ip_divert.c
View File

@ -228,12 +228,14 @@ divert_packet(struct mbuf *m, int incoming)
/* XXX why does only one socket match? */
if (inp->inp_lport == nport) {
sa = inp->inp_socket;
if (sbappendaddr(&sa->so_rcv,
SOCKBUF_LOCK(&sa->so_rcv);
if (sbappendaddr_locked(&sa->so_rcv,
(struct sockaddr *)&divsrc, m,
(struct mbuf *)0) == 0)
(struct mbuf *)0) == 0) {
sa = NULL; /* force mbuf reclaim below */
else
sorwakeup(sa);
SOCKBUF_UNLOCK(&sa->so_rcv);
} else
sorwakeup_locked(sa);
INP_UNLOCK(inp);
break;
}

7
sys/netinet/ip_mroute.c
View File

@ -1307,10 +1307,13 @@ static int
socket_send(struct socket *s, struct mbuf *mm, struct sockaddr_in *src)
{
if (s) {
if (sbappendaddr(&s->so_rcv, (struct sockaddr *)src, mm, NULL) != 0) {
sorwakeup(s);
SOCKBUF_LOCK(&s->so_rcv);
if (sbappendaddr_locked(&s->so_rcv, (struct sockaddr *)src, mm,
NULL) != 0) {
sorwakeup_locked(s);
return 0;
}
SOCKBUF_UNLOCK(&s->so_rcv);
}
m_freem(mm);
return -1;

10
sys/netinet/raw_ip.c
View File

@ -160,18 +160,22 @@ raw_append(struct inpcb *last, struct ip *ip, struct mbuf *n)
#endif
if (!policyfail) {
struct mbuf *opts = NULL;
struct socket *so;
so = last->inp_socket;
if ((last->inp_flags & INP_CONTROLOPTS) ||
(last->inp_socket->so_options & SO_TIMESTAMP))
(so->so_options & SO_TIMESTAMP))
ip_savecontrol(last, &opts, ip, n);
if (sbappendaddr(&last->inp_socket->so_rcv,
SOCKBUF_LOCK(&so->so_rcv);
if (sbappendaddr_locked(&so->so_rcv,
(struct sockaddr *)&ripsrc, n, opts) == 0) {
/* should notify about lost packet */
m_freem(n);
if (opts)
m_freem(opts);
SOCKBUF_UNLOCK(&so->so_rcv);
} else
sorwakeup(last->inp_socket);
sorwakeup_locked(so);
} else
m_freem(n);
return policyfail;

21
sys/netinet/tcp_input.c
View File

@ -353,22 +353,24 @@ tcp_reass(tp, th, tlenp, m)
q = LIST_FIRST(&tp->t_segq);
if (!q || q->tqe_th->th_seq != tp->rcv_nxt)
return (0);
SOCKBUF_LOCK(&so->so_rcv);
do {
tp->rcv_nxt += q->tqe_len;
flags = q->tqe_th->th_flags & TH_FIN;
nq = LIST_NEXT(q, tqe_q);
LIST_REMOVE(q, tqe_q);
/* Unlocked read. */
if (so->so_rcv.sb_state & SBS_CANTRCVMORE)
m_freem(q->tqe_m);
else
sbappendstream(&so->so_rcv, q->tqe_m);
sbappendstream_locked(&so->so_rcv, q->tqe_m);
uma_zfree(tcp_reass_zone, q);
tp->t_segqlen--;
tcp_reass_qsize--;
q = nq;
} while (q && q->tqe_th->th_seq == tp->rcv_nxt);
ND6_HINT(tp);
sorwakeup(so);
sorwakeup_locked(so);
return (flags);
}
@ -1262,13 +1264,15 @@ tcp_input(m, off0)
#endif
* Add data to socket buffer.
*/
/* Unlocked read. */
SOCKBUF_LOCK(&so->so_rcv);
if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
m_freem(m);
} else {
m_adj(m, drop_hdrlen); /* delayed header drop */
sbappendstream(&so->so_rcv, m);
sbappendstream_locked(&so->so_rcv, m);
}
sorwakeup(so);
sorwakeup_locked(so);
if (DELAY_ACK(tp)) {
tp->t_flags |= TF_DELACK;
} else {
@ -2153,8 +2157,7 @@ tcp_input(m, off0)
tp->snd_wnd -= acked;
ourfinisacked = 0;
}
SOCKBUF_UNLOCK(&so->so_snd);
sowwakeup(so);
sowwakeup_locked(so);
/* detect una wraparound */
if ((tcp_do_newreno || tp->sack_enable) &&
!IN_FASTRECOVERY(tp) &&
@ -2363,11 +2366,13 @@ tcp_input(m, off0)
tcpstat.tcps_rcvpack++;
tcpstat.tcps_rcvbyte += tlen;
ND6_HINT(tp);
/* Unlocked read. */
SOCKBUF_LOCK(&so->so_rcv);
if (so->so_rcv.sb_state & SBS_CANTRCVMORE)
m_freem(m);
else
sbappendstream(&so->so_rcv, m);
sorwakeup(so);
sbappendstream_locked(&so->so_rcv, m);
sorwakeup_locked(so);
} else {
thflags = tcp_reass(tp, th, &tlen, m);
tp->t_flags |= TF_ACKNOW;

21
sys/netinet/tcp_reass.c
View File

@ -353,22 +353,24 @@ tcp_reass(tp, th, tlenp, m)
q = LIST_FIRST(&tp->t_segq);
if (!q || q->tqe_th->th_seq != tp->rcv_nxt)
return (0);
SOCKBUF_LOCK(&so->so_rcv);
do {
tp->rcv_nxt += q->tqe_len;
flags = q->tqe_th->th_flags & TH_FIN;
nq = LIST_NEXT(q, tqe_q);
LIST_REMOVE(q, tqe_q);
/* Unlocked read. */
if (so->so_rcv.sb_state & SBS_CANTRCVMORE)
m_freem(q->tqe_m);
else
sbappendstream(&so->so_rcv, q->tqe_m);
sbappendstream_locked(&so->so_rcv, q->tqe_m);
uma_zfree(tcp_reass_zone, q);
tp->t_segqlen--;
tcp_reass_qsize--;
q = nq;
} while (q && q->tqe_th->th_seq == tp->rcv_nxt);
ND6_HINT(tp);
sorwakeup(so);
sorwakeup_locked(so);
return (flags);
}
@ -1262,13 +1264,15 @@ tcp_input(m, off0)
#endif
* Add data to socket buffer.
*/
/* Unlocked read. */
SOCKBUF_LOCK(&so->so_rcv);
if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
m_freem(m);
} else {
m_adj(m, drop_hdrlen); /* delayed header drop */
sbappendstream(&so->so_rcv, m);
sbappendstream_locked(&so->so_rcv, m);
}
sorwakeup(so);
sorwakeup_locked(so);
if (DELAY_ACK(tp)) {
tp->t_flags |= TF_DELACK;
} else {
@ -2153,8 +2157,7 @@ tcp_input(m, off0)
tp->snd_wnd -= acked;
ourfinisacked = 0;
}
SOCKBUF_UNLOCK(&so->so_snd);
sowwakeup(so);
sowwakeup_locked(so);
/* detect una wraparound */
if ((tcp_do_newreno || tp->sack_enable) &&
!IN_FASTRECOVERY(tp) &&
@ -2363,11 +2366,13 @@ tcp_input(m, off0)
tcpstat.tcps_rcvpack++;
tcpstat.tcps_rcvbyte += tlen;
ND6_HINT(tp);
/* Unlocked read. */
SOCKBUF_LOCK(&so->so_rcv);
if (so->so_rcv.sb_state & SBS_CANTRCVMORE)
m_freem(m);
else
sbappendstream(&so->so_rcv, m);
sorwakeup(so);
sbappendstream_locked(&so->so_rcv, m);
sorwakeup_locked(so);
} else {
thflags = tcp_reass(tp, th, &tlen, m);
tp->t_flags |= TF_ACKNOW;

9
sys/netinet/udp_usrreq.c
View File

@ -447,6 +447,7 @@ udp_append(last, ip, n, off)
int off;
{
struct sockaddr *append_sa;
struct socket *so;
struct mbuf *opts = 0;
INP_LOCK_ASSERT(last);
@ -496,13 +497,17 @@ udp_append(last, ip, n, off)
#endif
append_sa = (struct sockaddr *)&udp_in;
m_adj(n, off);
if (sbappendaddr(&last->inp_socket->so_rcv, append_sa, n, opts) == 0) {
so = last->inp_socket;
SOCKBUF_LOCK(&so->so_rcv);
if (sbappendaddr_locked(&so->so_rcv, append_sa, n, opts) == 0) {
m_freem(n);
if (opts)
m_freem(opts);
udpstat.udps_fullsock++;
SOCKBUF_UNLOCK(&so->so_rcv);
} else
sorwakeup(last->inp_socket);
sorwakeup_locked(so);
}
/*