From mboxrd@z Thu Jan 1 00:00:00 1970 From: Doug Oucharek Date: Wed, 12 Sep 2018 04:18:21 +0000 Subject: [lustre-devel] [PATCH 22/34] lnet: don't take reference in lnet_XX2ni_locked() In-Reply-To: <153628137211.8267.6066882916704220570.stgit@noble> References: <153628058697.8267.6056114844033479774.stgit@noble> <153628137211.8267.6066882916704220570.stgit@noble> Message-ID: <3D26740D-2ABC-4596-BDF1-D3E2F186608A@cray.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: lustre-devel@lists.lustre.org Reviewed-by: Doug Oucharek Doug ?On 9/6/18, 5:54 PM, "NeilBrown" wrote: lnet_net2ni_locked() and lnet_nid2ni_locked() no longer take a reference - as the lock is held, a ref isn't always needed. Instead, introduce lnet_nid2ni_addref() which does take the reference (but doesn't need the lock). Various places which called lnet_net2ni_locked() or lnet_nid2ni_locked() no longer need to drop the ref afterwards. This is part of 8cbb8cd3e771e7f7e0f99cafc19fad32770dc015 LU-7734 lnet: Multi-Rail local NI split Signed-off-by: NeilBrown --- .../staging/lustre/include/linux/lnet/lib-lnet.h | 1 + .../staging/lustre/lnet/klnds/o2iblnd/o2iblnd_cb.c | 2 + drivers/staging/lustre/lnet/lnet/acceptor.c | 2 + drivers/staging/lustre/lnet/lnet/api-ni.c | 27 +++++++++++++------- drivers/staging/lustre/lnet/lnet/lib-move.c | 17 +------------ 5 files changed, 21 insertions(+), 28 deletions(-) diff --git a/drivers/staging/lustre/include/linux/lnet/lib-lnet.h b/drivers/staging/lustre/include/linux/lnet/lib-lnet.h index 54a93235834c..6401d9a37b23 100644 --- a/drivers/staging/lustre/include/linux/lnet/lib-lnet.h +++ b/drivers/staging/lustre/include/linux/lnet/lib-lnet.h @@ -398,6 +398,7 @@ extern int avoid_asym_router_failure; int lnet_cpt_of_nid_locked(lnet_nid_t nid, struct lnet_ni *ni); int lnet_cpt_of_nid(lnet_nid_t nid, struct lnet_ni *ni); struct lnet_ni *lnet_nid2ni_locked(lnet_nid_t nid, int cpt); +struct lnet_ni *lnet_nid2ni_addref(lnet_nid_t nid); struct lnet_ni *lnet_net2ni_locked(__u32 net, int cpt); struct lnet_ni *lnet_net2ni(__u32 net); bool lnet_is_ni_healthy_locked(struct lnet_ni *ni); diff --git a/drivers/staging/lustre/lnet/klnds/o2iblnd/o2iblnd_cb.c b/drivers/staging/lustre/lnet/klnds/o2iblnd/o2iblnd_cb.c index e64c14914924..af8f863b6a68 100644 --- a/drivers/staging/lustre/lnet/klnds/o2iblnd/o2iblnd_cb.c +++ b/drivers/staging/lustre/lnet/klnds/o2iblnd/o2iblnd_cb.c @@ -2294,7 +2294,7 @@ kiblnd_passive_connect(struct rdma_cm_id *cmid, void *priv, int priv_nob) } nid = reqmsg->ibm_srcnid; - ni = lnet_net2ni(LNET_NIDNET(reqmsg->ibm_dstnid)); + ni = lnet_nid2ni_addref(reqmsg->ibm_dstnid); if (ni) { net = (struct kib_net *)ni->ni_data; diff --git a/drivers/staging/lustre/lnet/lnet/acceptor.c b/drivers/staging/lustre/lnet/lnet/acceptor.c index 88b90c1fdbaf..25205f686801 100644 --- a/drivers/staging/lustre/lnet/lnet/acceptor.c +++ b/drivers/staging/lustre/lnet/lnet/acceptor.c @@ -296,7 +296,7 @@ lnet_accept(struct socket *sock, __u32 magic) if (flip) __swab64s(&cr.acr_nid); - ni = lnet_net2ni(LNET_NIDNET(cr.acr_nid)); + ni = lnet_nid2ni_addref(cr.acr_nid); if (!ni || /* no matching net */ ni->ni_nid != cr.acr_nid) { /* right NET, wrong NID! */ if (ni) diff --git a/drivers/staging/lustre/lnet/lnet/api-ni.c b/drivers/staging/lustre/lnet/lnet/api-ni.c index ce3dd0f32e12..42e775e2a669 100644 --- a/drivers/staging/lustre/lnet/lnet/api-ni.c +++ b/drivers/staging/lustre/lnet/lnet/api-ni.c @@ -655,7 +655,6 @@ lnet_net2ni_locked(__u32 net_id, int cpt) if (net->net_id == net_id) { ni = list_entry(net->net_ni_list.next, struct lnet_ni, ni_netlist); - lnet_ni_addref_locked(ni, cpt); return ni; } } @@ -794,16 +793,29 @@ lnet_nid2ni_locked(lnet_nid_t nid, int cpt) list_for_each_entry(net, &the_lnet.ln_nets, net_list) { list_for_each_entry(ni, &net->net_ni_list, ni_netlist) { - if (ni->ni_nid == nid) { - lnet_ni_addref_locked(ni, cpt); + if (ni->ni_nid == nid) return ni; - } } } return NULL; } +struct lnet_ni * +lnet_nid2ni_addref(lnet_nid_t nid) +{ + struct lnet_ni *ni; + + lnet_net_lock(0); + ni = lnet_nid2ni_locked(nid, 0); + if (ni) + lnet_ni_addref_locked(ni, 0); + lnet_net_unlock(0); + + return ni; +} +EXPORT_SYMBOL(lnet_nid2ni_addref); + int lnet_islocalnid(lnet_nid_t nid) { @@ -812,8 +824,6 @@ lnet_islocalnid(lnet_nid_t nid) cpt = lnet_net_lock_current(); ni = lnet_nid2ni_locked(nid, cpt); - if (ni) - lnet_ni_decref_locked(ni, cpt); lnet_net_unlock(cpt); return !!ni; @@ -1412,6 +1422,7 @@ lnet_startup_lndnet(struct lnet_net *net, struct lnet_lnd_tunables *tun) if (rc < 0) goto failed1; + lnet_ni_addref(ni); list_add_tail(&ni->ni_netlist, &local_ni_list); ni_count++; @@ -2032,9 +2043,6 @@ lnet_dyn_del_ni(__u32 net) goto failed; } - /* decrement the reference counter taken by lnet_net2ni() */ - lnet_ni_decref_locked(ni, 0); - lnet_shutdown_lndni(ni); if (!lnet_count_acceptor_nets()) @@ -2264,7 +2272,6 @@ LNetCtl(unsigned int cmd, void *arg) else rc = ni->ni_net->net_lnd->lnd_ctl(ni, cmd, arg); - lnet_ni_decref(ni); return rc; } /* not reached */ diff --git a/drivers/staging/lustre/lnet/lnet/lib-move.c b/drivers/staging/lustre/lnet/lnet/lib-move.c index 00a89221c9b3..60f34c4b85d3 100644 --- a/drivers/staging/lustre/lnet/lnet/lib-move.c +++ b/drivers/staging/lustre/lnet/lnet/lib-move.c @@ -1127,11 +1127,7 @@ lnet_send(lnet_nid_t src_nid, struct lnet_msg *msg, lnet_nid_t rtr_nid) if (!src_ni) { src_ni = local_ni; src_nid = src_ni->ni_nid; - } else if (src_ni == local_ni) { - lnet_ni_decref_locked(local_ni, cpt); - } else { - lnet_ni_decref_locked(local_ni, cpt); - lnet_ni_decref_locked(src_ni, cpt); + } else if (src_ni != local_ni) { lnet_net_unlock(cpt); LCONSOLE_WARN("No route to %s via from %s\n", libcfs_nid2str(dst_nid), @@ -1149,16 +1145,10 @@ lnet_send(lnet_nid_t src_nid, struct lnet_msg *msg, lnet_nid_t rtr_nid) /* No send credit hassles with LOLND */ lnet_net_unlock(cpt); lnet_ni_send(src_ni, msg); - - lnet_net_lock(cpt); - lnet_ni_decref_locked(src_ni, cpt); - lnet_net_unlock(cpt); return 0; } rc = lnet_nid2peer_locked(&lp, dst_nid, cpt); - /* lp has ref on src_ni; lose mine */ - lnet_ni_decref_locked(src_ni, cpt); if (rc) { lnet_net_unlock(cpt); LCONSOLE_WARN("Error %d finding peer %s\n", rc, @@ -1173,8 +1163,6 @@ lnet_send(lnet_nid_t src_nid, struct lnet_msg *msg, lnet_nid_t rtr_nid) src_ni->ni_net : NULL, dst_nid, rtr_nid); if (!lp) { - if (src_ni) - lnet_ni_decref_locked(src_ni, cpt); lnet_net_unlock(cpt); LCONSOLE_WARN("No route to %s via %s (all routers down)\n", @@ -1192,8 +1180,6 @@ lnet_send(lnet_nid_t src_nid, struct lnet_msg *msg, lnet_nid_t rtr_nid) if (rtr_nid != lp->lp_nid) { cpt2 = lp->lp_cpt; if (cpt2 != cpt) { - if (src_ni) - lnet_ni_decref_locked(src_ni, cpt); lnet_net_unlock(cpt); rtr_nid = lp->lp_nid; @@ -1212,7 +1198,6 @@ lnet_send(lnet_nid_t src_nid, struct lnet_msg *msg, lnet_nid_t rtr_nid) src_nid = src_ni->ni_nid; } else { LASSERT(src_ni->ni_net == lp->lp_net); - lnet_ni_decref_locked(src_ni, cpt); } lnet_peer_addref_locked(lp);