diff options
Diffstat (limited to 'drivers/staging/lustre/lnet/lnet/lib-ptl.c')
| -rw-r--r-- | drivers/staging/lustre/lnet/lnet/lib-ptl.c | 938 |
1 files changed, 938 insertions, 0 deletions
diff --git a/drivers/staging/lustre/lnet/lnet/lib-ptl.c b/drivers/staging/lustre/lnet/lnet/lib-ptl.c new file mode 100644 index 000000000000..9b9e7d3139b0 --- /dev/null +++ b/drivers/staging/lustre/lnet/lnet/lib-ptl.c @@ -0,0 +1,938 @@ +/* + * GPL HEADER START + * + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 only, + * as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License version 2 for more details (a copy is included + * in the LICENSE file that accompanied this code). + * + * You should have received a copy of the GNU General Public License + * version 2 along with this program; if not, write to the + * Free Software Foundation, Inc., 59 Temple Place - Suite 330, + * Boston, MA 021110-1307, USA + * + * GPL HEADER END + */ +/* + * Copyright (c) 2012, Intel Corporation. + */ +/* + * This file is part of Lustre, http://www.lustre.org/ + * Lustre is a trademark of Sun Microsystems, Inc. + * + * lnet/lnet/lib-ptl.c + * + * portal & match routines + * + * Author: liang@whamcloud.com + */ + +#define DEBUG_SUBSYSTEM S_LNET + +#include <linux/lnet/lib-lnet.h> + +/* NB: add /proc interfaces in upcoming patches */ +int portal_rotor = LNET_PTL_ROTOR_HASH_RT; +CFS_MODULE_PARM(portal_rotor, "i", int, 0644, + "redirect PUTs to different cpu-partitions"); + +static int +lnet_ptl_match_type(unsigned int index, lnet_process_id_t match_id, + __u64 mbits, __u64 ignore_bits) +{ + struct lnet_portal *ptl = the_lnet.ln_portals[index]; + int unique; + + unique = ignore_bits == 0 && + match_id.nid != LNET_NID_ANY && + match_id.pid != LNET_PID_ANY; + + LASSERT(!lnet_ptl_is_unique(ptl) || !lnet_ptl_is_wildcard(ptl)); + + /* prefer to check w/o any lock */ + if (likely(lnet_ptl_is_unique(ptl) || lnet_ptl_is_wildcard(ptl))) + goto match; + + /* unset, new portal */ + lnet_ptl_lock(ptl); + /* check again with lock */ + if (unlikely(lnet_ptl_is_unique(ptl) || lnet_ptl_is_wildcard(ptl))) { + lnet_ptl_unlock(ptl); + goto match; + } + + /* still not set */ + if (unique) + lnet_ptl_setopt(ptl, LNET_PTL_MATCH_UNIQUE); + else + lnet_ptl_setopt(ptl, LNET_PTL_MATCH_WILDCARD); + + lnet_ptl_unlock(ptl); + + return 1; + + match: + if ((lnet_ptl_is_unique(ptl) && !unique) || + (lnet_ptl_is_wildcard(ptl) && unique)) + return 0; + return 1; +} + +static void +lnet_ptl_enable_mt(struct lnet_portal *ptl, int cpt) +{ + struct lnet_match_table *mtable = ptl->ptl_mtables[cpt]; + int i; + + /* with hold of both lnet_res_lock(cpt) and lnet_ptl_lock */ + LASSERT(lnet_ptl_is_wildcard(ptl)); + + mtable->mt_enabled = 1; + + ptl->ptl_mt_maps[ptl->ptl_mt_nmaps] = cpt; + for (i = ptl->ptl_mt_nmaps - 1; i >= 0; i--) { + LASSERT(ptl->ptl_mt_maps[i] != cpt); + if (ptl->ptl_mt_maps[i] < cpt) + break; + + /* swap to order */ + ptl->ptl_mt_maps[i + 1] = ptl->ptl_mt_maps[i]; + ptl->ptl_mt_maps[i] = cpt; + } + + ptl->ptl_mt_nmaps++; +} + +static void +lnet_ptl_disable_mt(struct lnet_portal *ptl, int cpt) +{ + struct lnet_match_table *mtable = ptl->ptl_mtables[cpt]; + int i; + + /* with hold of both lnet_res_lock(cpt) and lnet_ptl_lock */ + LASSERT(lnet_ptl_is_wildcard(ptl)); + + if (LNET_CPT_NUMBER == 1) + return; /* never disable the only match-table */ + + mtable->mt_enabled = 0; + + LASSERT(ptl->ptl_mt_nmaps > 0 && + ptl->ptl_mt_nmaps <= LNET_CPT_NUMBER); + + /* remove it from mt_maps */ + ptl->ptl_mt_nmaps--; + for (i = 0; i < ptl->ptl_mt_nmaps; i++) { + if (ptl->ptl_mt_maps[i] >= cpt) /* overwrite it */ + ptl->ptl_mt_maps[i] = ptl->ptl_mt_maps[i + 1]; + } +} + +static int +lnet_try_match_md(lnet_libmd_t *md, + struct lnet_match_info *info, struct lnet_msg *msg) +{ + /* ALWAYS called holding the lnet_res_lock, and can't lnet_res_unlock; + * lnet_match_blocked_msg() relies on this to avoid races */ + unsigned int offset; + unsigned int mlength; + lnet_me_t *me = md->md_me; + + /* MD exhausted */ + if (lnet_md_exhausted(md)) + return LNET_MATCHMD_NONE | LNET_MATCHMD_EXHAUSTED; + + /* mismatched MD op */ + if ((md->md_options & info->mi_opc) == 0) + return LNET_MATCHMD_NONE; + + /* mismatched ME nid/pid? */ + if (me->me_match_id.nid != LNET_NID_ANY && + me->me_match_id.nid != info->mi_id.nid) + return LNET_MATCHMD_NONE; + + if (me->me_match_id.pid != LNET_PID_ANY && + me->me_match_id.pid != info->mi_id.pid) + return LNET_MATCHMD_NONE; + + /* mismatched ME matchbits? */ + if (((me->me_match_bits ^ info->mi_mbits) & ~me->me_ignore_bits) != 0) + return LNET_MATCHMD_NONE; + + /* Hurrah! This _is_ a match; check it out... */ + + if ((md->md_options & LNET_MD_MANAGE_REMOTE) == 0) + offset = md->md_offset; + else + offset = info->mi_roffset; + + if ((md->md_options & LNET_MD_MAX_SIZE) != 0) { + mlength = md->md_max_size; + LASSERT(md->md_offset + mlength <= md->md_length); + } else { + mlength = md->md_length - offset; + } + + if (info->mi_rlength <= mlength) { /* fits in allowed space */ + mlength = info->mi_rlength; + } else if ((md->md_options & LNET_MD_TRUNCATE) == 0) { + /* this packet _really_ is too big */ + CERROR("Matching packet from %s, match "LPU64 + " length %d too big: %d left, %d allowed\n", + libcfs_id2str(info->mi_id), info->mi_mbits, + info->mi_rlength, md->md_length - offset, mlength); + + return LNET_MATCHMD_DROP; + } + + /* Commit to this ME/MD */ + CDEBUG(D_NET, "Incoming %s index %x from %s of " + "length %d/%d into md "LPX64" [%d] + %d\n", + (info->mi_opc == LNET_MD_OP_PUT) ? "put" : "get", + info->mi_portal, libcfs_id2str(info->mi_id), mlength, + info->mi_rlength, md->md_lh.lh_cookie, md->md_niov, offset); + + lnet_msg_attach_md(msg, md, offset, mlength); + md->md_offset = offset + mlength; + + if (!lnet_md_exhausted(md)) + return LNET_MATCHMD_OK; + + /* Auto-unlink NOW, so the ME gets unlinked if required. + * We bumped md->md_refcount above so the MD just gets flagged + * for unlink when it is finalized. */ + if ((md->md_flags & LNET_MD_FLAG_AUTO_UNLINK) != 0) + lnet_md_unlink(md); + + return LNET_MATCHMD_OK | LNET_MATCHMD_EXHAUSTED; +} + +static struct lnet_match_table * +lnet_match2mt(struct lnet_portal *ptl, lnet_process_id_t id, __u64 mbits) +{ + if (LNET_CPT_NUMBER == 1) + return ptl->ptl_mtables[0]; /* the only one */ + + /* if it's a unique portal, return match-table hashed by NID */ + return lnet_ptl_is_unique(ptl) ? + ptl->ptl_mtables[lnet_cpt_of_nid(id.nid)] : NULL; +} + +struct lnet_match_table * +lnet_mt_of_attach(unsigned int index, lnet_process_id_t id, + __u64 mbits, __u64 ignore_bits, lnet_ins_pos_t pos) +{ + struct lnet_portal *ptl; + struct lnet_match_table *mtable; + + /* NB: called w/o lock */ + LASSERT(index < the_lnet.ln_nportals); + + if (!lnet_ptl_match_type(index, id, mbits, ignore_bits)) + return NULL; + + ptl = the_lnet.ln_portals[index]; + + mtable = lnet_match2mt(ptl, id, mbits); + if (mtable != NULL) /* unique portal or only one match-table */ + return mtable; + + /* it's a wildcard portal */ + switch (pos) { + default: + return NULL; + case LNET_INS_BEFORE: + case LNET_INS_AFTER: + /* posted by no affinity thread, always hash to specific + * match-table to avoid buffer stealing which is heavy */ + return ptl->ptl_mtables[ptl->ptl_index % LNET_CPT_NUMBER]; + case LNET_INS_LOCAL: + /* posted by cpu-affinity thread */ + return ptl->ptl_mtables[lnet_cpt_current()]; + } +} + +static struct lnet_match_table * +lnet_mt_of_match(struct lnet_match_info *info, struct lnet_msg *msg) +{ + struct lnet_match_table *mtable; + struct lnet_portal *ptl; + int nmaps; + int rotor; + int routed; + int cpt; + + /* NB: called w/o lock */ + LASSERT(info->mi_portal < the_lnet.ln_nportals); + ptl = the_lnet.ln_portals[info->mi_portal]; + + LASSERT(lnet_ptl_is_wildcard(ptl) || lnet_ptl_is_unique(ptl)); + + mtable = lnet_match2mt(ptl, info->mi_id, info->mi_mbits); + if (mtable != NULL) + return mtable; + + /* it's a wildcard portal */ + routed = LNET_NIDNET(msg->msg_hdr.src_nid) != + LNET_NIDNET(msg->msg_hdr.dest_nid); + + if (portal_rotor == LNET_PTL_ROTOR_OFF || + (portal_rotor != LNET_PTL_ROTOR_ON && !routed)) { + cpt = lnet_cpt_current(); + if (ptl->ptl_mtables[cpt]->mt_enabled) + return ptl->ptl_mtables[cpt]; + } + + rotor = ptl->ptl_rotor++; /* get round-robin factor */ + if (portal_rotor == LNET_PTL_ROTOR_HASH_RT && routed) + cpt = lnet_cpt_of_nid(msg->msg_hdr.src_nid); + else + cpt = rotor % LNET_CPT_NUMBER; + + if (!ptl->ptl_mtables[cpt]->mt_enabled) { + /* is there any active entry for this portal? */ + nmaps = ptl->ptl_mt_nmaps; + /* map to an active mtable to avoid heavy "stealing" */ + if (nmaps != 0) { + /* NB: there is possibility that ptl_mt_maps is being + * changed because we are not under protection of + * lnet_ptl_lock, but it shouldn't hurt anything */ + cpt = ptl->ptl_mt_maps[rotor % nmaps]; + } + } + + return ptl->ptl_mtables[cpt]; +} + +static int +lnet_mt_test_exhausted(struct lnet_match_table *mtable, int pos) +{ + __u64 *bmap; + int i; + + if (!lnet_ptl_is_wildcard(the_lnet.ln_portals[mtable->mt_portal])) + return 0; + + if (pos < 0) { /* check all bits */ + for (i = 0; i < LNET_MT_EXHAUSTED_BMAP; i++) { + if (mtable->mt_exhausted[i] != (__u64)(-1)) + return 0; + } + return 1; + } + + LASSERT(pos <= LNET_MT_HASH_IGNORE); + /* mtable::mt_mhash[pos] is marked as exhausted or not */ + bmap = &mtable->mt_exhausted[pos >> LNET_MT_BITS_U64]; + pos &= (1 << LNET_MT_BITS_U64) - 1; + + return ((*bmap) & (1ULL << pos)) != 0; +} + +static void +lnet_mt_set_exhausted(struct lnet_match_table *mtable, int pos, int exhausted) +{ + __u64 *bmap; + + LASSERT(lnet_ptl_is_wildcard(the_lnet.ln_portals[mtable->mt_portal])); + LASSERT(pos <= LNET_MT_HASH_IGNORE); + + /* set mtable::mt_mhash[pos] as exhausted/non-exhausted */ + bmap = &mtable->mt_exhausted[pos >> LNET_MT_BITS_U64]; + pos &= (1 << LNET_MT_BITS_U64) - 1; + + if (!exhausted) + *bmap &= ~(1ULL << pos); + else + *bmap |= 1ULL << pos; +} + +struct list_head * +lnet_mt_match_head(struct lnet_match_table *mtable, + lnet_process_id_t id, __u64 mbits) +{ + struct lnet_portal *ptl = the_lnet.ln_portals[mtable->mt_portal]; + + if (lnet_ptl_is_wildcard(ptl)) { + return &mtable->mt_mhash[mbits & LNET_MT_HASH_MASK]; + } else { + unsigned long hash = mbits + id.nid + id.pid; + + LASSERT(lnet_ptl_is_unique(ptl)); + hash = cfs_hash_long(hash, LNET_MT_HASH_BITS); + return &mtable->mt_mhash[hash]; + } +} + +int +lnet_mt_match_md(struct lnet_match_table *mtable, + struct lnet_match_info *info, struct lnet_msg *msg) +{ + struct list_head *head; + lnet_me_t *me; + lnet_me_t *tmp; + int exhausted = 0; + int rc; + + /* any ME with ignore bits? */ + if (!list_empty(&mtable->mt_mhash[LNET_MT_HASH_IGNORE])) + head = &mtable->mt_mhash[LNET_MT_HASH_IGNORE]; + else + head = lnet_mt_match_head(mtable, info->mi_id, info->mi_mbits); + again: + /* NB: only wildcard portal needs to return LNET_MATCHMD_EXHAUSTED */ + if (lnet_ptl_is_wildcard(the_lnet.ln_portals[mtable->mt_portal])) + exhausted = LNET_MATCHMD_EXHAUSTED; + + list_for_each_entry_safe(me, tmp, head, me_list) { + /* ME attached but MD not attached yet */ + if (me->me_md == NULL) + continue; + + LASSERT(me == me->me_md->md_me); + + rc = lnet_try_match_md(me->me_md, info, msg); + if ((rc & LNET_MATCHMD_EXHAUSTED) == 0) + exhausted = 0; /* mlist is not empty */ + + if ((rc & LNET_MATCHMD_FINISH) != 0) { + /* don't return EXHAUSTED bit because we don't know + * whether the mlist is empty or not */ + return rc & ~LNET_MATCHMD_EXHAUSTED; + } + } + + if (exhausted == LNET_MATCHMD_EXHAUSTED) { /* @head is exhausted */ + lnet_mt_set_exhausted(mtable, head - mtable->mt_mhash, 1); + if (!lnet_mt_test_exhausted(mtable, -1)) + exhausted = 0; + } + + if (exhausted == 0 && head == &mtable->mt_mhash[LNET_MT_HASH_IGNORE]) { + head = lnet_mt_match_head(mtable, info->mi_id, info->mi_mbits); + goto again; /* re-check MEs w/o ignore-bits */ + } + + if (info->mi_opc == LNET_MD_OP_GET || + !lnet_ptl_is_lazy(the_lnet.ln_portals[info->mi_portal])) + return LNET_MATCHMD_DROP | exhausted; + + return LNET_MATCHMD_NONE | exhausted; +} + +static int +lnet_ptl_match_early(struct lnet_portal *ptl, struct lnet_msg *msg) +{ + int rc; + + /* message arrived before any buffer posting on this portal, + * simply delay or drop this message */ + if (likely(lnet_ptl_is_wildcard(ptl) || lnet_ptl_is_unique(ptl))) + return 0; + + lnet_ptl_lock(ptl); + /* check it again with hold of lock */ + if (lnet_ptl_is_wildcard(ptl) || lnet_ptl_is_unique(ptl)) { + lnet_ptl_unlock(ptl); + return 0; + } + + if (lnet_ptl_is_lazy(ptl)) { + if (msg->msg_rx_ready_delay) { + msg->msg_rx_delayed = 1; + list_add_tail(&msg->msg_list, + &ptl->ptl_msg_delayed); + } + rc = LNET_MATCHMD_NONE; + } else { + rc = LNET_MATCHMD_DROP; + } + + lnet_ptl_unlock(ptl); + return rc; +} + +static int +lnet_ptl_match_delay(struct lnet_portal *ptl, + struct lnet_match_info *info, struct lnet_msg *msg) +{ + int first = ptl->ptl_mt_maps[0]; /* read w/o lock */ + int rc = 0; + int i; + + /* steal buffer from other CPTs, and delay it if nothing to steal, + * this function is more expensive than a regular match, but we + * don't expect it can happen a lot */ + LASSERT(lnet_ptl_is_wildcard(ptl)); + + for (i = 0; i < LNET_CPT_NUMBER; i++) { + struct lnet_match_table *mtable; + int cpt; + + cpt = (first + i) % LNET_CPT_NUMBER; + mtable = ptl->ptl_mtables[cpt]; + if (i != 0 && i != LNET_CPT_NUMBER - 1 && !mtable->mt_enabled) + continue; + + lnet_res_lock(cpt); + lnet_ptl_lock(ptl); + + if (i == 0) { /* the first try, attach on stealing list */ + list_add_tail(&msg->msg_list, + &ptl->ptl_msg_stealing); + } + + if (!list_empty(&msg->msg_list)) { /* on stealing list */ + rc = lnet_mt_match_md(mtable, info, msg); + + if ((rc & LNET_MATCHMD_EXHAUSTED) != 0 && + mtable->mt_enabled) + lnet_ptl_disable_mt(ptl, cpt); + + if ((rc & LNET_MATCHMD_FINISH) != 0) + list_del_init(&msg->msg_list); + + } else { + /* could be matched by lnet_ptl_attach_md() + * which is called by another thread */ + rc = msg->msg_md == NULL ? + LNET_MATCHMD_DROP : LNET_MATCHMD_OK; + } + + if (!list_empty(&msg->msg_list) && /* not matched yet */ + (i == LNET_CPT_NUMBER - 1 || /* the last CPT */ + ptl->ptl_mt_nmaps == 0 || /* no active CPT */ + (ptl->ptl_mt_nmaps == 1 && /* the only active CPT */ + ptl->ptl_mt_maps[0] == cpt))) { + /* nothing to steal, delay or drop */ + list_del_init(&msg->msg_list); + + if (lnet_ptl_is_lazy(ptl)) { + msg->msg_rx_delayed = 1; + list_add_tail(&msg->msg_list, + &ptl->ptl_msg_delayed); + rc = LNET_MATCHMD_NONE; + } else { + rc = LNET_MATCHMD_DROP; + } + } + + lnet_ptl_unlock(ptl); + lnet_res_unlock(cpt); + + if ((rc & LNET_MATCHMD_FINISH) != 0 || msg->msg_rx_delayed) + break; + } + + return rc; +} + +int +lnet_ptl_match_md(struct lnet_match_info *info, struct lnet_msg *msg) +{ + struct lnet_match_table *mtable; + struct lnet_portal *ptl; + int rc; + + CDEBUG(D_NET, "Request from %s of length %d into portal %d " + "MB="LPX64"\n", libcfs_id2str(info->mi_id), + info->mi_rlength, info->mi_portal, info->mi_mbits); + + if (info->mi_portal >= the_lnet.ln_nportals) { + CERROR("Invalid portal %d not in [0-%d]\n", + info->mi_portal, the_lnet.ln_nportals); + return LNET_MATCHMD_DROP; + } + + ptl = the_lnet.ln_portals[info->mi_portal]; + rc = lnet_ptl_match_early(ptl, msg); + if (rc != 0) /* matched or delayed early message */ + return rc; + + mtable = lnet_mt_of_match(info, msg); + lnet_res_lock(mtable->mt_cpt); + + if (the_lnet.ln_shutdown) { + rc = LNET_MATCHMD_DROP; + goto out1; + } + + rc = lnet_mt_match_md(mtable, info, msg); + if ((rc & LNET_MATCHMD_EXHAUSTED) != 0 && mtable->mt_enabled) { + lnet_ptl_lock(ptl); + lnet_ptl_disable_mt(ptl, mtable->mt_cpt); + lnet_ptl_unlock(ptl); + } + + if ((rc & LNET_MATCHMD_FINISH) != 0) /* matched or dropping */ + goto out1; + + if (!msg->msg_rx_ready_delay) + goto out1; + + LASSERT(lnet_ptl_is_lazy(ptl)); + LASSERT(!msg->msg_rx_delayed); + + /* NB: we don't expect "delay" can happen a lot */ + if (lnet_ptl_is_unique(ptl) || LNET_CPT_NUMBER == 1) { + lnet_ptl_lock(ptl); + + msg->msg_rx_delayed = 1; + list_add_tail(&msg->msg_list, &ptl->ptl_msg_delayed); + + lnet_ptl_unlock(ptl); + lnet_res_unlock(mtable->mt_cpt); + + } else { + lnet_res_unlock(mtable->mt_cpt); + rc = lnet_ptl_match_delay(ptl, info, msg); + } + + if (msg->msg_rx_delayed) { + CDEBUG(D_NET, + "Delaying %s from %s ptl %d MB "LPX64" off %d len %d\n", + info->mi_opc == LNET_MD_OP_PUT ? "PUT" : "GET", + libcfs_id2str(info->mi_id), info->mi_portal, + info->mi_mbits, info->mi_roffset, info->mi_rlength); + } + goto out0; + out1: + lnet_res_unlock(mtable->mt_cpt); + out0: + /* EXHAUSTED bit is only meaningful for internal functions */ + return rc & ~LNET_MATCHMD_EXHAUSTED; +} + +void +lnet_ptl_detach_md(lnet_me_t *me, lnet_libmd_t *md) +{ + LASSERT(me->me_md == md && md->md_me == me); + + me->me_md = NULL; + md->md_me = NULL; +} + +/* called with lnet_res_lock held */ +void +lnet_ptl_attach_md(lnet_me_t *me, lnet_libmd_t *md, + struct list_head *matches, struct list_head *drops) +{ + struct lnet_portal *ptl = the_lnet.ln_portals[me->me_portal]; + struct lnet_match_table *mtable; + struct list_head *head; + lnet_msg_t *tmp; + lnet_msg_t *msg; + int exhausted = 0; + int cpt; + + LASSERT(md->md_refcount == 0); /* a brand new MD */ + + me->me_md = md; + md->md_me = me; + + cpt = lnet_cpt_of_cookie(md->md_lh.lh_cookie); + mtable = ptl->ptl_mtables[cpt]; + + if (list_empty(&ptl->ptl_msg_stealing) && + list_empty(&ptl->ptl_msg_delayed) && + !lnet_mt_test_exhausted(mtable, me->me_pos)) + return; + + lnet_ptl_lock(ptl); + head = &ptl->ptl_msg_stealing; + again: + list_for_each_entry_safe(msg, tmp, head, msg_list) { + struct lnet_match_info info; + lnet_hdr_t *hdr; + int rc; + + LASSERT(msg->msg_rx_delayed || head == &ptl->ptl_msg_stealing); + + hdr = &msg->msg_hdr; + info.mi_id.nid = hdr->src_nid; + info.mi_id.pid = hdr->src_pid; + info.mi_opc = LNET_MD_OP_PUT; + info.mi_portal = hdr->msg.put.ptl_index; + info.mi_rlength = hdr->payload_length; + info.mi_roffset = hdr->msg.put.offset; + info.mi_mbits = hdr->msg.put.match_bits; + + rc = lnet_try_match_md(md, &info, msg); + + exhausted = (rc & LNET_MATCHMD_EXHAUSTED) != 0; + if ((rc & LNET_MATCHMD_NONE) != 0) { + if (exhausted) + break; + continue; + } + + /* Hurrah! This _is_ a match */ + LASSERT((rc & LNET_MATCHMD_FINISH) != 0); + list_del_init(&msg->msg_list); + + if (head == &ptl->ptl_msg_stealing) { + if (exhausted) + break; + /* stealing thread will handle the message */ + continue; + } + + if ((rc & LNET_MATCHMD_OK) != 0) { + list_add_tail(&msg->msg_list, matches); + + CDEBUG(D_NET, "Resuming delayed PUT from %s portal %d " + "match "LPU64" offset %d length %d.\n", + libcfs_id2str(info.mi_id), + info.mi_portal, info.mi_mbits, + info.mi_roffset, info.mi_rlength); + } else { + list_add_tail(&msg->msg_list, drops); + } + + if (exhausted) + break; + } + + if (!exhausted && head == &ptl->ptl_msg_stealing) { + head = &ptl->ptl_msg_delayed; + goto again; + } + + if (lnet_ptl_is_wildcard(ptl) && !exhausted) { + lnet_mt_set_exhausted(mtable, me->me_pos, 0); + if (!mtable->mt_enabled) + lnet_ptl_enable_mt(ptl, cpt); + } + + lnet_ptl_unlock(ptl); +} + +void +lnet_ptl_cleanup(struct lnet_portal *ptl) +{ + struct lnet_match_table *mtable; + int i; + + if (ptl->ptl_mtables == NULL) /* uninitialized portal */ + return; + + LASSERT(list_empty(&ptl->ptl_msg_delayed)); + LASSERT(list_empty(&ptl->ptl_msg_stealing)); + cfs_percpt_for_each(mtable, i, ptl->ptl_mtables) { + struct list_head *mhash; + lnet_me_t *me; + int j; + + if (mtable->mt_mhash == NULL) /* uninitialized match-table */ + continue; + + mhash = mtable->mt_mhash; + /* cleanup ME */ + for (j = 0; j < LNET_MT_HASH_SIZE + 1; j++) { + while (!list_empty(&mhash[j])) { + me = list_entry(mhash[j].next, + lnet_me_t, me_list); + CERROR("Active ME %p on exit\n", me); + list_del(&me->me_list); + lnet_me_free(me); + } + } + /* the extra entry is for MEs with ignore bits */ + LIBCFS_FREE(mhash, sizeof(*mhash) * (LNET_MT_HASH_SIZE + 1)); + } + + cfs_percpt_free(ptl->ptl_mtables); + ptl->ptl_mtables = NULL; +} + +int +lnet_ptl_setup(struct lnet_portal *ptl, int index) +{ + struct lnet_match_table *mtable; + struct list_head *mhash; + int i; + int j; + + ptl->ptl_mtables = cfs_percpt_alloc(lnet_cpt_table(), + sizeof(struct lnet_match_table)); + if (ptl->ptl_mtables == NULL) { + CERROR("Failed to create match table for portal %d\n", index); + return -ENOMEM; + } + + ptl->ptl_index = index; + INIT_LIST_HEAD(&ptl->ptl_msg_delayed); + INIT_LIST_HEAD(&ptl->ptl_msg_stealing); + spin_lock_init(&ptl->ptl_lock); + cfs_percpt_for_each(mtable, i, ptl->ptl_mtables) { + /* the extra entry is for MEs with ignore bits */ + LIBCFS_CPT_ALLOC(mhash, lnet_cpt_table(), i, + sizeof(*mhash) * (LNET_MT_HASH_SIZE + 1)); + if (mhash == NULL) { + CERROR("Failed to create match hash for portal %d\n", + index); + goto failed; + } + + memset(&mtable->mt_exhausted[0], -1, + sizeof(mtable->mt_exhausted[0]) * + LNET_MT_EXHAUSTED_BMAP); + mtable->mt_mhash = mhash; + for (j = 0; j < LNET_MT_HASH_SIZE + 1; j++) + INIT_LIST_HEAD(&mhash[j]); + + mtable->mt_portal = index; + mtable->mt_cpt = i; + } + + return 0; + failed: + lnet_ptl_cleanup(ptl); + return -ENOMEM; +} + +void +lnet_portals_destroy(void) +{ + int i; + + if (the_lnet.ln_portals == NULL) + return; + + for (i = 0; i < the_lnet.ln_nportals; i++) + lnet_ptl_cleanup(the_lnet.ln_portals[i]); + + cfs_array_free(the_lnet.ln_portals); + the_lnet.ln_portals = NULL; +} + +int +lnet_portals_create(void) +{ + int size; + int i; + + size = offsetof(struct lnet_portal, ptl_mt_maps[LNET_CPT_NUMBER]); + + the_lnet.ln_nportals = MAX_PORTALS; + the_lnet.ln_portals = cfs_array_alloc(the_lnet.ln_nportals, size); + if (the_lnet.ln_portals == NULL) { + CERROR("Failed to allocate portals table\n"); + return -ENOMEM; + } + + for (i = 0; i < the_lnet.ln_nportals; i++) { + if (lnet_ptl_setup(the_lnet.ln_portals[i], i)) { + lnet_portals_destroy(); + return -ENOMEM; + } + } + + return 0; +} + +/** + * Turn on the lazy portal attribute. Use with caution! + * + * This portal attribute only affects incoming PUT requests to the portal, + * and is off by default. By default, if there's no matching MD for an + * incoming PUT request, it is simply dropped. With the lazy attribute on, + * such requests are queued indefinitely until either a matching MD is + * posted to the portal or the lazy attribute is turned off. + * + * It would prevent dropped requests, however it should be regarded as the + * last line of defense - i.e. users must keep a close watch on active + * buffers on a lazy portal and once it becomes too low post more buffers as + * soon as possible. This is because delayed requests usually have detrimental + * effects on underlying network connections. A few delayed requests often + * suffice to bring an underlying connection to a complete halt, due to flow + * control mechanisms. + * + * There's also a DOS attack risk. If users don't post match-all MDs on a + * lazy portal, a malicious peer can easily stop a service by sending some + * PUT requests with match bits that won't match any MD. A routed server is + * especially vulnerable since the connections to its neighbor routers are + * shared among all clients. + * + * \param portal Index of the portal to enable the lazy attribute on. + * + * \retval 0 On success. + * \retval -EINVAL If \a portal is not a valid index. + */ +int +LNetSetLazyPortal(int portal) +{ + struct lnet_portal *ptl; + + if (portal < 0 || portal >= the_lnet.ln_nportals) + return -EINVAL; + + CDEBUG(D_NET, "Setting portal %d lazy\n", portal); + ptl = the_lnet.ln_portals[portal]; + + lnet_res_lock(LNET_LOCK_EX); + lnet_ptl_lock(ptl); + + lnet_ptl_setopt(ptl, LNET_PTL_LAZY); + + lnet_ptl_unlock(ptl); + lnet_res_unlock(LNET_LOCK_EX); + + return 0; +} +EXPORT_SYMBOL(LNetSetLazyPortal); + +/** + * Turn off the lazy portal attribute. Delayed requests on the portal, + * if any, will be all dropped when this function returns. + * + * \param portal Index of the portal to disable the lazy attribute on. + * + * \retval 0 On success. + * \retval -EINVAL If \a portal is not a valid index. + */ +int +LNetClearLazyPortal(int portal) +{ + struct lnet_portal *ptl; + LIST_HEAD (zombies); + + if (portal < 0 || portal >= the_lnet.ln_nportals) + return -EINVAL; + + ptl = the_lnet.ln_portals[portal]; + + lnet_res_lock(LNET_LOCK_EX); + lnet_ptl_lock(ptl); + + if (!lnet_ptl_is_lazy(ptl)) { + lnet_ptl_unlock(ptl); + lnet_res_unlock(LNET_LOCK_EX); + return 0; + } + + if (the_lnet.ln_shutdown) + CWARN("Active lazy portal %d on exit\n", portal); + else + CDEBUG(D_NET, "clearing portal %d lazy\n", portal); + + /* grab all the blocked messages atomically */ + list_splice_init(&ptl->ptl_msg_delayed, &zombies); + + lnet_ptl_unsetopt(ptl, LNET_PTL_LAZY); + + lnet_ptl_unlock(ptl); + lnet_res_unlock(LNET_LOCK_EX); + + lnet_drop_delayed_msg_list(&zombies, "Clearing lazy portal attr"); + + return 0; +} +EXPORT_SYMBOL(LNetClearLazyPortal); |