From 432410cecf53f4d07ab7f67d1ad99acce895bdbb Mon Sep 17 00:00:00 2001 From: Liang Zhen Date: Tue, 19 Aug 2014 10:55:04 +0800 Subject: [PATCH] LU-5548 ptlrpc: avoid list scan in ptlrpcd_check ptlrpcd_check() always scan all requests on ptlrpc_request_set and try to finish completed requests, this is low efficiency. Even worse, l_wait_event() always checks condition for twice before sleeping and one more time after waking up, which means it will call ptlrpcd_check() for three times in each loop. This patch will move completed requests at the head of list in ptlrpc_check_set(), with this change ptlrpcd_check doesn't need to scan all requests anymore. Signed-off-by: Liang Zhen Change-Id: I84ef477717b53be9e508a596594f176c9de476bb Reviewed-on: http://review.whamcloud.com/11513 Tested-by: Maloo Tested-by: Jenkins Reviewed-by: Bobi Jam Reviewed-by: Andreas Dilger Reviewed-by: Johann Lombardi Reviewed-by: Oleg Drokin --- lustre/ptlrpc/client.c | 18 ++++++++++++++---- lustre/ptlrpc/ptlrpcd.c | 23 +++++++++-------------- 2 files changed, 23 insertions(+), 18 deletions(-) diff --git a/lustre/ptlrpc/client.c b/lustre/ptlrpc/client.c index 8c2a833..87f1c6a 100644 --- a/lustre/ptlrpc/client.c +++ b/lustre/ptlrpc/client.c @@ -1521,12 +1521,14 @@ static inline int ptlrpc_set_producer(struct ptlrpc_request_set *set) int ptlrpc_check_set(const struct lu_env *env, struct ptlrpc_request_set *set) { struct list_head *tmp, *next; - int force_timer_recalc = 0; - ENTRY; + struct list_head comp_reqs; + int force_timer_recalc = 0; + ENTRY; if (atomic_read(&set->set_remaining) == 0) - RETURN(1); + RETURN(1); + INIT_LIST_HEAD(&comp_reqs); list_for_each_safe(tmp, next, &set->set_requests) { struct ptlrpc_request *req = list_entry(tmp, struct ptlrpc_request, @@ -1601,8 +1603,10 @@ int ptlrpc_check_set(const struct lu_env *env, struct ptlrpc_request_set *set) ptlrpc_rqphase_move(req, req->rq_next_phase); } - if (req->rq_phase == RQ_PHASE_COMPLETE) + if (req->rq_phase == RQ_PHASE_COMPLETE) { + list_move_tail(&req->rq_set_chain, &comp_reqs); continue; + } if (req->rq_phase == RQ_PHASE_INTERPRET) GOTO(interpret, req->rq_status); @@ -1889,9 +1893,15 @@ int ptlrpc_check_set(const struct lu_env *env, struct ptlrpc_request_set *set) if (req->rq_status != 0) set->set_rc = req->rq_status; ptlrpc_req_finished(req); + } else { + list_move_tail(&req->rq_set_chain, &comp_reqs); } } + /* move completed request at the head of list so it's easier for + * caller to find them */ + list_splice(&comp_reqs, &set->set_requests); + /* If we hit an error, we want to recover promptly. */ RETURN(atomic_read(&set->set_remaining) == 0 || force_timer_recalc); } diff --git a/lustre/ptlrpc/ptlrpcd.c b/lustre/ptlrpc/ptlrpcd.c index 8f7fa9d..aa09f15 100644 --- a/lustre/ptlrpc/ptlrpcd.c +++ b/lustre/ptlrpc/ptlrpcd.c @@ -306,21 +306,16 @@ static int ptlrpcd_check(struct lu_env *env, struct ptlrpcd_ctl *pc) if (atomic_read(&set->set_remaining)) rc |= ptlrpc_check_set(env, set); - if (!list_empty(&set->set_requests)) { - /* - * XXX: our set never completes, so we prune the completed - * reqs after each iteration. boy could this be smarter. - */ - list_for_each_safe(pos, tmp, &set->set_requests) { - req = list_entry(pos, struct ptlrpc_request, - rq_set_chain); - if (req->rq_phase != RQ_PHASE_COMPLETE) - continue; + /* NB: ptlrpc_check_set has already moved complted request at the + * head of seq::set_requests */ + list_for_each_safe(pos, tmp, &set->set_requests) { + req = list_entry(pos, struct ptlrpc_request, rq_set_chain); + if (req->rq_phase != RQ_PHASE_COMPLETE) + break; - list_del_init(&req->rq_set_chain); - req->rq_set = NULL; - ptlrpc_req_finished(req); - } + list_del_init(&req->rq_set_chain); + req->rq_set = NULL; + ptlrpc_req_finished(req); } if (rc == 0) { -- 1.8.3.1