libfc: Reduce exchange lock contention in fc_exch_recv_abts()

Reduce the time during which the exchange lock is held by allocating
a frame before obtaining the exchange lock.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Cc: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
This commit is contained in:
Bart Van Assche 2013-08-14 15:38:24 +00:00 committed by Robert Love
parent cae7b6dd6c
commit f95b35cfca
1 changed files with 10 additions and 8 deletions

View File

@ -1307,9 +1307,16 @@ static void fc_exch_recv_abts(struct fc_exch *ep, struct fc_frame *rx_fp)
if (!ep)
goto reject;
fp = fc_frame_alloc(ep->lp, sizeof(*ap));
if (!fp)
goto free;
spin_lock_bh(&ep->ex_lock);
if (ep->esb_stat & ESB_ST_COMPLETE) {
spin_unlock_bh(&ep->ex_lock);
fc_frame_free(fp);
goto reject;
}
if (!(ep->esb_stat & ESB_ST_REC_QUAL)) {
@ -1317,12 +1324,6 @@ static void fc_exch_recv_abts(struct fc_exch *ep, struct fc_frame *rx_fp)
fc_exch_hold(ep); /* hold for REC_QUAL */
}
fc_exch_timer_set_locked(ep, ep->r_a_tov);
fp = fc_frame_alloc(ep->lp, sizeof(*ap));
if (!fp) {
spin_unlock_bh(&ep->ex_lock);
goto free;
}
fh = fc_frame_header_get(fp);
ap = fc_frame_payload_get(fp, sizeof(*ap));
memset(ap, 0, sizeof(*ap));
@ -1338,13 +1339,14 @@ static void fc_exch_recv_abts(struct fc_exch *ep, struct fc_frame *rx_fp)
fc_seq_send_last(sp, fp, FC_RCTL_BA_ACC, FC_TYPE_BLS);
ep->esb_stat |= ESB_ST_ABNORMAL;
spin_unlock_bh(&ep->ex_lock);
free:
fc_frame_free(rx_fp);
return;
reject:
fc_exch_send_ba_rjt(rx_fp, FC_BA_RJT_UNABLE, FC_BA_RJT_INV_XID);
free:
fc_frame_free(rx_fp);
goto free;
}
/**