From: Alexander Zarochentsev <[email protected]> two optimizations in the busy loop wait in class_cleanup(): (1) remove unnecessary spinlocks protecting obd_conn_inprogress access (2) replace cond_resched by more suitable yield to unconditionally yield the CPU if the condition check fails.
Signed-off-by: Alexander Zarochentsev <[email protected]> Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-5397 Xyratex-bug-id: MRP-1991 Reviewed-on: http://review.whamcloud.com/11198 Reviewed-by: Andreas Dilger <[email protected]> Reviewed-by: Dmitry Eremin <[email protected]> Reviewed-by: Oleg Drokin <[email protected]> Signed-off-by: James Simmons <[email protected]> --- .../staging/lustre/lustre/obdclass/obd_config.c | 13 ++++--------- 1 files changed, 4 insertions(+), 9 deletions(-) diff --git a/drivers/staging/lustre/lustre/obdclass/obd_config.c b/drivers/staging/lustre/lustre/obdclass/obd_config.c index 036f396..fddfc9c 100644 --- a/drivers/staging/lustre/lustre/obdclass/obd_config.c +++ b/drivers/staging/lustre/lustre/obdclass/obd_config.c @@ -414,17 +414,12 @@ static int class_cleanup(struct obd_device *obd, struct lustre_cfg *lcfg) } /* Leave this on forever */ obd->obd_stopping = 1; - - /* wait for already-arrived-connections to finish. */ - while (obd->obd_conn_inprogress > 0) { - spin_unlock(&obd->obd_dev_lock); - - cond_resched(); - - spin_lock(&obd->obd_dev_lock); - } spin_unlock(&obd->obd_dev_lock); + while (obd->obd_conn_inprogress > 0) + yield(); + smp_rmb(); + if (lcfg->lcfg_bufcount >= 2 && LUSTRE_CFG_BUFLEN(lcfg, 1) > 0) { for (flag = lustre_cfg_string(lcfg, 1); *flag != 0; flag++) switch (*flag) { -- 1.7.1 _______________________________________________ devel mailing list [email protected] http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
