diff mbox series

[22/28] lustre: lmv: skip qos for qos_threshold_rr=100

Message ID 1655560330-30743-23-git-send-email-jsimmons@infradead.org (mailing list archive)
State Not Applicable
Headers show
Series lustre: sync to OpenSFS June 15, 2022 | expand

Commit Message

James Simmons June 18, 2022, 1:52 p.m. UTC 
From: Alexander Boyko <alexander.boyko@hpe.com>

Current implementation of qos allocation is called for
every statfs update. It takes lq_rw_sem for write and
recalculate penalties, even whith setting qos_threshold_rr=100.
Which means always use rr allocation. Let's skip unnecessary
locking and calculation for 100% round robin allocation.

HPE-bug-id: LUS-10388
WC-bug-id: https://jira.whamcloud.com/browse/LU-15393
Lustre-commit: 2f23140d5c1396fd0 ("LU-15393 lod: skip qos for qos_threshold_rr=100")
Signed-off-by: Alexander Boyko <alexander.boyko@hpe.com>
Reviewed-on: https://review.whamcloud.com/46388
Reviewed-by: Andrew Perepechko <andrew.perepechko@hpe.com>
Reviewed-by: Alexey Lyashkov <alexey.lyashkov@hpe.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>
Signed-off-by: James Simmons <jsimmons@infradead.org>
---
 fs/lustre/include/lu_object.h     |  1 +
 fs/lustre/lmv/lproc_lmv.c         |  5 +++--
 fs/lustre/obdclass/lu_tgt_descs.c | 12 ++++++++----
 3 files changed, 12 insertions(+), 6 deletions(-)
diff mbox series

Patch

diff --git a/fs/lustre/include/lu_object.h b/fs/lustre/include/lu_object.h
index 3fb40c6..e4dd287c5 100644
--- a/fs/lustre/include/lu_object.h
+++ b/fs/lustre/include/lu_object.h
@@ -1503,6 +1503,7 @@  struct lu_tgt_desc_idx {
 };
 
 /* QoS data for LOD/LMV */
+#define QOS_THRESHOLD_MAX 256 /* should be power of two */
 struct lu_qos {
 	struct list_head	lq_svr_list;	 /* lu_svr_qos list */
 	struct rw_semaphore	lq_rw_sem;
diff --git a/fs/lustre/lmv/lproc_lmv.c b/fs/lustre/lmv/lproc_lmv.c
index b9efae9..6d4e8d9 100644
--- a/fs/lustre/lmv/lproc_lmv.c
+++ b/fs/lustre/lmv/lproc_lmv.c
@@ -158,7 +158,8 @@  static ssize_t qos_threshold_rr_show(struct kobject *kobj,
 					      obd_kset.kobj);
 
 	return scnprintf(buf, PAGE_SIZE, "%u%%\n",
-			(obd->u.lmv.lmv_qos.lq_threshold_rr * 100 + 255) >> 8);
+			(obd->u.lmv.lmv_qos.lq_threshold_rr * 100 +
+			(QOS_THRESHOLD_MAX - 1)) / QOS_THRESHOLD_MAX);
 }
 
 static ssize_t qos_threshold_rr_store(struct kobject *kobj,
@@ -190,7 +191,7 @@  static ssize_t qos_threshold_rr_store(struct kobject *kobj,
 	if (val > 100)
 		return -EINVAL;
 
-	lmv->lmv_qos.lq_threshold_rr = (val << 8) / 100;
+	lmv->lmv_qos.lq_threshold_rr = (val * QOS_THRESHOLD_MAX) / 100;
 	set_bit(LQ_DIRTY, &lmv->lmv_qos.lq_flags);
 
 	return count;
diff --git a/fs/lustre/obdclass/lu_tgt_descs.c b/fs/lustre/obdclass/lu_tgt_descs.c
index 935cff6..51d2e21 100644
--- a/fs/lustre/obdclass/lu_tgt_descs.c
+++ b/fs/lustre/obdclass/lu_tgt_descs.c
@@ -275,11 +275,13 @@  int lu_tgt_descs_init(struct lu_tgt_descs *ltd, bool is_mdt)
 		ltd->ltd_lmv_desc.ld_pattern = LMV_HASH_TYPE_DEFAULT;
 		ltd->ltd_qos.lq_prio_free = LMV_QOS_DEF_PRIO_FREE * 256 / 100;
 		ltd->ltd_qos.lq_threshold_rr =
-			LMV_QOS_DEF_THRESHOLD_RR_PCT * 256 / 100;
+			LMV_QOS_DEF_THRESHOLD_RR_PCT *
+			QOS_THRESHOLD_MAX / 100;
 	} else {
 		ltd->ltd_qos.lq_prio_free = LOV_QOS_DEF_PRIO_FREE * 256 / 100;
 		ltd->ltd_qos.lq_threshold_rr =
-			LOV_QOS_DEF_THRESHOLD_RR_PCT * 256 / 100;
+			LOV_QOS_DEF_THRESHOLD_RR_PCT *
+			QOS_THRESHOLD_MAX / 100;
 	}
 
 	return 0;
@@ -568,8 +570,10 @@  int ltd_qos_penalties_calc(struct lu_tgt_descs *ltd)
 	 * creation performance
 	 */
 	clear_bit(LQ_SAME_SPACE, &qos->lq_flags);
-	if ((ba_max * (256 - qos->lq_threshold_rr)) >> 8 < ba_min &&
-	    (ia_max * (256 - qos->lq_threshold_rr)) >> 8 < ia_min) {
+	if (((ba_max * (QOS_THRESHOLD_MAX - qos->lq_threshold_rr)) /
+	    QOS_THRESHOLD_MAX) < ba_min &&
+	    ((ia_max * (QOS_THRESHOLD_MAX - qos->lq_threshold_rr)) /
+	    QOS_THRESHOLD_MAX) < ia_min) {
 		set_bit(LQ_SAME_SPACE, &qos->lq_flags);
 		/* Reset weights for the next time we enter qos mode */
 		set_bit(LQ_RESET, &qos->lq_flags);