lkml.org 
[lkml]   [2021]   [Nov]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH RFC 5/9] block, bfq: do not idle if only one cgroup is activated
Date
Now that root group is counted into 'num_groups_with_pending_reqs',
'num_groups_with_pending_reqs > 0' is always true in
bfq_asymmetric_scenario().

If only one group is activated, there is no need to guarantee the
same share of the throughput of queues in the same group. Thus change
the condition to 'num_groups_with_pending_reqs > 1'.

Signed-off-by: Yu Kuai <yukuai3@huawei.com>
---
block/bfq-iosched.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c
index 47722f931ee3..63e4e13db92f 100644
--- a/block/bfq-iosched.c
+++ b/block/bfq-iosched.c
@@ -709,7 +709,7 @@ bfq_pos_tree_add_move(struct bfq_data *bfqd, struct bfq_queue *bfqq)
* much easier to maintain the needed state:
* 1) all active queues have the same weight,
* 2) all active queues belong to the same I/O-priority class,
- * 3) there are no active groups.
+ * 3) there are one active groups at most.
* In particular, the last condition is always true if hierarchical
* support or the cgroups interface are not enabled, thus no state
* needs to be maintained in this case.
@@ -741,7 +741,7 @@ static bool bfq_asymmetric_scenario(struct bfq_data *bfqd,

return varied_queue_weights || multiple_classes_busy
#ifdef CONFIG_BFQ_GROUP_IOSCHED
- || bfqd->num_groups_with_pending_reqs > 0
+ || bfqd->num_groups_with_pending_reqs > 1
#endif
;
}
--
2.31.1
\
 
 \ /
  Last update: 2021-11-27 11:02    [W:0.141 / U:0.108 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site