From: linan666@huaweicloud.com
To: tj@kernel.org, josef@toxicpanda.com, axboe@kernel.dk
Cc: hch@lst.de, cgroups@vger.kernel.org, linux-block@vger.kernel.org,
linux-kernel@vger.kernel.org, linan666@huaweicloud.com,
yukuai3@huawei.com, yi.zhang@huawei.com, houtao1@huawei.com,
yangerkun@huawei.com
Subject: [PATCH] blk-iocost: do not WARNING if iocg has already offlined
Date: Thu, 18 Apr 2024 15:23:40 +0800 [thread overview]
Message-ID: <20240418072340.2090877-1-linan666@huaweicloud.com> (raw)
From: Li Nan <linan122@huawei.com>
In iocg_pay_debt(), warn is triggered if 'active_list' is empty, which
is intended to confirm iocg is avitve when it has debt. However, warn
can be triggered during removing cgroup controller, as
iocg_waitq_timer_fn() is awakened at that time.
WARNING: CPU: 0 PID: 2344971 at block/blk-iocost.c:1402 iocg_pay_debt+0x14c/0x190
Call trace:
iocg_pay_debt+0x14c/0x190
iocg_kick_waitq+0x438/0x4c0
iocg_waitq_timer_fn+0xd8/0x130
__run_hrtimer+0x144/0x45c
__hrtimer_run_queues+0x16c/0x244
hrtimer_interrupt+0x2cc/0x7b0
The warn in this situation is meaningless. Since this iocg is being
removed, the state of the 'active_list' is irrelevant, and 'waitq_timer'
is canceled after removing 'active_list' in ioc_pd_free(), which ensure
iocg is freed after iocg_waitq_timer_fn() returns.
Therefore, add the check if iocg has already offlined to avoid warn
when removing cgroup controller.
Signed-off-by: Li Nan <linan122@huawei.com>
---
block/blk-iocost.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/block/blk-iocost.c b/block/blk-iocost.c
index baa20c85799d..2e109c016a39 100644
--- a/block/blk-iocost.c
+++ b/block/blk-iocost.c
@@ -1440,7 +1440,7 @@ static void iocg_pay_debt(struct ioc_gq *iocg, u64 abs_vpay,
lockdep_assert_held(&iocg->waitq.lock);
/* make sure that nobody messed with @iocg */
- WARN_ON_ONCE(list_empty(&iocg->active_list));
+ WARN_ON_ONCE(list_empty(&iocg->active_list) && iocg->pd.online);
WARN_ON_ONCE(iocg->inuse > 1);
iocg->abs_vdebt -= min(abs_vpay, iocg->abs_vdebt);
--
2.39.2
next reply other threads:[~2024-04-18 7:32 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-18 7:23 linan666 [this message]
2024-04-18 8:52 ` [PATCH] blk-iocost: do not WARNING if iocg has already offlined Yu Kuai
2024-04-18 12:21 ` Li Nan
2024-04-18 16:14 ` Tejun Heo
2024-04-19 9:20 ` Li Nan
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20240418072340.2090877-1-linan666@huaweicloud.com \
--to=linan666@huaweicloud.com \
--cc=axboe@kernel.dk \
--cc=cgroups@vger.kernel.org \
--cc=hch@lst.de \
--cc=houtao1@huawei.com \
--cc=josef@toxicpanda.com \
--cc=linux-block@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=tj@kernel.org \
--cc=yangerkun@huawei.com \
--cc=yi.zhang@huawei.com \
--cc=yukuai3@huawei.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).