From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>,
Tejun Heo <tj@kernel.org>, Jens Axboe <axboe@kernel.dk>,
Sasha Levin <sashal@kernel.org>,
cgroups@vger.kernel.org, linux-block@vger.kernel.org
Subject: [PATCH AUTOSEL 5.10 24/25] blk-cgroup: Use cond_resched() when destroy blkgs
Date: Tue, 2 Feb 2021 10:06:14 -0500 [thread overview]
Message-ID: <20210202150615.1864175-24-sashal@kernel.org> (raw)
In-Reply-To: <20210202150615.1864175-1-sashal@kernel.org>
From: Baolin Wang <baolin.wang@linux.alibaba.com>
[ Upstream commit 6c635caef410aa757befbd8857c1eadde5cc22ed ]
On !PREEMPT kernel, we can get below softlockup when doing stress
testing with creating and destroying block cgroup repeatly. The
reason is it may take a long time to acquire the queue's lock in
the loop of blkcg_destroy_blkgs(), or the system can accumulate a
huge number of blkgs in pathological cases. We can add a need_resched()
check on each loop and release locks and do cond_resched() if true
to avoid this issue, since the blkcg_destroy_blkgs() is not called
from atomic contexts.
[ 4757.010308] watchdog: BUG: soft lockup - CPU#11 stuck for 94s!
[ 4757.010698] Call trace:
[ 4757.010700] blkcg_destroy_blkgs+0x68/0x150
[ 4757.010701] cgwb_release_workfn+0x104/0x158
[ 4757.010702] process_one_work+0x1bc/0x3f0
[ 4757.010704] worker_thread+0x164/0x468
[ 4757.010705] kthread+0x108/0x138
Suggested-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
block/blk-cgroup.c | 18 +++++++++++++-----
1 file changed, 13 insertions(+), 5 deletions(-)
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 54fbe1e80cc41..f13688c4b9317 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -1017,6 +1017,8 @@ static void blkcg_css_offline(struct cgroup_subsys_state *css)
*/
void blkcg_destroy_blkgs(struct blkcg *blkcg)
{
+ might_sleep();
+
spin_lock_irq(&blkcg->lock);
while (!hlist_empty(&blkcg->blkg_list)) {
@@ -1024,14 +1026,20 @@ void blkcg_destroy_blkgs(struct blkcg *blkcg)
struct blkcg_gq, blkcg_node);
struct request_queue *q = blkg->q;
- if (spin_trylock(&q->queue_lock)) {
- blkg_destroy(blkg);
- spin_unlock(&q->queue_lock);
- } else {
+ if (need_resched() || !spin_trylock(&q->queue_lock)) {
+ /*
+ * Given that the system can accumulate a huge number
+ * of blkgs in pathological cases, check to see if we
+ * need to rescheduling to avoid softlockup.
+ */
spin_unlock_irq(&blkcg->lock);
- cpu_relax();
+ cond_resched();
spin_lock_irq(&blkcg->lock);
+ continue;
}
+
+ blkg_destroy(blkg);
+ spin_unlock(&q->queue_lock);
}
spin_unlock_irq(&blkcg->lock);
--
2.27.0
next prev parent reply other threads:[~2021-02-02 15:56 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-02 15:05 [PATCH AUTOSEL 5.10 01/25] af_key: relax availability checks for skb size calculation Sasha Levin
2021-02-02 15:05 ` [PATCH AUTOSEL 5.10 02/25] regulator: core: avoid regulator_resolve_supply() race condition Sasha Levin
2021-02-02 16:12 ` Mark Brown
2021-02-03 1:04 ` Sasha Levin
2021-02-03 12:12 ` Mark Brown
2021-02-02 15:05 ` [PATCH AUTOSEL 5.10 03/25] ASoC: wm_adsp: Fix control name parsing for multi-fw Sasha Levin
2021-02-02 15:05 ` [PATCH AUTOSEL 5.10 04/25] drm/nouveau/nvif: fix method count when pushing an array Sasha Levin
2021-02-02 15:05 ` [PATCH AUTOSEL 5.10 05/25] mac80211: 160MHz with extended NSS BW in CSA Sasha Levin
2021-02-02 15:05 ` [PATCH AUTOSEL 5.10 06/25] ASoC: Intel: Skylake: Zero snd_ctl_elem_value Sasha Levin
2021-02-02 15:05 ` [PATCH AUTOSEL 5.10 07/25] chtls: Fix potential resource leak Sasha Levin
2021-02-02 15:05 ` [PATCH AUTOSEL 5.10 08/25] pNFS/NFSv4: Try to return invalid layout in pnfs_layout_process() Sasha Levin
2021-02-02 15:05 ` [PATCH AUTOSEL 5.10 09/25] pNFS/NFSv4: Improve rejection of out-of-order layouts Sasha Levin
2021-02-02 15:06 ` [PATCH AUTOSEL 5.10 10/25] ALSA: hda: intel-dsp-config: add PCI id for TGL-H Sasha Levin
2021-02-02 15:06 ` [PATCH AUTOSEL 5.10 11/25] ASoC: ak4458: correct reset polarity Sasha Levin
2021-02-02 15:06 ` [PATCH AUTOSEL 5.10 12/25] ASoC: Intel: sof_sdw: set proper flags for Dell TGL-H SKU 0A5E Sasha Levin
2021-02-02 15:06 ` [PATCH AUTOSEL 5.10 13/25] iwlwifi: mvm: skip power command when unbinding vif during CSA Sasha Levin
2021-02-02 15:06 ` [PATCH AUTOSEL 5.10 14/25] iwlwifi: mvm: take mutex for calling iwl_mvm_get_sync_time() Sasha Levin
2021-02-02 15:06 ` [PATCH AUTOSEL 5.10 15/25] iwlwifi: pcie: add a NULL check in iwl_pcie_txq_unmap Sasha Levin
2021-02-02 15:06 ` [PATCH AUTOSEL 5.10 16/25] iwlwifi: pcie: fix context info memory leak Sasha Levin
2021-02-02 15:06 ` [PATCH AUTOSEL 5.10 17/25] iwlwifi: mvm: invalidate IDs of internal stations at mvm start Sasha Levin
2021-02-02 15:06 ` [PATCH AUTOSEL 5.10 18/25] iwlwifi: pcie: add rules to match Qu with Hr2 Sasha Levin
2021-02-02 15:06 ` [PATCH AUTOSEL 5.10 19/25] iwlwifi: mvm: guard against device removal in reprobe Sasha Levin
2021-02-02 15:06 ` [PATCH AUTOSEL 5.10 20/25] iwlwifi: queue: bail out on invalid freeing Sasha Levin
2021-02-02 15:06 ` [PATCH AUTOSEL 5.10 21/25] SUNRPC: Move simple_get_bytes and simple_get_netobj into private header Sasha Levin
2021-02-02 15:06 ` [PATCH AUTOSEL 5.10 22/25] SUNRPC: Handle 0 length opaque XDR object data properly Sasha Levin
2021-02-02 15:06 ` [PATCH AUTOSEL 5.10 23/25] i2c: mediatek: Move suspend and resume handling to NOIRQ phase Sasha Levin
2021-02-02 15:06 ` Sasha Levin [this message]
2021-02-02 15:06 ` [PATCH AUTOSEL 5.10 25/25] nvme-pci: add the DISABLE_WRITE_ZEROES quirk for a SPCC device Sasha Levin
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