From: "Theodore Ts'o" <tytso@mit.edu>
To: Guenter Roeck <linux@roeck-us.net>
Cc: Baokun Li <libaokun1@huawei.com>,
linux-ext4@vger.kernel.org, adilger.kernel@dilger.ca,
jack@suse.cz, linux-kernel@vger.kernel.org,
ojaswin@linux.ibm.com, julia.lawall@inria.fr,
yi.zhang@huawei.com, yangerkun@huawei.com,
libaokun@huaweicloud.com
Subject: Re: [PATCH v3 15/17] ext4: convert free groups order lists to xarrays
Date: Thu, 24 Jul 2025 00:54:56 -0400 [thread overview]
Message-ID: <20250724045456.GA80823@mit.edu> (raw)
In-Reply-To: <b0635ad0-7ebf-4152-a69b-58e7e87d5085@roeck-us.net>
On Wed, Jul 23, 2025 at 08:55:14PM -0700, Guenter Roeck wrote:
> Hi,
>
> On Mon, Jul 14, 2025 at 09:03:25PM +0800, Baokun Li wrote:
> > While traversing the list, holding a spin_lock prevents load_buddy, making
> > direct use of ext4_try_lock_group impossible. This can lead to a bouncing
> > scenario where spin_is_locked(grp_A) succeeds, but ext4_try_lock_group()
> > fails, forcing the list traversal to repeatedly restart from grp_A.
> >
>
> This patch causes crashes for pretty much every architecture when
> running unit tests as part of booting.
I'm assuming that you're using a randconfig that happened to enable
CONFIG_EXT4_KUNIT_TESTS=y.
A simpler reprducer is to have a .kunitconfig containing:
CONFIG_KUNIT=y
CONFIG_KUNIT_TEST=y
CONFIG_KUNIT_EXAMPLE_TEST=y
CONFIG_EXT4_KUNIT_TESTS=y
... and then run :./tools/testing/kunit/kunit.py run".
The first failure is actually with [11/17] ext4: fix largest free
orders lists corruption on mb_optimize_scan switch, which triggers a
failure of test_mb_mark_used.
Baokun, can you take a look please? Many thanks!
- Ted
next prev parent reply other threads:[~2025-07-24 4:56 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-07-14 13:03 [PATCH v3 00/17] ext4: better scalability for ext4 block allocation Baokun Li
2025-07-14 13:03 ` [PATCH v3 01/17] ext4: add ext4_try_lock_group() to skip busy groups Baokun Li
2025-07-17 10:09 ` Ojaswin Mujoo
2025-07-19 0:37 ` Baokun Li
2025-07-17 22:28 ` Andi Kleen
2025-07-18 3:09 ` Theodore Ts'o
2025-07-19 0:29 ` Baokun Li
2025-07-22 20:59 ` Andi Kleen
2025-07-14 13:03 ` [PATCH v3 02/17] ext4: separate stream goal hits from s_bal_goals for better tracking Baokun Li
2025-07-17 10:29 ` Ojaswin Mujoo
2025-07-19 1:37 ` Baokun Li
2025-07-14 13:03 ` [PATCH v3 03/17] ext4: remove unnecessary s_mb_last_start Baokun Li
2025-07-17 10:31 ` Ojaswin Mujoo
2025-07-14 13:03 ` [PATCH v3 04/17] ext4: remove unnecessary s_md_lock on update s_mb_last_group Baokun Li
2025-07-17 13:36 ` Ojaswin Mujoo
2025-07-19 1:54 ` Baokun Li
2025-07-14 13:03 ` [PATCH v3 05/17] ext4: utilize multiple global goals to reduce contention Baokun Li
2025-07-14 13:03 ` [PATCH v3 06/17] ext4: get rid of some obsolete EXT4_MB_HINT flags Baokun Li
2025-07-14 13:03 ` [PATCH v3 07/17] ext4: fix typo in CR_GOAL_LEN_SLOW comment Baokun Li
2025-07-14 13:03 ` [PATCH v3 08/17] ext4: convert sbi->s_mb_free_pending to atomic_t Baokun Li
2025-07-14 13:03 ` [PATCH v3 09/17] ext4: merge freed extent with existing extents before insertion Baokun Li
2025-07-14 13:03 ` [PATCH v3 10/17] ext4: fix zombie groups in average fragment size lists Baokun Li
2025-07-14 13:03 ` [PATCH v3 11/17] ext4: fix largest free orders lists corruption on mb_optimize_scan switch Baokun Li
2025-07-14 13:03 ` [PATCH v3 12/17] ext4: factor out __ext4_mb_scan_group() Baokun Li
2025-07-14 13:03 ` [PATCH v3 13/17] ext4: factor out ext4_mb_might_prefetch() Baokun Li
2025-07-14 13:03 ` [PATCH v3 14/17] ext4: factor out ext4_mb_scan_group() Baokun Li
2025-07-14 13:03 ` [PATCH v3 15/17] ext4: convert free groups order lists to xarrays Baokun Li
2025-07-21 11:07 ` Jan Kara
2025-07-21 12:33 ` Baokun Li
2025-07-21 13:45 ` Baokun Li
2025-07-21 18:01 ` Theodore Ts'o
2025-07-22 5:58 ` Baokun Li
2025-07-24 3:55 ` Guenter Roeck
2025-07-24 4:54 ` Theodore Ts'o [this message]
2025-07-24 5:20 ` Guenter Roeck
2025-07-24 11:14 ` Zhang Yi
2025-07-24 14:30 ` Guenter Roeck
2025-07-24 14:54 ` Theodore Ts'o
2025-07-25 2:28 ` Zhang Yi
2025-07-26 0:50 ` Baokun Li
2025-07-14 13:03 ` [PATCH v3 16/17] ext4: refactor choose group to scan group Baokun Li
2025-07-14 13:03 ` [PATCH v3 17/17] ext4: implement linear-like traversal across order xarrays Baokun Li
2025-07-15 1:11 ` [PATCH v3 00/17] ext4: better scalability for ext4 block allocation Zhang Yi
2025-07-19 21:45 ` Theodore Ts'o
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