[syzbot ci] Re: mm: reliable 1GB page allocation

[syzbot ci]

syzbot ci has tested the following series

[v1] mm: reliable 1GB page allocation
https://lore.kernel.org/all/20260520150018...@surriel.com
* [RFC PATCH 01/40] mm: page_alloc: replace pageblock_flags bitmap with struct pageblock_data
* [RFC PATCH 02/40] mm: page_alloc: per-cpu pageblock buddy allocator
* [RFC PATCH 03/40] mm: page_alloc: split-path PCP free with local-trylock + remote-llist
* [RFC PATCH 04/40] mm: mm_init: fix zone assignment for pages in unavailable ranges
* [RFC PATCH 05/40] mm: page_alloc: remove watermark boost mechanism
* [RFC PATCH 06/40] mm: page_alloc: async evacuation of stolen movable pageblocks
* [RFC PATCH 07/40] mm: page_alloc: track actual page contents in pageblock flags
* [RFC PATCH 08/40] mm: page_alloc: superpageblock metadata for 1GB anti-fragmentation
* [RFC PATCH 09/40] mm: page_alloc: support superpageblock resize for memory hotplug
* [RFC PATCH 10/40] mm: page_alloc: add superpageblock fullness lists for allocation steering
* [RFC PATCH 11/40] mm: page_alloc: steer pageblock stealing to tainted superpageblocks
* [RFC PATCH 12/40] mm: page_alloc: steer movable allocations to fullest clean superpageblocks
* [RFC PATCH 13/40] mm: page_alloc: extract claim_whole_block from try_to_claim_block
* [RFC PATCH 14/40] mm: page_alloc: add per-superpageblock free lists
* [RFC PATCH 15/40] mm: page_alloc: add background superpageblock defragmentation worker
* [RFC PATCH 16/40] mm: compaction: walk per-superpageblock free lists for migration targets
* [RFC PATCH 17/40] mm: page_alloc: superpageblock-aware contiguous and higher order allocation
* [RFC PATCH 18/40] mm: page_alloc: prevent atomic allocations from tainting clean SPBs
* [RFC PATCH 19/40] mm: page_alloc: aggressively pack non-movable allocs in tainted SPBs on large systems
* [RFC PATCH 20/40] mm: page_alloc: prefer reclaim over tainting clean superpageblocks
* [RFC PATCH 21/40] mm: page_alloc: adopt partial pageblocks from tainted superpageblocks
* [RFC PATCH 22/40] mm: page_alloc: add CONFIG_DEBUG_VM sanity checks for SPB counters
* [RFC PATCH 23/40] mm: page_alloc: targeted evacuation and dynamic reserves for tainted SPBs
* [RFC PATCH 24/40] mm: page_alloc: prevent UNMOVABLE/RECLAIMABLE mixing in pageblocks
* [RFC PATCH 25/40] mm: trigger deferred SPB evac when atomic allocs would taint a clean SPB
* [RFC PATCH 26/40] mm: page_alloc: refuse fragmenting fallback for callers with cheap fallback
* [RFC PATCH 27/40] mm: page_alloc: cross-migratetype buddy borrow within tainted SPBs
* [RFC PATCH 28/40] mm: page_alloc: drive slab shrink from SPB anti-fragmentation pressure
* [RFC PATCH 29/40] mm: page_reporting: walk per-superpageblock free lists
* [RFC PATCH 30/40] mm: show_mem: collect migratetype letters from per-superpageblock lists
* [RFC PATCH 31/40] mm: page_alloc: per-(zone, order, mt) PASS_1 hint cache
* [RFC PATCH 32/40] mm: debug: prevent infinite recursion in dump_page() with CMA
* [RFC PATCH 33/40] PM: hibernate: walk per-superpageblock free lists in mark_free_pages
* [RFC PATCH 34/40] btrfs: allocate eb-attached btree pages as movable
* [RFC PATCH 35/40] mm: page_alloc: refuse best-effort high-order allocs servable at lower orders
* [RFC PATCH 36/40] mm: page_alloc: set ALLOC_NOFRAGMENT on alloc_frozen_pages_nolock_noprof
* [RFC PATCH 37/40] mm: page_alloc: move spb_get_category and spb_tainted_reserve to mmzone.h
* [RFC PATCH 38/40] mm: compaction: skip empty tainted superpageblocks as migration source
* [RFC PATCH 39/40] mm: compaction: respect tainted SPB reserve in destination selection
* [RFC PATCH 40/40] mm: page_alloc: SPB tracepoint instrumentation [DO-NOT-MERGE]

and found the following issue:
WARNING in preempt_count_sub

Full report is available here:
https://ci.syzbot.org/series/8eef71e1-708c-40d0-9f9d-3a1bd637fc80

***

WARNING in preempt_count_sub

tree: mm-new
URL: https://kernel.googlesource.com/pub/scm/linux/kernel/git/akpm/mm.git
base: 4b83cbc4c15f09b000cc06f033f64b0824b6dc87
arch: amd64
compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8
config: https://ci.syzbot.org/builds/de024c89-d472-4f06-b5be-4f75f2acd1d9/config

------------[ cut here ]------------
DEBUG_LOCKS_WARN_ON(val > preempt_count())
WARNING: kernel/sched/core.c:5883 at preempt_count_sub+0x9e/0x170, CPU#0: kworker/0:0/9
Modules linked in:
CPU: 0 UID: 0 PID: 9 Comm: kworker/0:0 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Workqueue: events drain_vmap_area_work
RIP: 0010:preempt_count_sub+0xa5/0x170
Code: 29 31 90 48 c1 e8 03 0f b6 04 18 84 c0 0f 85 88 00 00 00 83 3d ff 50 9d 0e 00 75 13 48 8d 3d 32 37 a0 0e 48 c7 c6 c0 f8 cb 8b <67> 48 0f b9 3a 90 eb b8 90 e8 ed d6 1d 03 85 c0 74 2f 48 c7 c0 c4
RSP: 0000:ffffc900000e7590 EFLAGS: 00010246

RAX: 0000000000000000 RBX: dffffc0000000000 RCX: ffff8881007d5880
RDX: 0000000000000000 RSI: ffffffff8bcbf8c0 RDI: ffffffff90341000
RBP: ffff888121042dc0 R08: ffffffff903129c3 R09: 1ffffffff2062538
R10: dffffc0000000000 R11: fffffbfff2062539 R12: 0000000000000020
R13: dffffc0000000000 R14: ffff888121042d80 R15: ffff88815fffbae8
FS: 0000000000000000(0000) GS:ffff88818dc7e000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffff88823ffff000 CR3: 000000000e74a000 CR4: 00000000000006f0
Call Trace:
<TASK>
free_frozen_page_commit+0x737/0x1290
__free_frozen_pages+0x873/0x1070
kasan_depopulate_vmalloc_pte+0x6d/0x90
__apply_to_page_range+0xbdc/0x1420
__kasan_release_vmalloc+0xa2/0xd0
purge_vmap_node+0x220/0x960
__purge_vmap_area_lazy+0x779/0xb40
drain_vmap_area_work+0x27/0x40
process_scheduled_works+0xb5d/0x1860
worker_thread+0xa53/0xfc0
kthread+0x388/0x470
ret_from_fork+0x514/0xb70
ret_from_fork_asm+0x1a/0x30
</TASK>


***

If these findings have caused you to resend the series or submit a
separate fix, please add the following tag to your commit message:
Tested-by: syz...@syzkaller.appspotmail.com

---
This report is generated by a bot. It may contain errors.
syzbot ci engineers can be reached at syzk...@googlegroups.com.

To test a patch for this bug, please reply with `#syz test`
(should be on a separate line).

The patch should be attached to the email.
Note: arguments like custom git repos and branches are not supported.