Re: [PATCH v11 0/6] Use pageblock_order for cma and alloc_contig_range alignment.

From: Zi Yan <ziy@nvidia.com>
To: Qian Cai <quic_qiancai@quicinc.com>
Cc: David Hildenbrand <david@redhat.com>,
	linux-mm@kvack.org, linux-kernel@vger.kernel.org,
	virtualization@lists.linux-foundation.org,
	Vlastimil Babka <vbabka@suse.cz>,
	Mel Gorman <mgorman@techsingularity.net>,
	Eric Ren <renzhengeek@gmail.com>, Mike Rapoport <rppt@kernel.org>,
	Oscar Salvador <osalvador@suse.de>,
	Christophe Leroy <christophe.leroy@csgroup.eu>,
	Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [PATCH v11 0/6] Use pageblock_order for cma and alloc_contig_range alignment.
Date: Fri, 29 Apr 2022 09:38:01 -0400	[thread overview]
Message-ID: <8A0F8444-FF62-44EF-88C1-AFAE66D29E2A@nvidia.com> (raw)
In-Reply-To: <20220428161911.GB182@qian>

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On 28 Apr 2022, at 12:19, Qian Cai wrote:

> On Thu, Apr 28, 2022 at 08:39:06AM -0400, Zi Yan wrote:
>> How about the one attached? I can apply it to next-20220428. Let me know
>> if you are using a different branch. Thanks.
>
> The original endless loop is gone, but running some syscall fuzzer

Thanks for the confirmation.

> afterwards for a while would trigger the warning here. I have yet to
> figure out if this is related to this series.
>
>         /*
>          * There are several places where we assume that the order value is sane
>          * so bail out early if the request is out of bound.
>          */
>         if (unlikely(order >= MAX_ORDER)) {
>                 WARN_ON_ONCE(!(gfp & __GFP_NOWARN));
>                 return NULL;
>         }
>
>  WARNING: CPU: 26 PID: 172874 at mm/page_alloc.c:5368 __alloc_pages
>  CPU: 26 PID: 172874 Comm: trinity-main Not tainted 5.18.0-rc4-next-20220428-dirty #67
>  pstate: 20400009 (nzCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
>  tpidr_el2 : ffff28cf80a61000
>  pc : __alloc_pages
>  lr : alloc_pages
>  sp : ffff8000597b70f0
>  x29: ffff8000597b70f0 x28: ffff0801e68d34c0 x27: 0000000000000000
>  x26: 1ffff0000b2f6ea2 x25: ffff8000597b7510 x24: 0000000000000dc0
>  x23: ffff28cf80a61000 x22: 000000000000000e x21: 1ffff0000b2f6e28
>  x20: 0000000000040dc0 x19: ffffdf670d4a6fe0 x18: ffffdf66fa017d1c
>  x17: ffffdf66f42f8348 x16: 1fffe1003cd1a7b3 x15: 000000000000001a
>  x14: 1fffe1003cd1a7a6 x13: 0000000000000004 x12: ffff70000b2f6e05
>  x11: 1ffff0000b2f6e04 x10: 00000000f204f1f1 x9 : 000000000000f204
>  x8 : dfff800000000000 x7 : 00000000f3000000 x6 : 00000000f3f3f3f3
>  x5 : ffff70000b2f6e28 x4 : ffff0801e68d34c0 x3 : 0000000000000000
>  x2 : 0000000000000000 x1 : 0000000000000001 x0 : 0000000000040dc0
>  Call trace:
>   __alloc_pages
>   alloc_pages
>   kmalloc_order
>   kmalloc_order_trace
>   __kmalloc
>   __regset_get
>   regset_get_alloc
>   fill_thread_core_info
>   fill_note_info
>   elf_core_dump
>   do_coredump
>   get_signal
>   do_signal
>   do_notify_resume
>   el0_svc
>   el0t_64_sync_handler
>   el0t_64_sync
>  irq event stamp: 3614
>  hardirqs last  enabled at (3613):  _raw_spin_unlock_irqrestore
>  hardirqs last disabled at (3614):  el1_dbg
>  softirqs last  enabled at (2988):  fpsimd_preserve_current_state
>  softirqs last disabled at (2986):  fpsimd_preserve_current_state

I got an email this morning reporting a warning with the same call trace:
https://lore.kernel.org/linux-mm/CA+G9fYveMF-NU-rvrsbaora2g2QWxrkF7AWViuDrJyN9mNScJg@mail.gmail.com/

The email says the warning appeared from next-20220427, but my
patchset was in linux-next since next-20220426. In addition,
my patches do not touch any function in the call trace. I assume
this warning is not related to my patchset. But let me know
if my patchset is related.

Thanks.

--
Best Regards,
Yan, Zi

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