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Subject: Re: [PATCH] ia64: mca: allocate early mca with GFP_ATOMIC
To:     Sergei Trofimovich <slyfox@gentoo.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        linux-kernel@vger.kernel.org
Cc:     linux-ia64@vger.kernel.org
References: <20210315085045.204414-1-slyfox@gentoo.org>
From:   John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Message-ID: <f351183c-7d70-359f-eed7-4d1722cf41c5@physik.fu-berlin.de>
Date:   Tue, 23 Mar 2021 16:15:06 +0100
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Hi Andrew!

On 3/15/21 9:50 AM, Sergei Trofimovich wrote:
> The sleep warning happens at early boot right at
> secondary CPU activation bootup:
> 
>     smp: Bringing up secondary CPUs ...
>     BUG: sleeping function called from invalid context at mm/page_alloc.c:4942
>     in_atomic(): 0, irqs_disabled(): 1, non_block: 0, pid: 0, name: swapper/1
>     CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.12.0-rc2-00007-g79e228d0b611-dirty #99
> 
>     Call Trace:
>      [<a000000100014d10>] show_stack+0x90/0xc0
>      [<a000000101111d90>] dump_stack+0x150/0x1c0
>      [<a0000001000cbec0>] ___might_sleep+0x1c0/0x2a0
>      [<a0000001000cc040>] __might_sleep+0xa0/0x160
>      [<a000000100399960>] __alloc_pages_nodemask+0x1a0/0x600
>      [<a0000001003b71b0>] alloc_page_interleave+0x30/0x1c0
>      [<a0000001003b9b60>] alloc_pages_current+0x2c0/0x340
>      [<a00000010038c270>] __get_free_pages+0x30/0xa0
>      [<a000000100044730>] ia64_mca_cpu_init+0x2d0/0x3a0
>      [<a000000100023430>] cpu_init+0x8b0/0x1440
>      [<a000000100054680>] start_secondary+0x60/0x700
>      [<a00000010111e1d0>] start_ap+0x750/0x780
>     Fixed BSP b0 value from CPU 1
> 
> As I understand interrupts are not enabled yet and system has a lot
> of memory. There is little chance to sleep and switch to GFP_ATOMIC
> should be a no-op.
> 
> CC: Andrew Morton <akpm@linux-foundation.org>
> CC: linux-ia64@vger.kernel.org
> Signed-off-by: Sergei Trofimovich <slyfox@gentoo.org>
> ---
>  arch/ia64/kernel/mca.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/ia64/kernel/mca.c b/arch/ia64/kernel/mca.c
> index d4cae2fc69ca..adf6521525f4 100644
> --- a/arch/ia64/kernel/mca.c
> +++ b/arch/ia64/kernel/mca.c
> @@ -1824,7 +1824,7 @@ ia64_mca_cpu_init(void *cpu_data)
>  			data = mca_bootmem();
>  			first_time = 0;
>  		} else
> -			data = (void *)__get_free_pages(GFP_KERNEL,
> +			data = (void *)__get_free_pages(GFP_ATOMIC,
>  							get_order(sz));
>  		if (!data)
>  			panic("Could not allocate MCA memory for cpu %d\n",
> 

Has this one been picked up for your tree already?

Thanks,
Adrian

-- 
 .''`.  John Paul Adrian Glaubitz
: :' :  Debian Developer - glaubitz@debian.org
`. `'   Freie Universitaet Berlin - glaubitz@physik.fu-berlin.de
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