linux-kernel - [PATCH] ia64: mca: allocate early mca with GFP

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Date:   Mon, 15 Mar 2021 08:50:45 +0000
From:   Sergei Trofimovich <slyfox@...too.org>
To:     Andrew Morton <akpm@...ux-foundation.org>,
        linux-kernel@...r.kernel.org
Cc:     Sergei Trofimovich <slyfox@...too.org>, linux-ia64@...r.kernel.org
Subject: [PATCH] ia64: mca: allocate early mca with GFP_ATOMIC

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@...ux-foundation.org>
CC: linux-ia64@...r.kernel.org
Signed-off-by: Sergei Trofimovich <slyfox@...too.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",
-- 
2.30.2