linux-kernel - [PATCH 4.9 07/13] ia64: mca: allocate early mca with GFP

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Date:   Fri,  9 Apr 2021 11:53:27 +0200
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Sergei Trofimovich <slyfox@...too.org>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Linus Torvalds <torvalds@...ux-foundation.org>,
        Sasha Levin <sashal@...nel.org>
Subject: [PATCH 4.9 07/13] ia64: mca: allocate early mca with GFP_ATOMIC

From: Sergei Trofimovich <slyfox@...too.org>

[ Upstream commit f2a419cf495f95cac49ea289318b833477e1a0e2 ]

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:
      show_stack+0x90/0xc0
      dump_stack+0x150/0x1c0
      ___might_sleep+0x1c0/0x2a0
      __might_sleep+0xa0/0x160
      __alloc_pages_nodemask+0x1a0/0x600
      alloc_page_interleave+0x30/0x1c0
      alloc_pages_current+0x2c0/0x340
      __get_free_pages+0x30/0xa0
      ia64_mca_cpu_init+0x2d0/0x3a0
      cpu_init+0x8b0/0x1440
      start_secondary+0x60/0x700
      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.

Link: https://lkml.kernel.org/r/20210315085045.204414-1-slyfox@gentoo.org
Signed-off-by: Sergei Trofimovich <slyfox@...too.org>
Signed-off-by: Andrew Morton <akpm@...ux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@...ux-foundation.org>
Signed-off-by: Sasha Levin <sashal@...nel.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 9509cc73b9c6..64ae9cde8bdb 100644
--- a/arch/ia64/kernel/mca.c
+++ b/arch/ia64/kernel/mca.c
@@ -1858,7 +1858,7 @@ 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