Re: [LKP] Re: [mm/debug] fa6726c1e7: kernel_BUG_at_include/linux/mm.h
From: Chen, Rong A
Date: Wed Apr 29 2020 - 08:52:37 EST
On 4/29/2020 11:28 AM, Anshuman Khandual wrote:
On 04/28/2020 02:51 PM, Catalin Marinas wrote:
On Tue, Apr 28, 2020 at 04:41:11AM -0400, Qian Cai wrote:
On Apr 28, 2020, at 1:54 AM, Anshuman Khandual <Anshuman.Khandual@xxxxxxx> wrote:
That is true. There is a slight change in the rules, making it explicit yes
only when both ARCH_HAS_DEBUG_VM_PGTABLE and DEBUG_VM are enabled.
+config DEBUG_VM_PGTABLE
+ bool "Debug arch page table for semantics compliance"
+ depends on MMU
+ depends on !IA64 && !ARM
+ depends on ARCH_HAS_DEBUG_VM_PGTABLE || EXPERT
+ default y if ARCH_HAS_DEBUG_VM_PGTABLE && DEBUG_VM
+ help
The default is really irrelevant as the config option can be set explicitly.
That could also explain. Since not long time ago, it was only âdefault
y if DEBUG_VMâ, that caused the robot saved a .config with
DEBUG_VM_PGTABLE=y by default.
Even though you changed the rule recently, it has no effect as the
robot could âmake oldconfigâ from the saved config for each linux-next
tree execution and the breakage will go on.
I'm not entirely sure that's the case. This report still points at the
old commit fa6726c1e7 which has:
+ depends on ARCH_HAS_DEBUG_VM_PGTABLE || EXPERT
+ default n if !ARCH_HAS_DEBUG_VM_PGTABLE
+ default y if DEBUG_VM
In -next we now have commit 647d9a0de34c and subsequently modified by
commit 0a8646638865. So hopefully with the latest -next tree we won't
see this report.
Could some one from LKP test framework, please confirm if this still causes
above problem on the latest linux-next by default ?
Hi,
The .config is a rand config, the problem is still exist if run "make
oldconfig" for the config
with commit 0a8646638865.
$ grep -e CONFIG_MMU= -e CONFIG_EXPERT= -e
CONFIG_ARCH_HAS_DEBUG_VM_PGTABLE= -e CONFIG_DEBUG_VM= .config
CONFIG_EXPERT=y
CONFIG_MMU=y
CONFIG_DEBUG_VM=y
should we disable DEBUG_VM_PGTABLE by default?
Best Regards,
Rong Chen