On 2020/04/27 15:19, Vincent Chen wrote:
> The current max_pfn equals to zero. In this case, I found it caused users
> cannot get some page information through /proc such as kpagecount in v5.6
> kernel because of new sanity checks. The following message is displayed by
> stress-ng test suite with the command "stress-ng --verbose --physpage 1 -t
> 1" on HiFive unleashed board.
>
> # stress-ng --verbose --physpage 1 -t 1
> stress-ng: debug: [109] 4 processors online, 4 processors configured
> stress-ng: info: [109] dispatching hogs: 1 physpage
> stress-ng: debug: [109] cache allocate: reducing cache level from L3 (too high) to L0
> stress-ng: debug: [109] get_cpu_cache: invalid cache_level: 0
> stress-ng: info: [109] cache allocate: using built-in defaults as no suitable cache found
> stress-ng: debug: [109] cache allocate: default cache size: 2048K
> stress-ng: debug: [109] starting stressors
> stress-ng: debug: [109] 1 stressor spawned
> stress-ng: debug: [110] stress-ng-physpage: started [110] (instance 0)
> stress-ng: error: [110] stress-ng-physpage: cannot read page count for address 0x3fd34de000 in /proc/kpagecount, errno=0 (Success)
> stress-ng: error: [110] stress-ng-physpage: cannot read page count for address 0x3fd32db078 in /proc/kpagecount, errno=0 (Success)
> ...
> stress-ng: error: [110] stress-ng-physpage: cannot read page count for address 0x3fd32db078 in /proc/kpagecount, errno=0 (Success)
> stress-ng: debug: [110] stress-ng-physpage: exited [110] (instance 0)
> stress-ng: debug: [109] process [110] terminated
> stress-ng: info: [109] successful run completed in 1.00s
> #
>
> After applying this patch, the kernel can pass the test.
>
> # stress-ng --verbose --physpage 1 -t 1
> stress-ng: debug: [104] 4 processors online, 4 processors configured stress-ng: info: [104] dispatching hogs: 1 physpage
> stress-ng: info: [104] cache allocate: using defaults, can't determine cache details from sysfs
> stress-ng: debug: [104] cache allocate: default cache size: 2048K
> stress-ng: debug: [104] starting stressors
> stress-ng: debug: [104] 1 stressor spawned
> stress-ng: debug: [105] stress-ng-physpage: started [105] (instance 0) stress-ng: debug: [105] stress-ng-physpage: exited [105] (instance 0) stress-ng: debug: [104] process [105] terminated
> stress-ng: info: [104] successful run completed in 1.01s
> #
>
> Fixes: 0651c263c8e3 (RISC-V: Move setup_bootmem() to mm/init.c)
> Cc: stable@xxxxxxxxxxxxxxx
>
> Signed-off-by: Vincent Chen <vincent.chen@xxxxxxxxxx>
> Reviewed-by: Anup Patel <anup@xxxxxxxxxxxxxx>
email typo not fixed...
As Anup mentioned, it should be: anup@xxxxxxxxxxxxxx (".org", not ".ort").
> Reviewed-by: Yash Shah <yash.shah@xxxxxxxxxx>
> Tested-by: Yash Shah <yash.shah@xxxxxxxxxx>
>
> Changes since v1:
> 1. Add Fixes line and Cc stable kernel
> ---
> arch/riscv/mm/init.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
> index fab855963c73..157924baa191 100644
> --- a/arch/riscv/mm/init.c
> +++ b/arch/riscv/mm/init.c
> @@ -149,7 +149,8 @@ void __init setup_bootmem(void)
> memblock_reserve(vmlinux_start, vmlinux_end - vmlinux_start);
>
> set_max_mapnr(PFN_DOWN(mem_size));
> - max_low_pfn = PFN_DOWN(memblock_end_of_DRAM());
> + max_pfn = PFN_DOWN(memblock_end_of_DRAM());
> + max_low_pfn = max_pfn;
>
> #ifdef CONFIG_BLK_DEV_INITRD
> setup_initrd();
>
--
Damien Le Moal
Western Digital Research
