On Tue, Mar 19, 2024 at 01:00:23PM +0100, Robert Richter wrote:
> For configurations that have the kconfig option NUMA_KEEP_MEMINFO
> disabled, the SRAT lookup done with numa_fill_memblks() fails
> returning NUMA_NO_MEMBLK (-1). An existing SRAT memory range cannot be
> found for a CFMWS address range. This causes the addition of a
> duplicate numa_memblk with a different node id and a subsequent page
> fault and kernel crash during boot.
>
> numa_fill_memblks() is implemented and used in the init section only.
> The option NUMA_KEEP_MEMINFO is only for the case when NUMA data will
> be used outside of init. So fix the SRAT lookup by moving
> numa_fill_memblks() out of the NUMA_KEEP_MEMINFO block to make it
> always available in the init section.
>
> Note that the issue was initially introduced with [1]. But since
> phys_to_target_node() was originally used that returned the valid node
> 0, an additional numa_memblk was not added. Though, the node id was
> wrong too.
Hi Richard,
I recall a bit of wrangling w #defines to make ARM64 and LOONGARCH build.
I'm seeing an x86 build error today:
>> arch/x86/mm/numa.c:957:12: error: redefinition of 'numa_fill_memblks'
957 | int __init numa_fill_memblks(u64 start, u64 end)
include/linux/numa.h:40:26: note: previous definition of 'numa_fill_memblks' with type
+'int(u64, u64)' {aka 'int(long long unsigned int, long long unsigned int)'}
40 | static inline int __init numa_fill_memblks(u64 start, u64 end)
| ^~~~~~~~~~~~~~~~~
In addition to what you suggest, would something like this diff below be
a useful safety measure to distinguish num_fill_memblks() success (rc:0)
and possible non-existence (rc:-1). I don't think it hurts to take a
second look using phys_to_target_node() (totall untested)
diff --git a/drivers/acpi/numa/srat.c b/drivers/acpi/numa/srat.c
index 070a52e4daa8..0c48fe32ced4 100644
--- a/drivers/acpi/numa/srat.c
+++ b/drivers/acpi/numa/srat.c
@@ -437,9 +437,16 @@ static int __init acpi_parse_cfmws(union acpi_subtable_headers *header,
* found for any portion of the window to cover the entire
* window.
*/
- if (!numa_fill_memblks(start, end))
+ rc = numa_fill_memblks(start, end);
+ if (!rc)
return 0;
+ if (rc == NUMA_NO_MEMBLK) {
+ node = phys_to_target_node(start);
+ if (node != NUMA_NO_NODE)
+ return 0;
+ }
+
/* No SRAT description. Create a new node. */
--Alison
>
> [1] fd49f99c1809 ("ACPI: NUMA: Add a node and memblk for each CFMWS not in SRAT")
>
> Fixes: 8f1004679987 ("ACPI/NUMA: Apply SRAT proximity domain to entire CFMWS window")
> Cc: Derick Marks <derick.w.marks@xxxxxxxxx>
> Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
> Cc: Alison Schofield <alison.schofield@xxxxxxxxx>
> Signed-off-by: Robert Richter <rrichter@xxxxxxx>
> ---
> arch/x86/mm/numa.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/arch/x86/mm/numa.c b/arch/x86/mm/numa.c
> index 65e9a6e391c0..ce84ba86e69e 100644
> --- a/arch/x86/mm/numa.c
> +++ b/arch/x86/mm/numa.c
> @@ -929,6 +929,8 @@ int memory_add_physaddr_to_nid(u64 start)
> }
> EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
>
> +#endif
> +
> static int __init cmp_memblk(const void *a, const void *b)
> {
> const struct numa_memblk *ma = *(const struct numa_memblk **)a;
> @@ -1001,5 +1003,3 @@ int __init numa_fill_memblks(u64 start, u64 end)
> }
> return 0;
> }
> -
> -#endif
> --
> 2.39.2
>
