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[RESEND v7 3/3] acpi,srat: give memory block size advice based on CFMWS alignment

Gregory Price posted 3 patches 11 months, 1 week ago
There is a newer version of this series
[RESEND v7 3/3] acpi,srat: give memory block size advice based on CFMWS alignment
Posted by Gregory Price 11 months, 1 week ago 
Capacity is stranded when CFMWS regions are not aligned to block size.
On x86, block size increases with capacity (2G blocks @ 64G capacity).

Use CFMWS base/size to report memory block size alignment advice.

Suggested-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Gregory Price <gourry@gourry.net>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Tested-by: Fan Ni <fan.ni@samsung.com>
---
 drivers/acpi/numa/srat.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/drivers/acpi/numa/srat.c b/drivers/acpi/numa/srat.c
index 59fffe34c9d0..7526119fe945 100644
--- a/drivers/acpi/numa/srat.c
+++ b/drivers/acpi/numa/srat.c
@@ -14,6 +14,7 @@
 #include <linux/errno.h>
 #include <linux/acpi.h>
 #include <linux/memblock.h>
+#include <linux/memory.h>
 #include <linux/numa.h>
 #include <linux/nodemask.h>
 #include <linux/topology.h>
@@ -425,13 +426,22 @@ static int __init acpi_parse_cfmws(union acpi_subtable_headers *header,
 {
 	struct acpi_cedt_cfmws *cfmws;
 	int *fake_pxm = arg;
-	u64 start, end;
+	u64 start, end, align;
 	int node;
 
 	cfmws = (struct acpi_cedt_cfmws *)header;
 	start = cfmws->base_hpa;
 	end = cfmws->base_hpa + cfmws->window_size;
 
+	/* Align memblock size to CFMW regions if possible */
+	align = 1UL << __ffs(start | end);
+	if (align >= SZ_256M) {
+		if (memory_block_advise_max_size(align) < 0)
+			pr_warn("CFMWS: memblock size advise failed\n");
+	} else {
+		pr_err("CFMWS: [BIOS BUG] base/size alignment violates spec\n");
+	}
+
 	/*
 	 * The SRAT may have already described NUMA details for all,
 	 * or a portion of, this CFMWS HPA range. Extend the memblks
-- 
2.47.1
Re: [RESEND v7 3/3] acpi,srat: give memory block size advice based on CFMWS alignment
Posted by Ira Weiny 11 months, 1 week ago 
Gregory Price wrote:
> Capacity is stranded when CFMWS regions are not aligned to block size.
> On x86, block size increases with capacity (2G blocks @ 64G capacity).
> 
> Use CFMWS base/size to report memory block size alignment advice.
> 
> Suggested-by: Dan Williams <dan.j.williams@intel.com>
> Signed-off-by: Gregory Price <gourry@gourry.net>
> Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
> Acked-by: David Hildenbrand <david@redhat.com>
> Acked-by: Dan Williams <dan.j.williams@intel.com>
> Tested-by: Fan Ni <fan.ni@samsung.com>
> ---
>  drivers/acpi/numa/srat.c | 12 +++++++++++-
>  1 file changed, 11 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/acpi/numa/srat.c b/drivers/acpi/numa/srat.c
> index 59fffe34c9d0..7526119fe945 100644
> --- a/drivers/acpi/numa/srat.c
> +++ b/drivers/acpi/numa/srat.c
> @@ -14,6 +14,7 @@
>  #include <linux/errno.h>
>  #include <linux/acpi.h>
>  #include <linux/memblock.h>
> +#include <linux/memory.h>
>  #include <linux/numa.h>
>  #include <linux/nodemask.h>
>  #include <linux/topology.h>
> @@ -425,13 +426,22 @@ static int __init acpi_parse_cfmws(union acpi_subtable_headers *header,
>  {
>  	struct acpi_cedt_cfmws *cfmws;
>  	int *fake_pxm = arg;
> -	u64 start, end;
> +	u64 start, end, align;
>  	int node;
>  
>  	cfmws = (struct acpi_cedt_cfmws *)header;
>  	start = cfmws->base_hpa;
>  	end = cfmws->base_hpa + cfmws->window_size;
>  
> +	/* Align memblock size to CFMW regions if possible */
> +	align = 1UL << __ffs(start | end);
> +	if (align >= SZ_256M) {
> +		if (memory_block_advise_max_size(align) < 0)
> +			pr_warn("CFMWS: memblock size advise failed\n");

I wonder if it would be good to print the return value here so the user
knows why this failed?

But either way.

Reviewed-by: Ira Weiny <ira.weiny@intel.com>

> +	} else {
> +		pr_err("CFMWS: [BIOS BUG] base/size alignment violates spec\n");
> +	}
> +
>  	/*
>  	 * The SRAT may have already described NUMA details for all,
>  	 * or a portion of, this CFMWS HPA range. Extend the memblks
> -- 
> 2.47.1
> 
>
Re: [RESEND v7 3/3] acpi,srat: give memory block size advice based on CFMWS alignment
Posted by Gregory Price 11 months, 1 week ago 
On Mon, Jan 13, 2025 at 02:59:22PM -0600, Ira Weiny wrote:
> Gregory Price wrote:
> > +	/* Align memblock size to CFMW regions if possible */
> > +	align = 1UL << __ffs(start | end);
> > +	if (align >= SZ_256M) {
> > +		if (memory_block_advise_max_size(align) < 0)
> > +			pr_warn("CFMWS: memblock size advise failed\n");
> 
> I wonder if it would be good to print the return value here so the user
> knows why this failed?
> 

As someone who is often annoyed by this exact pattern, I am apparently
just as guilty at producing it *facepalm*

I'll pick this up and push it tomorrow.

> But either way.
> 
> Reviewed-by: Ira Weiny <ira.weiny@intel.com>
> 
> > +	} else {
> > +		pr_err("CFMWS: [BIOS BUG] base/size alignment violates spec\n");
> > +	}
> > +
> >  	/*
> >  	 * The SRAT may have already described NUMA details for all,
> >  	 * or a portion of, this CFMWS HPA range. Extend the memblks
> > -- 
> > 2.47.1
> > 
> > 
> 
>
Re: [RESEND v7 3/3] acpi,srat: give memory block size advice based on CFMWS alignment
Posted by Rafael J. Wysocki 11 months, 1 week ago 
On Mon, Jan 13, 2025 at 6:44 PM Gregory Price <gourry@gourry.net> wrote:
>
> Capacity is stranded when CFMWS regions are not aligned to block size.
> On x86, block size increases with capacity (2G blocks @ 64G capacity).
>
> Use CFMWS base/size to report memory block size alignment advice.
>
> Suggested-by: Dan Williams <dan.j.williams@intel.com>
> Signed-off-by: Gregory Price <gourry@gourry.net>
> Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
> Acked-by: David Hildenbrand <david@redhat.com>
> Acked-by: Dan Williams <dan.j.williams@intel.com>
> Tested-by: Fan Ni <fan.ni@samsung.com>

Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

> ---
>  drivers/acpi/numa/srat.c | 12 +++++++++++-
>  1 file changed, 11 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/acpi/numa/srat.c b/drivers/acpi/numa/srat.c
> index 59fffe34c9d0..7526119fe945 100644
> --- a/drivers/acpi/numa/srat.c
> +++ b/drivers/acpi/numa/srat.c
> @@ -14,6 +14,7 @@
>  #include <linux/errno.h>
>  #include <linux/acpi.h>
>  #include <linux/memblock.h>
> +#include <linux/memory.h>
>  #include <linux/numa.h>
>  #include <linux/nodemask.h>
>  #include <linux/topology.h>
> @@ -425,13 +426,22 @@ static int __init acpi_parse_cfmws(union acpi_subtable_headers *header,
>  {
>         struct acpi_cedt_cfmws *cfmws;
>         int *fake_pxm = arg;
> -       u64 start, end;
> +       u64 start, end, align;
>         int node;
>
>         cfmws = (struct acpi_cedt_cfmws *)header;
>         start = cfmws->base_hpa;
>         end = cfmws->base_hpa + cfmws->window_size;
>
> +       /* Align memblock size to CFMW regions if possible */
> +       align = 1UL << __ffs(start | end);
> +       if (align >= SZ_256M) {
> +               if (memory_block_advise_max_size(align) < 0)
> +                       pr_warn("CFMWS: memblock size advise failed\n");
> +       } else {
> +               pr_err("CFMWS: [BIOS BUG] base/size alignment violates spec\n");
> +       }
> +
>         /*
>          * The SRAT may have already described NUMA details for all,
>          * or a portion of, this CFMWS HPA range. Extend the memblks
> --
> 2.47.1
>

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