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Message-ID: <63cbc594-14cb-b5c3-485b-5c784315b04b@redhat.com>
Date:   Fri, 9 Sep 2022 13:41:26 +0200
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Subject: Re: [PATCH v5 1/4] memblock tests: add simulation of physical memory
 with multiple NUMA nodes
Content-Language: en-US
To:     Rebecca Mckeever <remckee0@gmail.com>,
        Mike Rapoport <rppt@kernel.org>, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org
References: <cover.1662698159.git.remckee0@gmail.com>
 <5ac0e2f8d6b6cb985e2d6f308edeec2b699ecbea.1662698159.git.remckee0@gmail.com>
From:   David Hildenbrand <david@redhat.com>
Organization: Red Hat
In-Reply-To: <5ac0e2f8d6b6cb985e2d6f308edeec2b699ecbea.1662698159.git.remckee0@gmail.com>
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On 09.09.22 06:46, Rebecca Mckeever wrote:
> Add function setup_numa_memblock() for setting up a memory layout with
> multiple NUMA nodes in a previously allocated dummy physical memory.
> This function can be used in place of setup_memblock() in tests that need
> to simulate a NUMA system.
> 
> setup_numa_memblock():
> - allows for setting up a memory layout by specifying the fraction of
>    MEM_SIZE in each node
> 
> Set CONFIG_NODES_SHIFT to 4 when building with NUMA=1 to allow for up to
> 16 NUMA nodes.
> 
> Signed-off-by: Rebecca Mckeever <remckee0@gmail.com>
> ---
>   .../testing/memblock/scripts/Makefile.include |  2 +-
>   tools/testing/memblock/tests/common.c         | 31 +++++++++++++++++++
>   tools/testing/memblock/tests/common.h         |  4 ++-
>   3 files changed, 35 insertions(+), 2 deletions(-)
> 
> diff --git a/tools/testing/memblock/scripts/Makefile.include b/tools/testing/memblock/scripts/Makefile.include
> index aa6d82d56a23..998281723590 100644
> --- a/tools/testing/memblock/scripts/Makefile.include
> +++ b/tools/testing/memblock/scripts/Makefile.include
> @@ -3,7 +3,7 @@
>   
>   # Simulate CONFIG_NUMA=y
>   ifeq ($(NUMA), 1)
> -	CFLAGS += -D CONFIG_NUMA
> +	CFLAGS += -D CONFIG_NUMA -D CONFIG_NODES_SHIFT=4
>   endif
>   
>   # Use 32 bit physical addresses.
> diff --git a/tools/testing/memblock/tests/common.c b/tools/testing/memblock/tests/common.c
> index eec6901081af..9d9ad7df298b 100644
> --- a/tools/testing/memblock/tests/common.c
> +++ b/tools/testing/memblock/tests/common.c
> @@ -9,6 +9,7 @@
>   #define INIT_MEMBLOCK_RESERVED_REGIONS		INIT_MEMBLOCK_REGIONS
>   #define PREFIXES_MAX				15
>   #define DELIM					": "
> +#define BASIS					10000
>   
>   static struct test_memory memory_block;
>   static const char __maybe_unused *prefixes[PREFIXES_MAX];
> @@ -72,6 +73,36 @@ void setup_memblock(void)
>   	fill_memblock();
>   }
>   
> +/**
> + * setup_numa_memblock:
> + * Set up a memory layout with multiple NUMA nodes in a previously allocated
> + * dummy physical memory.
> + * @node_fracs: an array representing the fraction of MEM_SIZE contained in
> + *              each node in basis point units (one hundredth of 1% or 1/10000).
> + *              For example, if node 0 should contain 1/8 of MEM_SIZE,
> + *              node_fracs[0] = 1250.
> + *
> + * The nids will be set to 0 through NUMA_NODES - 1.
> + */
> +void setup_numa_memblock(const int node_fracs[])

If you make it an unsigned int ...

> +{
> +	phys_addr_t base;
> +	int flags;
> +
> +	reset_memblock_regions();
> +	base = (phys_addr_t)memory_block.base;
> +	flags = (movable_node_is_enabled()) ? MEMBLOCK_NONE : MEMBLOCK_HOTPLUG;
> +
> +	for (int i = 0; i < NUMA_NODES; i++) {
> +		assert(node_fracs[i] <= BASIS && node_fracs[i] > 0);

You can drop the latter assertion.

Thanks!

Reviewed-by: David Hildenbrand <david@redhat.com>

-- 
Thanks,

David / dhildenb