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Message-ID: <93529fb7-f558-cc5f-d5bd-7923eb4b492c@maciej.szmigiero.name>
Date:   Tue, 18 Oct 2022 00:56:53 +0200
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Subject: Re: [PATCH 5/6] KVM: selftests: memslot_perf_test: Consolidate memory
 sizes
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To:     Gavin Shan <gshan@redhat.com>,
        Sean Christopherson <seanjc@google.com>
Cc:     kvmarm@lists.cs.columbia.edu, kvmarm@lists.linux.dev,
        kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
        ajones@ventanamicro.com, pbonzini@redhat.com, maz@kernel.org,
        shuah@kernel.org, oliver.upton@linux.dev, peterx@redhat.com,
        ricarkol@google.com, zhenyzha@redhat.com, shan.gavin@gmail.com
References: <20221014071914.227134-1-gshan@redhat.com>
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 <9781c88f-06f9-4d17-8fa6-3cd82a739ccb@redhat.com>
From:   "Maciej S. Szmigiero" <mail@maciej.szmigiero.name>
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On 18.10.2022 00:51, Gavin Shan wrote:
> On 10/18/22 6:08 AM, Sean Christopherson wrote:
>> On Mon, Oct 17, 2022, Maciej S. Szmigiero wrote:
>>>> +#define MEM_EXTRA_SIZE        0x10000
>>>
>>> Also, an expression like "(64 << 10)" is more readable than a "1"
>>> with a tail of zeroes (it's easy to add one zero too many or be one
>>> zero short).
>>
>> +1 to not open coding raw numbers.
>>
>> I think it's high time KVM selftests add #defines for the common sizes, e.g. SIZE_4KB,
>> 16KB, 64K, 2MB, 1GB, etc...
>>
>> Alternatively (or in addition), just #define 1KB, 1MB, 1GB, and 1TB, and then do
>> math off of those.
>>
> 
> Ok. I will have one separate patch to define those sizes in kvm_util_base.h,
> right after '#define NSEC_PER_SEC 1000000000L'. Sean, could you let me know
> if it looks good to you?
> 
>      #define KB         (1UL << 10)
>      #define MB         (1UL << 20)
>      #define GB         (1UL << 30)
>      #define TB         (1UL << 40)
> 
>      /* Base page and huge page size */
>      #define SIZE_4KB   (  4 * KB)
>      #define SIZE_16KB  ( 16 * KB)
>      #define SIZE_64KB  ( 64 * KB)
>      #define SIZE_2MB   (  2 * MB)
>      #define SIZE_32MB  ( 32 * MB)
>      #define SIZE_512MB (512 * MB)
>      #define SIZE_1GB   (  1 * GB)
>      #define SIZE_16GB  ( 16 * GB)

FYI, QEMU uses KiB, MiB, GiB, etc., see [1].

> Thanks,
> Gavin
> 

Thanks,
Maciej

[1]: https://git.qemu.org/?p=qemu.git;a=blob;f=include/qemu/units.h;hb=HEAD