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Date: Mon, 6 Oct 2025 12:46:01 -0500
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Subject: Re: [PATCH] mbuf: optimize segment prefree
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References: <20250827213535.21602-1-mb@smartsharesystems.com>
 <20250827161726.24cebd9c@hermes.local>
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From: Wathsala Vithanage <wathsala.vithanage@arm.com>
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On 8/27/25 18:17, Stephen Hemminger wrote:
> On Wed, 27 Aug 2025 21:35:34 +0000
> Morten Brørup <mb@smartsharesystems.com> wrote:
>
>>   
>> +/* GCC only optimizes single-bit MSB tests this way, so do it by hand with multi-bit. */
>> +#if defined(RTE_TOOLCHAIN_GCC) && defined(RTE_ARCH_X86)
>> +#undef RTE_MBUF_DIRECT
>> +#define RTE_MBUF_DIRECT(mb) \
>> +	(!(((const uint8_t *)(mb))[offsetof(struct rte_mbuf, ol_flags) + 7] & \
>> +	(uint8_t)((RTE_MBUF_F_INDIRECT | RTE_MBUF_F_EXTERNAL) >> 56)))
>> +#endif
> Complex enough expression that I would prefer this be an inline function
> with some more temporary variables and more comments.
> Like the magic 7 for mask??

+1

--wathsala