From: Stephen Hemminger <stephen@networkplumber.org>
To: "Morten Brørup" <mb@smartsharesystems.com>
Cc: dev@dpdk.org
Subject: Re: [PATCH] mbuf: optimize segment prefree
Date: Wed, 27 Aug 2025 16:17:26 -0700 [thread overview]
Message-ID: <20250827161726.24cebd9c@hermes.local> (raw)
In-Reply-To: <20250827213535.21602-1-mb@smartsharesystems.com>
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??
prev parent reply other threads:[~2025-08-27 23:17 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-08-27 21:35 Morten Brørup
2025-08-27 23:17 ` Stephen Hemminger [this message]
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