From: 吴亚东 <wuyd@outlook.com>
To: "dev@dpdk.org" <dev@dpdk.org>
Subject: [dpdk-dev] DPDK testpmd forwarding performace degradation
Date: Tue, 27 Jan 2015 02:49:27 +0000 [thread overview]
Message-ID: <BAY176-W12D96351C9C7B97C488C96C3320@phx.gbl> (raw)
65 bytes frame may degrade performace a lot.Thats related to DMA and cache.
When NIC dma packets to memory, NIC has to do read modify write if DMA size is partial cache line.So for 65 bytes, the first 64 bytes are ok. The next 1 byte NIC has to read the whole cache line, change one byte and update the cache line.
So in DPDK, CRC is not stripped and ethernet header aligned to cache line which causes ip header not aligned on 4 bytes.
next reply other threads:[~2015-01-27 2:49 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-01-27 2:49 吴亚东 [this message]
2015-01-27 8:04 ` Alexander Belyakov
-- strict thread matches above, loose matches on Subject: below --
2015-01-26 10:17 Alexander Belyakov
2015-01-26 14:22 ` De Lara Guarch, Pablo
[not found] ` <CAAQJX_RueTvfr7UnANbLSKceerkfs5DZNguKdPhSVVn9OCGtrw@mail.gmail.com>
2015-01-27 7:51 ` [dpdk-dev] Fwd: " Alexander Belyakov
2015-01-27 10:14 ` [dpdk-dev] " Alexander Belyakov
2015-01-27 16:21 ` De Lara Guarch, Pablo
2015-01-28 12:24 ` Alexander Belyakov
2015-01-29 12:43 ` Alexander Belyakov
2015-02-05 14:39 ` Alexander Belyakov
2015-01-26 17:08 ` Stephen Hemminger
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