From: Felix Fietkau <nbd@openwrt.org>
To: Eric Dumazet <eric.dumazet@gmail.com>
Cc: netdev@vger.kernel.org, zajec5@gmail.com, hauke@hauke-m.de
Subject: Re: [PATCH 4/4] bgmac: fix DMA rx corruption
Date: Sun, 12 Apr 2015 19:28:48 +0200 [thread overview]
Message-ID: <552AAB50.7010401@openwrt.org> (raw)
In-Reply-To: <1428859488.25985.347.camel@edumazet-glaptop2.roam.corp.google.com>
On 2015-04-12 19:24, Eric Dumazet wrote:
> On Sun, 2015-04-12 at 12:43 +0200, Felix Fietkau wrote:
>> On 2015-04-12 12:31, Eric Dumazet wrote:
>
>> > This might be better for performance to perform one single bgmac_write()
>> > at the end of bgmac_dma_rx_read(), and leave this one in place as well,
>> > not for performance since this is slow path, but correctness.
>> I intentionally made it write this field for every slot update, because
>> it might potentially allow the hardware to push frames faster when under
>> pressure. The CPU isn't fast enough to handle gigabit speeds anyway.
>
> If CPU is not fast enough, then it makes sense to optimize this part,
> and save cpu cycles for actual processing.
>
> You know, even a fast cpu is not able to keep up at 40Gbits.
>
> You have a clear opportunity to have batching right there, take it.
Already did that in v2. :)
- Felix
next prev parent reply other threads:[~2015-04-12 17:28 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-04-12 10:08 [PATCH 1/4] bgmac: simplify tx ring index handling Felix Fietkau
2015-04-12 10:08 ` [PATCH 2/4] bgmac: leave interrupts disabled as long as there is work to do Felix Fietkau
2015-04-12 10:08 ` [PATCH 3/4] bgmac: set received skb headroom to NET_SKB_PAD Felix Fietkau
2015-04-12 10:08 ` [PATCH 4/4] bgmac: fix DMA rx corruption Felix Fietkau
2015-04-12 10:31 ` Eric Dumazet
2015-04-12 10:43 ` Felix Fietkau
2015-04-12 17:24 ` Eric Dumazet
2015-04-12 17:28 ` Felix Fietkau [this message]
2015-04-12 10:31 ` Jakub Kiciński
2015-04-12 11:11 ` Sergei Shtylyov
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