From: Andi Kleen <ak@suse.de>
To: Chris Leech <christopher.leech@intel.com>
Cc: linux-kernel@vger.kernel.org, netdev@vger.kernel.org
Subject: Re: [PATCH 3/7] [I/OAT] Don't offload copies for loopback traffic
Date: Fri, 18 Aug 2006 20:17:18 +0200 [thread overview]
Message-ID: <200608182017.19248.ak@suse.de> (raw)
In-Reply-To: <20060816005341.8634.10380.stgit@gitlost.site>
> @@ -1136,7 +1137,8 @@ int tcp_recvmsg(struct kiocb *iocb, stru
> skb = skb_peek_tail(&sk->sk_receive_queue);
> if (skb)
> available = TCP_SKB_CB(skb)->seq + skb->len - (*seq);
> - if ((available < target) &&
> + dst = __sk_dst_get(sk);
> + if ((available < target) && (!dst || (dst->dev != &loopback_dev)) &&
You just added another potential cache miss to a critical
path. A bit flag in the socket would be better.
But is it really worth this ugly special case?
-Andi
next prev parent reply other threads:[~2006-08-18 17:09 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-08-16 0:53 [PATCH 1/7] [I/OAT] Push pending transactions to hardware more frequently Chris Leech
2006-08-16 0:53 ` [PATCH 2/7] [I/OAT] Only offload copies for TCP when there will be a context switch Chris Leech
2006-08-16 0:53 ` [PATCH 3/7] [I/OAT] Don't offload copies for loopback traffic Chris Leech
2006-08-18 18:17 ` Andi Kleen [this message]
2006-08-18 21:23 ` David Miller
2006-08-16 0:53 ` [PATCH 4/7] [I/OAT] Remove the wrappers around read(bwl)/write(bwl) in ioatdma Chris Leech
2006-08-18 0:05 ` I/OAT configuration ? Ravinandan Arakali
2006-08-16 0:53 ` [PATCH 5/7] [I/OAT] Remove the use of writeq from the ioatdma driver Chris Leech
2006-08-16 0:53 ` [PATCH 6/7] [I/OAT] Add documentation for the tcp_dma_copybreak sysctl Chris Leech
2006-08-16 0:53 ` [PATCH 7/7] [I/OAT] Add entries to MAINTAINERS for the DMA memcpy subsystem and ioatdma Chris Leech
2006-08-16 4:52 ` Randy.Dunlap
2006-08-16 16:57 ` [PATCH 7/7 v2] " Chris Leech
2006-08-18 7:11 ` [PATCH 1/7] [I/OAT] Push pending transactions to hardware more frequently Pavel Machek
2006-08-18 15:11 ` Chris Leech
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