From: Andrew Morton <akpm@osdl.org>
To: Chris Leech <christopher.leech@intel.com>
Cc: linux-kernel@vger.kernel.org, netdev@vger.kernel.org
Subject: Re: [PATCH 8/8] [I/OAT] TCP recv offload to I/OAT
Date: Sun, 5 Mar 2006 00:45:34 -0800 [thread overview]
Message-ID: <20060305004534.1d94b3cf.akpm@osdl.org> (raw)
In-Reply-To: <20060303214236.11908.98881.stgit@gitlost.site>
Chris Leech <christopher.leech@intel.com> wrote:
>
> +#ifdef CONFIG_NET_DMA
> + tp->ucopy.dma_chan = NULL;
> + if ((len > sysctl_tcp_dma_copybreak) && !(flags & MSG_PEEK) && !sysctl_tcp_low_latency && __get_cpu_var(softnet_data.net_dma))
> + dma_lock_iovec_pages(msg->msg_iov, len, &tp->ucopy.locked_list);
> +#endif
The __get_cpu_var() here will run smp_processor_id() from preemptible
context. You'll get a big warning if the correct debug options are set.
The reason for this is that preemption could cause this code to hop between
CPUs.
Please always test code with all debug options enabled and with full kernel
preemption.
next prev parent reply other threads:[~2006-03-05 8:47 UTC|newest]
Thread overview: 51+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-03-03 21:40 [PATCH 0/8] Intel I/O Acceleration Technology (I/OAT) Chris Leech
2006-03-03 21:42 ` [PATCH 1/8] [I/OAT] DMA memcpy subsystem Chris Leech
2006-03-04 1:40 ` David S. Miller
2006-03-06 19:39 ` Chris Leech
2006-03-04 19:20 ` Benjamin LaHaise
2006-03-06 19:48 ` Chris Leech
2006-03-03 21:42 ` [PATCH 3/8] [I/OAT] Setup the networking subsystem as a DMA client Chris Leech
2006-03-03 21:42 ` [PATCH 4/8] [I/OAT] Utility functions for offloading sk_buff to iovec copies Chris Leech
2006-03-05 7:15 ` Andrew Morton
2006-03-03 21:42 ` [PATCH 5/8] [I/OAT] Structure changes for TCP recv offload to I/OAT Chris Leech
2006-03-05 7:19 ` Andrew Morton
2006-03-03 21:42 ` [PATCH 6/8] [I/OAT] Rename cleanup_rbuf to tcp_cleanup_rbuf and make non-static Chris Leech
2006-03-03 21:42 ` [PATCH 7/8] [I/OAT] Add a sysctl for tuning the I/OAT offloaded I/O threshold Chris Leech
2006-03-04 11:22 ` Alexey Dobriyan
2006-03-05 7:21 ` Andrew Morton
2006-03-03 21:42 ` [PATCH 8/8] [I/OAT] TCP recv offload to I/OAT Chris Leech
2006-03-04 16:39 ` Pavel Machek
2006-03-04 23:18 ` Greg KH
2006-03-06 19:28 ` Chris Leech
2006-03-05 7:30 ` Andrew Morton
2006-03-05 8:45 ` Andrew Morton [this message]
2006-03-05 10:27 ` David S. Miller
2006-03-06 19:36 ` Chris Leech
2006-03-03 22:27 ` [PATCH 0/8] Intel I/O Acceleration Technology (I/OAT) Jeff Garzik
2006-03-03 22:39 ` Chris Leech
2006-03-03 22:45 ` Jeff Garzik
2006-03-04 11:35 ` Evgeniy Polyakov
2006-03-05 8:09 ` Andrew Morton
2006-03-05 9:02 ` Discourage duplicate symbols in the kernel? [Was: Intel I/O Acc...] Sam Ravnborg
2006-03-05 9:18 ` Andrew Morton
2006-03-06 19:56 ` Chris Leech
2006-03-03 22:58 ` [PATCH 0/8] Intel I/O Acceleration Technology (I/OAT) Kumar Gala
2006-03-03 23:32 ` Chris Leech
2006-03-04 18:46 ` Jan Engelhardt
2006-03-04 21:41 ` David S. Miller
2006-03-04 22:05 ` Gene Heskett
2006-03-04 22:16 ` David S. Miller
2006-03-05 13:45 ` Jan Engelhardt
2006-03-05 13:55 ` Arjan van de Ven
2006-03-05 16:14 ` Matthieu CASTET
2006-03-05 16:30 ` Jeff Garzik
2006-03-06 19:24 ` Chris Leech
2006-03-06 19:15 ` Chris Leech
2006-03-05 1:43 ` Evgeniy Polyakov
2006-03-05 2:08 ` David S. Miller
2006-03-06 17:44 ` Ingo Oeser
2006-03-07 7:44 ` Evgeniy Polyakov
2006-03-07 9:43 ` Ingo Oeser
2006-03-07 10:16 ` Evgeniy Polyakov
2006-03-11 2:27 Chris Leech
2006-03-11 2:29 ` [PATCH 8/8] [I/OAT] TCP recv offload to I/OAT Chris Leech
2006-03-11 9:41 ` Andrew Morton
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