Re: Unix sockets via TCP on localhost: is TCP slower?

From: Olaf van der Spek
Date: Fri Nov 14 2008 - 03:51:58 EST


On Fri, Nov 14, 2008 at 1:19 AM, J.R. Mauro <jrm8005@xxxxxxxxx> wrote:
> On Wed, Nov 12, 2008 at 6:20 PM, Olaf van der Spek <olafvdspek@xxxxxxxxx> wrote:
>> Hi,
>>
>> Quite often in discussions, I see people claiming Unix sockets are
>> faster then TCP sockets on a connection that stays inside localhost.
>
> Unix domain sockets should be faster because they're not subject to
> windowing, ACKs, flow control, encapsulation, etc. etc.

Why would you use windowing, ACKs, flow control and encapsulation on localhost?

I expected the kernel to copy data directly from user-space of the
sending process to a kernel buffer of the receiving process, much like
UNIX sockets.

>> Let's say from app A to app B.
>> Is this indeed the case and if so, how much and why?
>> My assumption is that the kernel can optimize the 'connection' and let
>> any performance differences disappear.
>>
>> Greetings,
>>
>> Olaf
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
>> the body of a message to majordomo@xxxxxxxxxxxxxxx
>> More majordomo info at http://vger.kernel.org/majordomo-info.html
>> Please read the FAQ at http://www.tux.org/lkml/
>>
>
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/