Re: SO_RCVLOWAT option to socket()

From: Alan Cox
Date: Fri Dec 10 2004 - 17:09:20 EST

On Gwe, 2004-12-10 at 04:06, Rob Sanders wrote:
> Hey y'all,
> Can anyone point me to a resource for why SO_RCVLOWAT is hardcoded
> to 1 in linux?

The 1003.1g drafts require it is supported.

> If you are using select or poll with timeouts it would be less costly
> to have the kernel tell you
> when all of the data you reqested (via SO_RCVLOWAT) is ready to be read

But is the cost of all those special case checks and all the handling
it such as select computing if enough tcp packets together accumulated
the cost on every app not using LOWAT for the microscopic gain given
essentially nobody uses it.


To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at
Please read the FAQ at