Re: What to expect after 0.99.8

From: Linus Torvalds <torvalds@osdl.org>
Date: Oct 5, 2005, 00:10 UTC
Message-ID: <Pine.LNX.4.64.0510041706330.31407@g5.osdl.org>
In-Reply-To: <7vu0fx9c1c.fsf@assigned-by-dhcp.cox.net>

On Tue, 4 Oct 2005, Junio C Hamano wrote:

Show 6 quoted lines

> 
> I vaguely recall there was an interesting regression in recent
> kernel history when the implementation of the pipe buffer was
> changed, with which, writing the same amount of data with
> different number of writes made things behave differently and
> making the worst case buffer size less than traditional 4K.

Just for performance reasons, I ended up doing merging anyway, so in fact regardless of how you write the current pipe buffer size is up to 16 pages.

I think you can safely assume that pretty much any file descriptor you use has at least 1kB of buffer. Even 4kB is likely a "safe assumption", and in reality, most of them end up having even more.

With something like ssh, you probably end up having even deeper ones, since you end up having the local pty or socket to ssh, and then ssh has the TCP buffer to the network..

			Linus