From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christian Schmid Subject: Re: Bug-hunting Date: Wed, 23 Feb 2005 00:21:31 +0100 Message-ID: <421BBE7B.1050009@rapidforum.com> References: <421B4AB7.9030003@rapidforum.com> <20050222104448.31373a99.davem@davemloft.net> <421B8563.9030608@rapidforum.com> <20050222115114.0d0e568e.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: netdev@oss.sgi.com To: "David S. Miller" In-Reply-To: <20050222115114.0d0e568e.davem@davemloft.net> Sender: netdev-bounce@oss.sgi.com Errors-to: netdev-bounce@oss.sgi.com List-Id: netdev.vger.kernel.org Hm can you tell me how to change the limit? It seems the limit is good for 3/1 systems but not for 2/2 systems. To reproduce this, you would have to create a server which is sending data to 4000 non-blocking sockets. It doesnt matter what you send. You should realize a slow-down the more sockets you use. You need Gigabit for this to appear. David S. Miller wrote: > On Tue, 22 Feb 2005 20:17:55 +0100 > Christian Schmid wrote: > > >>No. This is a new thing and this wasnt there before. In 2.6.10-rc2 the kernel aborted programs with >>"Out of memory" when too many buffers are allocated and low memory was full. NOW it just shrinks the >>buffers dynamically. I don't want that. I have a 2/2 system and I want 1600 MB for buffers but you >>only allow around 700 MB for buffers. This is definetly NEW. > > > It always shrinks the TCP socket buffer usage when the total socket > memory used by TCP is over the threshold. This code has been there > for 3 years at least. > > If the behavior has changed, that's interesting and probably due to > some other change. It could even be a MM layer change that is causing > things to behave differently now for you, and because things are > being tweaked in the memory management all the time (particularly > the handling of lowmem vs. highmem) this would not surprise me at > all. > > But the basic framework for shrinking socket buffers when total TCP > memory usage crosses some threshold has been there and has been > enabled for a long time. > > Anyways, we're stalled on figuring out exactly what is wrong due to > lack of information and difficulty in reproducing. The ball is still > in your court. > > Why don't you put together a very simple test case that others can > use to analyze and reproduce your bug? I bet we'll fix it or figure > out what is wrong with your app within 24 hours once you do that. :-) > >