Messages in this thread Patch in this message | | | Date | Thu, 29 Sep 2005 19:20:26 -0700 | From | Chris Wright <> | Subject | [PATCH 10/10] [TCP]: Dont over-clamp window in tcp_clamp_window() |
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-stable review patch. If anyone has any objections, please let us know. ------------------
Handle better the case where the sender sends full sized frames initially, then moves to a mode where it trickles out small amounts of data at a time.
This known problem is even mentioned in the comments above tcp_grow_window() in tcp_input.c, specifically:
.. * The scheme does not work when sender sends good segments opening * window and then starts to feed us spagetti. But it should work * in common situations. Otherwise, we have to rely on queue collapsing. ..
When the sender gives full sized frames, the "struct sk_buff" overhead from each packet is small. So we'll advertize a larger window. If the sender moves to a mode where small segments are sent, this ratio becomes tilted to the other extreme and we start overrunning the socket buffer space.
tcp_clamp_window() tries to address this, but it's clamping of tp->window_clamp is a wee bit too aggressive for this particular case.
Fix confirmed by Ion Badulescu.
Signed-off-by: "David S. Miller" <davem@davemloft.net> Signed-off-by: Chris Wright <chrisw@osdl.org> --- net/ipv4/tcp_input.c | 2 -- 1 files changed, 2 deletions(-)
Index: linux-2.6.13.y/net/ipv4/tcp_input.c =================================================================== --- linux-2.6.13.y.orig/net/ipv4/tcp_input.c +++ linux-2.6.13.y/net/ipv4/tcp_input.c @@ -350,8 +350,6 @@ static void tcp_clamp_window(struct sock app_win -= tp->ack.rcv_mss; app_win = max(app_win, 2U*tp->advmss); - if (!ofo_win) - tp->window_clamp = min(tp->window_clamp, app_win); tp->rcv_ssthresh = min(tp->window_clamp, 2U*tp->advmss); } } -- - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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