From: Jason Wang Date: Mon, 17 Jun 2019 09:20:54 +0000 (-0400) Subject: vhost_net: disable zerocopy by default X-Git-Url: http://git.osdn.net/view?a=commitdiff_plain;h=a7ef2978f61623902920938b1706d00db5258b4c;p=sagit-ice-cold%2Fkernel_xiaomi_msm8998.git vhost_net: disable zerocopy by default [ Upstream commit 098eadce3c622c07b328d0a43dda379b38cf7c5e ] Vhost_net was known to suffer from HOL[1] issues which is not easy to fix. Several downstream disable the feature by default. What's more, the datapath was split and datacopy path got the support of batching and XDP support recently which makes it faster than zerocopy part for small packets transmission. It looks to me that disable zerocopy by default is more appropriate. It cold be enabled by default again in the future if we fix the above issues. [1] https://patchwork.kernel.org/patch/3787671/ Signed-off-by: Jason Wang Acked-by: Michael S. Tsirkin Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c index 645b2197930e..f46317135224 100644 --- a/drivers/vhost/net.c +++ b/drivers/vhost/net.c @@ -30,7 +30,7 @@ #include "vhost.h" -static int experimental_zcopytx = 1; +static int experimental_zcopytx = 0; module_param(experimental_zcopytx, int, 0444); MODULE_PARM_DESC(experimental_zcopytx, "Enable Zero Copy TX;" " 1 -Enable; 0 - Disable");