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Revision 6e474083f3daf3a3546737f5d7d502ad12eb257c authored by Wei Xu on 01 December 2017, 10:10:36 UTC, committed by David S. Miller on 03 December 2017, 02:31:03 UTC 
vhost: fix skb leak in handle_rx()
 
Matthew found a roughly 40% tcp throughput regression with commit
c67df11f(vhost_net: try batch dequing from skb array) as discussed
in the following thread:
https://www.mail-archive.com/netdev@vger.kernel.org/msg187936.html

Eventually we figured out that it was a skb leak in handle_rx()
when sending packets to the VM. This usually happens when a guest
can not drain out vq as fast as vhost fills in, afterwards it sets
off the traffic jam and leaks skb(s) which occurs as no headcount
to send on the vq from vhost side.

This can be avoided by making sure we have got enough headcount
before actually consuming a skb from the batched rx array while
transmitting, which is simply done by moving checking the zero
headcount a bit ahead.

Signed-off-by: Wei Xu <wexu@redhat.com>
Reported-by: Matthew Rosato <mjrosato@linux.vnet.ibm.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
1 parent fa935ca
Raw File
XGIfb.h 
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_XGIFB
#define _LINUX_XGIFB
#include "vgatypes.h"
#include "vb_struct.h"

enum xgifb_display_type {
	XGIFB_DISP_NONE = 0,
	XGIFB_DISP_CRT,
	XGIFB_DISP_LCD,
	XGIFB_DISP_TV,
};

#define HASVB_NONE	    0x00
#define HASVB_301	    0x01
#define HASVB_LVDS	    0x02
#define HASVB_TRUMPION	    0x04
#define HASVB_LVDS_CHRONTEL 0x10
#define HASVB_302	    0x20
#define HASVB_CHRONTEL	    0x80

enum XGI_CHIP_TYPE {
	XG40 = 32,
	XG42,
	XG20 = 48,
	XG21,
	XG27,
};

enum xgi_tvtype {
	TVMODE_NTSC = 0,
	TVMODE_PAL,
	TVMODE_HIVISION,
	TVTYPE_PALM,
	TVTYPE_PALN,
	TVTYPE_NTSCJ,
	TVMODE_TOTAL
};

enum xgi_tv_plug {
	TVPLUG_UNKNOWN = 0,
	TVPLUG_COMPOSITE = 1,
	TVPLUG_SVIDEO = 2,
	TVPLUG_COMPOSITE_AND_SVIDEO = 3,
	TVPLUG_SCART = 4,
	TVPLUG_YPBPR_525i = 5,
	TVPLUG_YPBPR_525P = 6,
	TVPLUG_YPBPR_750P = 7,
	TVPLUG_YPBPR_1080i = 8,
	TVPLUG_TOTAL
};

struct xgifb_video_info {
	struct fb_info *fb_info;
	struct xgi_hw_device_info hw_info;
	struct vb_device_info dev_info;

	int mode_idx;
	int rate_idx;

	u32 pseudo_palette[17];

	int           chip_id;
	unsigned int  video_size;
	phys_addr_t   video_base;
	void __iomem *video_vbase;
	phys_addr_t   mmio_base;
	unsigned long mmio_size;
	void __iomem *mmio_vbase;
	unsigned long vga_base;
	int mtrr;

	int    video_bpp;
	int    video_cmap_len;
	int    video_width;
	int    video_height;
	int    video_vwidth;
	int    video_vheight;
	int    org_x;
	int    org_y;
	int    video_linelength;
	unsigned int refresh_rate;

	enum xgifb_display_type display2; /* the second display output type */
	bool display2_force;
	unsigned char hasVB;
	unsigned char TV_type;
	unsigned char TV_plug;

	struct XGI21_LVDSCapStruct lvds_data;

	enum XGI_CHIP_TYPE chip;
	unsigned char revision_id;

	unsigned short DstColor;
	unsigned long  XGI310_AccelDepth;
	unsigned long  CommandReg;

	unsigned int   pcibus;
	unsigned int   pcislot;
	unsigned int   pcifunc;

	unsigned short subsysvendor;
	unsigned short subsysdevice;

	char reserved[236];
};

#endif
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