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
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
soc.c
/*
* Copyright (C) 2015 Atmel
*
* Alexandre Belloni <alexandre.belloni@free-electrons.com
* Boris Brezillon <boris.brezillon@free-electrons.com
*
* This file is licensed under the terms of the GNU General Public
* License version 2. This program is licensed "as is" without any
* warranty of any kind, whether express or implied.
*
*/
#define pr_fmt(fmt) "AT91: " fmt
#include <linux/io.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_platform.h>
#include <linux/slab.h>
#include <linux/sys_soc.h>
#include "soc.h"
#define AT91_DBGU_CIDR 0x40
#define AT91_DBGU_EXID 0x44
#define AT91_CHIPID_CIDR 0x00
#define AT91_CHIPID_EXID 0x04
#define AT91_CIDR_VERSION(x) ((x) & 0x1f)
#define AT91_CIDR_EXT BIT(31)
#define AT91_CIDR_MATCH_MASK 0x7fffffe0
static const struct at91_soc __initconst socs[] = {
#ifdef CONFIG_SOC_AT91RM9200
AT91_SOC(AT91RM9200_CIDR_MATCH, 0, "at91rm9200 BGA", "at91rm9200"),
#endif
#ifdef CONFIG_SOC_AT91SAM9
AT91_SOC(AT91SAM9260_CIDR_MATCH, 0, "at91sam9260", NULL),
AT91_SOC(AT91SAM9261_CIDR_MATCH, 0, "at91sam9261", NULL),
AT91_SOC(AT91SAM9263_CIDR_MATCH, 0, "at91sam9263", NULL),
AT91_SOC(AT91SAM9G20_CIDR_MATCH, 0, "at91sam9g20", NULL),
AT91_SOC(AT91SAM9RL64_CIDR_MATCH, 0, "at91sam9rl64", NULL),
AT91_SOC(AT91SAM9G45_CIDR_MATCH, AT91SAM9M11_EXID_MATCH,
"at91sam9m11", "at91sam9g45"),
AT91_SOC(AT91SAM9G45_CIDR_MATCH, AT91SAM9M10_EXID_MATCH,
"at91sam9m10", "at91sam9g45"),
AT91_SOC(AT91SAM9G45_CIDR_MATCH, AT91SAM9G46_EXID_MATCH,
"at91sam9g46", "at91sam9g45"),
AT91_SOC(AT91SAM9G45_CIDR_MATCH, AT91SAM9G45_EXID_MATCH,
"at91sam9g45", "at91sam9g45"),
AT91_SOC(AT91SAM9X5_CIDR_MATCH, AT91SAM9G15_EXID_MATCH,
"at91sam9g15", "at91sam9x5"),
AT91_SOC(AT91SAM9X5_CIDR_MATCH, AT91SAM9G35_EXID_MATCH,
"at91sam9g35", "at91sam9x5"),
AT91_SOC(AT91SAM9X5_CIDR_MATCH, AT91SAM9X35_EXID_MATCH,
"at91sam9x35", "at91sam9x5"),
AT91_SOC(AT91SAM9X5_CIDR_MATCH, AT91SAM9G25_EXID_MATCH,
"at91sam9g25", "at91sam9x5"),
AT91_SOC(AT91SAM9X5_CIDR_MATCH, AT91SAM9X25_EXID_MATCH,
"at91sam9x25", "at91sam9x5"),
AT91_SOC(AT91SAM9N12_CIDR_MATCH, AT91SAM9CN12_EXID_MATCH,
"at91sam9cn12", "at91sam9n12"),
AT91_SOC(AT91SAM9N12_CIDR_MATCH, AT91SAM9N12_EXID_MATCH,
"at91sam9n12", "at91sam9n12"),
AT91_SOC(AT91SAM9N12_CIDR_MATCH, AT91SAM9CN11_EXID_MATCH,
"at91sam9cn11", "at91sam9n12"),
AT91_SOC(AT91SAM9XE128_CIDR_MATCH, 0, "at91sam9xe128", "at91sam9xe128"),
AT91_SOC(AT91SAM9XE256_CIDR_MATCH, 0, "at91sam9xe256", "at91sam9xe256"),
AT91_SOC(AT91SAM9XE512_CIDR_MATCH, 0, "at91sam9xe512", "at91sam9xe512"),
#endif
#ifdef CONFIG_SOC_SAMA5
AT91_SOC(SAMA5D2_CIDR_MATCH, SAMA5D21CU_EXID_MATCH,
"sama5d21", "sama5d2"),
AT91_SOC(SAMA5D2_CIDR_MATCH, SAMA5D22CU_EXID_MATCH,
"sama5d22", "sama5d2"),
AT91_SOC(SAMA5D2_CIDR_MATCH, SAMA5D225C_D1M_EXID_MATCH,
"sama5d225c 16MiB SiP", "sama5d2"),
AT91_SOC(SAMA5D2_CIDR_MATCH, SAMA5D23CU_EXID_MATCH,
"sama5d23", "sama5d2"),
AT91_SOC(SAMA5D2_CIDR_MATCH, SAMA5D24CX_EXID_MATCH,
"sama5d24", "sama5d2"),
AT91_SOC(SAMA5D2_CIDR_MATCH, SAMA5D24CU_EXID_MATCH,
"sama5d24", "sama5d2"),
AT91_SOC(SAMA5D2_CIDR_MATCH, SAMA5D26CU_EXID_MATCH,
"sama5d26", "sama5d2"),
AT91_SOC(SAMA5D2_CIDR_MATCH, SAMA5D27CU_EXID_MATCH,
"sama5d27", "sama5d2"),
AT91_SOC(SAMA5D2_CIDR_MATCH, SAMA5D27CN_EXID_MATCH,
"sama5d27", "sama5d2"),
AT91_SOC(SAMA5D2_CIDR_MATCH, SAMA5D27C_D1G_EXID_MATCH,
"sama5d27c 128MiB SiP", "sama5d2"),
AT91_SOC(SAMA5D2_CIDR_MATCH, SAMA5D27C_D5M_EXID_MATCH,
"sama5d27c 64MiB SiP", "sama5d2"),
AT91_SOC(SAMA5D2_CIDR_MATCH, SAMA5D28CU_EXID_MATCH,
"sama5d28", "sama5d2"),
AT91_SOC(SAMA5D2_CIDR_MATCH, SAMA5D28CN_EXID_MATCH,
"sama5d28", "sama5d2"),
AT91_SOC(SAMA5D2_CIDR_MATCH, SAMA5D28C_D1G_EXID_MATCH,
"sama5d28c 128MiB SiP", "sama5d2"),
AT91_SOC(SAMA5D3_CIDR_MATCH, SAMA5D31_EXID_MATCH,
"sama5d31", "sama5d3"),
AT91_SOC(SAMA5D3_CIDR_MATCH, SAMA5D33_EXID_MATCH,
"sama5d33", "sama5d3"),
AT91_SOC(SAMA5D3_CIDR_MATCH, SAMA5D34_EXID_MATCH,
"sama5d34", "sama5d3"),
AT91_SOC(SAMA5D3_CIDR_MATCH, SAMA5D35_EXID_MATCH,
"sama5d35", "sama5d3"),
AT91_SOC(SAMA5D3_CIDR_MATCH, SAMA5D36_EXID_MATCH,
"sama5d36", "sama5d3"),
AT91_SOC(SAMA5D4_CIDR_MATCH, SAMA5D41_EXID_MATCH,
"sama5d41", "sama5d4"),
AT91_SOC(SAMA5D4_CIDR_MATCH, SAMA5D42_EXID_MATCH,
"sama5d42", "sama5d4"),
AT91_SOC(SAMA5D4_CIDR_MATCH, SAMA5D43_EXID_MATCH,
"sama5d43", "sama5d4"),
AT91_SOC(SAMA5D4_CIDR_MATCH, SAMA5D44_EXID_MATCH,
"sama5d44", "sama5d4"),
#endif
#ifdef CONFIG_SOC_SAMV7
AT91_SOC(SAME70Q21_CIDR_MATCH, SAME70Q21_EXID_MATCH,
"same70q21", "same7"),
AT91_SOC(SAME70Q20_CIDR_MATCH, SAME70Q20_EXID_MATCH,
"same70q20", "same7"),
AT91_SOC(SAME70Q19_CIDR_MATCH, SAME70Q19_EXID_MATCH,
"same70q19", "same7"),
AT91_SOC(SAMS70Q21_CIDR_MATCH, SAMS70Q21_EXID_MATCH,
"sams70q21", "sams7"),
AT91_SOC(SAMS70Q20_CIDR_MATCH, SAMS70Q20_EXID_MATCH,
"sams70q20", "sams7"),
AT91_SOC(SAMS70Q19_CIDR_MATCH, SAMS70Q19_EXID_MATCH,
"sams70q19", "sams7"),
AT91_SOC(SAMV71Q21_CIDR_MATCH, SAMV71Q21_EXID_MATCH,
"samv71q21", "samv7"),
AT91_SOC(SAMV71Q20_CIDR_MATCH, SAMV71Q20_EXID_MATCH,
"samv71q20", "samv7"),
AT91_SOC(SAMV71Q19_CIDR_MATCH, SAMV71Q19_EXID_MATCH,
"samv71q19", "samv7"),
AT91_SOC(SAMV70Q20_CIDR_MATCH, SAMV70Q20_EXID_MATCH,
"samv70q20", "samv7"),
AT91_SOC(SAMV70Q19_CIDR_MATCH, SAMV70Q19_EXID_MATCH,
"samv70q19", "samv7"),
#endif
{ /* sentinel */ },
};
static int __init at91_get_cidr_exid_from_dbgu(u32 *cidr, u32 *exid)
{
struct device_node *np;
void __iomem *regs;
np = of_find_compatible_node(NULL, NULL, "atmel,at91rm9200-dbgu");
if (!np)
np = of_find_compatible_node(NULL, NULL,
"atmel,at91sam9260-dbgu");
if (!np)
return -ENODEV;
regs = of_iomap(np, 0);
of_node_put(np);
if (!regs) {
pr_warn("Could not map DBGU iomem range");
return -ENXIO;
}
*cidr = readl(regs + AT91_DBGU_CIDR);
*exid = readl(regs + AT91_DBGU_EXID);
iounmap(regs);
return 0;
}
static int __init at91_get_cidr_exid_from_chipid(u32 *cidr, u32 *exid)
{
struct device_node *np;
void __iomem *regs;
np = of_find_compatible_node(NULL, NULL, "atmel,sama5d2-chipid");
if (!np)
return -ENODEV;
regs = of_iomap(np, 0);
of_node_put(np);
if (!regs) {
pr_warn("Could not map DBGU iomem range");
return -ENXIO;
}
*cidr = readl(regs + AT91_CHIPID_CIDR);
*exid = readl(regs + AT91_CHIPID_EXID);
iounmap(regs);
return 0;
}
struct soc_device * __init at91_soc_init(const struct at91_soc *socs)
{
struct soc_device_attribute *soc_dev_attr;
const struct at91_soc *soc;
struct soc_device *soc_dev;
u32 cidr, exid;
int ret;
/*
* With SAMA5D2 and later SoCs, CIDR and EXID registers are no more
* in the dbgu device but in the chipid device whose purpose is only
* to expose these two registers.
*/
ret = at91_get_cidr_exid_from_dbgu(&cidr, &exid);
if (ret)
ret = at91_get_cidr_exid_from_chipid(&cidr, &exid);
if (ret) {
if (ret == -ENODEV)
pr_warn("Could not find identification node");
return NULL;
}
for (soc = socs; soc->name; soc++) {
if (soc->cidr_match != (cidr & AT91_CIDR_MATCH_MASK))
continue;
if (!(cidr & AT91_CIDR_EXT) || soc->exid_match == exid)
break;
}
if (!soc->name) {
pr_warn("Could not find matching SoC description\n");
return NULL;
}
soc_dev_attr = kzalloc(sizeof(*soc_dev_attr), GFP_KERNEL);
if (!soc_dev_attr)
return NULL;
soc_dev_attr->family = soc->family;
soc_dev_attr->soc_id = soc->name;
soc_dev_attr->revision = kasprintf(GFP_KERNEL, "%X",
AT91_CIDR_VERSION(cidr));
soc_dev = soc_device_register(soc_dev_attr);
if (IS_ERR(soc_dev)) {
kfree(soc_dev_attr->revision);
kfree(soc_dev_attr);
pr_warn("Could not register SoC device\n");
return NULL;
}
if (soc->family)
pr_info("Detected SoC family: %s\n", soc->family);
pr_info("Detected SoC: %s, revision %X\n", soc->name,
AT91_CIDR_VERSION(cidr));
return soc_dev;
}
static int __init atmel_soc_device_init(void)
{
at91_soc_init(socs);
return 0;
}
subsys_initcall(atmel_soc_device_init);
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