* [PATCH V3 1/2] xen-netback: limit xen vif max queues number to online cpus
2015-10-23 9:42 [PATCH V3 0/2] limit xen vnic max queues number to online cpus number Joe Jin
@ 2015-10-23 9:44 ` Joe Jin
2015-10-23 9:44 ` Joe Jin
` (4 subsequent siblings)
5 siblings, 0 replies; 12+ messages in thread
From: Joe Jin @ 2015-10-23 9:44 UTC (permalink / raw)
To: wei.liu2, Ian Campbell, Boris Ostrovsky, Konrad Rzeszutek Wilk,
David S. Miller, Jan Beulich
Cc: netdev, xen-devel
Should not allocate xen vif queues number more than online cpus.
Signed-off-by: Joe Jin <joe.jin@oracle.com>
Cc: Jan Beulich <JBeulich@suse.com>
Cc: Wei Liu <wei.liu2@citrix.com>
Cc: Ian Campbell <ian.campbell@citrix.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
---
drivers/net/xen-netback/netback.c | 28 ++++++++++++++++++++++------
1 files changed, 22 insertions(+), 6 deletions(-)
diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c
index ec98d43..021dcb0 100644
--- a/drivers/net/xen-netback/netback.c
+++ b/drivers/net/xen-netback/netback.c
@@ -68,7 +68,9 @@ unsigned int rx_stall_timeout_msecs = 60000;
module_param(rx_stall_timeout_msecs, uint, 0444);
unsigned int xenvif_max_queues;
-module_param_named(max_queues, xenvif_max_queues, uint, 0644);
+static int xennet_set_max_queues(const char *val, struct kernel_param *kp);
+module_param_call(max_queues, xennet_set_max_queues, param_get_uint,
+ &xenvif_max_queues, 0644);
MODULE_PARM_DESC(max_queues,
"Maximum number of queues per virtual interface");
@@ -107,6 +109,20 @@ static struct xen_netif_rx_response *make_rx_response(struct xenvif_queue *queue
u16 size,
u16 flags);
+static int xennet_set_max_queues(const char *val, struct kernel_param *kp)
+{
+ unsigned int cpus = num_online_cpus();
+ unsigned int max_queues = simple_strtoul(val, NULL, 10);
+
+ if (max_queues == 0 || max_queues > cpus) {
+ pr_info("max_queues %u is out of range [1 - %u]!\n",
+ max_queues, cpus);
+ return -ERANGE;
+ }
+
+ return param_set_uint(val, kp);
+}
+
static inline unsigned long idx_to_pfn(struct xenvif_queue *queue,
u16 idx)
{
@@ -2110,15 +2126,15 @@ int xenvif_dealloc_kthread(void *data)
static int __init netback_init(void)
{
int rc = 0;
+ unsigned int cpus = num_online_cpus();
if (!xen_domain())
return -ENODEV;
- /* Allow as many queues as there are CPUs if user has not
- * specified a value.
- */
- if (xenvif_max_queues == 0)
- xenvif_max_queues = num_online_cpus();
+ /* Allow at most as many queues as CPUs. */
+ if (xenvif_max_queues == 0 || xenvif_max_queues > cpus)
+ xenvif_max_queues = cpus;
+ pr_info("vif max_queues: %u\n", xenvif_max_queues);
if (fatal_skb_slots < XEN_NETBK_LEGACY_SLOTS_MAX) {
pr_info("fatal_skb_slots too small (%d), bump it to XEN_NETBK_LEGACY_SLOTS_MAX (%d)\n",
--
1.7.1
^ permalink raw reply related [flat|nested] 12+ messages in thread* [PATCH V3 1/2] xen-netback: limit xen vif max queues number to online cpus
2015-10-23 9:42 [PATCH V3 0/2] limit xen vnic max queues number to online cpus number Joe Jin
2015-10-23 9:44 ` [PATCH V3 1/2] xen-netback: limit xen vif max queues number to online cpus Joe Jin
@ 2015-10-23 9:44 ` Joe Jin
2015-10-23 9:51 ` [Xen-devel] " Andrew Cooper
` (3 more replies)
2015-10-23 9:45 ` [PATCH V3 2/2] xen-netfront: limit vnic max_queues " Joe Jin
` (3 subsequent siblings)
5 siblings, 4 replies; 12+ messages in thread
From: Joe Jin @ 2015-10-23 9:44 UTC (permalink / raw)
To: wei.liu2, Ian Campbell, Boris Ostrovsky, Konrad Rzeszutek Wilk,
David S. Miller, Jan Beulich
Cc: netdev, xen-devel
Should not allocate xen vif queues number more than online cpus.
Signed-off-by: Joe Jin <joe.jin@oracle.com>
Cc: Jan Beulich <JBeulich@suse.com>
Cc: Wei Liu <wei.liu2@citrix.com>
Cc: Ian Campbell <ian.campbell@citrix.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
---
drivers/net/xen-netback/netback.c | 28 ++++++++++++++++++++++------
1 files changed, 22 insertions(+), 6 deletions(-)
diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c
index ec98d43..021dcb0 100644
--- a/drivers/net/xen-netback/netback.c
+++ b/drivers/net/xen-netback/netback.c
@@ -68,7 +68,9 @@ unsigned int rx_stall_timeout_msecs = 60000;
module_param(rx_stall_timeout_msecs, uint, 0444);
unsigned int xenvif_max_queues;
-module_param_named(max_queues, xenvif_max_queues, uint, 0644);
+static int xennet_set_max_queues(const char *val, struct kernel_param *kp);
+module_param_call(max_queues, xennet_set_max_queues, param_get_uint,
+ &xenvif_max_queues, 0644);
MODULE_PARM_DESC(max_queues,
"Maximum number of queues per virtual interface");
@@ -107,6 +109,20 @@ static struct xen_netif_rx_response *make_rx_response(struct xenvif_queue *queue
u16 size,
u16 flags);
+static int xennet_set_max_queues(const char *val, struct kernel_param *kp)
+{
+ unsigned int cpus = num_online_cpus();
+ unsigned int max_queues = simple_strtoul(val, NULL, 10);
+
+ if (max_queues == 0 || max_queues > cpus) {
+ pr_info("max_queues %u is out of range [1 - %u]!\n",
+ max_queues, cpus);
+ return -ERANGE;
+ }
+
+ return param_set_uint(val, kp);
+}
+
static inline unsigned long idx_to_pfn(struct xenvif_queue *queue,
u16 idx)
{
@@ -2110,15 +2126,15 @@ int xenvif_dealloc_kthread(void *data)
static int __init netback_init(void)
{
int rc = 0;
+ unsigned int cpus = num_online_cpus();
if (!xen_domain())
return -ENODEV;
- /* Allow as many queues as there are CPUs if user has not
- * specified a value.
- */
- if (xenvif_max_queues == 0)
- xenvif_max_queues = num_online_cpus();
+ /* Allow at most as many queues as CPUs. */
+ if (xenvif_max_queues == 0 || xenvif_max_queues > cpus)
+ xenvif_max_queues = cpus;
+ pr_info("vif max_queues: %u\n", xenvif_max_queues);
if (fatal_skb_slots < XEN_NETBK_LEGACY_SLOTS_MAX) {
pr_info("fatal_skb_slots too small (%d), bump it to XEN_NETBK_LEGACY_SLOTS_MAX (%d)\n",
--
1.7.1
^ permalink raw reply related [flat|nested] 12+ messages in thread* Re: [Xen-devel] [PATCH V3 1/2] xen-netback: limit xen vif max queues number to online cpus
2015-10-23 9:44 ` Joe Jin
@ 2015-10-23 9:51 ` Andrew Cooper
2015-10-23 9:51 ` Andrew Cooper
` (2 subsequent siblings)
3 siblings, 0 replies; 12+ messages in thread
From: Andrew Cooper @ 2015-10-23 9:51 UTC (permalink / raw)
To: Joe Jin, wei.liu2, Ian Campbell, Boris Ostrovsky,
Konrad Rzeszutek Wilk, David S. Miller, Jan Beulich
Cc: netdev, xen-devel
On 23/10/15 10:44, Joe Jin wrote:
> Should not allocate xen vif queues number more than online cpus.
>
> Signed-off-by: Joe Jin <joe.jin@oracle.com>
> Cc: Jan Beulich <JBeulich@suse.com>
> Cc: Wei Liu <wei.liu2@citrix.com>
> Cc: Ian Campbell <ian.campbell@citrix.com>
> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
> ---
> drivers/net/xen-netback/netback.c | 28 ++++++++++++++++++++++------
> 1 files changed, 22 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c
> index ec98d43..021dcb0 100644
> --- a/drivers/net/xen-netback/netback.c
> +++ b/drivers/net/xen-netback/netback.c
> @@ -68,7 +68,9 @@ unsigned int rx_stall_timeout_msecs = 60000;
> module_param(rx_stall_timeout_msecs, uint, 0444);
>
> unsigned int xenvif_max_queues;
> -module_param_named(max_queues, xenvif_max_queues, uint, 0644);
> +static int xennet_set_max_queues(const char *val, struct kernel_param *kp);
> +module_param_call(max_queues, xennet_set_max_queues, param_get_uint,
> + &xenvif_max_queues, 0644);
> MODULE_PARM_DESC(max_queues,
> "Maximum number of queues per virtual interface");
>
> @@ -107,6 +109,20 @@ static struct xen_netif_rx_response *make_rx_response(struct xenvif_queue *queue
> u16 size,
> u16 flags);
>
> +static int xennet_set_max_queues(const char *val, struct kernel_param *kp)
> +{
> + unsigned int cpus = num_online_cpus();
This calculation is problematic in the scenario where a guest boots up,
then has more cpus hotplugged in, then wants to set up a sensible number
of queues.
~Andrew
^ permalink raw reply [flat|nested] 12+ messages in thread* Re: [PATCH V3 1/2] xen-netback: limit xen vif max queues number to online cpus
2015-10-23 9:44 ` Joe Jin
2015-10-23 9:51 ` [Xen-devel] " Andrew Cooper
@ 2015-10-23 9:51 ` Andrew Cooper
2015-10-26 14:54 ` Wei Liu
2015-10-26 14:54 ` Wei Liu
3 siblings, 0 replies; 12+ messages in thread
From: Andrew Cooper @ 2015-10-23 9:51 UTC (permalink / raw)
To: Joe Jin, wei.liu2, Ian Campbell, Boris Ostrovsky,
Konrad Rzeszutek Wilk, David S. Miller, Jan Beulich
Cc: netdev, xen-devel
On 23/10/15 10:44, Joe Jin wrote:
> Should not allocate xen vif queues number more than online cpus.
>
> Signed-off-by: Joe Jin <joe.jin@oracle.com>
> Cc: Jan Beulich <JBeulich@suse.com>
> Cc: Wei Liu <wei.liu2@citrix.com>
> Cc: Ian Campbell <ian.campbell@citrix.com>
> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
> ---
> drivers/net/xen-netback/netback.c | 28 ++++++++++++++++++++++------
> 1 files changed, 22 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c
> index ec98d43..021dcb0 100644
> --- a/drivers/net/xen-netback/netback.c
> +++ b/drivers/net/xen-netback/netback.c
> @@ -68,7 +68,9 @@ unsigned int rx_stall_timeout_msecs = 60000;
> module_param(rx_stall_timeout_msecs, uint, 0444);
>
> unsigned int xenvif_max_queues;
> -module_param_named(max_queues, xenvif_max_queues, uint, 0644);
> +static int xennet_set_max_queues(const char *val, struct kernel_param *kp);
> +module_param_call(max_queues, xennet_set_max_queues, param_get_uint,
> + &xenvif_max_queues, 0644);
> MODULE_PARM_DESC(max_queues,
> "Maximum number of queues per virtual interface");
>
> @@ -107,6 +109,20 @@ static struct xen_netif_rx_response *make_rx_response(struct xenvif_queue *queue
> u16 size,
> u16 flags);
>
> +static int xennet_set_max_queues(const char *val, struct kernel_param *kp)
> +{
> + unsigned int cpus = num_online_cpus();
This calculation is problematic in the scenario where a guest boots up,
then has more cpus hotplugged in, then wants to set up a sensible number
of queues.
~Andrew
^ permalink raw reply [flat|nested] 12+ messages in thread* Re: [PATCH V3 1/2] xen-netback: limit xen vif max queues number to online cpus
2015-10-23 9:44 ` Joe Jin
2015-10-23 9:51 ` [Xen-devel] " Andrew Cooper
2015-10-23 9:51 ` Andrew Cooper
@ 2015-10-26 14:54 ` Wei Liu
2015-10-26 14:54 ` Wei Liu
3 siblings, 0 replies; 12+ messages in thread
From: Wei Liu @ 2015-10-26 14:54 UTC (permalink / raw)
To: Joe Jin
Cc: wei.liu2, Ian Campbell, netdev, Jan Beulich, xen-devel,
Boris Ostrovsky, David S. Miller
On Fri, Oct 23, 2015 at 05:44:44PM +0800, Joe Jin wrote:
> Should not allocate xen vif queues number more than online cpus.
I think it's absolutely fine for administrators to override the value
should they choose to.
Wei.
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH V3 1/2] xen-netback: limit xen vif max queues number to online cpus
2015-10-23 9:44 ` Joe Jin
` (2 preceding siblings ...)
2015-10-26 14:54 ` Wei Liu
@ 2015-10-26 14:54 ` Wei Liu
3 siblings, 0 replies; 12+ messages in thread
From: Wei Liu @ 2015-10-26 14:54 UTC (permalink / raw)
To: Joe Jin
Cc: wei.liu2, Ian Campbell, Boris Ostrovsky, Konrad Rzeszutek Wilk,
David S. Miller, Jan Beulich, netdev, xen-devel
On Fri, Oct 23, 2015 at 05:44:44PM +0800, Joe Jin wrote:
> Should not allocate xen vif queues number more than online cpus.
I think it's absolutely fine for administrators to override the value
should they choose to.
Wei.
^ permalink raw reply [flat|nested] 12+ messages in thread
* [PATCH V3 2/2] xen-netfront: limit vnic max_queues number to online cpus
2015-10-23 9:42 [PATCH V3 0/2] limit xen vnic max queues number to online cpus number Joe Jin
2015-10-23 9:44 ` [PATCH V3 1/2] xen-netback: limit xen vif max queues number to online cpus Joe Jin
2015-10-23 9:44 ` Joe Jin
@ 2015-10-23 9:45 ` Joe Jin
2015-10-23 9:45 ` Joe Jin
` (2 subsequent siblings)
5 siblings, 0 replies; 12+ messages in thread
From: Joe Jin @ 2015-10-23 9:45 UTC (permalink / raw)
To: wei.liu2, Ian Campbell, Boris Ostrovsky, Konrad Rzeszutek Wilk,
David S. Miller, Jan Beulich
Cc: netdev, xen-devel
Should not allocate vnic queues number more than online cpus.
Signed-off-by: Joe Jin <joe.jin@oracle.com>
Cc: Jan Beulich <JBeulich@suse.com>
Cc: Wei Liu <wei.liu2@citrix.com>
Cc: Ian Campbell <ian.campbell@citrix.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
---
drivers/net/xen-netfront.c | 28 ++++++++++++++++++++++------
1 files changed, 22 insertions(+), 6 deletions(-)
diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c
index f821a97..5cc2f4a 100644
--- a/drivers/net/xen-netfront.c
+++ b/drivers/net/xen-netfront.c
@@ -58,7 +58,9 @@
/* Module parameters */
static unsigned int xennet_max_queues;
-module_param_named(max_queues, xennet_max_queues, uint, 0644);
+static int xennet_set_max_queues(const char *val, struct kernel_param *kp);
+module_param_call(max_queues, xennet_set_max_queues, param_get_uint,
+ &xennet_max_queues, 0644);
MODULE_PARM_DESC(max_queues,
"Maximum number of queues per virtual interface");
@@ -164,6 +166,19 @@ struct netfront_rx_info {
struct xen_netif_extra_info extras[XEN_NETIF_EXTRA_TYPE_MAX - 1];
};
+static int xennet_set_max_queues(const char *val, struct kernel_param *kp)
+{
+ unsigned int cpus = num_online_cpus();
+ unsigned int max_queues = simple_strtoul(val, NULL, 10);
+
+ if (max_queues == 0 || max_queues > cpus) {
+ pr_err("max_queues %u is out of range [1 - %u]!\n",
+ max_queues, cpus);
+ return -ERANGE;
+ }
+ return param_set_uint(val, kp);
+}
+
static void skb_entry_set_link(union skb_entry *list, unsigned short id)
{
list->link = id;
@@ -2126,6 +2141,8 @@ static struct xenbus_driver netfront_driver = {
static int __init netif_init(void)
{
+ unsigned int cpus = num_online_cpus();
+
if (!xen_domain())
return -ENODEV;
@@ -2134,11 +2151,10 @@ static int __init netif_init(void)
pr_info("Initialising Xen virtual ethernet driver\n");
- /* Allow as many queues as there are CPUs if user has not
- * specified a value.
- */
- if (xennet_max_queues == 0)
- xennet_max_queues = num_online_cpus();
+ /* Allow at most as many queues as there are CPUs. */
+ if (xennet_max_queues == 0 || xennet_max_queues > cpus)
+ xennet_max_queues = cpus;
+ pr_info("max_queues: %d\n", xennet_max_queues);
return xenbus_register_frontend(&netfront_driver);
}
--
1.7.1
^ permalink raw reply related [flat|nested] 12+ messages in thread* [PATCH V3 2/2] xen-netfront: limit vnic max_queues number to online cpus
2015-10-23 9:42 [PATCH V3 0/2] limit xen vnic max queues number to online cpus number Joe Jin
` (2 preceding siblings ...)
2015-10-23 9:45 ` [PATCH V3 2/2] xen-netfront: limit vnic max_queues " Joe Jin
@ 2015-10-23 9:45 ` Joe Jin
2015-10-23 9:50 ` [Xen-devel] [PATCH V3 0/2] limit xen vnic max queues number to online cpus number Andrew Cooper
2015-10-23 9:50 ` Andrew Cooper
5 siblings, 0 replies; 12+ messages in thread
From: Joe Jin @ 2015-10-23 9:45 UTC (permalink / raw)
To: wei.liu2, Ian Campbell, Boris Ostrovsky, Konrad Rzeszutek Wilk,
David S. Miller, Jan Beulich
Cc: netdev, xen-devel
Should not allocate vnic queues number more than online cpus.
Signed-off-by: Joe Jin <joe.jin@oracle.com>
Cc: Jan Beulich <JBeulich@suse.com>
Cc: Wei Liu <wei.liu2@citrix.com>
Cc: Ian Campbell <ian.campbell@citrix.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
---
drivers/net/xen-netfront.c | 28 ++++++++++++++++++++++------
1 files changed, 22 insertions(+), 6 deletions(-)
diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c
index f821a97..5cc2f4a 100644
--- a/drivers/net/xen-netfront.c
+++ b/drivers/net/xen-netfront.c
@@ -58,7 +58,9 @@
/* Module parameters */
static unsigned int xennet_max_queues;
-module_param_named(max_queues, xennet_max_queues, uint, 0644);
+static int xennet_set_max_queues(const char *val, struct kernel_param *kp);
+module_param_call(max_queues, xennet_set_max_queues, param_get_uint,
+ &xennet_max_queues, 0644);
MODULE_PARM_DESC(max_queues,
"Maximum number of queues per virtual interface");
@@ -164,6 +166,19 @@ struct netfront_rx_info {
struct xen_netif_extra_info extras[XEN_NETIF_EXTRA_TYPE_MAX - 1];
};
+static int xennet_set_max_queues(const char *val, struct kernel_param *kp)
+{
+ unsigned int cpus = num_online_cpus();
+ unsigned int max_queues = simple_strtoul(val, NULL, 10);
+
+ if (max_queues == 0 || max_queues > cpus) {
+ pr_err("max_queues %u is out of range [1 - %u]!\n",
+ max_queues, cpus);
+ return -ERANGE;
+ }
+ return param_set_uint(val, kp);
+}
+
static void skb_entry_set_link(union skb_entry *list, unsigned short id)
{
list->link = id;
@@ -2126,6 +2141,8 @@ static struct xenbus_driver netfront_driver = {
static int __init netif_init(void)
{
+ unsigned int cpus = num_online_cpus();
+
if (!xen_domain())
return -ENODEV;
@@ -2134,11 +2151,10 @@ static int __init netif_init(void)
pr_info("Initialising Xen virtual ethernet driver\n");
- /* Allow as many queues as there are CPUs if user has not
- * specified a value.
- */
- if (xennet_max_queues == 0)
- xennet_max_queues = num_online_cpus();
+ /* Allow at most as many queues as there are CPUs. */
+ if (xennet_max_queues == 0 || xennet_max_queues > cpus)
+ xennet_max_queues = cpus;
+ pr_info("max_queues: %d\n", xennet_max_queues);
return xenbus_register_frontend(&netfront_driver);
}
--
1.7.1
^ permalink raw reply related [flat|nested] 12+ messages in thread* Re: [Xen-devel] [PATCH V3 0/2] limit xen vnic max queues number to online cpus number
2015-10-23 9:42 [PATCH V3 0/2] limit xen vnic max queues number to online cpus number Joe Jin
` (3 preceding siblings ...)
2015-10-23 9:45 ` Joe Jin
@ 2015-10-23 9:50 ` Andrew Cooper
2015-10-23 9:50 ` Andrew Cooper
5 siblings, 0 replies; 12+ messages in thread
From: Andrew Cooper @ 2015-10-23 9:50 UTC (permalink / raw)
To: Joe Jin, wei.liu2, Ian Campbell, Boris Ostrovsky,
Konrad Rzeszutek Wilk, David S. Miller, Jan Beulich
Cc: netdev, xen-devel
On 23/10/15 10:42, Joe Jin wrote:
> Currently xen vnic allowed to create lots of queues by set module param
> max_queues(both netback and netfront), when queues number larger than
> cpus number, it does not help for performance but need more cpu time.
>
> This patchset limit netback and netfront max queues number to online
> cpus number.
>
> Joe Jin (2):
> xen-netback: limit xen vif max queues number to online cpus
> xen-netfront: limit vnic max_queues number to online cpus
Please do not exclude the possibility for making crazy numbers of queues.
I can appreciate the want to prevent people shooting themselves in the
foot, but being able oversubscribe the number of queues is important for
performance testing.
~Andrew
^ permalink raw reply [flat|nested] 12+ messages in thread* Re: [PATCH V3 0/2] limit xen vnic max queues number to online cpus number
2015-10-23 9:42 [PATCH V3 0/2] limit xen vnic max queues number to online cpus number Joe Jin
` (4 preceding siblings ...)
2015-10-23 9:50 ` [Xen-devel] [PATCH V3 0/2] limit xen vnic max queues number to online cpus number Andrew Cooper
@ 2015-10-23 9:50 ` Andrew Cooper
5 siblings, 0 replies; 12+ messages in thread
From: Andrew Cooper @ 2015-10-23 9:50 UTC (permalink / raw)
To: Joe Jin, wei.liu2, Ian Campbell, Boris Ostrovsky,
Konrad Rzeszutek Wilk, David S. Miller, Jan Beulich
Cc: netdev, xen-devel
On 23/10/15 10:42, Joe Jin wrote:
> Currently xen vnic allowed to create lots of queues by set module param
> max_queues(both netback and netfront), when queues number larger than
> cpus number, it does not help for performance but need more cpu time.
>
> This patchset limit netback and netfront max queues number to online
> cpus number.
>
> Joe Jin (2):
> xen-netback: limit xen vif max queues number to online cpus
> xen-netfront: limit vnic max_queues number to online cpus
Please do not exclude the possibility for making crazy numbers of queues.
I can appreciate the want to prevent people shooting themselves in the
foot, but being able oversubscribe the number of queues is important for
performance testing.
~Andrew
^ permalink raw reply [flat|nested] 12+ messages in thread