| Message ID | 20170110133252.5346-2-jgross@suse.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 01/10/2017 08:32 AM, Juergen Gross wrote: > The default for the number of tx/rx queues of one interface is the > number of vcpus of the system today. As each queue pair reserves 512 > grant pages this default consumes a ridiculous number of grants for > large guests. > > Limit the queue number to 8 as default. This value can be modified > via a module parameter if required. > > Signed-off-by: Juergen Gross <jgross@suse.com> > --- > drivers/net/xen-netfront.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c > index a479cd9..490c865 100644 > --- a/drivers/net/xen-netfront.c > +++ b/drivers/net/xen-netfront.c > @@ -57,6 +57,7 @@ > #include <xen/interface/grant_table.h> > > /* Module parameters */ > +#define MAX_QUEUES_DEFAULT 8 > static unsigned int xennet_max_queues; > module_param_named(max_queues, xennet_max_queues, uint, 0644); > MODULE_PARM_DESC(max_queues, > @@ -2164,11 +2165,12 @@ 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 > + /* Allow as many queues as there are CPUs inut max. 8 if user has not Based on comment change in the second patch: s/inut/but/ ? Also, comment style in both patches. Other than that, for both: Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> > * specified a value. > */ > if (xennet_max_queues == 0) > - xennet_max_queues = num_online_cpus(); > + xennet_max_queues = min_t(unsigned int, MAX_QUEUES_DEFAULT, > + num_online_cpus()); > > return xenbus_register_frontend(&netfront_driver); > }
On 10/01/17 15:53, Boris Ostrovsky wrote: > On 01/10/2017 08:32 AM, Juergen Gross wrote: >> The default for the number of tx/rx queues of one interface is the >> number of vcpus of the system today. As each queue pair reserves 512 >> grant pages this default consumes a ridiculous number of grants for >> large guests. >> >> Limit the queue number to 8 as default. This value can be modified >> via a module parameter if required. >> >> Signed-off-by: Juergen Gross <jgross@suse.com> >> --- >> drivers/net/xen-netfront.c | 6 ++++-- >> 1 file changed, 4 insertions(+), 2 deletions(-) >> >> diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c >> index a479cd9..490c865 100644 >> --- a/drivers/net/xen-netfront.c >> +++ b/drivers/net/xen-netfront.c >> @@ -57,6 +57,7 @@ >> #include <xen/interface/grant_table.h> >> >> /* Module parameters */ >> +#define MAX_QUEUES_DEFAULT 8 >> static unsigned int xennet_max_queues; >> module_param_named(max_queues, xennet_max_queues, uint, 0644); >> MODULE_PARM_DESC(max_queues, >> @@ -2164,11 +2165,12 @@ 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 >> + /* Allow as many queues as there are CPUs inut max. 8 if user has not > > Based on comment change in the second patch: s/inut/but/ ? Also, comment > style in both patches. Typo: yes Style: no. checkpatch tells me that the net directory doesn't follow common kernel style. > > Other than that, for both: > > Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Thanks, Juergen
diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c index a479cd9..490c865 100644 --- a/drivers/net/xen-netfront.c +++ b/drivers/net/xen-netfront.c @@ -57,6 +57,7 @@ #include <xen/interface/grant_table.h> /* Module parameters */ +#define MAX_QUEUES_DEFAULT 8 static unsigned int xennet_max_queues; module_param_named(max_queues, xennet_max_queues, uint, 0644); MODULE_PARM_DESC(max_queues, @@ -2164,11 +2165,12 @@ 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 + /* Allow as many queues as there are CPUs inut max. 8 if user has not * specified a value. */ if (xennet_max_queues == 0) - xennet_max_queues = num_online_cpus(); + xennet_max_queues = min_t(unsigned int, MAX_QUEUES_DEFAULT, + num_online_cpus()); return xenbus_register_frontend(&netfront_driver); }
The default for the number of tx/rx queues of one interface is the number of vcpus of the system today. As each queue pair reserves 512 grant pages this default consumes a ridiculous number of grants for large guests. Limit the queue number to 8 as default. This value can be modified via a module parameter if required. Signed-off-by: Juergen Gross <jgross@suse.com> --- drivers/net/xen-netfront.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)