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>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
#include <xen/interface/grant_table.h>
/* Module parameters */
#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,
static unsigned int xennet_max_queues;
module_param_named(max_queues, xennet_max_queues, uint, 0644);
MODULE_PARM_DESC(max_queues,
pr_info("Initialising Xen virtual ethernet driver\n");
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)
* 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);
}
return xenbus_register_frontend(&netfront_driver);
}