Hi, For miscdevices, the major device_no is same, so the minor device_no should be set to ditinguish different misc devices; if not set the minor, it may fail while insmod due to the default minor value, 0, has been used by other miscdevice. MISC_DYNAMIC_MINOR means to let Linux kernel dynamically assign one minor devide number while loading. You can refer to the kni_misc.c
Brgs, Chi Xiaobo -----Original Message----- From: dev [mailto:dev-boun...@dpdk.org] On Behalf Of EXT Yuanhan Liu Sent: Monday, November 09, 2015 12:23 PM To: Chi, Xiaobo (Nokia - CN/Hangzhou) Cc: dev at dpdk.org; changchun.ouyang at intel.com Subject: Re: [dpdk-dev] [PATCH] vhost: eventfd_link's minor number shall be specified On Fri, Nov 06, 2015 at 02:04:37PM +0800, Xiaobo Chi wrote: > eventfd_link_misc's minor number shall be MISC_DYNAMIC_MINOR to let Linux > kernel dynamically assign one while loading. For such (fix) patch, I'd like to see what exact issue your patch fixes. And if it fixes an issue, you'd better title your patch with something like "vhost: fix ...", so that it's likely Thomas will put it into high priority. --yliu > > Signed-off-by: Xiaobo Chi <xiaobo.chi at nokia.com> > --- > lib/librte_vhost/eventfd_link/eventfd_link.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/lib/librte_vhost/eventfd_link/eventfd_link.c > b/lib/librte_vhost/eventfd_link/eventfd_link.c > index c54a938..4b05b5a 100644 > --- a/lib/librte_vhost/eventfd_link/eventfd_link.c > +++ b/lib/librte_vhost/eventfd_link/eventfd_link.c > @@ -249,6 +249,7 @@ static const struct file_operations eventfd_link_fops = { > > > static struct miscdevice eventfd_link_misc = { > + .minor = MISC_DYNAMIC_MINOR, > .name = "eventfd-link", > .fops = &eventfd_link_fops, > }; > -- > 1.9.4.msysgit.2