Hi, And following is a test by me, we can see that if I firstly insert my kmod_test.ko, then insert eventfd_link.ko, error will happen with hint " Device or resource busy". This is because the default minor device number, 0, has been occupied by my kmod_test.ko .
root at distro:~/test$ lsmod Module Size Used by kmod_test 927 0 vboxsf 35930 4 vboxguest 222130 1 vboxsf microcode 10315 0 autofs4 25051 0 root at distro:~/test$ modinfo kmod_test modinfo: ERROR: Module kmod_test not found. root at distro:~/test$ modinfo kmod_test.ko filename: /root/test/kmod_test.ko alias: devname:test description: my test author: Xiaobo Chi license: GPL v2 version: 0.0.1 srcversion: C2BDEBC81A17F8197C7C44A depends: vermagic: 3.18.9-pc64-distro.git-v1.7 SMP mod_unload root at distro:~/test$ dmesg -c root at distro:~/test$ ls eventfd_link.ko kmod_test.ko kmod_test.mod.o main Makefile Module.symvers kmod_test.c kmod_test.mod.c kmod_test.o main.c modules.order root at distro:~/test$ insmod ./eventfd_link.ko insmod: ERROR: could not insert module ./eventfd_link.ko: Device or resource busy root at distro:~/test$ dmesg -c brgs, Xiaobo Chi -----Original Message----- From: dev [mailto:dev-boun...@dpdk.org] On Behalf Of EXT Chi, Xiaobo (Nokia - CN/Hangzhou) Sent: Monday, November 09, 2015 6:03 PM To: EXT Yuanhan Liu Cc: dev at dpdk.org; changchun.ouyang at intel.com Subject: Re: [dpdk-dev] [PATCH] vhost: eventfd_link's minor number shall be specified 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
