Has anyone else seen things like "xl list" or xentop hang on Fedora 24?
# rpm -q kernel xen kernel-4.5.5-300.fc24.x86_64 xen-4.6.1-10.fc24.x86_64
Running "strace xl list" produces the following, which seems to indicate that the hang occurs when "xl list" writes to /dev/xen/xenbus:
access("/dev/xen/xenbus", F_OK) = 0 stat("/dev/xen/xenbus", {st_mode=S_IFCHR|0600, st_rdev=makedev(10, 62), ...}) = 0 open("/dev/xen/xenbus", O_RDWR) = 6 open("/etc/xen/xl.conf", O_RDONLY) = 7 fstat(7, {st_mode=S_IFREG|0644, st_size=33, ...}) = 0 fstat(7, {st_mode=S_IFREG|0644, st_size=33, ...}) = 0 read(7, "vif.default.script = "vif-ethos""..., 4096) = 33 close(7) = 0 ioctl(5, _IOC(0, 0x50, 0x00, 0x30), 0x7ffdafc79e90) = 262150 mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS|MAP_LOCKED, -1, 0) = 0x7fef0d788000 madvise(0x7fef0d788000, 4096, MADV_DONTFORK) = 0 ioctl(5, _IOC(0, 0x50, 0x00, 0x30), 0x7ffdafc79e90) = 0 ioctl(5, _IOC(0, 0x50, 0x00, 0x30), 0x7ffdafc79e90) = 0 ioctl(5, _IOC(0, 0x50, 0x00, 0x30), 0x7ffdafc79e90) = 0 ioctl(5, _IOC(0, 0x50, 0x00, 0x30), 0x7ffdafc79e90) = 0 ioctl(5, _IOC(0, 0x50, 0x00, 0x30), 0x7ffdafc79e90) = 0 ioctl(5, _IOC(0, 0x50, 0x00, 0x30), 0x7ffdafc79e90) = 4096 ioctl(5, _IOC(0, 0x50, 0x00, 0x30), 0x7ffdafc79e90) = 0 mmap(NULL, 102400, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS|MAP_LOCKED, -1, 0) = 0x7fef0d76f000 madvise(0x7fef0d76f000, 102400, MADV_DONTFORK) = 0 ioctl(5, _IOC(0, 0x50, 0x00, 0x30), 0x7ffdafc61c70) = 0 madvise(0x7fef0d76f000, 102400, MADV_DOFORK) = 0 munmap(0x7fef0d76f000, 102400) = 0 mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS|MAP_LOCKED, -1, 0) = 0x7fef0d786000 madvise(0x7fef0d786000, 8192, MADV_DONTFORK) = 0 ioctl(5, _IOC(0, 0x50, 0x00, 0x30), 0x7ffdafc60c70) = 0 madvise(0x7fef0d786000, 8192, MADV_DOFORK) = 0 munmap(0x7fef0d786000, 8192) = 0 fstat(1, {st_mode=S_IFCHR|0620, st_rdev=makedev(136, 4), ...}) = 0 write(1, "Name "..., 73Name ID Mem VCPUs State Time(s) ) = 73 rt_sigaction(SIGPIPE, {SIG_IGN, [], SA_RESTORER, 0x7fef0ca7cc10}, {SIG_DFL, [], 0}, 8) = 0 write(6, "\2\0\0\0\0\0\0\0\0\0\0\0\25\0\0\0", 16) = 16 write(6, "/local/domain/0/name\0", 21 # [ HANGS HERE. ]
On Tue, May 31, 2016 at 03:42:14PM -0400, W. Michael Petullo wrote:
Has anyone else seen things like "xl list" or xentop hang on Fedora 24?
# rpm -q kernel xen kernel-4.5.5-300.fc24.x86_64 xen-4.6.1-10.fc24.x86_64
Running "strace xl list" produces the following, which seems to indicate that the hang occurs when "xl list" writes to /dev/xen/xenbus:
That is most likely to due to:
[Bug 1322625] SELinux is preventing systemd-modules from using the 'sys_module' capabilities.
which causes another issues as well.
access("/dev/xen/xenbus", F_OK) = 0 stat("/dev/xen/xenbus", {st_mode=S_IFCHR|0600, st_rdev=makedev(10, 62), ...}) = 0 open("/dev/xen/xenbus", O_RDWR) = 6 open("/etc/xen/xl.conf", O_RDONLY) = 7 fstat(7, {st_mode=S_IFREG|0644, st_size=33, ...}) = 0 fstat(7, {st_mode=S_IFREG|0644, st_size=33, ...}) = 0 read(7, "vif.default.script = "vif-ethos""..., 4096) = 33 close(7) = 0 ioctl(5, _IOC(0, 0x50, 0x00, 0x30), 0x7ffdafc79e90) = 262150 mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS|MAP_LOCKED, -1, 0) = 0x7fef0d788000 madvise(0x7fef0d788000, 4096, MADV_DONTFORK) = 0 ioctl(5, _IOC(0, 0x50, 0x00, 0x30), 0x7ffdafc79e90) = 0 ioctl(5, _IOC(0, 0x50, 0x00, 0x30), 0x7ffdafc79e90) = 0 ioctl(5, _IOC(0, 0x50, 0x00, 0x30), 0x7ffdafc79e90) = 0 ioctl(5, _IOC(0, 0x50, 0x00, 0x30), 0x7ffdafc79e90) = 0 ioctl(5, _IOC(0, 0x50, 0x00, 0x30), 0x7ffdafc79e90) = 0 ioctl(5, _IOC(0, 0x50, 0x00, 0x30), 0x7ffdafc79e90) = 4096 ioctl(5, _IOC(0, 0x50, 0x00, 0x30), 0x7ffdafc79e90) = 0 mmap(NULL, 102400, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS|MAP_LOCKED, -1, 0) = 0x7fef0d76f000 madvise(0x7fef0d76f000, 102400, MADV_DONTFORK) = 0 ioctl(5, _IOC(0, 0x50, 0x00, 0x30), 0x7ffdafc61c70) = 0 madvise(0x7fef0d76f000, 102400, MADV_DOFORK) = 0 munmap(0x7fef0d76f000, 102400) = 0 mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS|MAP_LOCKED, -1, 0) = 0x7fef0d786000 madvise(0x7fef0d786000, 8192, MADV_DONTFORK) = 0 ioctl(5, _IOC(0, 0x50, 0x00, 0x30), 0x7ffdafc60c70) = 0 madvise(0x7fef0d786000, 8192, MADV_DOFORK) = 0 munmap(0x7fef0d786000, 8192) = 0 fstat(1, {st_mode=S_IFCHR|0620, st_rdev=makedev(136, 4), ...}) = 0 write(1, "Name "..., 73Name ID Mem VCPUs State Time(s) ) = 73 rt_sigaction(SIGPIPE, {SIG_IGN, [], SA_RESTORER, 0x7fef0ca7cc10}, {SIG_DFL, [], 0}, 8) = 0 write(6, "\2\0\0\0\0\0\0\0\0\0\0\0\25\0\0\0", 16) = 16 write(6, "/local/domain/0/name\0", 21 # [ HANGS HERE. ]
-- Mike
:wq
xen mailing list xen@lists.fedoraproject.org https://lists.fedoraproject.org/admin/lists/xen@lists.fedoraproject.org
On Tue, 31 May 2016, W. Michael Petullo wrote:
Has anyone else seen things like "xl list" or xentop hang on Fedora 24?
# rpm -q kernel xen kernel-4.5.5-300.fc24.x86_64 xen-4.6.1-10.fc24.x86_64
Running "strace xl list" produces the following, which seems to indicate that the hang occurs when "xl list" writes to /dev/xen/xenbus:
access("/dev/xen/xenbus", F_OK) = 0 stat("/dev/xen/xenbus", {st_mode=S_IFCHR|0600, st_rdev=makedev(10, 62), ...}) = 0 open("/dev/xen/xenbus", O_RDWR) = 6 open("/etc/xen/xl.conf", O_RDONLY) = 7
I think this depends on having the right DomU running as I have used xl list with the above settings without problems (though I don't think anything I run depends on xenbus).
I also wonder what your selinux settings are. I had problems with xen-4.7.0 which uses /dev/xen/privcmd which had system_u:object_r:device_t:s0 permissions rather than system_u:object_r:xen_device_t:s0 (now fixed if you have a recent enough selinux). If you have selinux enabled could you try chcon -t xen_device_t /dev/xen/xenbus to see if that makes any difference or alternatively setenforce 0.
Michael Young
Has anyone else seen things like "xl list" or xentop hang on Fedora 24?
# rpm -q kernel xen kernel-4.5.5-300.fc24.x86_64 xen-4.6.1-10.fc24.x86_64
Running "strace xl list" produces the following, which seems to indicate that the hang occurs when "xl list" writes to /dev/xen/xenbus:
access("/dev/xen/xenbus", F_OK) = 0 stat("/dev/xen/xenbus", {st_mode=S_IFCHR|0600, st_rdev=makedev(10, 62), ...}) = 0 open("/dev/xen/xenbus", O_RDWR) = 6 open("/etc/xen/xl.conf", O_RDONLY) = 7
I think this depends on having the right DomU running as I have used xl list with the above settings without problems (though I don't think anything I run depends on xenbus).
I also wonder what your selinux settings are. I had problems with xen-4.7.0 which uses /dev/xen/privcmd which had system_u:object_r:device_t:s0 permissions rather than system_u:object_r:xen_device_t:s0 (now fixed if you have a recent enough selinux). If you have selinux enabled could you try chcon -t xen_device_t /dev/xen/xenbus to see if that makes any difference or alternatively setenforce 0.
Indeed, this looks SELinux related, possibly due to bug #1322625 as Konrad suggested. I will provide more details as I find them at:
https://bugzilla.redhat.com/show_bug.cgi?id=1341317
Thank you,
xen@lists.stg.fedoraproject.org