Hi Thomas,

I love your patch! Perhaps something to improve:

[auto build test WARNING on tip/x86/asm]
[also build test WARNING on tip/master linus/master tip/x86/core v5.11-rc6 next-20210125]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Thomas-Gleixner/x86-irq-64-Inline-irq-stack-switching/20210205-091059
base:   https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git 5c99720b28381bb400d4f546734c34ddaf608761
config: x86_64-rhel (attached as .config)
compiler: gcc-9 (Debian 9.3.0-15) 9.3.0
reproduce (this is a W=1 build):
        # https://github.com/0day-ci/linux/commit/ab3144e8d40d2a97101655f99804baa009bcdc36
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Thomas-Gleixner/x86-irq-64-Inline-irq-stack-switching/20210205-091059
        git checkout ab3144e8d40d2a97101655f99804baa009bcdc36
        # save the attached .config to linux build tree
        make W=1 ARCH=x86_64 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All warnings (new ones prefixed by >>):

>> arch/x86/entry/common.o: warning: objtool: xen_pv_evtchn_do_upcall()+0xa3: undefined stack state

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org