Greetings, 0day kernel testing robot got the below dmesg and the first bad commit is https://git.kernel.org/pub/scm/linux/kernel/git/peterz/queue.git x86/core commit 97a3901a1c1712174034d55c86e68d06ed444990 Author: Peter Zijlstra <peterz(a)infradead.org&gt; AuthorDate: Sun Mar 10 13:48:38 2019 +0100 Commit: Peter Zijlstra <peterz(a)infradead.org&gt; CommitDate: Wed May 8 00:10:35 2019 +0200 x86/percpu: Remove this_cpu_read_stable() this_cpu_read_stable() and it's implementation percpu_stable_cpu() read like a nasty hack because older compilers would not CSE things. This is no longer so; __this_cpu_read() _is_ very much affected by CSE, so remove this hack and use the proper function. 17642871 2157438 747808 20548117 1398a15 defconfig-pre/vmlinux.o 17639081 2157438 747808 20544327 1397b47 defconfig-post/vmlinux.o Signed-off-by: Peter Zijlstra (Intel) <peterz(a)infradead.org&gt; ed30334ac3 x86/percpu: Differentiate this_cpu_{}() and __this_cpu_{}() 97a3901a1c x86/percpu: Remove this_cpu_read_stable() 392054d663 x86/percpu: Optimize raw_cpu_xchg() +-------------------------------+------------+------------+------------+ | | ed30334ac3 | 97a3901a1c | 392054d663 | +-------------------------------+------------+------------+------------+ | boot_successes | 31 | 0 | 0 | | boot_failures | 0 | 11 | 13 | | BUG:kernel_hang_in_boot_stage | 0 | 11 | 13 | +-------------------------------+------------+------------+------------+ If you fix the issue, kindly add following tag Reported-by: kernel test robot <lkp(a)intel.com&gt; [ 0.307106] Last level dTLB entries: 4KB 0, 2MB 0, 4MB 0, 1GB 0 [ 0.307665] Spectre V2 : Spectre mitigation: kernel not compiled with retpoline; no mitigation available! [ 0.307666] Speculative Store Bypass: Vulnerable [ 0.308979] L1TF: Kernel not compiled for PAE. No mitigation for L1TF [ 0.309748] Freeing SMP alternatives memory: 28K BUG: kernel hang in boot stage # HH:MM RESULT GOOD BAD GOOD_BUT_DIRTY DIRTY_NOT_BAD git bisect start fcd4ab5c57863073312a0ebfe164f0ed6459a995 v5.1 -- git bisect good 8f147727030bf9e81331ab9b8f42d4611bb6a3d9 # 16:06 G 10 0 0 0 Merge branch 'x86-irq-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip git bisect good 8f5e823f9131a430b12f73e9436d7486e20c16f5 # 17:28 G 10 0 1 1 Merge tag 'pm-5.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm git bisect good b8a3dd5332efc1f1d6494b86e6bd8611bec6ef94 # 18:53 G 10 0 0 0 Merge branch 'x86/fpu' git bisect good a784df3c7c41ab7f99aed818c6d9dc034c55e8bc # 19:04 G 10 0 0 0 Merge branch 'core/urgent' git bisect good f8d6805068ad8dbef2489f6e02ca73c1d84517d7 # 19:04 G 11 0 0 0 Merge branch 'WIP.x86/fpu' into auto-latest git bisect good 0ba523ea6962d12c3d910b3a085026ffb48b0325 # 19:18 G 10 0 0 0 Merge branch 'sched/core' git bisect bad d5673e9b528947d645c8944e37fa3347a6da43a2 # 19:31 B 0 5 19 0 x86/percpu, x86/irq: Relax {set,get}_irq_regs() git bisect bad 97a3901a1c1712174034d55c86e68d06ed444990 # 19:48 B 0 11 25 0 x86/percpu: Remove this_cpu_read_stable() git bisect good ed30334ac3f954950e1e8fb70ff7cb3ccd636465 # 20:01 G 11 0 0 0 x86/percpu: Differentiate this_cpu_{}() and __this_cpu_{}() # first bad commit: [97a3901a1c1712174034d55c86e68d06ed444990] x86/percpu: Remove this_cpu_read_stable() git bisect good ed30334ac3f954950e1e8fb70ff7cb3ccd636465 # 20:05 G 30 0 0 0 x86/percpu: Differentiate this_cpu_{}() and __this_cpu_{}() # extra tests on HEAD of peterz-queue/master git bisect bad fcd4ab5c57863073312a0ebfe164f0ed6459a995 # 20:05 B 0 23 41 1 Merge branch 'x86/core' # extra tests on tree/branch peterz-queue/x86/core git bisect bad 392054d6637e50353f4088c45992dfbb82cf5b60 # 20:20 B 0 13 31 0 x86/percpu: Optimize raw_cpu_xchg() # extra tests with first bad commit reverted git bisect good d59acc3c063c2f044a91030af4868146ed34543e # 20:37 G 10 0 0 0 Revert "x86/percpu: Remove this_cpu_read_stable()" --- 0-DAY kernel test infrastructure Open Source Technology Center https://lists.01.org/pipermail/lkp Intel Corporation