After cpu hot-removing, kexec command fails with the following message. "/sys/devices" does not exist. Sysfs does not seem to be mounted. Try mounting sysfs. Of course sysfs is mounted. kexec tried to open /sys/devices/system/cpu/cpu30/crash_notes but it failed because /sys/devices/system/cpu/cpu30 did not exist. [Before hot-remove] # ls /sys/devices/system/cpu/ cpu0 cpu111 cpu18 cpu31 cpu45 cpu59 cpu72 cpu86 cpuidle cpu1 cpu112 cpu19 cpu32 cpu46 cpu6 cpu73 cpu87 intel_pstate cpu10 cpu113 cpu2 cpu33 cpu47 cpu60 cpu74 cpu88 kernel_max cpu100 cpu114 cpu20 cpu34 cpu48 cpu61 cpu75 cpu89 microcode cpu101 cpu115 cpu21 cpu35 cpu49 cpu62 cpu76 cpu9 modalias cpu102 cpu116 cpu22 cpu36 cpu5 cpu63 cpu77 cpu90 offline cpu103 cpu117 cpu23 cpu37 cpu50 cpu64 cpu78 cpu91 online cpu104 cpu118 cpu24 cpu38 cpu51 cpu65 cpu79 cpu92 possible cpu105 cpu119 cpu25 cpu39 cpu52 cpu66 cpu8 cpu93 power cpu106 cpu12 cpu26 cpu4 cpu53 cpu67 cpu80 cpu94 present cpu107 cpu13 cpu27 cpu40 cpu54 cpu68 cpu81 cpu95 probe cpu108 cpu14 cpu28 cpu41 cpu55 cpu69 cpu82 cpu96 release cpu109 cpu15 cpu29 cpu42 cpu56 cpu7 cpu83 cpu97 uevent cpu11 cpu16 cpu3 cpu43 cpu57 cpu70 cpu84 cpu98 cpu110 cpu17 cpu30 cpu44 cpu58 cpu71 cpu85 cpu99 [After hot-remove] # ls /sys/devices/system/cpu/ cpu0 cpu16 cpu23 cpu4 cpu65 cpu72 cpu8 cpu87 modalias uevent cpu1 cpu17 cpu24 cpu5 cpu66 cpu73 cpu80 cpu88 offline cpu10 cpu18 cpu25 cpu6 cpu67 cpu74 cpu81 cpu89 online cpu11 cpu19 cpu26 cpu60 cpu68 cpu75 cpu82 cpu9 possible cpu12 cpu2 cpu27 cpu61 cpu69 cpu76 cpu83 cpuidle power cpu13 cpu20 cpu28 cpu62 cpu7 cpu77 cpu84 intel_pstate present cpu14 cpu21 cpu29 cpu63 cpu70 cpu78 cpu85 kernel_max probe cpu15 cpu22 cpu3 cpu64 cpu71 cpu79 cpu86 microcode release You can see cpu30 to cpu59, and cpu90 to cpu119 does not exist, they are removed from this system by hot-remove operation. kexec command expects the number of each directory is contiguous. For example, if sysconf(_SC_NPROCESSORS_CONF) is 60, kexec thinks directory cpu0, cpu1, cpu2, .... cpu59 exists. But in this case, the number of directory is not contiguous. That is the root cause of this problem. This patches fix it. Takao Indoh (2): Enumerate all /sys/devices/system/cpu/cpuN when they are discontiguous Fix mistaken check of stat(2) return value kexec/crashdump-elf.c | 5 ++++- kexec/crashdump.c | 2 +- 2 files changed, 5 insertions(+), 2 deletions(-) -- 1.9.3
