Re: [Crash-utility] [PATCH 2/3] crash: ARM: get online CPUs from cpu_active_mask

On 2014/4/26 3:20, Dave Anderson wrote: > > > ----- Original Message ----- >> For ARM32 platfrom, The system will "offline" all CPUs except the >> crashing one, by clear the cpu_online_mask. So we need to find >> another way to get online-CPUs number for crash utility. >> >> This patch uses cpu_active_mask to get that value. >> >> Signed-off-by: Liu Hua <sdu.liu(a)huawei.com&gt; >> --- >> arm.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/arm.c b/arm.c >> index 3c38cd5..c94d7bf 100644 >> --- a/arm.c >> +++ b/arm.c >> @@ -1518,7 +1518,7 @@ arm_display_machine_stats(void) >> static int >> arm_get_smp_cpus(void) >> { >> - return get_cpus_online(); >> + return get_cpus_active(); >> } >> >> /* > > When did this start happening? I ask because no other ARM users have > reported this until now. I've only got one sample SMP vmcore, and > clearly the non-crashing cpu was not offlined: > Hi Dave, commit 36a2e5010fe87 "kexec: offline non panic CPUs on Kdump panic " introduces this change. <v3.10.27-1-g36a2e50> The following messges come from the ARM boards on my hand. The crash utility has added my patchs. (1) ARM A15 16 CPUs crash> sys KERNEL: vmlinux DUMPFILE: vmcore_my [PARTIAL DUMP] CPUS: 16 DATE: Fri Feb 28 10:07:55 2014 UPTIME: 00:03:57 LOAD AVERAGE: 0.03, 0.01, 0.01 TASKS: 140 NODENAME: arma15el RELEASE: 3.10.37+ VERSION: #2 SMP Thu Apr 24 21:13:28 CST 2014 MACHINE: armv7l (unknown Mhz) MEMORY: 3.1 GB PANIC: "Internal error: Oops: a07 [#1] SMP ARM" (check log for details crash> help -k .... cpu_possible_map: 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 cpu_present_map: 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 cpu_online_map: 0 ... (2) ARM A9 4 CPUs crash> sys KERNEL: vmlinux DUMPFILE: vmcore CPUS: 2 DATE: Mon Apr 14 11:09:10 2014 UPTIME: 00:06:17 LOAD AVERAGE: 0.16, 0.05, 0.02 TASKS: 45 NODENAME: arma9el RELEASE: 3.10.37+ VERSION: #6 SMP Tue Apr 22 13:23:30 CST 2014 MACHINE: armv7l (unknown Mhz) MEMORY: 1.5 GB PANIC: "Internal error: Oops: 817 [#1] SMP ARM" (check log for details) crash> help -k .... cpu_possible_map: 0 1 cpu_present_map: 0 1 cpu_online_map: 1 crash> p per_cpu__runqueues PER-CPU DATA TYPE: struct rq runqueues; PER-CPU ADDRESSES: [0]: c069a680 [1]: c06a2680 With my patches, "sys" command is ok. And I can get per_cpu variables correctly. But something should be done for "help -k". May be I should add fully support for cpu_active_mask. If necessory, I will resend this patch series.