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| author | Rusty Russell <rusty@rustcorp.com.au> | 2008-07-28 12:16:29 -0500 |
|---|---|---|
| committer | Rusty Russell <rusty@rustcorp.com.au> | 2008-07-28 12:16:29 +1000 |
| commit | 04321587584272f4e8b9818f319f40caf8eeee13 (patch) | |
| tree | 5bf00c36a182644cc2c4fe2577b14e050a49418b | |
| parent | ffdb5976c47609c862917d4c186ecbb5706d2dda (diff) | |
| download | linux-04321587584272f4e8b9818f319f40caf8eeee13.tar.gz linux-04321587584272f4e8b9818f319f40caf8eeee13.tar.bz2 linux-04321587584272f4e8b9818f319f40caf8eeee13.zip | |
Hotplug CPU: don't check cpu_online after take_cpu_down
Akinobu points out that if take_cpu_down() succeeds, the cpu must be offline.
Remove the cpu_online() check, and put a BUG_ON().
Quoting Akinobu Mita:
Actually the cpu_online() check was necessary before appling this
stop_machine: simplify patch.
With old __stop_machine_run(), __stop_machine_run() could succeed
(return !IS_ERR(p) value) even if take_cpu_down() returned non-zero value.
The return value of take_cpu_down() was obtained through kthread_stop()..
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: "Akinobu Mita" <akinobu.mita@gmail.com>
| -rw-r--r-- | kernel/cpu.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/kernel/cpu.c b/kernel/cpu.c index cf79bb911371..53cf508f975a 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -250,8 +250,7 @@ static int __ref _cpu_down(unsigned int cpu, int tasks_frozen) set_cpus_allowed_ptr(current, &tmp); err = __stop_machine_run(take_cpu_down, &tcd_param, cpu); - - if (err || cpu_online(cpu)) { + if (err) { /* CPU didn't die: tell everyone. Can't complain. */ if (raw_notifier_call_chain(&cpu_chain, CPU_DOWN_FAILED | mod, hcpu) == NOTIFY_BAD) @@ -259,6 +258,7 @@ static int __ref _cpu_down(unsigned int cpu, int tasks_frozen) goto out_allowed; } + BUG_ON(cpu_online(cpu)); /* Wait for it to sleep (leaving idle task). */ while (!idle_cpu(cpu)) |