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| author | Rusty Russell <rusty@rustcorp.com.au> | 2009-01-16 15:31:15 -0800 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-01-19 22:36:02 +0100 |
| commit | 31ad9081200c06ccc350625d41d1f8b2d1cef29f (patch) | |
| tree | 99768cf8eae9aaa2d1f4167103aa7ea9c70068a1 /kernel | |
| parent | c7f8562a51c2e5dcc1a00a2bdd232b9965ff960d (diff) | |
| download | lwn-31ad9081200c06ccc350625d41d1f8b2d1cef29f.tar.gz lwn-31ad9081200c06ccc350625d41d1f8b2d1cef29f.zip | |
work_on_cpu: don't try to get_online_cpus() in work_on_cpu.
Impact: remove potential circular lock dependency with cpu hotplug lock
This has caused more problems than it solved, with a pile of cpu
hotplug locking issues.
Followup patches will get_online_cpus() in callers that need it, but
if they don't do it they're no worse than before when they were using
set_cpus_allowed without locking.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/workqueue.c | 14 |
1 files changed, 4 insertions, 10 deletions
diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 2f445833ae37..a35afdbc0161 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -991,8 +991,8 @@ static void do_work_for_cpu(struct work_struct *w) * @fn: the function to run * @arg: the function arg * - * This will return -EINVAL in the cpu is not online, or the return value - * of @fn otherwise. + * This will return the value @fn returns. + * It is up to the caller to ensure that the cpu doesn't go offline. */ long work_on_cpu(unsigned int cpu, long (*fn)(void *), void *arg) { @@ -1001,14 +1001,8 @@ long work_on_cpu(unsigned int cpu, long (*fn)(void *), void *arg) INIT_WORK(&wfc.work, do_work_for_cpu); wfc.fn = fn; wfc.arg = arg; - get_online_cpus(); - if (unlikely(!cpu_online(cpu))) - wfc.ret = -EINVAL; - else { - schedule_work_on(cpu, &wfc.work); - flush_work(&wfc.work); - } - put_online_cpus(); + schedule_work_on(cpu, &wfc.work); + flush_work(&wfc.work); return wfc.ret; } |