Messages in this thread | | | Date | Mon, 2 Nov 2009 14:30:28 -0800 | From | "Paul E. McKenney" <> | Subject | Re: [2.6.32-rc5-git5] synchronize_sched() inside spin_lock()? |
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On Mon, Nov 02, 2009 at 09:00:06PM +0900, Tetsuo Handa wrote: > Commit: 4ea7e38696c7e798c47ebbecadfd392f23f814f9 > > tracepoint_synchronize_unregister() calls synchronize_sched(), but it is > between spin_lock() and spin_unlock(). Is it OK?
Calling synchronize_sched() while holding a spinlock would indeed be very bad, but the code below seems to instead be invoking call_rcu(), which is no problem.
Or am I missing something here?
Thanx, Paul
> static int set_all_monitor_traces(int state) > { > int rc = 0; > struct dm_hw_stat_delta *new_stat = NULL; > struct dm_hw_stat_delta *temp; > > spin_lock(&trace_state_lock); > > switch (state) { > case TRACE_ON: > rc |= register_trace_kfree_skb(trace_kfree_skb_hit); > rc |= register_trace_napi_poll(trace_napi_poll_hit); > break; > case TRACE_OFF: > rc |= unregister_trace_kfree_skb(trace_kfree_skb_hit); > rc |= unregister_trace_napi_poll(trace_napi_poll_hit); > > tracepoint_synchronize_unregister(); > > /* > * Clean the device list > */ > list_for_each_entry_safe(new_stat, temp, &hw_stats_list, list) { > if (new_stat->dev == NULL) { > list_del_rcu(&new_stat->list); > call_rcu(&new_stat->rcu, free_dm_hw_stat); > } > } > break; > default: > rc = 1; > break; > } > > if (!rc) > trace_state = state; > > spin_unlock(&trace_state_lock); > > if (rc) > return -EINPROGRESS; > return rc; > } > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/
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