On Wed, Oct 21, 2015 at 07:49:34PM +0800, Wangnan (F) wrote: > If our task is sampling cycle events during a function is running, > and if two cores start that function overlap: > > Time: ...................A > Core 0: sys_write----\ > \ > \ > Core 1: sys_write%return > Core 2: ................sys_write > > Then without counter at time A it is highly possible that > BPF program on core 1 and core 2 get conflict with each other. > The final result is we make some of those events be turned on > and others turned off. Using atomic counter can avoid this > problem.
But but, how and why can an eBPF program access a !local event? I thought we had hard restrictions on that. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
