On Mon, Jan 23, 2023 at 11:01 PM +02, Yaniv Agman wrote: > בתאריך יום ב׳, 23 בינו׳ 2023 ב-22:06 מאת Martin KaFai Lau > <martin.lau@xxxxxxxxx>: >> >> On 1/23/23 9:32 AM, Yaniv Agman wrote: >> >>> interrupted the first one. But even then, I will need to find a way to >> >>> know if my program currently interrupts the run of another program - >> >>> is there a way to do that? >> May be a percpu atomic counter to see if the bpf prog has been re-entered on the >> same cpu. > > Not sure I understand how this will help. If I want to save local > program data on a percpu map and I see that the counter is bigger then > zero, should I ignore the event? map_update w/ BPF_F_LOCK disables preemption, if you're after updating an entry atomically. But it can't be used with PERCPU maps today. Perhaps that's needed now too.
