בתאריך יום ב׳, 23 בינו׳ 2023 ב-23:25 מאת Jakub Sitnicki <jakub@xxxxxxxxxxxxxx>: > > 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. Yep. I think what is needed here is the ability to disable preemption from the bpf program - maybe even adding a helper for that?
