On 22.06.2020 13:21, Jiri Olsa wrote: > On Mon, Jun 22, 2020 at 12:47:19PM +0300, Alexey Budankov wrote: > > SNIP > >>>>>>>> fdarray__del(array, fdkey); >>>>>>> >>>>>>> I think there's solution without having filterable type, >>>>>>> I'm not sure why you think this is needed >>>>>>> >>>>>>> I'm busy with other things this week, but I think I can >>>>>>> come up with some patch early next week if needed >>>>>> >>>>>> Friendly reminder. >>>>> >>>>> hm? I believe we discussed this in here: >>>>> https://lore.kernel.org/lkml/20200609145611.GI1558310@krava/ >>>> >>>> Do you want it to be implemented like in the patch posted by the link? >>> >>> no idea.. looking for good solution ;-) >>> >>> how about switching completely to epoll? I tried and it >>> does not look that bad >> >> Well, epoll() is perhaps possible but why does it want switching to epoll()? >> What are the benefits and/or specific task being solved by this switch? > > epoll change fixes the same issues as the patch you took in v8 > > on top of it it's not a hack and wil make polling more user > friendly because of the clear interface
Clear. The opposite thing is /proc/sys/fs/epoll/max_user_watches limit that will affect Perf tool usage additionally to the current process limit on a number of simultaneously open file descriptors (ulimit -n). So move to epoll() will impose one limit what can affect Perf tool scalability. > >> >>> >>> there might be some loose ends (interface change), but >>> I think this would solve our problems with fdarray >> >> Your first patch accomodated in v8 actually avoids fds typing >> and solves pos (=fdarray__add()) staleness issue with fdarray. > > yea, it was a change meant for discussion (which never happened), > and I considered it to be more a hack than a solution > > I suppose we can live with that for a while, but I'd like to > have clean solution for polling as well I wouldn't treat it as a hack but more as a fix because returned pos is now a part of interface that can be safely used in callers. Can we go with this fix for the patch set? Thanks, Alexey
