>>> Hi, Glauber Hi. > > In memcg_update_kmem_limit() we do the whole process of limit > initialization under a mutex so the situation we need protection from in > tcp_update_limit() is impossible. BTW once set, the 'activated' flag is > never cleared and never checked alone, only along with the 'active' > flag, that's why I doubt we need it at all. The updates are protected by a mutex, but the readers are not, and should not. So we can still be patching the readers, and the double-flag was initially used so we can make sure that both flags are only set after the static branches are in. Note that one of the flags is set inside memcg_update_cache_sizes(). After that, we call static_key_slow_inc(). At this point, someone whose code is patched in could start accounting, but it shouldn't - because not all sites are patched in. So after the update is done, we set the other flag, and now everybody will start going through. Could you do something clever with just one flag? Probably yes. But I doubt it would be that much cleaner, this is just the way that patching sites work. -- E Mare, Libertas -- To unsubscribe from this list: send the line "unsubscribe cgroups" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
