On 02/23, Heinrich Schuchardt wrote: > > On 23.02.2015 21:54, Oleg Nesterov wrote: > > > >> And it changes the swapper/0's rlimits. This is pointless after we fork > >> /sbin/init. > > So should writing to /proc/sys/max_threads update the limits of all > processes?
Why? No, I think it should not touch rlimits at all. > >> It seems to me these patches need some cleanups. Plus I am not sure the > >> kernel should update max_threads automatically, we have the "threads-max" > >> sysctl. > > The idea in the original version of fork_init is that max_threads should > be chosen such that the memory needed to store the meta-information of > max_threads threads should only be 1/8th of the total memory. > > Somebody adding or removing memory will not necessarily update > /proc/sys/kernel/threads-max. > > This means that if I remove 90 % of the memory I get to a situation > where max_threads allows so many threads to be created that the > meta-information occupies all memory. > > With patch 4/4 max_threads is automatically reduced in this case. I understand. But I think that if you remove 90 % of the memory you can also update /proc/sys/kernel/threads-max. And, suppose that admin specially limited max_threads, then you add more memory. Should the kernel bump the limit silently? And if hotplug should update max_threads, why it doesn't update, say, files_stat.max_files? IOW, I do not think that kernel should control max_threads after boot. But I won't really argue. Just this looks a bit strange to me. Oleg. -- 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/
