Thanks for your time. Tejun Heo wrote on 2021/7/27 5:27: > On Thu, Jul 22, 2021 at 11:20:17PM +0800, brookxu wrote: >> From: Chunguang Xu <brookxu@xxxxxxxxxxx> >> >> Since the global open files are limited, in order to avoid the >> abnormal behavior of some containers from generating too many >> files, causing other containers to be unavailable, we need to >> limit the open files of some containers. >> >> v2: fix compile error while CONFIG_CGROUP_MISC not set. >> >> Signed-off-by: Chunguang Xu <brookxu@xxxxxxxxxxx> >> Reported-by: kernel test robot <lkp@xxxxxxxxx> > > This is different from pid in that there's no actual limit on how many open > files there can be in the system other than the total amount of available > memory. I don't see why this would need a separate limit outside of memory > control. A couple machines I looked at all have file-max at LONG_MAX by > default too. According to files_maxfiles_init(), we only allow about 10% of free memory to create filps, and each filp occupies about 1K of cache. In this way, on a 16G memory machine, the maximum usable filp is about 1,604,644. In general scenarios, this may not be a big problem, but if the task is abnormal, it will very likely become a bottleneck and affect other modules. > Thanks. >
