On Mon 18-09-17 11:22:37, kemi wrote: > > > On 2017年09月15日 19:49, Michal Hocko wrote: > > On Fri 15-09-17 17:23:24, Kemi Wang wrote: > >> This patch adds a tunable interface that allows VM stats configurable, as > >> suggested by Dave Hansen and Ying Huang. > >> > >> When performance becomes a bottleneck and you can tolerate some possible > >> tool breakage and some decreased counter precision (e.g. numa counter), you > >> can do: > >> echo [C|c]oarse > /proc/sys/vm/vmstat_mode > >> > >> When performance is not a bottleneck and you want all tooling to work, you > >> can do: > >> echo [S|s]trict > /proc/sys/vm/vmstat_mode > >> > >> We recommend automatic detection of virtual memory statistics by system, > >> this is also system default configuration, you can do: > >> echo [A|a]uto > /proc/sys/vm/vmstat_mode > >> > >> The next patch handles numa statistics distinctively based-on different VM > >> stats mode. > > > > I would just merge this with the second patch so that it is clear how > > those modes are implemented. I am also wondering why cannot we have a > > much simpler interface and implementation to enable/disable numa stats > > (btw. sysctl_vm_numa_stats would be more descriptive IMHO). > > > > Apologize for resending it, because I found my previous reply mixed with > Michal's in many email client. > > The motivation is that we propose a general tunable interface for VM stats. > This would be more scalable, since we don't have to add an individual > Interface for each type of counter that can be configurable. Can you envision which other counters would fall into the same category? > In the second patch, NUMA stats, as an example, can benefit for that. > If you still hold your idea, I don't mind to merge them together. Well, I would prefer simplicy in the first place. -- Michal Hocko SUSE Labs
