On Mon 15-07-24 16:36:26, David Finkel wrote: > Other mechanisms for querying the peak memory usage of either a process > or v1 memory cgroup allow for resetting the high watermark. Restore > parity with those mechanisms. > > For example: > - Any write to memory.max_usage_in_bytes in a cgroup v1 mount resets > the high watermark. > - writing "5" to the clear_refs pseudo-file in a processes's proc > directory resets the peak RSS. > > This change copies the cgroup v1 behavior so any write to the > memory.peak and memory.swap.peak pseudo-files reset the high watermark > to the current usage. > > This behavior is particularly useful for work scheduling systems that > need to track memory usage of worker processes/cgroups per-work-item. > Since memory can't be squeezed like CPU can (the OOM-killer has > opinions), these systems need to track the peak memory usage to compute > system/container fullness when binpacking workitems. > > Signed-off-by: David Finkel <davidf@xxxxxxxxx> As mentioned down the email thread, I consider usefulness of peak value rather limited. It is misleading when memory is reclaimed. But fundamentally I do not oppose to unifying the write behavior to reset values. The chnagelog could use some of the clarifications down the thread. Acked-by: Michal Hocko <mhocko@xxxxxxxx> -- Michal Hocko SUSE Labs
