On Wed, Jan 14, 2015 at 03:22:25PM +0000, Petr Cermak wrote: > On Wed, Jan 07, 2015 at 07:24:52PM +0200, Kirill A. Shutemov wrote: > > And how it's not an ABI break? > I don't think this is an ABI break because the current behaviour is not > changed unless you write "5" to /proc/pid/clear_refs. If you do, you are > explicitly requesting the new functionality. > > > We have never-lowering VmHWM for 9+ years. How can you know that nobody > > expects this behaviour? > This is why we sent an RFC [1] several weeks ago. We expect this to be > used mainly by performance-related tools (e.g. profilers) and from the > comments in the code [2] VmHWM seems to be a best-effort counter. If this > is strictly a no-go, I can only think of the following two alternatives: > > 1. Add an extra resettable field to /proc/pid/status (e.g. > resettable_hiwater_rss). While this doesn't violate the current > definition of VmHWM, it adds an extra line to /proc/pid/status, > which I think is a much bigger issue. > 2. Introduce a new proc fs file to task_mmu (e.g. > /proc/pid/profiler_stats), but this feels like overengineering. BTW, we have memory.max_usage_in_byte in memory cgroup. And it's resetable. Wouldn't it be enough for your profiling use-case? -- Kirill A. Shutemov -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>