On Wed, Jan 21, 2015 at 10:58 PM, David Rientjes <rientjes@xxxxxxxxxx> wrote: > I think the bigger concern would be that this, and any new line such as > resettable_hiwater_rss, invalidates itself entirely. Any process that > checks the hwm will not know of other processes that reset it, so the > value itself has no significance anymore. > It would just be the mark since the last clear at an unknown time. How is that different from the current logic of clear_refs and the corresponding PG_Referenced bit? > Userspace can monitor the rss of a > process by reading /proc/pid/stat, there's no need for the kernel to do > something that userspace can do. I disagree here. The driving motivation of this patch is precisely the opposite. There are peak events that last for very short time (order: 10-100 ms) and are practically invisible from user-space (even doing something awkward like polling in a tight loop). Concrete examples are: GPU memory transfers, image decoding, compression / decompression. These kinds of tasks, which use scratch buffers for few ms, can create significant (yet short lasting) memory pressure which is desirable to monitor. -- 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>