Hello Pekka, On Mon, Apr 30, 2012 at 10:35:02AM +0300, Pekka Enberg wrote: > > vmevent_smaple gathers all registered values to report to user if vmevent match. > > But the time gap between vmevent match check and vmevent_sample_attr could make error > > so user could confuse. > > > > Q 1. Why do we report _all_ registered vmstat value? > > In my opinion, it's okay just to report _a_ value vmevent_match happens. > > It makes the userspace side simpler for "lowmem notification" use > case. I'm open to changing the ABI if it doesn't make the userspace > side too complex. Yep. Actually, I'd like to add something like 'file_pages - shmem' attribute, and reporting both (i.e. this new attr and free_pages) values at the same time (even if just one crossed the threshold). Reporting all the values would help userspace logic (so it won't need to read /proc again). > > Q 4. Do you have any plan for this patchset to merge into mainline? > > Yes, I'm interested in pushing it forward if we can show that the ABI > makes sense, is stable and generic enough, and fixes real world > problems. It seems to be a pretty nice driver. Speaking of ABI, the only thing I personally dislike is VMEVENT_CONFIG_MAX_ATTRS (i.e. fixed-size array in vmevent_config)... but I guess it's pretty easy to make it variable-sized array... was there any particular reason to make the _MAX thing? Thanks! -- Anton Vorontsov Email: cbouatmailru@xxxxxxxxx -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>