> [Summery] > > In order to evaluate page cache efficiency, system admins are happy to > know whether a block of data is cached for subsequent use, or whether > the page is read-in but seldom used. This patch extends an effort to > provide such kind of information. We adds three counters, which are > exported to the user space, for the Page Cache that is almost > transparent to the applications. This would benifit some heavy page > cache users that might try to tune the performance in hybrid storage > situation. I think you need to explain exact and concrete use-case. Typically, cache-hit ratio doesn't help administrator at all. because merely backup operation (eg. cp, dd, et al) makes prenty cache-miss. But it is no sign of memory shortage. Usually, vmscan stastics may help memroy utilization obzavation. Plus, as ingo said, you have to consider to use trancepoint framework at first. Because, it is zero cost if an admin don't enable such tracepoint. At last, I don't think disk_stats have to have page cache stastics. It seems slightly layer violation. Thanks. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx 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>