>> Because your test program is too artificial. 20sec/100000times = >> 200usec. And your >> program repeat mlock and munlock the exact same address. so, yes, if >> lru_add_drain_all() is removed, it become near no-op. but it's >> worthless comparision. >> none of any practical program does such strange mlock usage. > yes, I should say it is artificial. But mlock did cause the problem in > our product system and perf shows that the mlock uses the system time > much more than others. That's the reason we created this program to test > whether mlock really sucks. And we compared the result with > rhel5(2.6.18) which runs much much faster. > > And from the commit log you described, we can remove lru_add_drain_all > safely here, so why add it? At least removing it makes mlock much faster > compared to the vanilla kernel. If we remove it, we lose to a test way of mlock. "Memlocked" field of /proc/meminfo show inaccurate number very easily. So, if 200usec is no avoidable, I'll ack you. But I'm not convinced yet. -- 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>