Starting with 3.7 rc1, my workstation seems to loose ram. Up until (and including) 3.6, used-(buffers+cached) was roughly the same as sum(rss) (taking shared into account). Now there is an approx 6G gap.
When the box first starts, it is clearly less swappy than with <= 3.6; I can't tell whether that is related. The reduced swappiness persists. It seems to get worse when I update packages (it runs Gentoo). The portage tree and overlays are on btrfs filesystems. As is /var/log (with compression, except for the distfiles fs). The compilations themselves are done in a tmpfs. I CCed l-b because of that apparent correlation. My postgress db is on xfs (tested faster) and has a 3G shared segment, but that recovers when the pg process is stopped; neither of those seem to be implicated. There are also several ext4 partitions, including / and /home. Cgroups are configured, and openrc does put everything it starts into its own directory under /sys/fs/cgroup/openrc. But top(1) shows all of the processes, and its idea of free mem does change with pg's use of its shared segment. So it doesn't *look* like the ram is hiding in some cgroup. The kernel does not log anything relevant to this. Slabinfo gives some odd output. It seems to think there are negative quantities of some slabs: Name Objects Objsize Space Slabs/Part/Cpu O/S O %Fr %Ef Flg :at-0000016 5632 16 90.1K 18446744073709551363/0/275 256 0 0 100 *a :t-0000048 3386 48 249.8K 18446744073709551558/22/119 85 0 36 65 * :t-0000120 1022 120 167.9K 18446744073709551604/14/53 34 0 34 73 * blkdev_requests 182 376 122.8K 18446744073709551604/7/27 21 1 46 55 ext4_io_end 348 1128 393.2K 18446744073709551588/0/40 29 3 0 99 a The largest entries it reports are: Name Objects Objsize Space Slabs/Part/Cpu O/S O %Fr %Ef Flg ext4_inode_cache 38448 864 106.1M 3201/566/39 37 3 17 31 a :at-0000104 316429 104 36.5M 8840/3257/92 39 0 36 89 *a btrfs_inode 13271 984 35.7M 1078/0/14 33 3 0 36 a radix_tree_node 43785 560 34.7M 2075/1800/45 28 2 84 70 a dentry 64281 192 14.3M 3439/1185/55 21 0 33 86 a proc_inode_cache 15695 608 12.1M 693/166/51 26 2 22 78 a inode_cache 10730 544 6.0M 349/0/21 29 2 0 96 a task_struct 628 5896 4.3M 123/23/10 5 3 17 84 The total Space is much smaller than the missing ram. The only other difference I see is that one process has left behind several score zombies. It is structured as a parent with several worker kids, but the kids stay zombie even when the parent process is stopped and restarted. wchan shows that they are stuck in exit. Their normal rss isn't enough to account for the missing ram, even if it isn't reclaimed. (Not to mention, ram != brains. :) I haven't tried bisecting because of the time it takes to confirm the problem (several hours of uptime). I've only compiled (each of) the rc tags, so v3.6 is that last known good and v3.7-rc1 is the first known bad. If there is anything that I missed, please let me know! -JimC -- James Cloos <cl...@jhcloos.com> OpenPGP: 1024D/ED7DAEA6 -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
