@SaveTheRbtz I did get to the cause, and added a lot of notes about it in the comments for this bug. I even wrote some code to provide a more balanced compromise between memory usage and performance, but once the memory issues were alleviated it seems no one cared about it enough to even try out the test kernels.
I don't know if things have improved upstream with the ram usage of CONFIG_SQUASHFS_DECOMP_MULTI_PERCPU. It's probably worth a look. On most systems with a small number of possible cpus and a small number of squashfs mounts it no doubt works fine, but the introduction of snaps caused a big increase in the number of squashfs mounts in Ubuntu systems, which makes CONFIG_SQUASHFS_DECOMP_MULTI_PERCPU problematic if it still has the same behavior. -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1636847 Title: unexpectedly large memory usage of mounted snaps Status in Snappy: Fix Released Status in linux package in Ubuntu: Fix Released Status in linux source package in Xenial: Fix Released Status in linux source package in Yakkety: Fix Released Status in linux source package in Zesty: Fix Released Bug description: This is a tracking bug for what might be kernel bugs or kernel configuration changes. As described [1], memory used by simply mounting a squashfs file (even an empty one) is ranging from almost nothing (on certain distributions) to 131MB on Ubuntu 16.04 and 16.10 on a single-core machine or VM. The amount is excessive and should be investigated by the kernel team. We may need to change the kernel or at least the configuration we ship in our packages and kernel snaps. [1] https://github.com/zyga/mounted-fs-memory-checker To manage notifications about this bug go to: https://bugs.launchpad.net/snappy/+bug/1636847/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
