After using the CONFING_SQUASHFS_DECOMP_SINGLE=y option in an experimental kernel the memory usage dropped significantly. The traces below are for -45 and the experimental -46 kernel. The 1 and 4 are the number of CPUs on the system.
A single CPU system used to consumer 131MB per mounted snap, this is now reduced to just 4MB/snap. A four-CPU system has less dramatic improvement where the numbers are 7MB -> 4MB. This suggests some kind of bug in the CONFIG_SQUASHFS_DECOMP_MULTI_PERCPU option perhaps + echo Ubuntu 16.04 Ubuntu 16.04 + ./analyze.py ubuntu 16.04 4.4.0-45-generic 1 size-1m.squashfs.xz.heavy # num-mounted extra-memory delta 0: 142.60MB 1: 274.71MB (delta: 132.11MB) 2: 406.55MB (delta: 131.84MB) 3: 538.36MB (delta: 131.81MB) 4: 670.19MB (delta: 131.82MB) + ./analyze.py ubuntu 16.04 4.4.0-46-generic 1 size-1m.squashfs.xz.heavy # num-mounted extra-memory delta 0: 62.28MB 1: 66.99MB (delta: 4.71MB) 2: 71.05MB (delta: 4.07MB) 3: 75.12MB (delta: 4.06MB) 4: 79.19MB (delta: 4.07MB) + ./analyze.py ubuntu 16.04 4.4.0-45-generic 4 size-1m.squashfs.xz.heavy # num-mounted extra-memory delta 0: 235.43MB 1: 242.38MB (delta: 6.96MB) 2: 249.38MB (delta: 7.00MB) 3: 256.45MB (delta: 7.06MB) 4: 263.42MB (delta: 6.97MB) + ./analyze.py ubuntu 16.04 4.4.0-46-generic 4 size-1m.squashfs.xz.heavy # num-mounted extra-memory delta 0: 72.79MB 1: 75.90MB (delta: 3.11MB) 2: 79.96MB (delta: 4.06MB) 3: 83.93MB (delta: 3.97MB) 4: 88.00MB (delta: 4.07MB) -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1636847 Title: unexpectedly large memory usage of mounted snaps To manage notifications about this bug go to: https://bugs.launchpad.net/snappy/+bug/1636847/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
