On Wed, May 25, 2022 at 01:25:57PM -0700, Roman Gushchin wrote: > Currently shrinkers are anonymous objects. For debugging purposes they > can be identified by count/scan function names, but it's not always > useful: e.g. for superblock's shrinkers it's nice to have at least > an idea of to which superblock the shrinker belongs. > > This commit adds names to shrinkers. register_shrinker() and > prealloc_shrinker() functions are extended to take a format and > arguments to master a name. > > In some cases it's not possible to determine a good name at the time > when a shrinker is allocated. For such cases shrinker_debugfs_rename() > is provided. > > After this change the shrinker debugfs directory looks like: > $ cd /sys/kernel/debug/shrinker/ > $ ls > dqcache-16 sb-hugetlbfs-17 sb-rootfs-2 sb-tmpfs-49 > kfree_rcu-0 sb-hugetlbfs-33 sb-securityfs-6 sb-tracefs-13 > sb-aio-20 sb-iomem-12 sb-selinuxfs-22 sb-xfs:vda1-36 > sb-anon_inodefs-15 sb-mqueue-21 sb-sockfs-8 sb-zsmalloc-19 > sb-bdev-3 sb-nsfs-4 sb-sysfs-26 shadow-18 > sb-bpf-32 sb-pipefs-14 sb-tmpfs-1 thp_deferred_split-10 > sb-btrfs:vda2-24 sb-proc-25 sb-tmpfs-27 thp_zero-9 > sb-cgroup2-30 sb-proc-39 sb-tmpfs-29 xfs_buf-vda1-37 > sb-configfs-23 sb-proc-41 sb-tmpfs-35 xfs_inodegc-vda1-38 sb-xfs:vda1-36 xfs_buf-vda1-37 xfs_inodegc-vda1-38 That's a parsing nightmare right there. Please use the same format for everything. You have <subsystem>-<type>:<instance>-<id> for superblock stuff, but <subsys>_<type>-<instance>-<id> for the XFS stuff. Make it consistent so we aren't reduced to pulling out our hair trying to parse this in any useful way: sb-xfs:vda1-36 xfs-buf:vda1-37 xfs-inodegc:vda1-38 FWIW, how we are supposed to know what actually owns these: sb-tmpfs-1 sb-tmpfs-27 sb-tmpfs-29 sb-tmpfs-35 sb-tmpfs-49 tmpfs-27 might own all the memory - how do we link that back to a mount point, container, user, workload, etc? Cheers, Dave. -- Dave Chinner dchinner@xxxxxxxxxx
