On Wed, Aug 28, 2024 at 11:51:34AM GMT, Dave Chinner wrote: > On Sat, Aug 24, 2024 at 03:10:07PM -0400, Kent Overstreet wrote: > > recently new OOMs have been cropping up, and reclaim is implicated, so > > I've had to dust off these patches. > > > > nothing significant has changed since the last time I posted, and they > > have been valuable - Dave, think we can get them in? > > You need to describe what this does. What does the output look like? > Where does it go (console, dmesg, etc). When is it called, etc. > Links to previous review threads so people can get back up to speed > on what was discussed last time and determine whether issues raised > were solved. A changelog since the last posting is helpful, too... Not much has changed since last posting, besides tweaking/improving counters... objects, requested to free, objects freed: so we can tell if a shrinker isn't freeing as requested last scanned and last freed are new - so we can tell if a shrinker's gotten stuck (perhaps it requires a lock that it isn't able to get) bcachefs shrinkers additionally have counters for every distinct reason an object wasn't freed - this has been quite useful in the past: BTW - the next thing I want to get done is adding an interface for shrinkers to report the amount of memory they own in bytes. This will greatly aid the show_mem report, so it can skip reporting on shrinkers entirely if they don't control much memory or pick a number to show more intelligently. It'll also let us finally fix the free command. root@moria-kvm:/sys/kernel/debug/shrinker$ cat 05baba83-05ef-4d71-be0e-121bdabfee36-btree_key_cache-43/report 05baba83-05ef-4d71-be0e-121bdabfee36-btree_key_cache objects: 122411 requested to free: 63 objects freed: 0 last scanned: 198 sec ago last freed: 42949578 sec ago ns per object freed: 0 keys: 129119 dirty: 6580 table size: 262144 shrinker: requested_to_free: 0 freed: 0 skipped_dirty: 21 skipped_accessed: 42 skipped_lock_fail: 0 pending: 114727 root@moria-kvm:/sys/kernel/debug/shrinker# cat sb-bcachefs-44/report sb-bcachefs objects: 1 requested to free: 0 objects freed: 0 last scanned: 42949693 sec ago last freed: 42949693 sec ago ns per object freed: 0 inodes: total 2 shrinkable 0 dentries: toal 2 shrinkbale 1
