| Message ID | 20220421234837.3629927-1-kent.overstreet@gmail.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | Printbufs & shrinker OOM reporting | expand |
Hi Kent, On Fri, 22 Apr 2022 at 07:56, Kent Overstreet <kent.overstreet@gmail.com> wrote: > > Debugging OOMs has been one of my sources of frustration, so this patch series > is an attempt to do something about it. > > The first patch in the series is something I've been slowly evolving in bcachefs > for years: simple heap allocated strings meant for appending to and building up > structured log/error messages. They make it easy and straightforward to write > pretty-printers for everything, which in turn makes good logging and error > messages something that just happens naturally. > > We want it here because that means the reporting I'm adding to shrinkers can be > used by both OOM reporting, and for the sysfs (or is it debugfs now) interface > that Roman is adding. > I added the kexec list in cc. It seems like a nice enhancement to oom reporting. I suspect kdump tooling need changes to retrieve the kmsg log from vmcore, could you confirm it? For example makedumpfile, crash, and kexec-tools (its vmcore-dmesg tool). > This patch series also: > - adds OOM reporting on shrinkers, reporting on top 10 shrinkers (in sorted > order!) > - changes slab reporting to be always-on, also reporting top 10 slabs in sorted > order > - starts centralizing OOM reporting in mm/show_mem.c > > The last patch in the series is only a demonstration of how to implement the > shrinker .to_text() method, since bcachefs isn't upstream yet. > > Kent Overstreet (4): > lib/printbuf: New data structure for heap-allocated strings > mm: Add a .to_text() method for shrinkers > mm: Centralize & improve oom reporting in show_mem.c > bcachefs: shrinker.to_text() methods > > fs/bcachefs/btree_cache.c | 18 ++- > fs/bcachefs/btree_key_cache.c | 18 ++- > include/linux/printbuf.h | 140 ++++++++++++++++++ > include/linux/shrinker.h | 5 + > lib/Makefile | 4 +- > lib/printbuf.c | 271 ++++++++++++++++++++++++++++++++++ > mm/Makefile | 2 +- > mm/oom_kill.c | 23 --- > {lib => mm}/show_mem.c | 14 ++ > mm/slab.h | 6 +- > mm/slab_common.c | 53 ++++++- > mm/vmscan.c | 75 ++++++++++ > 12 files changed, 587 insertions(+), 42 deletions(-) > create mode 100644 include/linux/printbuf.h > create mode 100644 lib/printbuf.c > rename {lib => mm}/show_mem.c (78%) > > -- > 2.35.2 > Thanks Dave
Debugging OOMs has been one of my sources of frustration, so this patch series is an attempt to do something about it. The first patch in the series is something I've been slowly evolving in bcachefs for years: simple heap allocated strings meant for appending to and building up structured log/error messages. They make it easy and straightforward to write pretty-printers for everything, which in turn makes good logging and error messages something that just happens naturally. We want it here because that means the reporting I'm adding to shrinkers can be used by both OOM reporting, and for the sysfs (or is it debugfs now) interface that Roman is adding. This patch series also: - adds OOM reporting on shrinkers, reporting on top 10 shrinkers (in sorted order!) - changes slab reporting to be always-on, also reporting top 10 slabs in sorted order - starts centralizing OOM reporting in mm/show_mem.c The last patch in the series is only a demonstration of how to implement the shrinker .to_text() method, since bcachefs isn't upstream yet. Kent Overstreet (4): lib/printbuf: New data structure for heap-allocated strings mm: Add a .to_text() method for shrinkers mm: Centralize & improve oom reporting in show_mem.c bcachefs: shrinker.to_text() methods fs/bcachefs/btree_cache.c | 18 ++- fs/bcachefs/btree_key_cache.c | 18 ++- include/linux/printbuf.h | 140 ++++++++++++++++++ include/linux/shrinker.h | 5 + lib/Makefile | 4 +- lib/printbuf.c | 271 ++++++++++++++++++++++++++++++++++ mm/Makefile | 2 +- mm/oom_kill.c | 23 --- {lib => mm}/show_mem.c | 14 ++ mm/slab.h | 6 +- mm/slab_common.c | 53 ++++++- mm/vmscan.c | 75 ++++++++++ 12 files changed, 587 insertions(+), 42 deletions(-) create mode 100644 include/linux/printbuf.h create mode 100644 lib/printbuf.c rename {lib => mm}/show_mem.c (78%)