[PATCH 00/18] kfree_rcu() improvements for -rcu dev

[Joel Fernandes (Google)]

Hello,
These patches improve kfree_rcu() to support:
- kfree_rcu() headless usage.
- both vmalloc() and slab free'ing support using array of pointers.
- simpler debugobjects handling.

It applies on rcu/dev branch as of March 29th.

Testing with rcuperf shows following changes. The memory footprint reduces and
batches go slightly up. This is assumed an acceptable change.

with all patches:
Total time taken by all kfree'ers: 27312964461 ns, loops: 20000, batches: 3120, memory footprint: 211MB
Total time taken by all kfree'ers: 26773272309 ns, loops: 20000, batches: 3084, memory footprint: 208M

without:
Total time taken by all kfree'ers: 25711621811 ns, loops: 20000, batches: 2814, memory footprint: 230MB Â Â Â Â Â
ÂTotal time taken by all kfree'ers: 25775800546 ns, loops: 20000, batches: 2755, memory footprint: 230MB

These have been pushed to the git tree at:
git://git.kernel.org/pub/scm/linux/kernel/git/jfern/linux.git (branch rcu/kfree)

cgit view:
https://git.kernel.org/pub/scm/linux/kernel/git/jfern/linux.git/log/?h=rcu/kfree

thanks,

 - Joel

Joel Fernandes (Google) (5):
rcu/tree: Simplify debug_objects handling
rcu/tree: Clarify emergency path comment better
rcu/tree: Remove extra next variable in kfree worker function
rcu/tree: Simplify is_vmalloc_addr expression
rcu/tree: Make kvfree_rcu() tolerate any alignment

Uladzislau Rezki (Sony) (13):
mm/list_lru.c: Rename kvfree_rcu() to local variant
rcu: Introduce kvfree_rcu() interface
rcu: Rename rcu_invoke_kfree_callback/rcu_kfree_callback
rcu: Rename __is_kfree_rcu_offset() macro
rcu: Rename kfree_call_rcu() to the kvfree_call_rcu().
mm/list_lru.c: Remove kvfree_rcu_local() function
rcu/tree: Simplify KFREE_BULK_MAX_ENTR macro
rcu/tree: Maintain separate array for vmalloc ptrs
rcu/tree: Introduce expedited_drain flag
rcu/tree: Support reclaim for head-less object
rcu/tiny: Move kvfree_call_rcu() out of header
rcu/tiny: Support reclaim for head-less object
rcu: Support headless variant in the kvfree_rcu()

include/linux/rcupdate.h   |  53 ++++++-
include/linux/rcutiny.h    |   6 +-
include/linux/rcutree.h    |   2 +-
include/trace/events/rcu.h |   8 +-
kernel/rcu/tiny.c          | 168 +++++++++++++++++++-
kernel/rcu/tree.c          | 315 ++++++++++++++++++++++++++-----------
mm/list_lru.c              |  11 +-
7 files changed, 443 insertions(+), 120 deletions(-)

--
2.26.0.rc2.310.g2932bb562d-goog