kernel_optimize_test/include
Uladzislau Rezki (Sony) 3042f83f19 rcu: Support reclaim for head-less object
Update the kvfree_call_rcu() function with head-less support.
This allows RCU to reclaim objects without an embedded rcu_head.

tree-RCU:
We introduce two chains of arrays to store SLAB-backed and vmalloc
pointers, each.  Storage in either of these arrays does not require
embedding an rcu_head within the object.

Maintaining the arrays may become impossible due to high memory
pressure. For such cases there is an emergency path. Objects with
rcu_head inside are just queued on a backup rcu_head list. Later on
that list is drained. As for the head-less variant, as the current
context can sleep, the following emergency measures are applied:
   a) Synchronously wait until a grace period has elapsed.
   b) Call kvfree().

tiny-RCU:
For double argument calls, there are no new changes in behavior. For
single argument call, kvfree() is directly inlined on the current
stack after a synchronize_rcu() call. Note that for tiny-RCU, any
call to synchronize_rcu() is actually a quiescent state, therefore
it does nothing.

Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Co-developed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-06-29 11:59:26 -07:00
..
acpi
asm-generic
clocksource
crypto
drm
dt-bindings
keys
kunit
kvm
linux rcu: Support reclaim for head-less object 2020-06-29 11:59:26 -07:00
math-emu
media
misc
net
pcmcia
ras
rdma
scsi
soc
sound
target
trace rcu: Rename *_kfree_callback/*_kfree_rcu_offset/kfree_call_* 2020-06-29 11:59:25 -07:00
uapi VFIO fixes for v5.8-rc3 2020-06-27 15:17:21 -07:00
vdso
video
xen