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McKenney wrote: > Hello! > > This v4 patch series re-implements RCU Tasks Trace in terms of SRCU-fast, > reducing the size of the Linux-kernel RCU implementation by several > hundred lines of code. The patches are as follows: > > 1. Re-implement RCU Tasks Trace in terms of SRCU-fast. > > 2. context_tracking: Remove > rcu_task_trace_heavyweight_{enter,exit}(). > > 3. Clean up after the SRCU-fastification of RCU Tasks Trace. > > 4. Move rcu_tasks_trace_srcu_struct out of #ifdef > CONFIG_TASKS_RCU_GENERIC. > > 5. Add noinstr-fast rcu_read_{,un}lock_tasks_trace() APIs. > > 6. Update Requirements.rst for RCU Tasks Trace. > > 7. Deprecate rcu_read_{,un}lock_trace(). > > 8. Create an rcu_tasks_trace_expedite_current() function. > > 9. Test rcu_tasks_trace_expedite_current(). > > Changes since v3: > > o Rebase onto v6.19-rc1. > > o Wait for arm64 per-CPU variable speedups to reach mainline. > > https://lore.kernel.org/all/a1e505e4-931b-45cf-8ca7-337442aa598e@paulmck-laptop/#r > > Changes since v2: > > o SRCU improvments not strictly related to RCU tasks trace have > been moved out to a separate series. > > o Use the new DEFINE_SRCU_FAST(). > > https://lore.kernel.org/all/7fa58961-2dce-4e08-8174-1d1cc592210f@paulmck-laptop/ > > Changes since v1: > > o Consolidate RCU Tasks Trace cleanup patches per Alexei Starovoitov > feedback. This explains the decrease from 34 patches in v1 to > only 21 in this v2 series. > > o While consolidating, consolidate the noinstr-fast patches and the > DEFINE_SRCU_FAST()/init_srcu_struct_fast() patches. > > o Upgrade comments per Peter Zijlstra feedback. > > o Extract Tiny SRCU bug fix into its own commit per Andrii Nakryiko > feedback. > > o Switch srcu_expedite_current() from preempt_disable() to > migrate_disable() for PREEMPT_RT kernels per Zqiang feedback. > > o Apply tags. > > https://lore.kernel.org/all/580ea2de-799a-4ddc-bde9-c16f3fb1e6e7@paulmck-laptop/ > > Thanx, Paul > > ------------------------------------------------------------------------ > > b/Documentation/RCU/Design/Requirements/Requirements.rst | 12 > b/Documentation/admin-guide/kernel-parameters.txt | 15 > b/include/linux/rcupdate.h | 31 > b/include/linux/rcupdate_trace.h | 107 +- > b/include/linux/sched.h | 1 > b/init/init_task.c | 3 > b/kernel/context_tracking.c | 20 > b/kernel/fork.c | 3 > b/kernel/rcu/Kconfig | 18 > b/kernel/rcu/rcu.h | 9 > b/kernel/rcu/rcuscale.c | 7 > b/kernel/rcu/rcutorture.c | 2 > b/kernel/rcu/tasks.h | 621 --------------- > b/scripts/checkpatch.pl | 4 > b/tools/testing/selftests/rcutorture/configs/rcu/TRACE01 | 1 > b/tools/testing/selftests/rcutorture/configs/rcu/TRACE02 | 1 > include/linux/rcupdate_trace.h | 81 + > include/linux/sched.h | 5 > kernel/rcu/Kconfig | 25 > kernel/rcu/rcutorture.c | 1 > kernel/rcu/tasks.h | 121 -- > 21 files changed, 219 insertions(+), 869 deletions(-) Reviewed-by: Joel Fernandes thanks