From 189a6883dcf7fa70e17403ae4225c60ffc9e404b Mon Sep 17 00:00:00 2001 From: "Joel Fernandes (Google)" Date: Fri, 30 Aug 2019 12:36:33 -0400 Subject: [PATCH] rcu: Remove kfree_call_rcu_nobatch() Now that the kfree_rcu() special-casing has been removed from tree RCU, this commit removes kfree_call_rcu_nobatch() since it is no longer needed. Signed-off-by: Joel Fernandes (Google) Signed-off-by: Paul E. McKenney --- .../admin-guide/kernel-parameters.txt | 4 ---- include/linux/rcutiny.h | 5 ----- include/linux/rcutree.h | 1 - kernel/rcu/rcuperf.c | 10 +--------- kernel/rcu/tree.c | 18 ++++-------------- 5 files changed, 5 insertions(+), 33 deletions(-) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 3ce270b56f3a..ed83d6d90cc3 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -3991,10 +3991,6 @@ Number of loops doing rcuperf.kfree_alloc_num number of allocations and frees. - rcuperf.kfree_no_batch= [KNL] - Use the non-batching (less efficient) version of kfree_rcu(). - This is useful for comparing with the batched version. - rcuperf.nreaders= [KNL] Set number of RCU readers. The value -1 selects N, where N is the number of CPUs. A value diff --git a/include/linux/rcutiny.h b/include/linux/rcutiny.h index 1bd166aab6f3..b2b2dc990da9 100644 --- a/include/linux/rcutiny.h +++ b/include/linux/rcutiny.h @@ -39,11 +39,6 @@ static inline void kfree_call_rcu(struct rcu_head *head, rcu_callback_t func) call_rcu(head, func); } -static inline void kfree_call_rcu_nobatch(struct rcu_head *head, rcu_callback_t func) -{ - call_rcu(head, func); -} - void rcu_qs(void); static inline void rcu_softirq_qs(void) diff --git a/include/linux/rcutree.h b/include/linux/rcutree.h index 6a65d3a16dbd..2f787b9029d1 100644 --- a/include/linux/rcutree.h +++ b/include/linux/rcutree.h @@ -34,7 +34,6 @@ static inline void rcu_virt_note_context_switch(int cpu) void synchronize_rcu_expedited(void); void kfree_call_rcu(struct rcu_head *head, rcu_callback_t func); -void kfree_call_rcu_nobatch(struct rcu_head *head, rcu_callback_t func); void rcu_barrier(void); bool rcu_eqs_special_set(int cpu); diff --git a/kernel/rcu/rcuperf.c b/kernel/rcu/rcuperf.c index c1e25fd10f2a..da94b89cd531 100644 --- a/kernel/rcu/rcuperf.c +++ b/kernel/rcu/rcuperf.c @@ -593,7 +593,6 @@ rcu_perf_shutdown(void *arg) torture_param(int, kfree_nthreads, -1, "Number of threads running loops of kfree_rcu()."); torture_param(int, kfree_alloc_num, 8000, "Number of allocations and frees done in an iteration."); torture_param(int, kfree_loops, 10, "Number of loops doing kfree_alloc_num allocations and frees."); -torture_param(int, kfree_no_batch, 0, "Use the non-batching (slower) version of kfree_rcu()."); static struct task_struct **kfree_reader_tasks; static int kfree_nrealthreads; @@ -632,14 +631,7 @@ kfree_perf_thread(void *arg) if (!alloc_ptr) return -ENOMEM; - if (!kfree_no_batch) { - kfree_rcu(alloc_ptr, rh); - } else { - rcu_callback_t cb; - - cb = (rcu_callback_t)(unsigned long)offsetof(struct kfree_obj, rh); - kfree_call_rcu_nobatch(&(alloc_ptr->rh), cb); - } + kfree_rcu(alloc_ptr, rh); } cond_resched(); diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index a8dd612098bf..31d2d9255d95 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -2763,8 +2763,10 @@ static void kfree_rcu_work(struct work_struct *work) rcu_lock_acquire(&rcu_callback_map); trace_rcu_invoke_kfree_callback(rcu_state.name, head, offset); - /* Could be possible to optimize with kfree_bulk in future */ - kfree((void *)head - offset); + if (!WARN_ON_ONCE(!__is_kfree_rcu_offset(offset))) { + /* Could be optimized with kfree_bulk() in future. */ + kfree((void *)head - offset); + } rcu_lock_release(&rcu_callback_map); cond_resched_tasks_rcu_qs(); @@ -2835,16 +2837,6 @@ static void kfree_rcu_monitor(struct work_struct *work) spin_unlock_irqrestore(&krcp->lock, flags); } -/* - * This version of kfree_call_rcu does not do batching of kfree_rcu() requests. - * Used only by rcuperf torture test for comparison with kfree_rcu_batch(). - */ -void kfree_call_rcu_nobatch(struct rcu_head *head, rcu_callback_t func) -{ - __call_rcu(head, func); -} -EXPORT_SYMBOL_GPL(kfree_call_rcu_nobatch); - /* * Queue a request for lazy invocation of kfree() after a grace period. * @@ -2864,8 +2856,6 @@ void kfree_call_rcu(struct rcu_head *head, rcu_callback_t func) unsigned long flags; struct kfree_rcu_cpu *krcp; - head->func = func; - local_irq_save(flags); // For safely calling this_cpu_ptr(). krcp = this_cpu_ptr(&krc); if (krcp->initialized) -- 2.45.2