Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx> --- kernel/events/core.c | 30 ++++++++++-------------------- 1 file changed, 10 insertions(+), 20 deletions(-) --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -5971,10 +5971,10 @@ static void perf_event_init_userpage(str struct perf_event_mmap_page *userpg; struct perf_buffer *rb; - rcu_read_lock(); + guard(rcu)(); rb = rcu_dereference(event->rb); if (!rb) - goto unlock; + return; userpg = rb->user_page; @@ -5983,9 +5983,6 @@ static void perf_event_init_userpage(str userpg->size = offsetof(struct perf_event_mmap_page, __reserved); userpg->data_offset = PAGE_SIZE; userpg->data_size = perf_data_size(rb); - -unlock: - rcu_read_unlock(); } void __weak arch_perf_update_userpage( @@ -6004,10 +6001,10 @@ void perf_event_update_userpage(struct p struct perf_buffer *rb; u64 enabled, running, now; - rcu_read_lock(); + guard(rcu)(); rb = rcu_dereference(event->rb); if (!rb) - goto unlock; + return; /* * compute total_time_enabled, total_time_running @@ -6025,7 +6022,7 @@ void perf_event_update_userpage(struct p * Disable preemption to guarantee consistent time stamps are stored to * the user page. */ - preempt_disable(); + guard(preempt)(); ++userpg->lock; barrier(); userpg->index = perf_event_index(event); @@ -6043,9 +6040,6 @@ void perf_event_update_userpage(struct p barrier(); ++userpg->lock; - preempt_enable(); -unlock: - rcu_read_unlock(); } EXPORT_SYMBOL_GPL(perf_event_update_userpage); @@ -6061,27 +6055,23 @@ static vm_fault_t perf_mmap_fault(struct return ret; } - rcu_read_lock(); + guard(rcu)(); rb = rcu_dereference(event->rb); if (!rb) - goto unlock; + return ret; if (vmf->pgoff && (vmf->flags & FAULT_FLAG_WRITE)) - goto unlock; + return ret; vmf->page = perf_mmap_to_page(rb, vmf->pgoff); if (!vmf->page) - goto unlock; + return ret; get_page(vmf->page); vmf->page->mapping = vmf->vma->vm_file->f_mapping; vmf->page->index = vmf->pgoff; - ret = 0; -unlock: - rcu_read_unlock(); - - return ret; + return 0; } static void ring_buffer_attach(struct perf_event *event,
