diff options
Diffstat (limited to 'c_src/linux/preempt.c')
-rw-r--r-- | c_src/linux/preempt.c | 37 |
1 files changed, 0 insertions, 37 deletions
diff --git a/c_src/linux/preempt.c b/c_src/linux/preempt.c deleted file mode 100644 index 72eceed3..00000000 --- a/c_src/linux/preempt.c +++ /dev/null @@ -1,37 +0,0 @@ -#include <pthread.h> - -#include "linux/preempt.h" - -/* - * In userspace, pthreads are preemptible and can migrate CPUs at any time. - * - * In the kernel, preempt_disable() logic essentially guarantees that a marked - * critical section owns its CPU for the relevant block. This is necessary for - * various code paths, critically including the percpu system as it allows for - * non-atomic reads and writes to CPU-local data structures. - * - * The high performance userspace equivalent would be to use thread local - * storage to replace percpu data, but that would be complicated. It should be - * correct to instead guarantee mutual exclusion for the critical sections. - */ - -static pthread_mutex_t preempt_lock; - -__attribute__((constructor)) -static void preempt_init(void) { - pthread_mutexattr_t attr; - pthread_mutexattr_init(&attr); - pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE); - pthread_mutex_init(&preempt_lock, &attr); - pthread_mutexattr_destroy(&attr); -} - -void preempt_disable(void) -{ - pthread_mutex_lock(&preempt_lock); -} - -void preempt_enable(void) -{ - pthread_mutex_unlock(&preempt_lock); -} |