radix tree test suite: delete unused rcupdate.c

This file was used to implement call_rcu() before liburcu implemented
that function.  It hasn't even been compiled since before the test suite
was added to the kernel.  Remove it to reduce confusion.

Link: http://lkml.kernel.org/r/1481667692-14500-5-git-send-email-mawilcox@linuxonhyperv.comSigned-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

tools/testing/radix-tree/rcupdate.c

-#include <linux/rcupdate.h>
-#include <pthread.h>
-#include <stdio.h>
-#include <assert.h>
-
-static pthread_mutex_t rculock = PTHREAD_MUTEX_INITIALIZER;
-static struct rcu_head *rcuhead_global = NULL;
-static __thread int nr_rcuhead = 0;
-static __thread struct rcu_head *rcuhead = NULL;
-static __thread struct rcu_head *rcutail = NULL;
-
-static pthread_cond_t rcu_worker_cond = PTHREAD_COND_INITIALIZER;
-
-/* switch to urcu implementation when it is merged. */
-void call_rcu(struct rcu_head *head, void (*func)(struct rcu_head *head))
-{
-	head->func = func;
-	head->next = rcuhead;
-	rcuhead = head;
-	if (!rcutail)
-		rcutail = head;
-	nr_rcuhead++;
-	if (nr_rcuhead >= 1000) {
-		int signal = 0;
-
-		pthread_mutex_lock(&rculock);
-		if (!rcuhead_global)
-			signal = 1;
-		rcutail->next = rcuhead_global;
-		rcuhead_global = head;
-		pthread_mutex_unlock(&rculock);
-
-		nr_rcuhead = 0;
-		rcuhead = NULL;
-		rcutail = NULL;
-
-		if (signal) {
-			pthread_cond_signal(&rcu_worker_cond);
-		}
-	}
-}
-
-static void *rcu_worker(void *arg)
-{
-	struct rcu_head *r;
-
-	rcupdate_thread_init();
-
-	while (1) {
-		pthread_mutex_lock(&rculock);
-		while (!rcuhead_global) {
-			pthread_cond_wait(&rcu_worker_cond, &rculock);
-		}
-		r = rcuhead_global;
-		rcuhead_global = NULL;
-
-		pthread_mutex_unlock(&rculock);
-
-		synchronize_rcu();
-
-		while (r) {
-			struct rcu_head *tmp = r->next;
-			r->func(r);
-			r = tmp;
-		}
-	}
-
-	rcupdate_thread_exit();
-
-	return NULL;
-}
-
-static pthread_t worker_thread;
-void rcupdate_init(void)
-{
-	pthread_create(&worker_thread, NULL, rcu_worker, NULL);
-}
-
-void rcupdate_thread_init(void)
-{
-	rcu_register_thread();
-}
-void rcupdate_thread_exit(void)
-{
-	rcu_unregister_thread();
-}