Merge branch 'sched-wait-for-linus' of git://git.kernel.org/pub/scm/l…

…inux/kernel/git/tip/tip

Pull wait_var_event updates from Ingo Molnar:
 "This introduces the new wait_var_event() API, which is a more flexible
  waiting primitive than wait_on_atomic_t().

  All wait_on_atomic_t() users are migrated over to the new API and
  wait_on_atomic_t() is removed. The migration fixes one bug and should
  result in no functional changes for the other usecases"

* 'sched-wait-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/wait: Improve __var_waitqueue() code generation
  sched/wait: Remove the wait_on_atomic_t() API
  sched/wait, arch/mips: Fix and convert wait_on_atomic_t() usage to the new wait_var_event() API
  sched/wait, fs/ocfs2: Convert wait_on_atomic_t() usage to the new wait_var_event() API
  sched/wait, fs/nfs: Convert wait_on_atomic_t() usage to the new wait_var_event() API
  sched/wait, fs/fscache: Convert wait_on_atomic_t() usage to the new wait_var_event() API
  sched/wait, fs/btrfs: Convert wait_on_atomic_t() usage to the new wait_var_event() API
  sched/wait, fs/afs: Convert wait_on_atomic_t() usage to the new wait_var_event() API
  sched/wait, drivers/media: Convert wait_on_atomic_t() usage to the new wait_var_event() API
  sched/wait, drivers/drm: Convert wait_on_atomic_t() usage to the new wait_var_event() API
  sched/wait: Introduce wait_var_event()

arch/mips/kernel/process.c

@@ -781,6 +781,8 @@ int mips_set_process_fp_mode(struct task_struct *task, unsigned int value)
 	atomic_set(&task->mm->context.fp_mode_switching, 0);
 	preempt_enable();
 
+	wake_up_var(&task->mm->context.fp_mode_switching);
+
 	return 0;
 }
 

arch/mips/kernel/traps.c

@@ -1248,8 +1248,8 @@ static int enable_restore_fp_context(int msa)
 	 * If an FP mode switch is currently underway, wait for it to
 	 * complete before proceeding.
 	 */
-	wait_on_atomic_t(&current->mm->context.fp_mode_switching,
-			 atomic_t_wait, TASK_KILLABLE);
+	wait_var_event(&current->mm->context.fp_mode_switching,
+		       !atomic_read(&current->mm->context.fp_mode_switching));
 
 	if (!used_math()) {
 		/* First time FP context user. */

drivers/gpu/drm/drm_dp_aux_dev.c

@@ -177,8 +177,9 @@ static ssize_t auxdev_read_iter(struct kiocb *iocb, struct iov_iter *to)
 		res = pos - iocb->ki_pos;
 	iocb->ki_pos = pos;
 
-	atomic_dec(&aux_dev->usecount);
-	wake_up_atomic_t(&aux_dev->usecount);
+	if (atomic_dec_and_test(&aux_dev->usecount))
+		wake_up_var(&aux_dev->usecount);
+
 	return res;
 }
 
@@ -218,8 +219,9 @@ static ssize_t auxdev_write_iter(struct kiocb *iocb, struct iov_iter *from)
 		res = pos - iocb->ki_pos;
 	iocb->ki_pos = pos;
 
-	atomic_dec(&aux_dev->usecount);
-	wake_up_atomic_t(&aux_dev->usecount);
+	if (atomic_dec_and_test(&aux_dev->usecount))
+		wake_up_var(&aux_dev->usecount);
+
 	return res;
 }
 
@@ -277,8 +279,7 @@ void drm_dp_aux_unregister_devnode(struct drm_dp_aux *aux)
 	mutex_unlock(&aux_idr_mutex);
 
 	atomic_dec(&aux_dev->usecount);
-	wait_on_atomic_t(&aux_dev->usecount, atomic_t_wait,
-			 TASK_UNINTERRUPTIBLE);
+	wait_var_event(&aux_dev->usecount, !atomic_read(&aux_dev->usecount));
 
 	minor = aux_dev->index;
 	if (aux_dev->dev)

drivers/gpu/drm/i915/selftests/intel_breadcrumbs.c

@@ -271,18 +271,13 @@ struct igt_wakeup {
 	u32 seqno;
 };
 
-static int wait_atomic_timeout(atomic_t *p, unsigned int mode)
-{
-	return schedule_timeout(10 * HZ) ? 0 : -ETIMEDOUT;
-}
-
 static bool wait_for_ready(struct igt_wakeup *w)
 {
 	DEFINE_WAIT(ready);
 
 	set_bit(IDLE, &w->flags);
 	if (atomic_dec_and_test(w->done))
-		wake_up_atomic_t(w->done);
+		wake_up_var(w->done);
 
 	if (test_bit(STOP, &w->flags))
 		goto out;
@@ -299,7 +294,7 @@ static bool wait_for_ready(struct igt_wakeup *w)
 out:
 	clear_bit(IDLE, &w->flags);
 	if (atomic_dec_and_test(w->set))
-		wake_up_atomic_t(w->set);
+		wake_up_var(w->set);
 
 	return !test_bit(STOP, &w->flags);
 }
@@ -342,15 +337,14 @@ static void igt_wake_all_sync(atomic_t *ready,
 	atomic_set(ready, 0);
 	wake_up_all(wq);
 
-	wait_on_atomic_t(set, atomic_t_wait, TASK_UNINTERRUPTIBLE);
+	wait_var_event(set, !atomic_read(set));
 	atomic_set(ready, count);
 	atomic_set(done, count);
 }
 
 static int igt_wakeup(void *arg)
 {
 	I915_RND_STATE(prng);
-	const int state = TASK_UNINTERRUPTIBLE;
 	struct intel_engine_cs *engine = arg;
 	struct igt_wakeup *waiters;
 	DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
@@ -418,7 +412,7 @@ static int igt_wakeup(void *arg)
 		 * that they are ready for the next test. We wait until all
 		 * threads are complete and waiting for us (i.e. not a seqno).
 		 */
-		err = wait_on_atomic_t(&done, wait_atomic_timeout, state);
+		err = wait_var_event_timeout(&done, !atomic_read(&done), 10 * HZ);
 		if (err) {
 			pr_err("Timed out waiting for %d remaining waiters\n",
 			       atomic_read(&done));

drivers/media/platform/qcom/venus/hfi.c

@@ -106,8 +106,8 @@ int hfi_core_deinit(struct venus_core *core, bool blocking)
 
 	if (!empty) {
 		mutex_unlock(&core->lock);
-		wait_on_atomic_t(&core->insts_count, atomic_t_wait,
-				 TASK_UNINTERRUPTIBLE);
+		wait_var_event(&core->insts_count,
+			       !atomic_read(&core->insts_count));
 		mutex_lock(&core->lock);
 	}
 
@@ -229,8 +229,8 @@ void hfi_session_destroy(struct venus_inst *inst)
 
 	mutex_lock(&core->lock);
 	list_del_init(&inst->list);
-	atomic_dec(&core->insts_count);
-	wake_up_atomic_t(&core->insts_count);
+	if (atomic_dec_and_test(&core->insts_count))
+		wake_up_var(&core->insts_count);
 	mutex_unlock(&core->lock);
 }
 EXPORT_SYMBOL_GPL(hfi_session_destroy);

fs/afs/cell.c

@@ -25,7 +25,7 @@ static void afs_manage_cell(struct work_struct *);
 static void afs_dec_cells_outstanding(struct afs_net *net)
 {
 	if (atomic_dec_and_test(&net->cells_outstanding))
-		wake_up_atomic_t(&net->cells_outstanding);
+		wake_up_var(&net->cells_outstanding);
 }
 
 /*
@@ -764,7 +764,7 @@ void afs_cell_purge(struct afs_net *net)
 	afs_queue_cell_manager(net);
 
 	_debug("wait");
-	wait_on_atomic_t(&net->cells_outstanding, atomic_t_wait,
-			 TASK_UNINTERRUPTIBLE);
+	wait_var_event(&net->cells_outstanding,
+		       !atomic_read(&net->cells_outstanding));
 	_leave("");
 }

fs/afs/rxrpc.c

@@ -103,8 +103,8 @@ void afs_close_socket(struct afs_net *net)
 	}
 
 	_debug("outstanding %u", atomic_read(&net->nr_outstanding_calls));
-	wait_on_atomic_t(&net->nr_outstanding_calls, atomic_t_wait,
-			 TASK_UNINTERRUPTIBLE);
+	wait_var_event(&net->nr_outstanding_calls,
+		       !atomic_read(&net->nr_outstanding_calls));
 	_debug("no outstanding calls");
 
 	kernel_sock_shutdown(net->socket, SHUT_RDWR);
@@ -175,7 +175,7 @@ void afs_put_call(struct afs_call *call)
 		trace_afs_call(call, afs_call_trace_free, 0, o,
 			       __builtin_return_address(0));
 		if (o == 0)
-			wake_up_atomic_t(&net->nr_outstanding_calls);
+			wake_up_var(&net->nr_outstanding_calls);
 	}
 }
 

fs/afs/server.c

@@ -25,7 +25,7 @@ static void afs_inc_servers_outstanding(struct afs_net *net)
 static void afs_dec_servers_outstanding(struct afs_net *net)
 {
 	if (atomic_dec_and_test(&net->servers_outstanding))
-		wake_up_atomic_t(&net->servers_outstanding);
+		wake_up_var(&net->servers_outstanding);
 }
 
 /*
@@ -521,8 +521,8 @@ void afs_purge_servers(struct afs_net *net)
 	afs_queue_server_manager(net);
 
 	_debug("wait");
-	wait_on_atomic_t(&net->servers_outstanding, atomic_t_wait,
-			 TASK_UNINTERRUPTIBLE);
+	wait_var_event(&net->servers_outstanding,
+		       !atomic_read(&net->servers_outstanding));
 	_leave("");
 }
 

fs/btrfs/extent-tree.c

@@ -3990,7 +3990,7 @@ void btrfs_dec_nocow_writers(struct btrfs_fs_info *fs_info, u64 bytenr)
 	bg = btrfs_lookup_block_group(fs_info, bytenr);
 	ASSERT(bg);
 	if (atomic_dec_and_test(&bg->nocow_writers))
-		wake_up_atomic_t(&bg->nocow_writers);
+		wake_up_var(&bg->nocow_writers);
 	/*
 	 * Once for our lookup and once for the lookup done by a previous call
 	 * to btrfs_inc_nocow_writers()
@@ -4001,8 +4001,7 @@ void btrfs_dec_nocow_writers(struct btrfs_fs_info *fs_info, u64 bytenr)
 
 void btrfs_wait_nocow_writers(struct btrfs_block_group_cache *bg)
 {
-	wait_on_atomic_t(&bg->nocow_writers, atomic_t_wait,
-			 TASK_UNINTERRUPTIBLE);
+	wait_var_event(&bg->nocow_writers, !atomic_read(&bg->nocow_writers));
 }
 
 static const char *alloc_name(u64 flags)
@@ -6526,7 +6525,7 @@ void btrfs_dec_block_group_reservations(struct btrfs_fs_info *fs_info,
 	bg = btrfs_lookup_block_group(fs_info, start);
 	ASSERT(bg);
 	if (atomic_dec_and_test(&bg->reservations))
-		wake_up_atomic_t(&bg->reservations);
+		wake_up_var(&bg->reservations);
 	btrfs_put_block_group(bg);
 }
 
@@ -6552,8 +6551,7 @@ void btrfs_wait_block_group_reservations(struct btrfs_block_group_cache *bg)
 	down_write(&space_info->groups_sem);
 	up_write(&space_info->groups_sem);
 
-	wait_on_atomic_t(&bg->reservations, atomic_t_wait,
-			 TASK_UNINTERRUPTIBLE);
+	wait_var_event(&bg->reservations, !atomic_read(&bg->reservations));
 }
 
 /**
@@ -11061,7 +11059,7 @@ void btrfs_wait_for_snapshot_creation(struct btrfs_root *root)
 		ret = btrfs_start_write_no_snapshotting(root);
 		if (ret)
 			break;
-		wait_on_atomic_t(&root->will_be_snapshotted, atomic_t_wait,
-				 TASK_UNINTERRUPTIBLE);
+		wait_var_event(&root->will_be_snapshotted,
+			       !atomic_read(&root->will_be_snapshotted));
 	}
 }

fs/btrfs/ioctl.c

@@ -723,7 +723,7 @@ static int create_snapshot(struct btrfs_root *root, struct inode *dir,
 	btrfs_subvolume_release_metadata(fs_info, &pending_snapshot->block_rsv);
 dec_and_free:
 	if (atomic_dec_and_test(&root->will_be_snapshotted))
-		wake_up_atomic_t(&root->will_be_snapshotted);
+		wake_up_var(&root->will_be_snapshotted);
 free_pending:
 	kfree(pending_snapshot->root_item);
 	btrfs_free_path(pending_snapshot->path);

fs/fscache/cookie.c

@@ -557,9 +557,10 @@ void __fscache_disable_cookie(struct fscache_cookie *cookie, bool invalidate)
 	 * n_active reaches 0).  This makes sure outstanding reads and writes
 	 * have completed.
 	 */
-	if (!atomic_dec_and_test(&cookie->n_active))
-		wait_on_atomic_t(&cookie->n_active, atomic_t_wait,
-				 TASK_UNINTERRUPTIBLE);
+	if (!atomic_dec_and_test(&cookie->n_active)) {
+		wait_var_event(&cookie->n_active,
+			       !atomic_read(&cookie->n_active));
+	}
 
 	/* Make sure any pending writes are cancelled. */
 	if (cookie->def->type != FSCACHE_COOKIE_TYPE_INDEX)

fs/nfs/inode.c

@@ -85,11 +85,6 @@ int nfs_wait_bit_killable(struct wait_bit_key *key, int mode)
 }
 EXPORT_SYMBOL_GPL(nfs_wait_bit_killable);
 
-int nfs_wait_atomic_killable(atomic_t *p, unsigned int mode)
-{
-	return nfs_wait_killable(mode);
-}
-
 /**
  * nfs_compat_user_ino64 - returns the user-visible inode number
  * @fileid: 64-bit fileid

fs/nfs/pagelist.c

@@ -98,8 +98,8 @@ nfs_page_free(struct nfs_page *p)
 int
 nfs_iocounter_wait(struct nfs_lock_context *l_ctx)
 {
-	return wait_on_atomic_t(&l_ctx->io_count, nfs_wait_atomic_killable,
-			TASK_KILLABLE);
+	return wait_var_event_killable(&l_ctx->io_count,
+				       !atomic_read(&l_ctx->io_count));
 }
 
 /**
@@ -395,7 +395,7 @@ static void nfs_clear_request(struct nfs_page *req)
 	}
 	if (l_ctx != NULL) {
 		if (atomic_dec_and_test(&l_ctx->io_count)) {
-			wake_up_atomic_t(&l_ctx->io_count);
+			wake_up_var(&l_ctx->io_count);
 			if (test_bit(NFS_CONTEXT_UNLOCK, &ctx->flags))
 				rpc_wake_up(&NFS_SERVER(d_inode(ctx->dentry))->uoc_rpcwaitq);
 		}

fs/nfs/pnfs_nfs.c

@@ -245,7 +245,7 @@ pnfs_generic_commit_cancel_empty_pagelist(struct list_head *pages,
 {
 	if (list_empty(pages)) {
 		if (atomic_dec_and_test(&cinfo->mds->rpcs_out))
-			wake_up_atomic_t(&cinfo->mds->rpcs_out);
+			wake_up_var(&cinfo->mds->rpcs_out);
 		/* don't call nfs_commitdata_release - it tries to put
 		 * the open_context which is not acquired until nfs_init_commit
 		 * which has not been called on @data */

fs/nfs/write.c

@@ -1620,8 +1620,8 @@ static void nfs_writeback_result(struct rpc_task *task,
 
 static int wait_on_commit(struct nfs_mds_commit_info *cinfo)
 {
-	return wait_on_atomic_t(&cinfo->rpcs_out,
-			nfs_wait_atomic_killable, TASK_KILLABLE);
+	return wait_var_event_killable(&cinfo->rpcs_out,
+				       !atomic_read(&cinfo->rpcs_out));
 }
 
 static void nfs_commit_begin(struct nfs_mds_commit_info *cinfo)
@@ -1632,7 +1632,7 @@ static void nfs_commit_begin(struct nfs_mds_commit_info *cinfo)
 static void nfs_commit_end(struct nfs_mds_commit_info *cinfo)
 {
 	if (atomic_dec_and_test(&cinfo->rpcs_out))
-		wake_up_atomic_t(&cinfo->rpcs_out);
+		wake_up_var(&cinfo->rpcs_out);
 }
 
 void nfs_commitdata_release(struct nfs_commit_data *data)

fs/ocfs2/filecheck.c

@@ -134,9 +134,10 @@ ocfs2_filecheck_sysfs_free(struct ocfs2_filecheck_sysfs_entry *entry)
 {
 	struct ocfs2_filecheck_entry *p;
 
-	if (!atomic_dec_and_test(&entry->fs_count))
-		wait_on_atomic_t(&entry->fs_count, atomic_t_wait,
-				 TASK_UNINTERRUPTIBLE);
+	if (!atomic_dec_and_test(&entry->fs_count)) {
+		wait_var_event(&entry->fs_count,
+			       !atomic_read(&entry->fs_count));
+	}
 
 	spin_lock(&entry->fs_fcheck->fc_lock);
 	while (!list_empty(&entry->fs_fcheck->fc_head)) {
@@ -183,7 +184,7 @@ static void
 ocfs2_filecheck_sysfs_put(struct ocfs2_filecheck_sysfs_entry *entry)
 {
 	if (atomic_dec_and_test(&entry->fs_count))
-		wake_up_atomic_t(&entry->fs_count);
+		wake_up_var(&entry->fs_count);
 }
 
 static struct ocfs2_filecheck_sysfs_entry *

include/linux/fscache-cache.h

@@ -496,7 +496,7 @@ static inline bool __fscache_unuse_cookie(struct fscache_cookie *cookie)
 
 static inline void __fscache_wake_unused_cookie(struct fscache_cookie *cookie)
 {
-	wake_up_atomic_t(&cookie->n_active);
+	wake_up_var(&cookie->n_active);
 }
 
 /**