Commit f3c1b59a authored by Ben Walker's avatar Ben Walker Committed by Tomasz Zawadzki
Browse files

thread: Always wrap interrupt handlers to set the thread correctly 



Eventually, we want to allow merging of spdk_fd_groups, removing a level
of indirection. That means that some interrupt handlers won't
necessarily fire with the spdk_thread context already set. Set it in the
wrappers to ensure it's right.

Change-Id: Ief18d58cf3ee005c2969a9c0ee132b34b24cbd61
Signed-off-by: default avatarBen Walker <benjamin.walker@intel.com>
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/15476


Reviewed-by: default avatarTomasz Zawadzki <tomasz.zawadzki@intel.com>
Reviewed-by: default avatarJim Harris <james.r.harris@intel.com>
Tested-by: default avatarSPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: default avatarJohn Levon <levon@movementarian.org>
parent 01dca5ed

lib/thread/thread.c

+45 −12
Original line number Diff line number Diff line
@@ -46,6 +46,8 @@ static struct spdk_thread *g_app_thread; 
struct spdk_interrupt {

	int			efd;

	struct spdk_thread	*thread;

	spdk_interrupt_fn	fn;

	void			*arg;

	char			name[SPDK_MAX_POLLER_NAME_LEN + 1];

};
@@ -1101,7 +1103,6 @@ spdk_thread_poll(struct spdk_thread *thread, uint32_t max_msgs, uint64_t now) 
{

	struct spdk_thread *orig_thread;

	int rc;

	uint64_t notify = 1;



	orig_thread = _get_thread();

	tls_thread = thread;
@@ -1122,16 +1123,6 @@ spdk_thread_poll(struct spdk_thread *thread, uint32_t max_msgs, uint64_t now) 
	} else {

		/* Non-block wait on thread's fd_group */

		rc = spdk_fd_group_wait(thread->fgrp, 0);

		SPIN_ASSERT(thread->lock_count == 0, SPIN_ERR_HOLD_DURING_SWITCH);

		if (spdk_unlikely(!thread->in_interrupt)) {

			/* The thread transitioned to poll mode in a msg during the above processing.

			 * Clear msg_fd since thread messages will be polled directly in poll mode.

			 */

			rc = read(thread->msg_fd, &notify, sizeof(notify));

			if (rc < 0 && errno != EAGAIN) {

				SPDK_ERRLOG("failed to acknowledge msg queue: %s.\n", spdk_strerror(errno));

			}

		}



		/* Reap unregistered pollers out of poller execution in intr mode */

		if (spdk_unlikely(thread->poller_unregistered)) {
@@ -2661,6 +2652,7 @@ static int 
thread_interrupt_msg_process(void *arg)

{

	struct spdk_thread *thread = arg;

	struct spdk_thread *orig_thread;

	uint32_t msg_count;

	spdk_msg_fn critical_msg;

	int rc = 0;
@@ -2668,6 +2660,9 @@ thread_interrupt_msg_process(void *arg) 


	assert(spdk_interrupt_mode_is_enabled());



	orig_thread = spdk_get_thread();

	spdk_set_thread(thread);



	/* There may be race between msg_acknowledge and another producer's msg_notify,

	 * so msg_acknowledge should be applied ahead. And then check for self's msg_notify.

	 * This can avoid msg notification missing.
@@ -2689,6 +2684,18 @@ thread_interrupt_msg_process(void *arg) 
		rc = 1;

	}



	SPIN_ASSERT(thread->lock_count == 0, SPIN_ERR_HOLD_DURING_SWITCH);

	if (spdk_unlikely(!thread->in_interrupt)) {

		/* The thread transitioned to poll mode in a msg during the above processing.

		 * Clear msg_fd since thread messages will be polled directly in poll mode.

		 */

		rc = read(thread->msg_fd, &notify, sizeof(notify));

		if (rc < 0 && errno != EAGAIN) {

			SPDK_ERRLOG("failed to acknowledge msg queue: %s.\n", spdk_strerror(errno));

		}

	}



	spdk_set_thread(orig_thread);

	return rc;

}
@@ -2724,6 +2731,30 @@ thread_interrupt_create(struct spdk_thread *thread) 
}

#endif



static int

_interrupt_wrapper(void *ctx)

{

	struct spdk_interrupt *intr = ctx;

	struct spdk_thread *orig_thread, *thread;

	int rc;



	orig_thread = spdk_get_thread();

	thread = intr->thread;



	spdk_set_thread(thread);



	SPDK_DTRACE_PROBE4(interrupt_fd_process, intr->name, intr->efd,

			   intr->fn, intr->arg);



	rc = intr->fn(intr->arg);



	SPIN_ASSERT(thread->lock_count == 0, SPIN_ERR_HOLD_DURING_SWITCH);



	spdk_set_thread(orig_thread);



	return rc;

}



struct spdk_interrupt *

spdk_interrupt_register(int efd, spdk_interrupt_fn fn,

			void *arg, const char *name)
@@ -2757,8 +2788,10 @@ spdk_interrupt_register(int efd, spdk_interrupt_fn fn, 


	intr->efd = efd;

	intr->thread = thread;

	intr->fn = fn;

	intr->arg = arg;



	ret = spdk_fd_group_add(thread->fgrp, efd, fn, arg, name);

	ret = spdk_fd_group_add(thread->fgrp, efd, _interrupt_wrapper, intr, name);



	if (ret != 0) {

		SPDK_ERRLOG("thread %s: failed to add fd %d: %s\n",

lib/util/fd_group.c

+0 −3
Original line number Diff line number Diff line
@@ -286,9 +286,6 @@ spdk_fd_group_wait(struct spdk_fd_group *fgrp, int timeout) 
			continue;

		}



		SPDK_DTRACE_PROBE4(interrupt_fd_process, ehdlr->name, ehdlr->fd,

				   ehdlr->fn, ehdlr->fn_arg);



		g_event = &events[n];

		/* call the interrupt response function */

		ehdlr->fn(ehdlr->fn_arg);