Commit 1c6ce082 authored by NeilBrown's avatar NeilBrown Committed by Greg Kroah-Hartman
Browse files

staging: lustre: replace l_wait_event_exclusive_head() with wait_event_idle_exclusive 



This l_wait_event_exclusive_head() will wait indefinitely
if the timeout is zero.  If it does wait with a timeout
and times out, the timeout for next time is set to zero.

The can be mapped to a call to either
 wait_event_idle_exclusive()
or
 wait_event_idle_exclusive_timeout()
depending in the timeout setting.

The current code arranges for LIFO queuing of waiters,
but include/event.h doesn't support that yet.
Until it does, fall back on FIFO with
wait_event_idle_exclusive{,_timeout}().

Reviewed-by: default avatarJames Simmons <jsimmons@infradead.org>
Signed-off-by: default avatarNeilBrown <neilb@suse.com>
Reviewed-by: default avatarPatrick Farrell <paf@cray.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent cda35204

drivers/staging/lustre/lustre/ptlrpc/service.c

+25 −18
Original line number Diff line number Diff line
@@ -1897,15 +1897,6 @@ ptlrpc_check_rqbd_pool(struct ptlrpc_service_part *svcpt) 
	}

}



static int

ptlrpc_retry_rqbds(void *arg)

{

	struct ptlrpc_service_part *svcpt = arg;



	svcpt->scp_rqbd_timeout = 0;

	return -ETIMEDOUT;

}



static inline int

ptlrpc_threads_enough(struct ptlrpc_service_part *svcpt)

{
@@ -1968,13 +1959,17 @@ ptlrpc_server_request_incoming(struct ptlrpc_service_part *svcpt) 
	return !list_empty(&svcpt->scp_req_incoming);

}



/* We perfer lifo queuing, but kernel doesn't provide that yet. */

#ifndef wait_event_idle_exclusive_lifo

#define wait_event_idle_exclusive_lifo wait_event_idle_exclusive

#define wait_event_idle_exclusive_lifo_timeout wait_event_idle_exclusive_timeout

#endif



static __attribute__((__noinline__)) int

ptlrpc_wait_event(struct ptlrpc_service_part *svcpt,

		  struct ptlrpc_thread *thread)

{

	/* Don't exit while there are replies to be handled */

	struct l_wait_info lwi = LWI_TIMEOUT(svcpt->scp_rqbd_timeout,

					     ptlrpc_retry_rqbds, svcpt);



	/* XXX: Add this back when libcfs watchdog is merged upstream

	lc_watchdog_disable(thread->t_watchdog);
@@ -1982,13 +1977,25 @@ ptlrpc_wait_event(struct ptlrpc_service_part *svcpt, 


	cond_resched();



	l_wait_event_exclusive_head(svcpt->scp_waitq,

	if (svcpt->scp_rqbd_timeout == 0)

		wait_event_idle_exclusive_lifo(

			svcpt->scp_waitq,

			ptlrpc_thread_stopping(thread) ||

			ptlrpc_server_request_incoming(svcpt) ||

			ptlrpc_server_request_pending(svcpt,

						      false) ||

			ptlrpc_rqbd_pending(svcpt) ||

			ptlrpc_at_check(svcpt));

	else if (0 == wait_event_idle_exclusive_lifo_timeout(

			 svcpt->scp_waitq,

			 ptlrpc_thread_stopping(thread) ||

			 ptlrpc_server_request_incoming(svcpt) ||

			 ptlrpc_server_request_pending(svcpt,

						       false) ||

			 ptlrpc_rqbd_pending(svcpt) ||

				    ptlrpc_at_check(svcpt), &lwi);

			 ptlrpc_at_check(svcpt),

			 svcpt->scp_rqbd_timeout))

		svcpt->scp_rqbd_timeout = 0;



	if (ptlrpc_thread_stopping(thread))

		return -EINTR;

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