Commit 9b86071c authored Dec 07, 2016 by Sebastian Sanchez Committed by Doug Ledford Dec 11, 2016

IB/hfi1: Remove critical section gap in sc_buffer_alloc()



In sc_buffer_alloc(), the sc->alloc_lock is released
before calling sc_release_update(), and it is reacquired
after the function call. This causes CPU lock trading.
Fix it by not dropping the lock before calling
sc_release_update().

Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Sebastian Sanchez <sebastian.sanchez@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

parent b777f154

drivers/infiniband/hw/hfi1/pio.c

+0 −2

Original line number	Diff line number	Diff line
		@@ -1419,9 +1419,7 @@ retry:
		(sc->fill - sc->alloc_free);
		if (blocks > avail) {
		/* still no room, actively update */
		spin_unlock_irqrestore(&sc->alloc_lock, flags);
		sc_release_update(sc);
		spin_lock_irqsave(&sc->alloc_lock, flags);
		sc->alloc_free = ACCESS_ONCE(sc->free);
		trycount++;
		goto retry;

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