As said we cannot wait_event, because those reserved bh will be released
only by the VM if there is memory pressure. If we sleep in wait_event
while I/O is in progress on the reserved bh and a big chunk of memory is
released under us, then those reserved bh may never get released and we
will hang in wait_event until there's memory pressure again, so unless
we implement another logic we need to somehow poll there and to try to
allocate again later. We should enter that path very seldom so I'm not
very concerned about the performance during the polling loop.
Andrea
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/