Re: RAID1 might_sleep() warning on 3.19-rc7

On Fri, Feb 13, 2015 at 07:49:53PM +1100, NeilBrown wrote:

quoted

Like said, that will still recursive call delayacct_blkio_*() and would
increase nr_iowait for a second time; while arguably its still the same
one io-wait instance.

No it doesn't.  There is no "blk_flush_plug" call between the
delayacct_blkio_*() calls.

Duh, clearly I needed to still wake up :/

I've moved blk_flush_plug to the beginning of the function.

I wondered if it really make sense to call blk_flush_plug with nr_iowait
elevated and delayacct_blkio active.  blk_flush_plug() could call schedule()
for non-"io" reasons and maybe that could upset stuff???

Yeah, good question that. Lemme ponder that a bit.

I don't really know.  I'm happy with your version.  I don't suppose anyone
else is paying attention and could give a third opinion....

:-)