[PATCH V3 6/6] blk-mq: support concurrent queue quiesce/unquiesce

[Ming Lei]

On Tue, Oct 12, 2021 at 05:08:27PM +0200, Christoph Hellwig wrote:
> On Tue, Oct 12, 2021 at 11:06:51PM +0800, Ming Lei wrote:
> > > We can get rid of the QUEUE_FLAG_QUIESCED flag now and just look
> > > at ->quiesce_depth directly.
> > 
> > I'd rather not to do that given we need to check QUEUE_FLAG_QUIESCED in fast
> > path.
> 
> Checking an integer vs checking a bit is easier actually faster or at
> least the same speed depending on the architecture / micro architecture.

->queue_flag is always hot, but quiesce_depth can't be and shouldn't be
since it is used very less.


-- 
Ming