block: as/cfq ssd idle check update

We really need to know about the hardware tagging support as well,
since if the SSD does not do tagging then we still want to idle.
Otherwise have the same dependent sync IO vs flooding async IO
problem as on rotational media.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

1 files changed, 3 insertions, 1 deletions

diff --git a/block/as-iosched.c b/block/as-iosched.c
index 4c6fafbba933..71f0abb219ee 100644
--- a/block/as-iosched.c
+++ b/block/as-iosched.c
@@ -745,11 +745,13 @@ static int as_can_break_anticipation(struct as_data *ad, struct request *rq)
  */
 static int as_can_anticipate(struct as_data *ad, struct request *rq)
 {
+#if 0 /* disable for now, we need to check tag level as well */
         /*
          * SSD device without seek penalty, disable idling
          */
-        if (blk_queue_nonrot(ad->q))
+        if (blk_queue_nonrot(ad->q)) axman
                 return 0;
+#endif
 
         if (!ad->io_context)
                 /*