On 03/18/2015 05:07 PM, Sam Bradshaw wrote:
When allocating from the reserved tags pool, bt_get() is called with
a NULL hctx. If all tags are in use, the hw queue is kicked to push
out any pending IO, potentially freeing tags, and tag allocation is
retried. The problem is that blk_mq_run_hw_queue() doesn't check for
a NULL hctx. So we avoid it with a simple NULL hctx test.
This issue was introduced by:
b32232073e80: blk-mq: fix hang in bt_get()
Tested by hammering mtip32xx with concurrent smartctl/hdparm.
Signed-off-by: Sam Bradshaw <[email protected]>
Signed-off-by: Selvan Mani <[email protected]>
Thanks Sam, added to the current series.
--
Jens Axboe
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