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Date:   Thu, 13 Apr 2023 08:14:28 +0200
From:   Christoph Hellwig <hch@lst.de>
To:     Damien Le Moal <dlemoal@kernel.org>
Cc:     Christoph Hellwig <hch@lst.de>, Jens Axboe <axboe@kernel.dk>,
        Bart Van Assche <bvanassche@acm.org>,
        linux-block@vger.kernel.org
Subject: Re: [PATCH 08/18] blk-mq: fold __blk_mq_insert_req_list into
 blk_mq_insert_request
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On Wed, Apr 12, 2023 at 04:33:04PM +0900, Damien Le Moal wrote:
> I am not worried about the values shown by the trace entries, but rather the
> order of the inserts: with the trace call outside the lock, the trace may end up
> showing an incorrect insertion order ?

... turns out none of the other calls to trace_block_rq_insert is
under ctx->lock either.  The I/O scheduler ones are under their
own per-request_queue locks, so maybe that counts as ordering,
but blk_mq_insert_requests doesn't lock at all.