From: Kanchan Joshi <joshi.k@samsung.com>
To: Ming Lei <ming.lei@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>, Keith Busch <kbusch@kernel.org>,
linux-nvme@lists.infradead.org, Sagi Grimberg <sagi@grimberg.me>,
Guangwu Zhang <guazhang@redhat.com>,
Anuj Gupta <anuj20.g@samsung.com>
Subject: Re: [PATCH] nvme: core: don't hold rcu read lock in nvme_ns_chr_uring_cmd_iopoll
Date: Thu, 10 Aug 2023 12:04:11 +0530 [thread overview]
Message-ID: <20230810063411.GA13970@green245> (raw)
In-Reply-To: <ZNNF/2NEPYCeiXlM@fedora>
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On Wed, Aug 09, 2023 at 03:53:35PM +0800, Ming Lei wrote:
>On Wed, Aug 09, 2023 at 12:29:20PM +0530, Kanchan Joshi wrote:
>> On Wed, Aug 09, 2023 at 10:04:40AM +0800, Ming Lei wrote:
>> > Now nvme_ns_chr_uring_cmd_iopoll() has switched to request based io
>> > polling, and the associated NS is guaranteed to be live in case of
>> > io polling, so request is guaranteed to be valid because blk-mq uses
>> > pre-allocated request pool.
>> >
>> > Remove the rcu read lock in nvme_ns_chr_uring_cmd_iopoll(), which
>> > isn't needed any more after switching to request based io polling.
>>
>> > Fix "BUG: sleeping function called from invalid context" because
>> > set_page_dirty_lock() from blk_rq_unmap_user() may sleep.
>> >
>> > Fixes: 585079b6e425 ("nvme: wire up async polling for io passthrough commands")
>> > Reported-by: Guangwu Zhang <guazhang@redhat.com>
>>
>> Thanks Ming. Looks fine, but any link to this report?
>> I don't see this breaking in my tests. So I wonder how to reproduce and
>> improve the coverage.
>
>It is reported in RH BZ2227639, and follows the stack trace:
Tried to access, but no luck.
Any chance that steps can be posted here?
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next prev parent reply other threads:[~2023-08-10 6:37 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CGME20230809020844epcas5p30e520491fa59ab8c20836d4275931e8f@epcas5p3.samsung.com>
2023-08-09 2:04 ` [PATCH] nvme: core: don't hold rcu read lock in nvme_ns_chr_uring_cmd_iopoll Ming Lei
2023-08-09 6:59 ` Kanchan Joshi
2023-08-09 7:53 ` Ming Lei
2023-08-10 6:34 ` Kanchan Joshi [this message]
2023-08-10 8:14 ` Ming Lei
2023-08-11 14:12 ` Jens Axboe
2023-08-11 14:12 ` Jens Axboe
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