From: Damien Le Moal <dlemoal@kernel.org>
To: Chaitanya Kulkarni <ckulkarnilinux@gmail.com>,
linux-block@vger.kernel.org
Cc: axboe@kernel.dk, hch@lst.de, kch@nvidia.com
Subject: Re: [PATCH 2/2] zloop: respect REQ_NOWAIT for memory allocation
Date: Sun, 16 Nov 2025 12:44:49 +0900 [thread overview]
Message-ID: <5631b99a-dd89-4f89-a5ac-e8a445ae954d@kernel.org> (raw)
In-Reply-To: <20251116025229.29136-2-ckulkarnilinux@gmail.com>
On 11/16/25 11:52, Chaitanya Kulkarni wrote:
> 6. Zloop driver:
> zloop_queue_rq()
> zloop_rw()
> kmalloc_array(..., GFP_NOIO) <-- BLOCKS (REQ_NOWAIT violation)
Absolutely not. Please re-read the code and see that zloop_queue_rq() adds the
request (zloop command) to a workqueue and zloop_rw() is executed within the
work item context, that is, a different context from zloop_queue_rq.
So this patch is not necessary at all, there is no blocking violation as
zloop_queue_rq() never blocks.
> -> Should use GFP_NOWAIT when rq->cmd_flags & REQ_NOWAIT
--
Damien Le Moal
Western Digital Research
next prev parent reply other threads:[~2025-11-16 3:44 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-11-16 2:52 [PATCH 1/2] loop: respect REQ_NOWAIT for memory allocation Chaitanya Kulkarni
2025-11-16 2:52 ` [PATCH 2/2] zloop: " Chaitanya Kulkarni
2025-11-16 3:44 ` Damien Le Moal [this message]
2025-11-16 3:50 ` [PATCH 1/2] loop: " Damien Le Moal
2025-11-16 5:43 ` Chaitanya Kulkarni
2025-11-16 6:26 ` Damien Le Moal
2025-11-18 1:52 ` Chaitanya Kulkarni
2025-11-18 5:21 ` hch
2025-11-18 13:57 ` Jens Axboe
2025-11-19 0:39 ` Chaitanya Kulkarni
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