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Date:   Tue, 15 Mar 2022 09:57:09 +0100
From:   Christoph Hellwig <hch@lst.de>
To:     Kanchan Joshi <joshiiitr@gmail.com>
Cc:     Christoph Hellwig <hch@lst.de>,
        Kanchan Joshi <joshi.k@samsung.com>,
        Jens Axboe <axboe@kernel.dk>, Keith Busch <kbusch@kernel.org>,
        Pavel Begunkov <asml.silence@gmail.com>,
        io-uring@vger.kernel.org, linux-nvme@lists.infradead.org,
        linux-block@vger.kernel.org, sbates@raithlin.com,
        logang@deltatee.com, Pankaj Raghav <pankydev8@gmail.com>,
        Javier =?iso-8859-1?Q?Gonz=E1lez?= <javier@javigon.com>,
        Luis Chamberlain <mcgrof@kernel.org>,
        Adam Manzanares <a.manzanares@samsung.com>,
        Anuj Gupta <anuj20.g@samsung.com>
Subject: Re: [PATCH 12/17] nvme: enable bio-cache for fixed-buffer passthru
Message-ID: <20220315085709.GD4132@lst.de>
References: <20220308152105.309618-1-joshi.k@samsung.com> <CGME20220308152718epcas5p3afd2c8a628f4e9733572cbb39270989d@epcas5p3.samsung.com> <20220308152105.309618-13-joshi.k@samsung.com> <20220311064847.GA17728@lst.de> <CA+1E3rJshMVkLwpAQwM1L6L_xcrK9drKP+rpcrfizYuFsQOGjA@mail.gmail.com>
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On Mon, Mar 14, 2022 at 11:48:43PM +0530, Kanchan Joshi wrote:
> Yes, the only reason to switch from kmalloc to bio-set was being able
> to use bio-cache.
> Towards the goal of matching peak perf of io_uring's block io path.
> Is it too bad to go down this route; Is there any different way to
> enable bio-cache for passthru.

How does this actually make a difference vs say a slab cache?  Slab/slub
seems to be very fine tuned for these kinds of patters using per-cpu
caches.