From: Jens Axboe <axboe@kernel.dk>
To: Chaitanya Kulkarni <Chaitanya.Kulkarni@wdc.com>,
Kanchan Joshi <joshiiitr@gmail.com>
Cc: Kanchan Joshi <joshi.k@samsung.com>, "hch@lst.de" <hch@lst.de>,
"kbusch@kernel.org" <kbusch@kernel.org>,
"io-uring@vger.kernel.org" <io-uring@vger.kernel.org>,
"linux-nvme@lists.infradead.org" <linux-nvme@lists.infradead.org>,
"anuj20.g@samsung.com" <anuj20.g@samsung.com>,
"javier.gonz@samsung.com" <javier.gonz@samsung.com>
Subject: Re: [RFC 3/3] nvme: wire up support for async passthrough
Date: Thu, 4 Mar 2021 18:46:59 -0700 [thread overview]
Message-ID: <54a2df06-8dde-1302-1109-d54d38ade488@kernel.dk> (raw)
In-Reply-To: <BYAPR04MB49656F0B96D7D1190B293C1186979@BYAPR04MB4965.namprd04.prod.outlook.com>
On 3/4/21 3:59 PM, Chaitanya Kulkarni wrote:
> On 3/4/21 03:01, Kanchan Joshi wrote:
>> On Thu, Mar 4, 2021 at 3:14 AM Chaitanya Kulkarni
>> <Chaitanya.Kulkarni@wdc.com> wrote:
>>> On 3/2/21 23:22, Kanchan Joshi wrote:
>>>> + if (!ioucmd)
>>>> + cptr = &c;
>>>> + else {
>>>> + /*for async - allocate cmd dynamically */
>>>> + cptr = kmalloc(sizeof(struct nvme_command), GFP_KERNEL);
>>>> + if (!cptr)
>>>> + return -ENOMEM;
>>>> + }
>>>> +
>>>> + memset(cptr, 0, sizeof(c));
>>> Why not kzalloc and remove memset() ?
>> Yes sure. Ideally I want to get rid of the allocation cost. Perhaps
>> employing kmem_cache/mempool can help. Do you think there is a better
>> way?
>>
>
> Is this hot path ?
It's command issue, and for a bypass (kind of) solution. It's most
definitely the hot path.
--
Jens Axboe
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next prev parent reply other threads:[~2021-03-05 1:47 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CGME20210302160907epcas5p4d04ab7c4ef4d467302498f06ed656b24@epcas5p4.samsung.com>
2021-03-02 16:07 ` [RFC 0/3] Async nvme passthrough Kanchan Joshi
2021-03-02 16:07 ` [RFC 1/3] io_uring: add helper for uring_cmd completion in submitter-task Kanchan Joshi
2021-03-02 16:07 ` [RFC 2/3] nvme: passthrough helper with callback Kanchan Joshi
2021-03-03 7:52 ` Chaitanya Kulkarni
2021-03-04 11:13 ` Kanchan Joshi
2021-03-05 4:14 ` Chaitanya Kulkarni
2021-03-05 10:40 ` Kanchan Joshi
2021-03-02 16:07 ` [RFC 3/3] nvme: wire up support for async passthrough Kanchan Joshi
2021-03-03 7:34 ` Chaitanya Kulkarni
2021-03-04 11:01 ` Kanchan Joshi
2021-03-04 22:59 ` Chaitanya Kulkarni
2021-03-05 1:46 ` Jens Axboe [this message]
2021-03-05 2:41 ` Keith Busch
2021-03-05 10:44 ` Kanchan Joshi
2021-03-05 13:17 ` hch
2021-03-03 7:35 ` Chaitanya Kulkarni
2021-03-04 10:55 ` Kanchan Joshi
2021-03-05 13:22 ` hch
2021-03-03 7:37 ` Chaitanya Kulkarni
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