From: Can Guo <cang@codeaurora.org>
To: daejun7.park@samsung.com
Cc: Greg KH <gregkh@linuxfoundation.org>,
avri.altman@wdc.com, jejb@linux.ibm.com,
martin.petersen@oracle.com, asutoshd@codeaurora.org,
stanley.chu@mediatek.com, bvanassche@acm.org, huobean@gmail.com,
ALIM AKHTAR <alim.akhtar@samsung.com>,
linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org,
JinHwan Park <jh.i.park@samsung.com>,
Javier Gonzalez <javier.gonz@samsung.com>,
SEUNGUK SHIN <seunguk.shin@samsung.com>,
Sung-Jun Park <sungjun07.park@samsung.com>,
Jinyoung CHOI <j-young.choi@samsung.com>,
BoRam Shin <boram.shin@samsung.com>
Subject: Re: [PATCH v29 4/4] scsi: ufs: Add HPB 2.0 support
Date: Mon, 15 Mar 2021 15:47:02 +0800 [thread overview]
Message-ID: <a18909e8f4db023455b7513bf6c60312@codeaurora.org> (raw)
In-Reply-To: <d6a4511fd85e6e47c5aef22e335bb253@codeaurora.org>
On 2021-03-15 15:23, Can Guo wrote:
> On 2021-03-15 15:07, Daejun Park wrote:
>>>> This patch supports the HPB 2.0.
>>>>
>>>> The HPB 2.0 supports read of varying sizes from 4KB to 512KB.
>>>> In the case of Read (<= 32KB) is supported as single HPB read.
>>>> In the case of Read (36KB ~ 512KB) is supported by as a combination
>>>> of
>>>> write buffer command and HPB read command to deliver more PPN.
>>>> The write buffer commands may not be issued immediately due to busy
>>>> tags.
>>>> To use HPB read more aggressively, the driver can requeue the write
>>>> buffer
>>>> command. The requeue threshold is implemented as timeout and can be
>>>> modified with requeue_timeout_ms entry in sysfs.
>>>>
>>>> Signed-off-by: Daejun Park <daejun7.park@samsung.com>
>>>> ---
>>>> +static struct attribute *hpb_dev_param_attrs[] = {
>>>> + &dev_attr_requeue_timeout_ms.attr,
>>>> + NULL,
>>>> +};
>>>> +
>>>> +struct attribute_group ufs_sysfs_hpb_param_group = {
>>>> + .name = "hpb_param_sysfs",
>>>> + .attrs = hpb_dev_param_attrs,
>>>> +};
>>>> +
>>>> +static int ufshpb_pre_req_mempool_init(struct ufshpb_lu *hpb)
>>>> +{
>>>> + struct ufshpb_req *pre_req = NULL;
>>>> + int qd = hpb->sdev_ufs_lu->queue_depth / 2;
>>>> + int i, j;
>>>> +
>>>> + INIT_LIST_HEAD(&hpb->lh_pre_req_free);
>>>> +
>>>> + hpb->pre_req = kcalloc(qd, sizeof(struct ufshpb_req),
>>>> GFP_KERNEL);
>>>> + hpb->throttle_pre_req = qd;
>>>> + hpb->num_inflight_pre_req = 0;
>>>> +
>>>> + if (!hpb->pre_req)
>>>> + goto release_mem;
>>>> +
>>>> + for (i = 0; i < qd; i++) {
>>>> + pre_req = hpb->pre_req + i;
>>>> + INIT_LIST_HEAD(&pre_req->list_req);
>>>> + pre_req->req = NULL;
>>>> + pre_req->bio = NULL;
>>>
>>> Why don't prepare bio as same as wb.m_page? Won't that save more time
>>> for ufshpb_issue_pre_req()?
>>
>> It is pre_req pool. So although we prepare bio at this time, it just
>> only for first pre_req.
>
> I meant removing the bio_alloc() in ufshpb_issue_pre_req() and
> bio_put()
> in ufshpb_pre_req_compl_fn(). bios, in pre_req's case, just hold a
> page.
> So, prepare 16 (if queue depth is 32) bios here, just use them along
> with
> wb.m_page and call bio_reset() in ufshpb_pre_req_compl_fn(). Shall it
> work?
>
If it works, you can even have the bio_add_pc_page() called here. Later
in
ufshpb_execute_pre_req(), you don't need to call
ufshpb_pre_req_add_bio_page(),
just call ufshpb_prep_entry() once instead - it save many repeated steps
for a
pre_req, and you don't even need to call bio_reset() in this case, since
for a
bio, nothing changes after it is binded with a specific page...
Can Guo.
> Thanks,
> Can Guo.
>
>> After use it, it should be prepared bio at issue phase.
>>
>> Thanks,
>> Daejun
>>
>>>
>>> Thanks,
>>> Can Guo.
>>>
>>>> +
>>>> + pre_req->wb.m_page = alloc_page(GFP_KERNEL |
>>>> __GFP_ZERO);
>>>> + if (!pre_req->wb.m_page) {
>>>> + for (j = 0; j < i; j++)
>>>> +
>>>> __free_page(hpb->pre_req[j].wb.m_page);
>>>> +
>>>> + goto release_mem;
>>>> + }
>>>> + list_add_tail(&pre_req->list_req,
>>>> &hpb->lh_pre_req_free);
>>>> + }
>>>> +
>>>> + return 0;
>>>> +release_mem:
>>>> + kfree(hpb->pre_req);
>>>> + return -ENOMEM;
>>>> +}
>>>> +
>>>
>>>
>>>
next prev parent reply other threads:[~2021-03-15 7:47 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CGME20210315012850epcms2p361447b689e925561c48aa9ca54434eb5@epcms2p3>
2021-03-15 1:28 ` [PATCH v29 0/4] scsi: ufs: Add Host Performance Booster Support Daejun Park
[not found] ` <CGME20210315012850epcms2p361447b689e925561c48aa9ca54434eb5@epcms2p4>
2021-03-15 1:29 ` [PATCH v29 1/4] scsi: ufs: Introduce HPB feature Daejun Park
2021-03-15 1:30 ` [PATCH v29 3/4] scsi: ufs: Prepare HPB read for cached sub-region Daejun Park
[not found] ` <CGME20210315012850epcms2p361447b689e925561c48aa9ca54434eb5@epcms2p5>
2021-03-15 1:30 ` [PATCH v29 2/4] scsi: ufs: L2P map management for HPB read Daejun Park
[not found] ` <CGME20210315012850epcms2p361447b689e925561c48aa9ca54434eb5@epcms2p8>
2021-03-15 1:31 ` [PATCH v29 4/4] scsi: ufs: Add HPB 2.0 support Daejun Park
2021-03-15 5:05 ` Can Guo
2021-03-15 6:36 ` Can Guo
2021-03-21 10:05 ` Avri Altman
2021-03-15 7:07 ` Daejun Park
2021-03-15 7:23 ` Can Guo
2021-03-15 7:47 ` Can Guo [this message]
[not found] ` <CGME20210315012850epcms2p361447b689e925561c48aa9ca54434eb5@epcms2p1>
2021-03-17 1:42 ` Daejun Park
2021-03-17 2:45 ` Can Guo
2021-03-18 7:13 ` Daejun Park
2021-03-22 0:50 ` Daejun Park
2021-03-18 2:02 ` Daejun Park
2021-03-18 2:25 ` Can Guo
2021-03-18 4:49 ` Can Guo
2021-03-18 2:29 ` Daejun Park
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