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Message-ID: <2038148563.21615960081843.JavaMail.epsvc@epcpadp4>
Date: Wed, 17 Mar 2021 14:42:37 +0900
From: Daejun Park <daejun7.park@...sung.com>
To: Can Guo <cang@...eaurora.org>,
Daejun Park <daejun7.park@...sung.com>
CC: Avri Altman <Avri.Altman@....com>,
"James E . J . Bottomley" <jejb@...ux.vnet.ibm.com>,
"Martin K . Petersen" <martin.petersen@...cle.com>,
"linux-scsi@...r.kernel.org" <linux-scsi@...r.kernel.org>,
"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
"gregkh@...uxfoundation.org" <gregkh@...uxfoundation.org>,
Bart Van Assche <bvanassche@....org>,
yongmyung lee <ymhungry.lee@...sung.com>,
ALIM AKHTAR <alim.akhtar@...sung.com>,
"asutoshd@...eaurora.org" <asutoshd@...eaurora.org>,
Zang Leigang <zangleigang@...ilicon.com>,
Avi Shchislowski <Avi.Shchislowski@....com>,
Bean Huo <beanhuo@...ron.com>,
"stanley.chu@...iatek.com" <stanley.chu@...iatek.com>
Subject: RE: Re: [PATCH v5 05/10] scsi: ufshpb: Region inactivation in host
mode
>>>>>> >> ---
>>>>>> >> drivers/scsi/ufs/ufshpb.c | 14 ++++++++++++++
>>>>>> >> drivers/scsi/ufs/ufshpb.h | 1 +
>>>>>> >> 2 files changed, 15 insertions(+)
>>>>>> >>
>>>>>> >> diff --git a/drivers/scsi/ufs/ufshpb.c b/drivers/scsi/ufs/ufshpb.c
>>>>>> >> index 6f4fd22eaf2f..0744feb4d484 100644
>>>>>> >> --- a/drivers/scsi/ufs/ufshpb.c
>>>>>> >> +++ b/drivers/scsi/ufs/ufshpb.c
>>>>>> >> @@ -907,6 +907,7 @@ static int ufshpb_execute_umap_req(struct
>>>>>> >> ufshpb_lu *hpb,
>>>>>> >>
>>>>>> >> blk_execute_rq_nowait(q, NULL, req, 1, ufshpb_umap_req_compl_fn);
>>>>>> >>
>>>>>> >> + hpb->stats.umap_req_cnt++;
>>>>>> >> return 0;
>>>>>> >> }
>>>>>> >>
>>>>>> >> @@ -1103,6 +1104,12 @@ static int ufshpb_issue_umap_req(struct
>>>>>> >> ufshpb_lu *hpb,
>>>>>> >> return -EAGAIN;
>>>>>> >> }
>>>>>> >>
>>>>>> >> +static int ufshpb_issue_umap_single_req(struct ufshpb_lu *hpb,
>>>>>> >> + struct ufshpb_region *rgn)
>>>>>> >> +{
>>>>>> >> + return ufshpb_issue_umap_req(hpb, rgn);
>>>>>> >> +}
>>>>>> >> +
>>>>>> >> static int ufshpb_issue_umap_all_req(struct ufshpb_lu *hpb)
>>>>>> >> {
>>>>>> >> return ufshpb_issue_umap_req(hpb, NULL);
>>>>>> >> @@ -1115,6 +1122,10 @@ static void __ufshpb_evict_region(struct
>>>>>> >> ufshpb_lu *hpb,
>>>>>> >> struct ufshpb_subregion *srgn;
>>>>>> >> int srgn_idx;
>>>>>> >>
>>>>>> >> +
>>>>>> >> + if (hpb->is_hcm && ufshpb_issue_umap_single_req(hpb, rgn))
>>>>>> >
>>>>>> > __ufshpb_evict_region() is called with rgn_state_lock held and IRQ
>>>>>> > disabled,
>>>>>> > when ufshpb_issue_umap_single_req() invokes blk_execute_rq_nowait(),
>>>>>> > below
>>>>>> > warning shall pop up every time, fix it?
>>>>>> >
>>>>>> > void blk_execute_rq_nowait(struct request_queue *q, struct gendisk
>>>>>> > *bd_disk,
>>>>>> > struct request *rq, int at_head,
>>>>>> > rq_end_io_fn *done)
>>>>>> > {
>>>>>> > WARN_ON(irqs_disabled());
>>>>>> > ...
>>>>>> >
>>>>>>
>>>>>> Moreover, since we are here with rgn_state_lock held and IRQ
>>>>>> disabled,
>>>>>> in ufshpb_get_req(), rq = kmem_cache_alloc(hpb->map_req_cache,
>>>>>> GFP_KERNEL)
>>>>>> has the GFP_KERNEL flag, scheduling while atomic???
>>>>> I think your comment applies to ufshpb_issue_umap_all_req as well,
>>>>> Which is called from slave_configure/scsi_add_lun.
>>>>>
>>>>> Since the host-mode series is utilizing the framework laid by the
>>>>> device-mode,
>>>>> Maybe you can add this comment to Daejun's last version?
>>>>
>>>> Hi Avri, Can Guo
>>>>
>>>> I think ufshpb_issue_umap_single_req() can be moved to end of
>>>> ufshpb_evict_region().
>>>> Then we can avoid rgn_state_lock when it sends unmap command.
>>>
>>> I am not the expert here, please you two fix it. I am just reporting
>>> what can be wrong. Anyways, ufshpb_issue_umap_single_req() should not
>>> be called with rgn_state_lock held - think about below (another
>>> deadly)
>>> scenario.
>>>
>>> lock(rgn_state_lock)
>>> ufshpb_issue_umap_single_req()
>>> ufshpb_prep()
>>> lock(rgn_state_lock) <---------- recursive spin_lock
>>>
>>> BTW, @Daejun shouldn't we stop passthrough cmds from stepping
>>> into ufshpb_prep()? In current code, you are trying to use below
>>> check to block cmds other than write/discard/read, but a passthrough
>>> cmd can not be blocked by the check.
>>>
>>> if (!ufshpb_is_write_or_discard_cmd(cmd) &&
>>> !ufshpb_is_read_cmd(cmd) )
>>> return 0;
>>
>> I found this problem too. I fixed it and submit next patch.
>
>You mean in V30, which has not been uploaded yet, right?
Yes, it is about v30.
Thanks,
Daejun
>Thanks,
>Can Guo.
>
>>
>> if (blk_rq_is_scsi(cmd->request) ||
>> (!ufshpb_is_write_or_discard_cmd(cmd) &&
>> !ufshpb_is_read_cmd(cmd)))
>> return 0;
>>
>>
>> Thanks,
>> Daejun
>>
>>> Thanks,
>>> Can Guo.
>>>
>>>>
>>>> Thanks,
>>>> Daejun
>>>>
>>>>
>>>>> Thanks,
>>>>> Avri
>>>>>
>>>>>>
>>>>>> Can Guo.
>>>>>>
>>>>>> > Thanks.
>>>>>> > Can Guo.
>>>>>> >
>>>>>> >> + return;
>>>>>> >> +
>>>>>> >> lru_info = &hpb->lru_info;
>>>>>> >>
>>>>>> >> dev_dbg(&hpb->sdev_ufs_lu->sdev_dev, "evict region %d\n",
>>>>>> >> rgn->rgn_idx);
>>>>>> >> @@ -1855,6 +1866,7 @@ ufshpb_sysfs_attr_show_func(rb_noti_cnt);
>>>>>> >> ufshpb_sysfs_attr_show_func(rb_active_cnt);
>>>>>> >> ufshpb_sysfs_attr_show_func(rb_inactive_cnt);
>>>>>> >> ufshpb_sysfs_attr_show_func(map_req_cnt);
>>>>>> >> +ufshpb_sysfs_attr_show_func(umap_req_cnt);
>>>>>> >>
>>>>>> >> static struct attribute *hpb_dev_stat_attrs[] = {
>>>>>> >> &dev_attr_hit_cnt.attr,
>>>>>> >> @@ -1863,6 +1875,7 @@ static struct attribute *hpb_dev_stat_attrs[] =
>>>>>> >> {
>>>>>> >> &dev_attr_rb_active_cnt.attr,
>>>>>> >> &dev_attr_rb_inactive_cnt.attr,
>>>>>> >> &dev_attr_map_req_cnt.attr,
>>>>>> >> + &dev_attr_umap_req_cnt.attr,
>>>>>> >> NULL,
>>>>>> >> };
>>>>>> >>
>>>>>> >> @@ -1978,6 +1991,7 @@ static void ufshpb_stat_init(struct ufshpb_lu
>>>>>> >> *hpb)
>>>>>> >> hpb->stats.rb_active_cnt = 0;
>>>>>> >> hpb->stats.rb_inactive_cnt = 0;
>>>>>> >> hpb->stats.map_req_cnt = 0;
>>>>>> >> + hpb->stats.umap_req_cnt = 0;
>>>>>> >> }
>>>>>> >>
>>>>>> >> static void ufshpb_param_init(struct ufshpb_lu *hpb)
>>>>>> >> diff --git a/drivers/scsi/ufs/ufshpb.h b/drivers/scsi/ufs/ufshpb.h
>>>>>> >> index bd4308010466..84598a317897 100644
>>>>>> >> --- a/drivers/scsi/ufs/ufshpb.h
>>>>>> >> +++ b/drivers/scsi/ufs/ufshpb.h
>>>>>> >> @@ -186,6 +186,7 @@ struct ufshpb_stats {
>>>>>> >> u64 rb_inactive_cnt;
>>>>>> >> u64 map_req_cnt;
>>>>>> >> u64 pre_req_cnt;
>>>>>> >> + u64 umap_req_cnt;
>>>>>> >> };
>>>>>> >>
>>>>>> >> struct ufshpb_lu {
>>>>>
>>>>>
>>>>>
>>>
>>>
>>>
>
>
>
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