Messages in this thread Patch in this message | | | Date | Wed, 17 Mar 2021 12:41:18 +0800 | From | Can Guo <> | Subject | Re: [PATCH v5 05/10] scsi: ufshpb: Region inactivation in host mode |
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On 2021-03-17 10:28, Daejun Park wrote: >>> >> --- >>> >> 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;
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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