| Message ID | 20240116033927.628524-1-shinichiro.kawasaki@wdc.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [for-next] null_blk: add configfs variable shared_tags | expand |
On 1/15/24 19:39, Shin'ichiro Kawasaki wrote: > Allow setting shared_tags through configfs, which could only be set as a > module parameter. For that purpose, delay tag_set initialization from > null_init() to null_add_dev(). Introduce the flag tag_set_initialized to > manage the initialization status of tag_set. > > The following parameters can not be set through configfs yet: > > timeout > requeue > init_hctx > > Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com> > --- > This patch will allow running the blktests test cases block/010 and block/022 > using the built-in null_blk driver. Corresponding blktests side changes are > drafted here [1]. > > [1] https://github.com/kawasaki/blktests/tree/shared_tags > > drivers/block/null_blk/main.c | 38 ++++++++++++++++--------------- > drivers/block/null_blk/null_blk.h | 1 + > 2 files changed, 21 insertions(+), 18 deletions(-) > > diff --git a/drivers/block/null_blk/main.c b/drivers/block/null_blk/main.c > index 36755f263e8e..c3361e521564 100644 > --- a/drivers/block/null_blk/main.c > +++ b/drivers/block/null_blk/main.c > @@ -69,6 +69,7 @@ static LIST_HEAD(nullb_list); > static struct mutex lock; > static int null_major; > static DEFINE_IDA(nullb_indexes); > +static bool tag_set_initialized = false; explicit initializing global bool to false really needed ? unless I did something see [1]. -ck [1] nvme (nvme-6.8) # git diff drivers/block/null_blk/ diff --git a/drivers/block/null_blk/main.c b/drivers/block/null_blk/main.c index 9f7695f00c2d..12686aeaae38 100644 --- a/drivers/block/null_blk/main.c +++ b/drivers/block/null_blk/main.c @@ -68,6 +68,8 @@ struct nullb_page { static LIST_HEAD(nullb_list); static struct mutex lock; static int null_major; +static bool abcd; +static bool abcd_init = false; static DEFINE_IDA(nullb_indexes); static struct blk_mq_tag_set tag_set; @@ -2280,6 +2282,7 @@ static int __init null_init(void) unsigned int i; struct nullb *nullb; + pr_info("%s %d abcd %d abcd_init %d\n", __func__, __LINE__, abcd, abcd_init); if (g_bs > PAGE_SIZE) { pr_warn("invalid block size\n"); pr_warn("defaults block size to %lu\n", PAGE_SIZE); nvme (nvme-6.8) # makej M=drivers/block/ clean CLEAN drivers/block/Module.symvers nvme (nvme-6.8) # makej M=drivers/block/ CC [M] drivers/block/floppy.o CC [M] drivers/block/brd.o CC [M] drivers/block/loop.o CC [M] drivers/block/nbd.o CC [M] drivers/block/virtio_blk.o CC [M] drivers/block/xen-blkback/blkback.o CC [M] drivers/block/xen-blkfront.o CC [M] drivers/block/rbd.o CC [M] drivers/block/xen-blkback/xenbus.o CC [M] drivers/block/zram/zcomp.o CC [M] drivers/block/mtip32xx/mtip32xx.o CC [M] drivers/block/drbd/drbd_bitmap.o CC [M] drivers/block/drbd/drbd_buildtag.o CC [M] drivers/block/zram/zram_drv.o CC [M] drivers/block/drbd/drbd_proc.o CC [M] drivers/block/drbd/drbd_worker.o CC [M] drivers/block/drbd/drbd_receiver.o CC [M] drivers/block/null_blk/main.o CC [M] drivers/block/drbd/drbd_req.o CC [M] drivers/block/null_blk/trace.o CC [M] drivers/block/drbd/drbd_actlog.o CC [M] drivers/block/drbd/drbd_main.o CC [M] drivers/block/null_blk/zoned.o CC [M] drivers/block/drbd/drbd_strings.o CC [M] drivers/block/drbd/drbd_nl.o CC [M] drivers/block/drbd/drbd_interval.o CC [M] drivers/block/drbd/drbd_state.o CC [M] drivers/block/drbd/drbd_nla.o CC [M] drivers/block/drbd/drbd_debugfs.o LD [M] drivers/block/zram/zram.o LD [M] drivers/block/xen-blkback/xen-blkback.o LD [M] drivers/block/null_blk/null_blk.o LD [M] drivers/block/drbd/drbd.o MODPOST drivers/block/Module.symvers CC [M] drivers/block/floppy.mod.o CC [M] drivers/block/brd.mod.o CC [M] drivers/block/loop.mod.o CC [M] drivers/block/nbd.mod.o CC [M] drivers/block/virtio_blk.mod.o CC [M] drivers/block/xen-blkfront.mod.o CC [M] drivers/block/xen-blkback/xen-blkback.mod.o CC [M] drivers/block/drbd/drbd.mod.o CC [M] drivers/block/rbd.mod.o CC [M] drivers/block/mtip32xx/mtip32xx.mod.o CC [M] drivers/block/zram/zram.mod.o CC [M] drivers/block/null_blk/null_blk.mod.o LD [M] drivers/block/brd.ko LD [M] drivers/block/xen-blkback/xen-blkback.ko LD [M] drivers/block/drbd/drbd.ko LD [M] drivers/block/loop.ko LD [M] drivers/block/floppy.ko LD [M] drivers/block/virtio_blk.ko LD [M] drivers/block/null_blk/null_blk.ko LD [M] drivers/block/rbd.ko LD [M] drivers/block/mtip32xx/mtip32xx.ko LD [M] drivers/block/zram/zram.ko LD [M] drivers/block/nbd.ko LD [M] drivers/block/xen-blkfront.ko nvme (nvme-6.8) # insmod drivers/block/null_blk/null_blk.ko nvme (nvme-6.8) # dmesg -c [23228.355423] null_blk: null_init 2285 abcd 0 abcd_init 0 [23228.357571] null_blk: disk nullb0 created [23228.357574] null_blk: module loaded nvme (nvme-6.8) #
On Jan 17, 2024 / 04:13, Chaitanya Kulkarni wrote: ... > > diff --git a/drivers/block/null_blk/main.c b/drivers/block/null_blk/main.c > > index 36755f263e8e..c3361e521564 100644 > > --- a/drivers/block/null_blk/main.c > > +++ b/drivers/block/null_blk/main.c > > @@ -69,6 +69,7 @@ static LIST_HEAD(nullb_list); > > static struct mutex lock; > > static int null_major; > > static DEFINE_IDA(nullb_indexes); > > +static bool tag_set_initialized = false; > > explicit initializing global bool to false really needed ? That was the point I was not clear. Some of global variables in drivers/block/null_blk/main.c are explicitly initialized, like: ... static bool g_virt_boundary = false; module_param_named(virt_boundary, g_virt_boundary, bool, 0444); MODULE_PARM_DESC(virt_boundary, "Require a virtual boundary for the device. Default: False"); ... But I guess these existing global variables are explicitly initialized because they are used to store module parameters. The variable I introduced is not a module parameter, so now I think it should not be initialized. Will send v2 with the fix.
On 1/16/24 9:13 PM, Chaitanya Kulkarni wrote: > On 1/15/24 19:39, Shin'ichiro Kawasaki wrote: >> Allow setting shared_tags through configfs, which could only be set as a >> module parameter. For that purpose, delay tag_set initialization from >> null_init() to null_add_dev(). Introduce the flag tag_set_initialized to >> manage the initialization status of tag_set. >> >> The following parameters can not be set through configfs yet: >> >> timeout >> requeue >> init_hctx >> >> Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com> >> --- >> This patch will allow running the blktests test cases block/010 and block/022 >> using the built-in null_blk driver. Corresponding blktests side changes are >> drafted here [1]. >> >> [1] https://github.com/kawasaki/blktests/tree/shared_tags >> >> drivers/block/null_blk/main.c | 38 ++++++++++++++++--------------- >> drivers/block/null_blk/null_blk.h | 1 + >> 2 files changed, 21 insertions(+), 18 deletions(-) >> >> diff --git a/drivers/block/null_blk/main.c b/drivers/block/null_blk/main.c >> index 36755f263e8e..c3361e521564 100644 >> --- a/drivers/block/null_blk/main.c >> +++ b/drivers/block/null_blk/main.c >> @@ -69,6 +69,7 @@ static LIST_HEAD(nullb_list); >> static struct mutex lock; >> static int null_major; >> static DEFINE_IDA(nullb_indexes); >> +static bool tag_set_initialized = false; > > explicit initializing global bool to false really needed ? > unless I did something see [1]. > > -ck > > nvme (nvme-6.8) # insmod drivers/block/null_blk/null_blk.ko > nvme (nvme-6.8) # dmesg -c > [23228.355423] null_blk: null_init 2285 abcd 0 abcd_init 0 > [23228.357571] null_blk: disk nullb0 created > [23228.357574] null_blk: module loaded Just as a heads-up, a single test is not proof of anything. That said, static variables are cleared, so they never need to be setup to false.
>> explicit initializing global bool to false really needed ? >> unless I did something see [1]. >> >> -ck >> >> nvme (nvme-6.8) # insmod drivers/block/null_blk/null_blk.ko >> nvme (nvme-6.8) # dmesg -c >> [23228.355423] null_blk: null_init 2285 abcd 0 abcd_init 0 >> [23228.357571] null_blk: disk nullb0 created >> [23228.357574] null_blk: module loaded > Just as a heads-up, a single test is not proof of anything. That said, > static variables are cleared, so they never need to be setup to false. > thanks for the suggestion, will provide detailed explanation for the test to justify the overall impact from next time as I did it last time for similar issue ... -ck
diff --git a/drivers/block/null_blk/main.c b/drivers/block/null_blk/main.c index 36755f263e8e..c3361e521564 100644 --- a/drivers/block/null_blk/main.c +++ b/drivers/block/null_blk/main.c @@ -69,6 +69,7 @@ static LIST_HEAD(nullb_list); static struct mutex lock; static int null_major; static DEFINE_IDA(nullb_indexes); +static bool tag_set_initialized = false; static struct blk_mq_tag_set tag_set; enum { @@ -165,8 +166,8 @@ static bool g_blocking; module_param_named(blocking, g_blocking, bool, 0444); MODULE_PARM_DESC(blocking, "Register as a blocking blk-mq driver device"); -static bool shared_tags; -module_param(shared_tags, bool, 0444); +static bool g_shared_tags; +module_param_named(shared_tags, g_shared_tags, bool, 0444); MODULE_PARM_DESC(shared_tags, "Share tag set between devices for blk-mq"); static bool g_shared_tag_bitmap; @@ -426,6 +427,7 @@ NULLB_DEVICE_ATTR(zone_max_open, uint, NULL); NULLB_DEVICE_ATTR(zone_max_active, uint, NULL); NULLB_DEVICE_ATTR(virt_boundary, bool, NULL); NULLB_DEVICE_ATTR(no_sched, bool, NULL); +NULLB_DEVICE_ATTR(shared_tags, bool, NULL); NULLB_DEVICE_ATTR(shared_tag_bitmap, bool, NULL); static ssize_t nullb_device_power_show(struct config_item *item, char *page) @@ -571,6 +573,7 @@ static struct configfs_attribute *nullb_device_attrs[] = { &nullb_device_attr_zone_offline, &nullb_device_attr_virt_boundary, &nullb_device_attr_no_sched, + &nullb_device_attr_shared_tags, &nullb_device_attr_shared_tag_bitmap, NULL, }; @@ -653,10 +656,11 @@ static ssize_t memb_group_features_show(struct config_item *item, char *page) "badblocks,blocking,blocksize,cache_size," "completion_nsec,discard,home_node,hw_queue_depth," "irqmode,max_sectors,mbps,memory_backed,no_sched," - "poll_queues,power,queue_mode,shared_tag_bitmap,size," - "submit_queues,use_per_node_hctx,virt_boundary,zoned," - "zone_capacity,zone_max_active,zone_max_open," - "zone_nr_conv,zone_offline,zone_readonly,zone_size\n"); + "poll_queues,power,queue_mode,shared_tag_bitmap," + "shared_tags,size,submit_queues,use_per_node_hctx," + "virt_boundary,zoned,zone_capacity,zone_max_active," + "zone_max_open,zone_nr_conv,zone_offline,zone_readonly," + "zone_size\n"); } CONFIGFS_ATTR_RO(memb_group_, features); @@ -738,6 +742,7 @@ static struct nullb_device *null_alloc_dev(void) dev->zone_max_active = g_zone_max_active; dev->virt_boundary = g_virt_boundary; dev->no_sched = g_no_sched; + dev->shared_tags = g_shared_tags; dev->shared_tag_bitmap = g_shared_tag_bitmap; return dev; } @@ -2124,7 +2129,13 @@ static int null_add_dev(struct nullb_device *dev) goto out_free_nullb; if (dev->queue_mode == NULL_Q_MQ) { - if (shared_tags) { + if (dev->shared_tags) { + if (!tag_set_initialized) { + rv = null_init_tag_set(NULL, &tag_set); + if (rv) + goto out_cleanup_queues; + tag_set_initialized = true; + } nullb->tag_set = &tag_set; rv = 0; } else { @@ -2311,18 +2322,12 @@ static int __init null_init(void) g_submit_queues = 1; } - if (g_queue_mode == NULL_Q_MQ && shared_tags) { - ret = null_init_tag_set(NULL, &tag_set); - if (ret) - return ret; - } - config_group_init(&nullb_subsys.su_group); mutex_init(&nullb_subsys.su_mutex); ret = configfs_register_subsystem(&nullb_subsys); if (ret) - goto err_tagset; + return ret; mutex_init(&lock); @@ -2349,9 +2354,6 @@ static int __init null_init(void) unregister_blkdev(null_major, "nullb"); err_conf: configfs_unregister_subsystem(&nullb_subsys); -err_tagset: - if (g_queue_mode == NULL_Q_MQ && shared_tags) - blk_mq_free_tag_set(&tag_set); return ret; } @@ -2370,7 +2372,7 @@ static void __exit null_exit(void) } mutex_unlock(&lock); - if (g_queue_mode == NULL_Q_MQ && shared_tags) + if (tag_set_initialized) blk_mq_free_tag_set(&tag_set); } diff --git a/drivers/block/null_blk/null_blk.h b/drivers/block/null_blk/null_blk.h index 929f659dd255..7bcfc0922ae8 100644 --- a/drivers/block/null_blk/null_blk.h +++ b/drivers/block/null_blk/null_blk.h @@ -119,6 +119,7 @@ struct nullb_device { bool zoned; /* if device is zoned */ bool virt_boundary; /* virtual boundary on/off for the device */ bool no_sched; /* no IO scheduler for the device */ + bool shared_tags; /* share tag set between devices for blk-mq */ bool shared_tag_bitmap; /* use hostwide shared tags */ };
Allow setting shared_tags through configfs, which could only be set as a module parameter. For that purpose, delay tag_set initialization from null_init() to null_add_dev(). Introduce the flag tag_set_initialized to manage the initialization status of tag_set. The following parameters can not be set through configfs yet: timeout requeue init_hctx Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com> --- This patch will allow running the blktests test cases block/010 and block/022 using the built-in null_blk driver. Corresponding blktests side changes are drafted here [1]. [1] https://github.com/kawasaki/blktests/tree/shared_tags drivers/block/null_blk/main.c | 38 ++++++++++++++++--------------- drivers/block/null_blk/null_blk.h | 1 + 2 files changed, 21 insertions(+), 18 deletions(-)