Re: [PATCH 1/2] Convert target drivers to use sbitmap

2018-06-12 Thread Matthew Wilcox 
On Tue, Jun 12, 2018 at 03:22:42PM +, Bart Van Assche wrote:
> On Tue, 2018-05-15 at 09:00 -0700, Matthew Wilcox wrote:
> > diff --git a/drivers/scsi/qla2xxx/qla_target.c 
> > b/drivers/scsi/qla2xxx/qla_target.c
> > index 025dc2d3f3de..cdf671c2af61 100644
> > --- a/drivers/scsi/qla2xxx/qla_target.c
> > +++ b/drivers/scsi/qla2xxx/qla_target.c
> > @@ -3719,7 +3719,8 @@ void qlt_free_cmd(struct qla_tgt_cmd *cmd)
> > return;
> > }
> > cmd->jiffies_at_free = get_jiffies_64();
> > -   percpu_ida_free(>se_sess->sess_tag_pool, cmd->se_cmd.map_tag);
> > +   sbitmap_queue_clear(>se_sess->sess_tag_pool, cmd->se_cmd.map_tag,
> > +   cmd->se_cmd.map_cpu);
> >  }
> >  EXPORT_SYMBOL(qlt_free_cmd);
> 
> Please introduce functions in the target core for allocating and freeing a tag
> instead of spreading the knowledge of how to allocate and free tags over all
> target drivers.

I can't without doing an unreasonably large amount of work on drivers that
I have no way to test.  Some of the drivers have the se_cmd already; some
of them don't.  I'd be happy to introduce a common function for freeing
a tag.

> > +int iscsit_wait_for_tag(struct se_session *se_sess, int state, int *cpup)
> > +{
> > +   int tag = -1;
> > +   DEFINE_WAIT(wait);
> > +   struct sbq_wait_state *ws;
> > +
> > +   if (state == TASK_RUNNING)
> > +   return tag;
> > +
> > +   ws = _sess->sess_tag_pool.ws[0];
> > +   for (;;) {
> > +   prepare_to_wait_exclusive(>wait, , state);
> > +   if (signal_pending_state(state, current))
> > +   break;
> 
> This looks weird to me. Shouldn't target code ignore signals instead of 
> causing
> tag allocation to fail if a signal is received?

It's what the current code did:

-   if (signal_pending_state(state, current)) {
-   tag = -ERESTARTSYS;
-   break;
-   }

and the current callers literally indicate that they want signals:

drivers/infiniband/ulp/isert/ib_isert.c:cmd = iscsit_allocate_cmd(conn, 
TASK_INTERRUPTIBLE);
drivers/target/iscsi/iscsi_target.c:cmd = iscsit_allocate_cmd(conn, 
TASK_INTERRUPTIBLE);

(etc)

Re: [PATCH 1/2] Convert target drivers to use sbitmap

2018-06-12 Thread Matthew Wilcox 
On Tue, Jun 12, 2018 at 03:22:42PM +, Bart Van Assche wrote:
> On Tue, 2018-05-15 at 09:00 -0700, Matthew Wilcox wrote:
> > diff --git a/drivers/scsi/qla2xxx/qla_target.c 
> > b/drivers/scsi/qla2xxx/qla_target.c
> > index 025dc2d3f3de..cdf671c2af61 100644
> > --- a/drivers/scsi/qla2xxx/qla_target.c
> > +++ b/drivers/scsi/qla2xxx/qla_target.c
> > @@ -3719,7 +3719,8 @@ void qlt_free_cmd(struct qla_tgt_cmd *cmd)
> > return;
> > }
> > cmd->jiffies_at_free = get_jiffies_64();
> > -   percpu_ida_free(>se_sess->sess_tag_pool, cmd->se_cmd.map_tag);
> > +   sbitmap_queue_clear(>se_sess->sess_tag_pool, cmd->se_cmd.map_tag,
> > +   cmd->se_cmd.map_cpu);
> >  }
> >  EXPORT_SYMBOL(qlt_free_cmd);
> 
> Please introduce functions in the target core for allocating and freeing a tag
> instead of spreading the knowledge of how to allocate and free tags over all
> target drivers.

I can't without doing an unreasonably large amount of work on drivers that
I have no way to test.  Some of the drivers have the se_cmd already; some
of them don't.  I'd be happy to introduce a common function for freeing
a tag.

> > +int iscsit_wait_for_tag(struct se_session *se_sess, int state, int *cpup)
> > +{
> > +   int tag = -1;
> > +   DEFINE_WAIT(wait);
> > +   struct sbq_wait_state *ws;
> > +
> > +   if (state == TASK_RUNNING)
> > +   return tag;
> > +
> > +   ws = _sess->sess_tag_pool.ws[0];
> > +   for (;;) {
> > +   prepare_to_wait_exclusive(>wait, , state);
> > +   if (signal_pending_state(state, current))
> > +   break;
> 
> This looks weird to me. Shouldn't target code ignore signals instead of 
> causing
> tag allocation to fail if a signal is received?

It's what the current code did:

-   if (signal_pending_state(state, current)) {
-   tag = -ERESTARTSYS;
-   break;
-   }

and the current callers literally indicate that they want signals:

drivers/infiniband/ulp/isert/ib_isert.c:cmd = iscsit_allocate_cmd(conn, 
TASK_INTERRUPTIBLE);
drivers/target/iscsi/iscsi_target.c:cmd = iscsit_allocate_cmd(conn, 
TASK_INTERRUPTIBLE);

(etc)

Re: [PATCH 1/2] Convert target drivers to use sbitmap

2018-05-16 Thread kbuild test robot 
Hi Matthew,

I love your patch! Perhaps something to improve:

[auto build test WARNING on linus/master]
[also build test WARNING on v4.17-rc5 next-20180516]
[cannot apply to target/master]
[if your patch is applied to the wrong git tree, please drop us a note to help 
improve the system]

url:
https://github.com/0day-ci/linux/commits/Matthew-Wilcox/Use-sbitmap-instead-of-percpu_ida/20180516-143658
reproduce:
# apt-get install sparse
make ARCH=x86_64 allmodconfig
make C=1 CF=-D__CHECK_ENDIAN__


sparse warnings: (new ones prefixed by >>)

>> drivers/target/iscsi/iscsi_target_util.c:150:5: sparse: symbol 
>> 'iscsit_wait_for_tag' was not declared. Should it be static?
   drivers/target/iscsi/iscsi_target_util.c:1174:31: sparse: expression using 
sizeof(void)
   drivers/target/iscsi/iscsi_target_util.c:1174:31: sparse: expression using 
sizeof(void)

Please review and possibly fold the followup patch.

---
0-DAY kernel test infrastructureOpen Source Technology Center
https://lists.01.org/pipermail/kbuild-all   Intel Corporation

Re: [PATCH 1/2] Convert target drivers to use sbitmap

2018-05-16 Thread kbuild test robot 
Hi Matthew,

I love your patch! Perhaps something to improve:

[auto build test WARNING on linus/master]
[also build test WARNING on v4.17-rc5 next-20180516]
[cannot apply to target/master]
[if your patch is applied to the wrong git tree, please drop us a note to help 
improve the system]

url:
https://github.com/0day-ci/linux/commits/Matthew-Wilcox/Use-sbitmap-instead-of-percpu_ida/20180516-143658
reproduce:
# apt-get install sparse
make ARCH=x86_64 allmodconfig
make C=1 CF=-D__CHECK_ENDIAN__


sparse warnings: (new ones prefixed by >>)

>> drivers/target/iscsi/iscsi_target_util.c:150:5: sparse: symbol 
>> 'iscsit_wait_for_tag' was not declared. Should it be static?
   drivers/target/iscsi/iscsi_target_util.c:1174:31: sparse: expression using 
sizeof(void)
   drivers/target/iscsi/iscsi_target_util.c:1174:31: sparse: expression using 
sizeof(void)

Please review and possibly fold the followup patch.

---
0-DAY kernel test infrastructureOpen Source Technology Center
https://lists.01.org/pipermail/kbuild-all   Intel Corporation

Re: [PATCH 1/2] Convert target drivers to use sbitmap

2018-05-15 Thread Felipe Balbi 

Hi,

Matthew Wilcox  writes:
> From: Matthew Wilcox 
>
> The sbitmap and the percpu_ida perform essentially the same task,
> allocating tags for commands.  Since the sbitmap is more used than
> the percpu_ida, convert the percpu_ida users to the sbitmap API.
>
> Signed-off-by: Matthew Wilcox 
> ---

[...]

>  drivers/usb/gadget/function/f_tcm.c  |  8 +++---

for drivers/usb/gadget/function/f_tcm.c

Acked-by: Felipe Balbi 

-- 
balbi


signature.asc
Description: PGP signature

Re: [PATCH 1/2] Convert target drivers to use sbitmap

2018-05-15 Thread Felipe Balbi 

Hi,

Matthew Wilcox  writes:
> From: Matthew Wilcox 
>
> The sbitmap and the percpu_ida perform essentially the same task,
> allocating tags for commands.  Since the sbitmap is more used than
> the percpu_ida, convert the percpu_ida users to the sbitmap API.
>
> Signed-off-by: Matthew Wilcox 
> ---

[...]

>  drivers/usb/gadget/function/f_tcm.c  |  8 +++---

for drivers/usb/gadget/function/f_tcm.c

Acked-by: Felipe Balbi 

-- 
balbi


signature.asc
Description: PGP signature

Re: [PATCH 1/2] Convert target drivers to use sbitmap

2018-05-15 Thread Jens Axboe 
On 5/15/18 10:11 AM, Jens Axboe wrote:
> On 5/15/18 10:00 AM, Matthew Wilcox wrote:
>> From: Matthew Wilcox 
>>
>> The sbitmap and the percpu_ida perform essentially the same task,
>> allocating tags for commands.  Since the sbitmap is more used than
>> the percpu_ida, convert the percpu_ida users to the sbitmap API.
> 
> It should also be the same performance as percpu_ida in light use, and
> performs much better at > 50% utilization of the tag space. I think
> that's better justification than "more used than".

Had to search long and hard for the perf numbers I did for percpu_ida
on higher utilization, but here it is:

https://lkml.org/lkml/2014/4/22/553

-- 
Jens Axboe

Re: [PATCH 1/2] Convert target drivers to use sbitmap

2018-05-15 Thread Jens Axboe 
On 5/15/18 10:11 AM, Jens Axboe wrote:
> On 5/15/18 10:00 AM, Matthew Wilcox wrote:
>> From: Matthew Wilcox 
>>
>> The sbitmap and the percpu_ida perform essentially the same task,
>> allocating tags for commands.  Since the sbitmap is more used than
>> the percpu_ida, convert the percpu_ida users to the sbitmap API.
> 
> It should also be the same performance as percpu_ida in light use, and
> performs much better at > 50% utilization of the tag space. I think
> that's better justification than "more used than".

Had to search long and hard for the perf numbers I did for percpu_ida
on higher utilization, but here it is:

https://lkml.org/lkml/2014/4/22/553

-- 
Jens Axboe

Re: [PATCH 1/2] Convert target drivers to use sbitmap

2018-05-15 Thread Jens Axboe 
On 5/15/18 10:00 AM, Matthew Wilcox wrote:
> From: Matthew Wilcox 
> 
> The sbitmap and the percpu_ida perform essentially the same task,
> allocating tags for commands.  Since the sbitmap is more used than
> the percpu_ida, convert the percpu_ida users to the sbitmap API.

It should also be the same performance as percpu_ida in light use, and
performs much better at > 50% utilization of the tag space. I think
that's better justification than "more used than".

> diff --git a/drivers/target/iscsi/iscsi_target_util.c 
> b/drivers/target/iscsi/iscsi_target_util.c
> index 4435bf374d2d..28bcffae609f 100644
> --- a/drivers/target/iscsi/iscsi_target_util.c
> +++ b/drivers/target/iscsi/iscsi_target_util.c
> @@ -17,7 +17,7 @@
>   
> **/
>  
>  #include 
> -#include 
> +#include 
>  #include  /* ipv6_addr_equal() */
>  #include 
>  #include 
> @@ -147,6 +147,28 @@ void iscsit_free_r2ts_from_list(struct iscsi_cmd *cmd)
>   spin_unlock_bh(>r2t_lock);
>  }
>  
> +int iscsit_wait_for_tag(struct se_session *se_sess, int state, int *cpup)
> +{
> + int tag = -1;
> + DEFINE_WAIT(wait);
> + struct sbq_wait_state *ws;
> +
> + if (state == TASK_RUNNING)
> + return tag;
> +
> + ws = _sess->sess_tag_pool.ws[0];
> + for (;;) {
> + prepare_to_wait_exclusive(>wait, , state);
> + if (signal_pending_state(state, current))
> + break;
> + schedule();
> + tag = sbitmap_queue_get(_sess->sess_tag_pool, cpup);
> + }
> +
> + finish_wait(>wait, );
> + return tag;
> +}

Seems like that should be:


ws = _sess->sess_tag_pool.ws[0];
for (;;) {
prepare_to_wait_exclusive(>wait, , state);
if (signal_pending_state(state, current))
break;
tag = sbitmap_queue_get(_sess->sess_tag_pool, cpup);
if (tag != -1)
break;
schedule();
}

finish_wait(>wait, );
return tag;

>  /*
>   * May be called from software interrupt (timer) context for allocating
>   * iSCSI NopINs.
> @@ -155,9 +177,11 @@ struct iscsi_cmd *iscsit_allocate_cmd(struct iscsi_conn 
> *conn, int state)
>  {
>   struct iscsi_cmd *cmd;
>   struct se_session *se_sess = conn->sess->se_sess;
> - int size, tag;
> + int size, tag, cpu;
>  
> - tag = percpu_ida_alloc(_sess->sess_tag_pool, state);
> + tag = sbitmap_queue_get(_sess->sess_tag_pool, );
> + if (tag < 0)
> + tag = iscsit_wait_for_tag(se_sess, state, );
>   if (tag < 0)
>   return NULL;

Might make sense to just roll the whole thing into iscsi_get_tag(), that
would be cleaner.

sbitmap should provide a helper for that, but we can do that cleanup
later. That would encapsulate things like the per-cpu caching hint too,
for instance.

Rest looks fine to me.

-- 
Jens Axboe

Re: [PATCH 1/2] Convert target drivers to use sbitmap

2018-05-15 Thread Jens Axboe 
On 5/15/18 10:00 AM, Matthew Wilcox wrote:
> From: Matthew Wilcox 
> 
> The sbitmap and the percpu_ida perform essentially the same task,
> allocating tags for commands.  Since the sbitmap is more used than
> the percpu_ida, convert the percpu_ida users to the sbitmap API.

It should also be the same performance as percpu_ida in light use, and
performs much better at > 50% utilization of the tag space. I think
that's better justification than "more used than".

> diff --git a/drivers/target/iscsi/iscsi_target_util.c 
> b/drivers/target/iscsi/iscsi_target_util.c
> index 4435bf374d2d..28bcffae609f 100644
> --- a/drivers/target/iscsi/iscsi_target_util.c
> +++ b/drivers/target/iscsi/iscsi_target_util.c
> @@ -17,7 +17,7 @@
>   
> **/
>  
>  #include 
> -#include 
> +#include 
>  #include  /* ipv6_addr_equal() */
>  #include 
>  #include 
> @@ -147,6 +147,28 @@ void iscsit_free_r2ts_from_list(struct iscsi_cmd *cmd)
>   spin_unlock_bh(>r2t_lock);
>  }
>  
> +int iscsit_wait_for_tag(struct se_session *se_sess, int state, int *cpup)
> +{
> + int tag = -1;
> + DEFINE_WAIT(wait);
> + struct sbq_wait_state *ws;
> +
> + if (state == TASK_RUNNING)
> + return tag;
> +
> + ws = _sess->sess_tag_pool.ws[0];
> + for (;;) {
> + prepare_to_wait_exclusive(>wait, , state);
> + if (signal_pending_state(state, current))
> + break;
> + schedule();
> + tag = sbitmap_queue_get(_sess->sess_tag_pool, cpup);
> + }
> +
> + finish_wait(>wait, );
> + return tag;
> +}

Seems like that should be:


ws = _sess->sess_tag_pool.ws[0];
for (;;) {
prepare_to_wait_exclusive(>wait, , state);
if (signal_pending_state(state, current))
break;
tag = sbitmap_queue_get(_sess->sess_tag_pool, cpup);
if (tag != -1)
break;
schedule();
}

finish_wait(>wait, );
return tag;

>  /*
>   * May be called from software interrupt (timer) context for allocating
>   * iSCSI NopINs.
> @@ -155,9 +177,11 @@ struct iscsi_cmd *iscsit_allocate_cmd(struct iscsi_conn 
> *conn, int state)
>  {
>   struct iscsi_cmd *cmd;
>   struct se_session *se_sess = conn->sess->se_sess;
> - int size, tag;
> + int size, tag, cpu;
>  
> - tag = percpu_ida_alloc(_sess->sess_tag_pool, state);
> + tag = sbitmap_queue_get(_sess->sess_tag_pool, );
> + if (tag < 0)
> + tag = iscsit_wait_for_tag(se_sess, state, );
>   if (tag < 0)
>   return NULL;

Might make sense to just roll the whole thing into iscsi_get_tag(), that
would be cleaner.

sbitmap should provide a helper for that, but we can do that cleanup
later. That would encapsulate things like the per-cpu caching hint too,
for instance.

Rest looks fine to me.

-- 
Jens Axboe

[PATCH 1/2] Convert target drivers to use sbitmap

2018-05-15 Thread Matthew Wilcox 
From: Matthew Wilcox 

The sbitmap and the percpu_ida perform essentially the same task,
allocating tags for commands.  Since the sbitmap is more used than
the percpu_ida, convert the percpu_ida users to the sbitmap API.

Signed-off-by: Matthew Wilcox 
---
 drivers/scsi/qla2xxx/qla_target.c| 16 ++-
 drivers/target/iscsi/iscsi_target_util.c | 34 +---
 drivers/target/sbp/sbp_target.c  |  8 +++---
 drivers/target/target_core_transport.c   |  5 ++--
 drivers/target/tcm_fc/tfc_cmd.c  | 11 
 drivers/usb/gadget/function/f_tcm.c  |  8 +++---
 drivers/vhost/scsi.c |  9 ---
 drivers/xen/xen-scsiback.c   |  8 +++---
 include/target/iscsi/iscsi_target_core.h |  1 +
 include/target/target_core_base.h|  5 ++--
 10 files changed, 73 insertions(+), 32 deletions(-)

diff --git a/drivers/scsi/qla2xxx/qla_target.c 
b/drivers/scsi/qla2xxx/qla_target.c
index 025dc2d3f3de..cdf671c2af61 100644
--- a/drivers/scsi/qla2xxx/qla_target.c
+++ b/drivers/scsi/qla2xxx/qla_target.c
@@ -3719,7 +3719,8 @@ void qlt_free_cmd(struct qla_tgt_cmd *cmd)
return;
}
cmd->jiffies_at_free = get_jiffies_64();
-   percpu_ida_free(>se_sess->sess_tag_pool, cmd->se_cmd.map_tag);
+   sbitmap_queue_clear(>se_sess->sess_tag_pool, cmd->se_cmd.map_tag,
+   cmd->se_cmd.map_cpu);
 }
 EXPORT_SYMBOL(qlt_free_cmd);
 
@@ -4084,7 +4085,8 @@ static void __qlt_do_work(struct qla_tgt_cmd *cmd)
qlt_send_term_exchange(qpair, NULL, >atio, 1, 0);
 
qlt_decr_num_pend_cmds(vha);
-   percpu_ida_free(>se_sess->sess_tag_pool, cmd->se_cmd.map_tag);
+   sbitmap_queue_clear(>se_sess->sess_tag_pool, cmd->se_cmd.map_tag,
+   cmd->se_cmd.map_cpu);
spin_unlock_irqrestore(qpair->qp_lock_ptr, flags);
 
spin_lock_irqsave(>tgt.sess_lock, flags);
@@ -4215,9 +4217,9 @@ static struct qla_tgt_cmd *qlt_get_tag(scsi_qla_host_t 
*vha,
 {
struct se_session *se_sess = sess->se_sess;
struct qla_tgt_cmd *cmd;
-   int tag;
+   int tag, cpu;
 
-   tag = percpu_ida_alloc(_sess->sess_tag_pool, TASK_RUNNING);
+   tag = sbitmap_queue_get(_sess->sess_tag_pool, );
if (tag < 0)
return NULL;
 
@@ -4230,6 +4232,7 @@ static struct qla_tgt_cmd *qlt_get_tag(scsi_qla_host_t 
*vha,
qlt_incr_num_pend_cmds(vha);
cmd->vha = vha;
cmd->se_cmd.map_tag = tag;
+   cmd->se_cmd.map_cpu = cpu;
cmd->sess = sess;
cmd->loop_id = sess->loop_id;
cmd->conf_compl_supported = sess->conf_compl_supported;
@@ -5212,7 +5215,7 @@ qlt_alloc_qfull_cmd(struct scsi_qla_host *vha,
struct fc_port *sess;
struct se_session *se_sess;
struct qla_tgt_cmd *cmd;
-   int tag;
+   int tag, cpu;
unsigned long flags;
 
if (unlikely(tgt->tgt_stop)) {
@@ -5244,7 +5247,7 @@ qlt_alloc_qfull_cmd(struct scsi_qla_host *vha,
 
se_sess = sess->se_sess;
 
-   tag = percpu_ida_alloc(_sess->sess_tag_pool, TASK_RUNNING);
+   tag = sbitmap_queue_get(_sess->sess_tag_pool, );
if (tag < 0)
return;
 
@@ -5275,6 +5278,7 @@ qlt_alloc_qfull_cmd(struct scsi_qla_host *vha,
cmd->reset_count = ha->base_qpair->chip_reset;
cmd->q_full = 1;
cmd->qpair = ha->base_qpair;
+   cmd->se_cmd.map_cpu = cpu;
 
if (qfull) {
cmd->q_full = 1;
diff --git a/drivers/target/iscsi/iscsi_target_util.c 
b/drivers/target/iscsi/iscsi_target_util.c
index 4435bf374d2d..28bcffae609f 100644
--- a/drivers/target/iscsi/iscsi_target_util.c
+++ b/drivers/target/iscsi/iscsi_target_util.c
@@ -17,7 +17,7 @@
  
**/
 
 #include 
-#include 
+#include 
 #include  /* ipv6_addr_equal() */
 #include 
 #include 
@@ -147,6 +147,28 @@ void iscsit_free_r2ts_from_list(struct iscsi_cmd *cmd)
spin_unlock_bh(>r2t_lock);
 }
 
+int iscsit_wait_for_tag(struct se_session *se_sess, int state, int *cpup)
+{
+   int tag = -1;
+   DEFINE_WAIT(wait);
+   struct sbq_wait_state *ws;
+
+   if (state == TASK_RUNNING)
+   return tag;
+
+   ws = _sess->sess_tag_pool.ws[0];
+   for (;;) {
+   prepare_to_wait_exclusive(>wait, , state);
+   if (signal_pending_state(state, current))
+   break;
+   schedule();
+   tag = sbitmap_queue_get(_sess->sess_tag_pool, cpup);
+   }
+
+   finish_wait(>wait, );
+   return tag;
+}
+
 /*
  * May be called from software interrupt (timer) context for allocating
  * iSCSI NopINs.
@@ -155,9 +177,11 @@ struct iscsi_cmd *iscsit_allocate_cmd(struct iscsi_conn 
*conn, int state)
 {
struct iscsi_cmd *cmd;
struct se_session *se_sess = conn->sess->se_sess;
-   int size, tag;
+   int

[PATCH 1/2] Convert target drivers to use sbitmap

2018-05-15 Thread Matthew Wilcox 
From: Matthew Wilcox 

The sbitmap and the percpu_ida perform essentially the same task,
allocating tags for commands.  Since the sbitmap is more used than
the percpu_ida, convert the percpu_ida users to the sbitmap API.

Signed-off-by: Matthew Wilcox 
---
 drivers/scsi/qla2xxx/qla_target.c| 16 ++-
 drivers/target/iscsi/iscsi_target_util.c | 34 +---
 drivers/target/sbp/sbp_target.c  |  8 +++---
 drivers/target/target_core_transport.c   |  5 ++--
 drivers/target/tcm_fc/tfc_cmd.c  | 11 
 drivers/usb/gadget/function/f_tcm.c  |  8 +++---
 drivers/vhost/scsi.c |  9 ---
 drivers/xen/xen-scsiback.c   |  8 +++---
 include/target/iscsi/iscsi_target_core.h |  1 +
 include/target/target_core_base.h|  5 ++--
 10 files changed, 73 insertions(+), 32 deletions(-)

diff --git a/drivers/scsi/qla2xxx/qla_target.c 
b/drivers/scsi/qla2xxx/qla_target.c
index 025dc2d3f3de..cdf671c2af61 100644
--- a/drivers/scsi/qla2xxx/qla_target.c
+++ b/drivers/scsi/qla2xxx/qla_target.c
@@ -3719,7 +3719,8 @@ void qlt_free_cmd(struct qla_tgt_cmd *cmd)
return;
}
cmd->jiffies_at_free = get_jiffies_64();
-   percpu_ida_free(>se_sess->sess_tag_pool, cmd->se_cmd.map_tag);
+   sbitmap_queue_clear(>se_sess->sess_tag_pool, cmd->se_cmd.map_tag,
+   cmd->se_cmd.map_cpu);
 }
 EXPORT_SYMBOL(qlt_free_cmd);
 
@@ -4084,7 +4085,8 @@ static void __qlt_do_work(struct qla_tgt_cmd *cmd)
qlt_send_term_exchange(qpair, NULL, >atio, 1, 0);
 
qlt_decr_num_pend_cmds(vha);
-   percpu_ida_free(>se_sess->sess_tag_pool, cmd->se_cmd.map_tag);
+   sbitmap_queue_clear(>se_sess->sess_tag_pool, cmd->se_cmd.map_tag,
+   cmd->se_cmd.map_cpu);
spin_unlock_irqrestore(qpair->qp_lock_ptr, flags);
 
spin_lock_irqsave(>tgt.sess_lock, flags);
@@ -4215,9 +4217,9 @@ static struct qla_tgt_cmd *qlt_get_tag(scsi_qla_host_t 
*vha,
 {
struct se_session *se_sess = sess->se_sess;
struct qla_tgt_cmd *cmd;
-   int tag;
+   int tag, cpu;
 
-   tag = percpu_ida_alloc(_sess->sess_tag_pool, TASK_RUNNING);
+   tag = sbitmap_queue_get(_sess->sess_tag_pool, );
if (tag < 0)
return NULL;
 
@@ -4230,6 +4232,7 @@ static struct qla_tgt_cmd *qlt_get_tag(scsi_qla_host_t 
*vha,
qlt_incr_num_pend_cmds(vha);
cmd->vha = vha;
cmd->se_cmd.map_tag = tag;
+   cmd->se_cmd.map_cpu = cpu;
cmd->sess = sess;
cmd->loop_id = sess->loop_id;
cmd->conf_compl_supported = sess->conf_compl_supported;
@@ -5212,7 +5215,7 @@ qlt_alloc_qfull_cmd(struct scsi_qla_host *vha,
struct fc_port *sess;
struct se_session *se_sess;
struct qla_tgt_cmd *cmd;
-   int tag;
+   int tag, cpu;
unsigned long flags;
 
if (unlikely(tgt->tgt_stop)) {
@@ -5244,7 +5247,7 @@ qlt_alloc_qfull_cmd(struct scsi_qla_host *vha,
 
se_sess = sess->se_sess;
 
-   tag = percpu_ida_alloc(_sess->sess_tag_pool, TASK_RUNNING);
+   tag = sbitmap_queue_get(_sess->sess_tag_pool, );
if (tag < 0)
return;
 
@@ -5275,6 +5278,7 @@ qlt_alloc_qfull_cmd(struct scsi_qla_host *vha,
cmd->reset_count = ha->base_qpair->chip_reset;
cmd->q_full = 1;
cmd->qpair = ha->base_qpair;
+   cmd->se_cmd.map_cpu = cpu;
 
if (qfull) {
cmd->q_full = 1;
diff --git a/drivers/target/iscsi/iscsi_target_util.c 
b/drivers/target/iscsi/iscsi_target_util.c
index 4435bf374d2d..28bcffae609f 100644
--- a/drivers/target/iscsi/iscsi_target_util.c
+++ b/drivers/target/iscsi/iscsi_target_util.c
@@ -17,7 +17,7 @@
  
**/
 
 #include 
-#include 
+#include 
 #include  /* ipv6_addr_equal() */
 #include 
 #include 
@@ -147,6 +147,28 @@ void iscsit_free_r2ts_from_list(struct iscsi_cmd *cmd)
spin_unlock_bh(>r2t_lock);
 }
 
+int iscsit_wait_for_tag(struct se_session *se_sess, int state, int *cpup)
+{
+   int tag = -1;
+   DEFINE_WAIT(wait);
+   struct sbq_wait_state *ws;
+
+   if (state == TASK_RUNNING)
+   return tag;
+
+   ws = _sess->sess_tag_pool.ws[0];
+   for (;;) {
+   prepare_to_wait_exclusive(>wait, , state);
+   if (signal_pending_state(state, current))
+   break;
+   schedule();
+   tag = sbitmap_queue_get(_sess->sess_tag_pool, cpup);
+   }
+
+   finish_wait(>wait, );
+   return tag;
+}
+
 /*
  * May be called from software interrupt (timer) context for allocating
  * iSCSI NopINs.
@@ -155,9 +177,11 @@ struct iscsi_cmd *iscsit_allocate_cmd(struct iscsi_conn 
*conn, int state)
 {
struct iscsi_cmd *cmd;
struct se_session *se_sess = conn->sess->se_sess;
-   int size, tag;
+   int size, tag, cpu;
 
-   tag =