Only unlock the root node, if current node (rnp) is not
root node.
Signed-off-by: Neeraj Upadhyay <[email protected]>
---
kernel/rcu/tree_stall.h | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/kernel/rcu/tree_stall.h b/kernel/rcu/tree_stall.h
index f65a73a..0651833 100644
--- a/kernel/rcu/tree_stall.h
+++ b/kernel/rcu/tree_stall.h
@@ -630,7 +630,9 @@ static void rcu_check_gp_start_stall(struct rcu_node *rnp, struct rcu_data *rdp,
time_before(j, rcu_state.gp_req_activity + gpssdelay) ||
time_before(j, rcu_state.gp_activity + gpssdelay) ||
atomic_xchg(&warned, 1)) {
- raw_spin_unlock_rcu_node(rnp_root); /* irqs remain disabled. */
+ if (rnp_root != rnp)
+ /* irqs remain disabled. */
+ raw_spin_unlock_rcu_node(rnp_root);
raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
return;
}
--
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a
member of the Code Aurora Forum, hosted by The Linux Foundation
On 3/29/2019 4:57 PM, Neeraj Upadhyay wrote:
> Only unlock the root node, if current node (rnp) is not
> root node.
>
> Signed-off-by: Neeraj Upadhyay <[email protected]>
> ---
> kernel/rcu/tree_stall.h | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/kernel/rcu/tree_stall.h b/kernel/rcu/tree_stall.h
> index f65a73a..0651833 100644
> --- a/kernel/rcu/tree_stall.h
> +++ b/kernel/rcu/tree_stall.h
why this is showing as under tree_stall.h while it is under
"kernel/rcu/tree.c"
> @@ -630,7 +630,9 @@ static void rcu_check_gp_start_stall(struct rcu_node *rnp, struct rcu_data *rdp,
> time_before(j, rcu_state.gp_req_activity + gpssdelay) ||
> time_before(j, rcu_state.gp_activity + gpssdelay) ||
> atomic_xchg(&warned, 1)) {
> - raw_spin_unlock_rcu_node(rnp_root); /* irqs remain disabled. */
> + if (rnp_root != rnp)
> + /* irqs remain disabled. */
> + raw_spin_unlock_rcu_node(rnp_root);
Looks good as it will balance the lock .if it is the root_node, which
was not there earlier, and unlock was happening without any lock on root.
Reviewed-by: Mukesh Ojha <[email protected]>
Cheers,
-Mukesh
> raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
> return;
> }
On 3/29/19 6:58 PM, Mukesh Ojha wrote:
>
> On 3/29/2019 4:57 PM, Neeraj Upadhyay wrote:
>> Only unlock the root node, if current node (rnp) is not
>> root node.
>>
>> Signed-off-by: Neeraj Upadhyay <[email protected]>
>
>
>
>> ---
>> kernel/rcu/tree_stall.h | 4 +++-
>> 1 file changed, 3 insertions(+), 1 deletion(-)
>>
>> diff --git a/kernel/rcu/tree_stall.h b/kernel/rcu/tree_stall.h
>> index f65a73a..0651833 100644
>> --- a/kernel/rcu/tree_stall.h
>> +++ b/kernel/rcu/tree_stall.h
>
>
> why this is showing as under tree_stall.h while it is under
> "kernel/rcu/tree.c"
It's moved in
https://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git/commit/?h=dev&id=10462d6f58fb6dbde7563e9343505d98d5bfba3d
Please see linux-rcu dev tree for other changes, which moves code to
this file.
Thanks
Neeraj
>
>> @@ -630,7 +630,9 @@ static void rcu_check_gp_start_stall(struct
>> rcu_node *rnp, struct rcu_data *rdp,
>> time_before(j, rcu_state.gp_req_activity + gpssdelay) ||
>> time_before(j, rcu_state.gp_activity + gpssdelay) ||
>> atomic_xchg(&warned, 1)) {
>> - raw_spin_unlock_rcu_node(rnp_root); /* irqs remain disabled. */
>> + if (rnp_root != rnp)
>> + /* irqs remain disabled. */
>> + raw_spin_unlock_rcu_node(rnp_root);
>
> Looks good as it will balance the lock .if it is the root_node, which
> was not there earlier, and unlock was happening without any lock on root.
>
> Reviewed-by: Mukesh Ojha <[email protected]>
>
> Cheers,
> -Mukesh
>
>> raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
>> return;
>> }
--
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a
member of the Code Aurora Forum, hosted by The Linux Foundation
On Fri, Mar 29, 2019 at 07:52:15PM +0530, Neeraj Upadhyay wrote:
>
>
> On 3/29/19 6:58 PM, Mukesh Ojha wrote:
> >
> >On 3/29/2019 4:57 PM, Neeraj Upadhyay wrote:
> >>Only unlock the root node, if current node (rnp) is not
> >>root node.
> >>
> >>Signed-off-by: Neeraj Upadhyay <[email protected]>
> >
> >
> >
> >>---
> >>? kernel/rcu/tree_stall.h | 4 +++-
> >>? 1 file changed, 3 insertions(+), 1 deletion(-)
> >>
> >>diff --git a/kernel/rcu/tree_stall.h b/kernel/rcu/tree_stall.h
> >>index f65a73a..0651833 100644
> >>--- a/kernel/rcu/tree_stall.h
> >>+++ b/kernel/rcu/tree_stall.h
> >
> >
> >why this is showing as under tree_stall.h while it is under
> >"kernel/rcu/tree.c"
>
> It's moved in https://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git/commit/?h=dev&id=10462d6f58fb6dbde7563e9343505d98d5bfba3d
>
> Please see linux-rcu dev tree for other changes, which moves code to
> this file.
>
>
> Thanks
> Neeraj
>
> >
> >>@@ -630,7 +630,9 @@ static void rcu_check_gp_start_stall(struct
> >>rcu_node *rnp, struct rcu_data *rdp,
> >>????????? time_before(j, rcu_state.gp_req_activity + gpssdelay) ||
> >>????????? time_before(j, rcu_state.gp_activity + gpssdelay) ||
> >>????????? atomic_xchg(&warned, 1)) {
> >>-??????? raw_spin_unlock_rcu_node(rnp_root); /* irqs remain disabled. */
> >>+??????? if (rnp_root != rnp)
> >>+??????????? /* irqs remain disabled. */
> >>+??????????? raw_spin_unlock_rcu_node(rnp_root);
> >
> >Looks good as it will balance the lock .if it is the root_node,
> >which was not there earlier, and unlock was happening without any
> >lock on root.
> >
> >Reviewed-by: Mukesh Ojha <[email protected]>
Applied, again thank you both!
In both cases, I updated the commit log, so please check to make sure
that I didn't mess anything up.
Thanx, Paul
> >Cheers,
> >-Mukesh
> >
> >>????????? raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
> >>????????? return;
> >>????? }
>
> --
> QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a
> member of the Code Aurora Forum, hosted by The Linux Foundation
>
On 3/30/19 2:57 AM, Paul E. McKenney wrote:
> On Fri, Mar 29, 2019 at 07:52:15PM +0530, Neeraj Upadhyay wrote:
>>
>>
>> On 3/29/19 6:58 PM, Mukesh Ojha wrote:
>>>
>>> On 3/29/2019 4:57 PM, Neeraj Upadhyay wrote:
>>>> Only unlock the root node, if current node (rnp) is not
>>>> root node.
>>>>
>>>> Signed-off-by: Neeraj Upadhyay <[email protected]>
>>>
>>>
>>>
>>>> ---
>>>> kernel/rcu/tree_stall.h | 4 +++-
>>>> 1 file changed, 3 insertions(+), 1 deletion(-)
>>>>
>>>> diff --git a/kernel/rcu/tree_stall.h b/kernel/rcu/tree_stall.h
>>>> index f65a73a..0651833 100644
>>>> --- a/kernel/rcu/tree_stall.h
>>>> +++ b/kernel/rcu/tree_stall.h
>>>
>>>
>>> why this is showing as under tree_stall.h while it is under
>>> "kernel/rcu/tree.c"
>>
>> It's moved in https://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git/commit/?h=dev&id=10462d6f58fb6dbde7563e9343505d98d5bfba3d
>>
>> Please see linux-rcu dev tree for other changes, which moves code to
>> this file.
>>
>>
>> Thanks
>> Neeraj
>>
>>>
>>>> @@ -630,7 +630,9 @@ static void rcu_check_gp_start_stall(struct
>>>> rcu_node *rnp, struct rcu_data *rdp,
>>>> time_before(j, rcu_state.gp_req_activity + gpssdelay) ||
>>>> time_before(j, rcu_state.gp_activity + gpssdelay) ||
>>>> atomic_xchg(&warned, 1)) {
>>>> - raw_spin_unlock_rcu_node(rnp_root); /* irqs remain disabled. */
>>>> + if (rnp_root != rnp)
>>>> + /* irqs remain disabled. */
>>>> + raw_spin_unlock_rcu_node(rnp_root);
>>>
>>> Looks good as it will balance the lock .if it is the root_node,
>>> which was not there earlier, and unlock was happening without any
>>> lock on root.
>>>
>>> Reviewed-by: Mukesh Ojha <[email protected]>
>
> Applied, again thank you both!
>
> In both cases, I updated the commit log, so please check to make sure
> that I didn't mess anything up.
>
> Thanx, Paul
>
Thanks Paul. One minor comment on
https://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git/commit/?h=dev&id=ec6530e763046b6bb1f4c2c2aed49ebc68aae2a0
"it clearly does not make sense to release
both rnp->lock and rnp->lock"
should be rnp->lock and rnp_root->lock
Thanks
Neeraj
>>> Cheers,
>>> -Mukesh
>>>
>>>> raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
>>>> return;
>>>> }
>>
>> --
>> QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a
>> member of the Code Aurora Forum, hosted by The Linux Foundation
>>
>
--
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a
member of the Code Aurora Forum, hosted by The Linux Foundation
On Sat, Mar 30, 2019 at 09:14:36AM +0530, Neeraj Upadhyay wrote:
> On 3/30/19 2:57 AM, Paul E. McKenney wrote:
> >On Fri, Mar 29, 2019 at 07:52:15PM +0530, Neeraj Upadhyay wrote:
> >>
> >>
> >>On 3/29/19 6:58 PM, Mukesh Ojha wrote:
> >>>
> >>>On 3/29/2019 4:57 PM, Neeraj Upadhyay wrote:
> >>>>Only unlock the root node, if current node (rnp) is not
> >>>>root node.
> >>>>
> >>>>Signed-off-by: Neeraj Upadhyay <[email protected]>
> >>>
> >>>
> >>>
> >>>>---
> >>>> ? kernel/rcu/tree_stall.h | 4 +++-
> >>>> ? 1 file changed, 3 insertions(+), 1 deletion(-)
> >>>>
> >>>>diff --git a/kernel/rcu/tree_stall.h b/kernel/rcu/tree_stall.h
> >>>>index f65a73a..0651833 100644
> >>>>--- a/kernel/rcu/tree_stall.h
> >>>>+++ b/kernel/rcu/tree_stall.h
> >>>
> >>>
> >>>why this is showing as under tree_stall.h while it is under
> >>>"kernel/rcu/tree.c"
> >>
> >>It's moved in https://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git/commit/?h=dev&id=10462d6f58fb6dbde7563e9343505d98d5bfba3d
> >>
> >>Please see linux-rcu dev tree for other changes, which moves code to
> >>this file.
> >>
> >>
> >>Thanks
> >>Neeraj
> >>
> >>>
> >>>>@@ -630,7 +630,9 @@ static void rcu_check_gp_start_stall(struct
> >>>>rcu_node *rnp, struct rcu_data *rdp,
> >>>> ????????? time_before(j, rcu_state.gp_req_activity + gpssdelay) ||
> >>>> ????????? time_before(j, rcu_state.gp_activity + gpssdelay) ||
> >>>> ????????? atomic_xchg(&warned, 1)) {
> >>>>-??????? raw_spin_unlock_rcu_node(rnp_root); /* irqs remain disabled. */
> >>>>+??????? if (rnp_root != rnp)
> >>>>+??????????? /* irqs remain disabled. */
> >>>>+??????????? raw_spin_unlock_rcu_node(rnp_root);
> >>>
> >>>Looks good as it will balance the lock .if it is the root_node,
> >>>which was not there earlier, and unlock was happening without any
> >>>lock on root.
> >>>
> >>>Reviewed-by: Mukesh Ojha <[email protected]>
> >
> >Applied, again thank you both!
> >
> >In both cases, I updated the commit log, so please check to make sure
> >that I didn't mess anything up.
> >
> > Thanx, Paul
> >
>
> Thanks Paul. One minor comment on https://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git/commit/?h=dev&id=ec6530e763046b6bb1f4c2c2aed49ebc68aae2a0
>
>
> "it clearly does not make sense to release
> both rnp->lock and rnp->lock"
>
> should be rnp->lock and rnp_root->lock
Good eyes, fixed, thank you!
Thanx, Paul
> Thanks
> Neeraj
>
> >>>Cheers,
> >>>-Mukesh
> >>>
> >>>> ????????? raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
> >>>> ????????? return;
> >>>> ????? }
> >>
> >>--
> >>QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a
> >>member of the Code Aurora Forum, hosted by The Linux Foundation
> >>
> >
>
> --
> QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a
> member of the Code Aurora Forum, hosted by The Linux Foundation
>