Re: Mutex and Spinlock locked together

[Devesh Sharma]

Check this out:

drivers/infiniband/core/cache.c

function: ib_cache_gid_add

Line: 338

mutex_lock(>lock);
write_lock_irq(>rwlock);
.
.
.
.
 write_unlock_irq(>rwlock);
mutex_unlock(>lock);

On Thu, Feb 25, 2016 at 3:42 PM, priyaranjan 
wrote:

> >On Thu, Feb 25, 2016 at 2:53 PM, Devesh Sharma 
> wrote:
> >Hi
>
> >In running kernel there are many places you can look to get the usage.
> But the bottom line is
>
> Can you tell me the specific use case?  or give me the file name/driver
> where this is used.
>
> >* You can take a spinlock under a mutex. e.g.
> mutex_lock--->spinlock-critical section-spinunlock--->mutex_unlock.
>
> >* You can not take a mutex under a spinlock. e.g. spinlock--->mutex_lock
> -critical section mutex_unlock>spinunlock is not allowed.
>
>
> On Thu, Feb 25, 2016 at 11:37 AM, priyaranjan 
> wrote:
> Hello All,
>
> Do you have any idea of a situation where we would need mutex and spinlock
> to be locked together? I think there is an example for this in Linux
> kernel. Can anyone help me?
>
> Regards,
> Priyaranjan
>
> ___
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>
>
>
>


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Re: Mutex and Spinlock locked together

[priyaranjan]

>On Thu, Feb 25, 2016 at 2:53 PM, Devesh Sharma  wrote:
>Hi

>In running kernel there are many places you can look to get the usage. But
the bottom line is

Can you tell me the specific use case?  or give me the file name/driver
where this is used.

>* You can take a spinlock under a mutex. e.g.
mutex_lock--->spinlock-critical section-spinunlock--->mutex_unlock.

>* You can not take a mutex under a spinlock. e.g. spinlock--->mutex_lock
-critical section mutex_unlock>spinunlock is not allowed.


On Thu, Feb 25, 2016 at 11:37 AM, priyaranjan 
wrote:
Hello All,

Do you have any idea of a situation where we would need mutex and spinlock
to be locked together? I think there is an example for this in Linux
kernel. Can anyone help me?

Regards,
Priyaranjan

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Re: Mutex and Spinlock locked together

[Devesh Sharma]

Hi

In running kernel there are many places you can look to get the usage. But
the bottom line is

* You can take a spinlock under a mutex. e.g.
mutex_lock--->spinlock-critical section-spinunlock--->mutex_unlock.

* You can not take a mutex under a spinlock. e.g. spinlock--->mutex_lock
-critical section mutex_unlock>spinunlock is not allowed.


On Thu, Feb 25, 2016 at 11:37 AM, priyaranjan 
wrote:

> Hello All,
>
> Do you have any idea of a situation where we would need mutex and spinlock
> to be locked together? I think there is an example for this in Linux
> kernel. Can anyone help me?
>
> Regards,
> Priyaranjan
>
> ___
> Kernelnewbies mailing list
> Kernelnewbies@kernelnewbies.org
> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
>
>


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Mutex and Spinlock locked together

[priyaranjan]

Hello All,

Do you have any idea of a situation where we would need mutex and spinlock
to be locked together? I think there is an example for this in Linux
kernel. Can anyone help me?

Regards,
Priyaranjan
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