Mutex and Spinlock locked together

[Devesh Sharma]

Check this out:

drivers/infiniband/core/cache.c

function: ib_cache_gid_add

Line: 338

mutex_lock(&table->lock);
        write_lock_irq(&table->rwlock);
.
.
.
.
 write_unlock_irq(&table->rwlock);
        mutex_unlock(&table->lock);

On Thu, Feb 25, 2016 at 3:42 PM, priyaranjan <priyaranjan45678 at gmail.com>
wrote:

> >On Thu, Feb 25, 2016 at 2:53 PM, Devesh Sharma <devesh28 at gmail.com>
> 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 <priyaranjan45678 at gmail.com>
> 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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