Re: Mutex and Spinlock locked together

[Devesh Sharma <devesh28@xxxxxxxxx>]

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@xxxxxxxxx> wrote:

>On Thu, Feb 25, 2016 at 2:53 PM, Devesh Sharma <devesh28@xxxxxxxxx> 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@xxxxxxxxx> 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@xxxxxxxxxxxxxxxxx

http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

--

Please don't print this E- mail unless you really need to - this will preserve trees on planet earth.

_______________________________________________
Kernelnewbies mailing list
Kernelnewbies@xxxxxxxxxxxxxxxxx
http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies