What is Big Kernel Lock?

[Greg Freemyer]

On Thu, Dec 29, 2011 at 10:51 AM, Matt Schulte
<matts at commtech-fastcom.com> wrote:
> On Thu, Dec 29, 2011 at 3:03 AM, sandeep kumar
> <coolsandyforyou at gmail.com> wrote:
>> Hi All,
>> Can any one tell me the significance of BKL?
>>
>> --
>> With regards,
>> Sandeep Kumar Anantapalli,
>
> In a very small nutshell, the BKL makes it so that only one thread of
> the kernel can be running at any one time.  It made it nice for
> kernel/driver developers to not have to worry about SMP issues when
> running on multiple CPUs.  But at the same time it makes the kernel
> very inefficient when executing in an SMP system.
>
> Matt Schulte

Just remember that is past tense.  BKL was removed in the not too distant past.

So you only have it if you are working with an older kernel.

Greg