[arch-general] kernel 2.6.37 BKL

Alexander Lam lambchop468 at gmail.com
Wed Jan 5 20:57:39 EST 2011

At this point the BKL doesn't cause much performance loss:

"The Big Kernel Lock is a giant lock that was introduced in Linux 2.0,
when Alan Cox introduced SMP support for first time. But it was just
an step to achieve SMP scalability - only one process can run kernel
code at the same time in Linux 2.0, long term the BKL must be replaced
by fine-grained locking to allow multiple processes running kernel
code in parallel. In this version, it is possible to compile a kernel
completely free of BKL support. Note that this doesn't have
performance impact: all the critical Linux codepaths have been
BKL-free for a long time. It still was used in many non-performance
critical places -ioctls, drivers, non-mainstream filesystems, etc-,
which are the ones that are being cleaned up in this version. But the
BKL is being replaced in these places with mutexes, which doesn't
improve parallelism (these places are not performance critical
anyway). "


On Wed, Jan 5, 2011 at 8:38 PM, Bernardo Barros
<bernardobarros2 at gmail.com> wrote:
> 2011/1/5 Ng Oon-Ee <ngoonee at gmail.com>:
>> At this point in time leaving it enabled for compatibility in kernel26
>> is fine IMO. Those who need it disabled for specific reasons (the one I
>> can think of is task latency for audio) should already be used to
>> compiling patched kernels, so it wouldn't be a big deal for now.
> +1 for patched kernels for audio (including kernel26-rt) in community

Alexander Lam

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