LL and SC instruction simulation

["Sathesh Babu Edara" <satheshbabu.edara@analog.com>]

Hi,
   We have ported linux-2.4.18 and linux-2-6.12 kernel (mips.org)onto MIPS
processor (CPU type lx4189).

 We observed that on 2.4 kernel,ll and sc instruction exception handlers
hitting very often.
Where as on linux-2.6.12 this is not happening.

Can anybody have idea why this instructions are hitting on 2.4.18 kernel and
not on 2-6.12 kernel.

What is the significance of these instructions?.

Note :
   For linux-2.4.18 : We use GCC version -3.3.4 binutils version -2.15 and
uClibc version -0.9.26 For linux-2.6.12 : We use GCC version -3.4.3 binutils
version -2.15 and uClibc version -0.9.28.

Thanks in advance.

Regards,
Sathesh