d04c8a563c
This patch is another step towards updating the code to handle the 32-bit kernels which I have not been regularly testing. This changes do not really impact the common case I'm expected which is the latest kernel running on an x86_64 arch. Until the linux-2.6.31 kernel the x86 arch did not have support for 64-bit atomic operations. Additionally, the new atomic_compat.h support for this case was wrong because it embedded a spinlock in the atomic variable which must always and only be 64-bits total. To handle these 32-bit issues we now simply fall back to the --enable-atomic-spinlock implementation if the kernel does not provide the 64-bit atomic funcs. The second issue this patch addresses is the DEBUG_KMEM assumption that there will always be atomic64 funcs available. On 32-bit archs this may not be true, and actually that's just fine. In that case the kernel will will never be able to allocate more the 32-bits worth anyway. So just check if atomic64 funcs are available, if they are not it means this is a 32-bit machine and we can safely use atomic_t's instead.