27 Mar
2015
27 Mar
'15
11:11 a.m.
On Fri, 27 Mar 2015, Peter Zijlstra wrote:
We could align the base on 8 bytes to gain an extra bit in the pointer and use that bit to indicate the running state. Then these sites can spin on that bit while we can change the actual base pointer.
Even though tvec_base has ____cacheline_aligned stuck on, most are allocated using kzalloc_node() which does not actually respect that but already guarantees a minimum u64 alignment, so I think we can use that third bit without too much magic.
Create a new slab cache for this purpose that does the proper aligning?