Re: [PATCHES] update i386 spinlock for hyperthreading

Manfred Spraul <manfred@colorfullife.com> writes:
> Are there strategies that do not rely on a global lock? The Linux kernel 
> uses a lazy LRU with referenced bits: on access, the referenced bit is 
> set. The freespace logic takes pages from the end of a linked list, and 
> checks that bit: if it's set, then the page is moved back to the top of 
> the list. Otherwise it's a candidate for replacement.

I think this is the same idea as what I was just suggesting: add an
extra check when looking for a free page, and thereby avoid having to
lock/update the global datastructure during ReadBuffer.
        regards, tom lane