Subj : Re: load-after-store reordering for x86 wrt smr...
To   : comp.programming.threads
From : SenderX
Date : Mon Mar 14 2005 08:21 pm

>> Do you think that the store fence is needed in line 8:
>>
>>
> [...]
>>
>>
>> Line 7 would be the first store, line 9 would be the load-after-store 
>> from
>> another location condition. It seems that smr requires explicit barriers 
>> on
>> x86 to prevent the algorithm from crashing...
>>
>>
>>
> It has to be an mfence.  sfence is just store/store.

I made the change, and now as I expected... Iterating a huge linked-list 
using hazard-pointers is more expensive than using a rw-mutex; you need a 
fence for each item! It looks like proxy collectors are the way to go...

.