Hi. On 10/05/2010 08:42, lihaidong wrote: > Hi, > I have a question about atomic operations. > According to IB specification o10-48, all atomic operation request made to > the same HCA, referencing the same physical memory are serialized with > respect to each other. I know this should be complied with if HCA supports > atomic operations, right? > Right. > According to IB specification o10-49, all atomic operations requests that > referencing the same physical memory are serialized with respect to each > other. This means that atomic operations performed by processors should > serialized with atomic operations performed by HCAs, too, if they were > referencing the same physical memory. > So far so good. > I want to know whether Mellanox implementation for atomic operations comply > with o10-49 or not. > if not ,to what extent it comply with the rule? > I also was intrested in how this rule is complied with by others vendors? > > Let give you a general answer: The struct ibv_device_attr contains the atomic_cap attribute, this attribute defines the atomicity level that the HCA support (None, only within the HCA, between all HCAs (global)).
I think that your code should check this attribute (This way your code will support all vendors HCAs). As much as i know, atomic operations are only supported within one HCA. I hope that this answer helped you .. Dotan -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
