On Wed, Jul 22, 2015 at 08:33:16PM +0300, Sagi Grimberg wrote: > >> memset(&fr_wr, 0, sizeof(fr_wr)); > >>+ ib_set_fastreg_wr(mr, mr->lkey, ISER_FASTREG_LI_WRID, > >>+ false, &fr_wr); > > > >Shouldn't ib_set_fastreg_wr take care of this memset? Also it seems > >instead of the singalled flag to it we might just set that or > >other flags later if we really want to.
Seems reasonable. If you want to micro optimize then just zero the few items that are defined to be accessed for fastreg, no need to zero the whole structure. Infact, you may have already done that, so just drop the memset entirely. > The reason I didn't put it in was that ib_send_wr is not a small struct > (92 bytes IIRC). So I'm a bit reluctant to add an unconditional memset. > Maybe it's better that the callers can carefully set it to save some > cycles? If you want to optimize this path, then Sean is right, move the post into the driver and stop pretending that ib_post_send is a performance API. ib_post_fastreg_wr would be a function that needs 3 register passed arguments and does a simple copy to the driver's actual sendq No 96 byte structure memset, no stack traffic, no conditional jumps. Jason -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
