On 2020/11/6 21:37, Jason Gunthorpe wrote: > On Fri, Nov 06, 2020 at 01:52:57AM +0000, liweihang wrote: > >> There are 8 banks and each of them has a counter which represents >> how many QPs are using this bank. We first find the bank with the >> smallest count, and then try to find a QPN belongs to this bank >> according to the bitmap. The ida will find an unused ID starting >> from 0, I think it can't meet our needs. If we use ida here, the >> code may looks like: > > I don't understand, why wouldn't the ida give you a free QPN in a bank > directly? > > Jason > Hi Jason, Here is the QPN that belongs to each bank: QPN on bank0：0, 8, 16, 24 ... <lower three bits is 0> QPN on bank1: 1, 9, 17, 25 ... <lower three bits is 1> QPN on bank2: 2, 10, 18, 26 ... <lower three bits is 2> .. QPN on bank6: 6, 14, 22, 30 ... <lower three bits is 6> QPN on bank7: 7, 15, 23, 31 ... <lower three bits is 7> If bank 6 is the one with the lowest load, then we need to find a valid QPN belongs to bank6, that means, the lower 3 bits of QPN is 6 and it hasn't been used. We can't find out a way to use ida in this situation because the QPNs of each bank are discontinuous. Thank you Weihang
